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The prone hip extension test is used as a clinical tool to diagnose specific motor control impairments that have been identified in individuals with chronic low back pain. However, conventional protocols for performing the test are subjective and lack evidence for their effectiveness. The objective of the current study was to quantify lumbopelvic motion and muscle activation during this test and identify which motor control patterns best distinguish individuals with low back pain from asymptomatic controls. 18 individuals with sub-acute or chronic low back pain and 32 asymptomatic controls performed the prone hip extension test while a 3D motion capture system measured lumbar and pelvic movement patterns and an electromyography system measured the muscle activation patterns of the paraspinal, gluteus maximus, and hamstring muscles. A three-stage statistical analysis was performed, the final stage being a stepwise logistic regression analysis aimed at identifying the movement and muscle activation pattern variables that best distinguished the two groups. The final regression model included three lumbar kinematic variables and several electromyographic amplitude variables for the gluteus maximus and hamstring muscles during right-sided prone hip extension. The final model correctly classified 86.7 % of the control group and 83.3 % of the low back pain group. The subject of asymmetrical gluteus maximus and hamstring muscle activation appears to be a potentially interesting area for future research on the utility of the prone hip extension test as a clinical tool in diagnosing motor control impairments associated with low back pain. • Low back pain is not associated with different lumbo-pelvic motion patterns. • Delayed gluteus maximus activation is not exclusive to low back pain sufferers. • Asymmetry in hip extensor activation may be a promising line of future research. [ABSTRACT FROM AUTHOR]

A flatfoot has been believed to be closely associated with the development of hallux valgus; however, the association is still controversial. Abnormal foot kinematics has been identified as a possible risk factor for the development of hallux valgus, but it remains unclear whether foot posture contributes to abnormal foot kinematics. This is the first study to investigate the differences in foot kinematics during gait between individuals with and without hallux valgus, while controlling for foot posture. Twenty-five females with hallux valgus and 25 healthy females aged 18 to 22 were recruited. Foot posture was measured using normalized navicular height truncated and the leg-heel angle. Foot kinematic and kinetic data during gait were recorded by a three-dimensional motion capture system. To investigate the characteristics of foot kinematics in individuals with hallux valgus while controlling for foot posture, we used a propensity score matching method. The matching was obtained by using the 1:1 nearest-neighbor procedure and a caliper width of 0.2. Twelve pairs were matched. Individuals with hallux valgus had significantly increased midfoot dorsiflexion from 56% to 80% during stance phase, rearfoot eversion from 53% to 71%, and forefoot abduction from 5% to 29% compared with control. Individuals with hallux valgus have a flexible foot that cannot suppress the dynamic deformation of the rearfoot and midfoot during gait. To suppress the development of hallux valgus, interventions that aim to prevent dynamic deformations of the rearfoot and midfoot during gait may be necessary, regardless of their static foot posture. • We investigated foot kinematics during gait in hallux valgus and control. • Differences in foot kinematics between groups were controlled by foot posture. • Increased rearfoot eversion and midfoot dorsiflexion was observed in hallux valgus. • Hallux valgus have a flexible foot regardless of their static foot posture. [ABSTRACT FROM AUTHOR]

Covid-19 has dramatically increased the number of admissions in intensive care units due to respiratory complications. In some cases, the arousal of neurological impairments, such as peripheral neuropathies, have been revealed. The purpose of this research was to characterize the gait pattern and muscle activity changes in Covid-19 survivors compared to physiological gait. Twelve post-Covid-19 participants admitted to intensive care units and twelve non-disabled controls were considered. Kinematics, kinetics and surface electromyographic data were collected for each participant during walking. Post Covid-19 participants were further divided into two sub-groups, according to the number of days spent in the intensive care units. Lower limb joint angles, moments and powers were extracted as well as the muscle activity of four muscles bilaterally, the spatial, temporal and spatiotemporal parameters of gait and the ground reaction forces. The extracted variables were compared through OneWay-ANOVA or Kruskal-Wallis tests where appropriate (p < 0.05). Overall, the considered parameters revealed statistically significant reduction in gait speed, cadence, range of motion in the sagittal plane, anteroposterior and vertical ground reaction forces between pathological and control participants. Larger alterations of the gait patterns were highlighted in the post-Covid-19 group hospitalized in intensive care units longer than 35 days, where a reduced muscle activity was observed on all the analyzed muscles. Results suggested that the severity of gait impairments in post-Covid-19 participants might be correlated with intensive care units-bedding period. Gait biomechanics assessment could be adopted in the clinical decision-making process to improve treatment protocols in post-Covid-19 survivors. [ABSTRACT FROM AUTHOR]

Multiple sclerosis can cause locomotor and cognitive impairments even at lower levels of disability, which can impact daily life. The cognitive-motor dual task is commonly used to assess everyday locomotion. Thus, this study aimed to examine the effect of cognitive-motor dual tasks on gait parameters among patients with multiple sclerosis in the early disease stages and to determine whether dual tasks could be used as a clinical test to detect locomotion impairments. A systematic search of five databases was conducted in May 2024. The population of interest was patients with multiple sclerosis with an Expanded Disability Status Scale score of 4 or less. The following outcome measures were examined: spatiotemporal and kinematic parameters. The Newcastle–Ottawa Scale was used to assess the quality of the studies. Eleven studies including 270 patients with multiple sclerosis and 221 healthy controls. Three spatiotemporal parameters were modified both in patients with multiple sclerosis and healthy controls during dual-task performance: gait speed, stride length and the double support phase. No spatiotemporal parameter was affected during dual-task performance in patients with multiple sclerosis alone. Dual-task performance could be useful for assessing gait impairments in patients with multiple sclerosis provided that assessments and protocols are standardized. Nevertheless, the spatiotemporal parameters did not allow discrimination between patients with multiple sclerosis at an early stage and healthy controls. Three-dimensional gait analysis during dual-task performance could be a useful approach for detecting early gait impairments in patients with multiple sclerosis, assessing their progression and adjusting rehabilitation programs. • Three gait parameters were often modified in patients and controls during dual-task. • These parameters are not specific to early gait disorders in multiple sclerosis. • The review highlighted the heterogeneity of clinical, cognitive assessments and tasks. • 3D gait analysis could characterize early gait disorders in multiple sclerosis. [ABSTRACT FROM AUTHOR]

Females with acetabular dysplasia and/or labral tears (hip pain) exhibit altered walking kinematics, with studies reporting mixed results in sagittal and frontal planes compared to pain-free controls, often conducting only discrete analyses and warranting further investigation. The objective of this study was to investigate discrete and continuous hip and pelvic kinematics between females with and without hip pain in two walking conditions. We collected kinematic walking data from 69 females (35 with hip pain, 34 controls) using motion capture and an instrumented treadmill in two conditions: preferred and fast (125% preferred). We used a general linear model and one-dimensional statistical parametric mapping to conduct discrete and continuous analyses comparing kinematics between groups, with and without adjustment for gait speed. The hip pain group walked with reduced peak hip extension (Preferred: P =.046, Cohen's d = 0.41; Fast: P =.028, d = 0.48) and greater peak anterior pelvic tilt (Preferred: P =.011, d = 0.57; Fast: P =.012, d = 0.58) compared to controls. From continuous analyses, the hip pain group walked with reduced hip extension during terminal stance (Fast: P =.040), greater anterior pelvic tilt throughout (Preferred: P =.007; Fast: P =.004), and greater contralateral pelvic drop (Preferred: P =.045) during midstance. Adjusting for speed slightly affected p -values, but significance was retained for all prior variables except pelvic drop. Kinematic differences between individuals with and without hip pain may provide insight into potential predisposing factors for hip pathology and/or compensations for pain or pathological processes. This work furthers understanding of altered movement patterns in individuals with hip pain and may inform physical therapy treatments. • Females with dysplasia and/or labral tears (hip pain) walk with altered kinematics. • Females with hip pain walk with less hip extension than pain-free controls. • Females with hip pain walk with more anterior pelvic tilt than pain-free controls. • Kinematic differences exist between groups at peaks and throughout the gait cycle. [ABSTRACT FROM AUTHOR]

Patients with hallux valgus are known to alter lower limb joint kinematics during gait. However, little information is available about gait changes following hallux valgus surgery. We aimed to longitudinally investigate lower limb kinematic changes at the mid and terminal stances of gait after hallux valgus surgery. This prospective observational study included 11 female patients (17 feet), who underwent first metatarsal osteotomy. Gait analyses were performed preoperatively and 1- and 2-year postoperatively using a three-dimensional motion capture system. Toe-out angle, ankle, knee, and hip joint angles during gait were calculated from the recorded data. The spatiotemporal parameters and these angles at the mid and terminal stances of gait were statistically compared between preoperative and postoperative periods. All spatiotemporal parameters remained unchanged postoperatively. The toe-out angle was significantly greater at 1- and 2-year postoperatively. The ankle pronation angle, the knee abduction angle, and the hip adduction angle at the mid and terminal stances of gait were smaller postoperatively compared to the preoperative. These angular changes showed a similar trend at 1 and 2 years postoperatively. However, the postoperative changes of the sagittal joint angles were relatively small. Hallux valgus surgery can affect the toe-out angle and the lower limb coronal kinematics at the mid and terminal stances of gait in patients with hallux valgus. However, surgical correction of hallux valgus deformity did not directly improve the gait characteristics in patients with hallux valgus. • Kinematic effects of ankle, knee, and hip joints during gait in bunion surgery. • Preoperative and 1- and 2-year postoperative gait analyses by a motion capture system. • Bunion surgery changes toe-out angle and lower limb coronal kinematics during gait. [ABSTRACT FROM AUTHOR]

Knee osteoarthritis negatively affects the gait of patients, especially that of elderly people. However, the assessment of wearable sensors in knee osteoarthritis patients has been under-researched. During clinical assessments, patients may change their gait patterns under the placebo effect, whereas wearable sensors can be used in any environment. Sixty patients with knee osteoarthritis and 20 control subjects were included in the study. Wearing shoes with an IMU sensor embedded in the insoles, the participants were required to walk along a walkway. The sensor data were collected during the gait. To discriminate between healthy and knee osteoarthritis patients and to classify different subgroups of knee osteoarthritis patients (patients scheduled for surgery vs. patients not scheduled for surgery; bilateral knee osteoarthritis diagnosis vs. unilateral knee osteoarthritis diagnosis), we used a machine learning approach called the support vector machine. A total of 88 features were extracted and used for classification. The patients vs. healthy participants were classified with 71% accuracy, 85% sensitivity, and 56% specificity. The "patients scheduled for surgery" vs. "patients not scheduled for surgery" were classified with 83% accuracy, 83% sensitivity, and 81% specificity. The bilateral knee osteoarthritis diagnosis vs. unilateral knee osteoarthritis diagnosis was classified with 81% accuracy, 75% sensitivity, and 79% specificity. Gait analysis using wearable sensors and machine learning can discriminate between healthy and knee osteoarthritis patients and classify different subgroups with reasonable accuracy, sensitivity, and specificity. The proposed approach requires no complex gait factors and is not limited to controlled laboratory settings. • Insole Inertial measurement Unit can help assess the gait Kinematics in daily life. • Gait kinematics showed differences between healthy control and knee osteoarthritis. • Simple gait features using machine learning can be used to analyze the gait. [ABSTRACT FROM AUTHOR]

Altered gait could influence knee joint moment magnitudes and cumulative damage over time. Gait modifications have been shown to reduce knee loading in people with knee osteoarthritis during walking, although this has not been explored in multiple daily activities. Therefore, this study investigated the effect of different foot orientations on knee loading during multiple daily activities in people with and without knee osteoarthritis. Thirty people with knee osteoarthritis and twenty-nine without (control) performed walking, stair ambulation and sit-to-stand across a range of foot progression angles (neutral, toe-in, toe-out and preferred). Peak knee adduction moment, knee adduction moment impulse and knee pain were compared across a continuous range of foot orientations, between activities, and groups. Increased foot progression angle (more toe-in) reduced 1st peak knee adduction moment across all activities in both knee osteoarthritis and control (P < 0.001). There was a greater reduction in knee adduction moment in the control group during walking and stair ambulation (P ≤ 0.006), where the knee osteoarthritis group already walked preferably less toe-out than the control group. Under preferred condition, stair descent had the greatest knee loading and knee pain compared to other activities. Although increased foot progression angle (toward toe-in) appeared to be more effective in reducing knee loading for all activities, toe-in modification might not benefit stair ambulation. Future gait modification should likely be personalised to each patient considering the individual difference in preferred gait and knee alignment required to shift the loading medially or laterally. [ABSTRACT FROM AUTHOR]

Severity of dyskinesia in children with cerebral palsy is often assessed using observation-based clinical tools. Instrumented methods to objectively measure dyskinesia have been proposed to improve assessment accuracy and reliability. Here, we investigated the technique and movement features that were most suitable to objectively measure the severity of dystonia in children with cerebral palsy. A prospective observational study was conducted with 12 participants with cerebral palsy with a predominant motor type of dyskinesia, spasticity, or mixed dyskinesia/spasticity who had upper limb involvement (mean age: 12.6 years, range: 6.7–18.2 years). Kinematic and electromyography data were collected bilaterally during three upper limb tasks. Spearman rank correlations of kinematic or electromyography features were calculated against dystonia severity, quantified by the Dyskinesia Impairment Scale. Kinematic features were more influential compared to electromyography features at grading the severity of dystonia in children with cerebral palsy. Kinematic measures quantifying jerkiness of volitional movement during an upper limb task with a reaching component performed best (|r s | = 0.78–0.9, p < 0.001). This study provides guidance on the types of data, features of movement, and activity protocols that instrumented methods should focus on when objectively measuring the severity of dystonia in children with cerebral palsy. • Instrumented methods can be used to assess dystonia severity in cerebral palsy. • Kinematic features show greater accuracy compared to electromyography features. • Jerkiness during a volitional upper limb reaching task quantifies dystonia best. [ABSTRACT FROM AUTHOR]

Community ambulation involves complex walking adaptability tasks such as stepping over obstacles or taking long steps, which require adequate propulsion generation by the trailing leg. Individuals post-stroke often have an increased reliance on their trailing nonparetic leg and favor leading with their paretic leg, which can limit mobility. Ankle-foot-orthoses are prescribed to address common deficits post-stroke such as foot drop and ankle instability. However, it is not clear if walking with an ankle-foot-orthosis improves inter-limb propulsion symmetry during adaptability tasks. This study sought to examine this hypothesis. Individuals post-stroke (n = 9) that were previously prescribed a custom fabricated plantarflexion-stop articulated ankle-foot-orthosis participated. Participants performed steady-state walking and adaptability tasks overground with and without their orthosis. The adaptability tasks included obstacle crossing and long-step tasks, leading with both their paretic and nonparetic leg. Inter-limb propulsion symmetry was calculated using trailing limb ground-reaction-forces. During the obstacle crossing task, ankle-foot-orthosis use resulted in a significant improvement in inter-limb propulsion symmetry. The orthosis also improved ankle dorsiflexion during stance, reduced knee hyperextension, increased gastrocnemius muscle activity, and increased peak paretic leg ankle plantarflexor moment. In contrast, there were no differences in propulsion symmetry during steady-state walking and taking a long-step when using the orthosis. Plantarflexion-stop articulated ankle-foot-orthoses can improve propulsion symmetry during obstacle crossing tasks in individuals post-stroke, promoting paretic leg use and reduced reliance on the nonparetic leg. • Ankle-foot-orthosis improved propulsion symmetry during obstacle crossing, post-stroke. • Improved propulsion symmetry can promote paretic leg use in community ambulation. • The orthosis also improved paretic leg kinematics and neuromuscular output. [ABSTRACT FROM AUTHOR]

Rocker shoes can be used to reduce foot pressure and adjust lower limb kinetics for various patient population, such as people with diabetic peripheral neuropathy. Selecting adequate properties of the rocker sole is of great importance for its efficacy. This study investigated the capability of human-in-the-loop optimization (HILO) to individually optimize apex position and angle of rocker shoe to reduce peak pressure and collision work simultaneously. Peak pressure, kinetic, and kinematic data were recorded from 10 healthy participants while walking at preferred speed wearing rocker shoes with adjustable apex position and angle. An evolutionary algorithm was used to find optimal apex parameters to reduce both peak pressure in medial forefoot and collision work. The optimized shoe (HILO shoe) was compared with generic optimal rocker settings (Chapman settings) and normal shoe. Compared to normal shoe, the HILO shoe had lower plantar pressure (p HILO = 0.007; p Chapman = 0.044) and Chapman shoe showed higher collision work (p HILO = 0.025; p Chapman = 0.014). Both HILO and Chapman shoe had smaller push-off work than normal shoe (p HILO = 0.001; p Chapman < 0.001) with the Chapman shoe exhibited earlier push-off onset (p HILO = 0.257; p Chapman = 0.016). The Human-in-the-loop optimization approach resulted in individualized apex settings which performed on average similar to Chapman settings but, were superior in selected cases. In these cases, medial forefoot could be further offloaded with apex angles larger than generic settings. The larger apex angle might increase the external ankle moment arm and push-off work. However, there is limited room for improvement on collision work compared to generic settings. • Human-in-the-loop optimization found individualized rocker shoe settings. • On group level the settings reduced plantar pressure similar to current standards. • On individual level medial forefoot was offloaded more than current gold standard. • Optimized apex position was similar to standard but with larger and varying angles. • Limited room to improve collision work was found while offloading the forefoot. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the biomechanical stress and stability of calcaneal fixations with and without bone defect, before and after bone grafting, through a computational approach. A finite element model of foot-ankle complex was reconstructed, impoverished with a Sanders III calcaneal fracture without bone defect and with moderate and severe bone defects. Plate fixations with and without bone grafting were introduced with walking stance simulated. The stress and fragment displacement of the calcaneus were evaluated. Moderate and severe defect increased the calcaneus stress by 16.11% and 32.51%, respectively and subsequently decreased by 10.76% and 20.78% after bone grafting. The total displacement was increased by 3.99% and 24.26%, respectively by moderate and severe defect, while that of posterior joint facet displacement was 86.66% and 104.44%. The former was decreased by 25.73% and 35.96% after grafting, while that of the latter was reduced by 88.09% and 84.78% for moderate and severe defect, respectively. Our finite element prediction supported that bone grafting for fixation could enhance the stability and reduce the risk of secondary stress fracture in cases of bone defect in calcaneal fracture. • Calcaneal fracture fixation with and without a bone defect was simulated. • Defects in calcaneal fracture elevated the stress and displacement of fragments. • Bone defects might induce instability and risk of stress fracture. • Stress concentration appeared at the cavity of the bone defect. [ABSTRACT FROM AUTHOR]

Total knee replacements are used to improve function and reduce pain in patients with advanced osteoarthritis. The medially stabilising implant is designed to mimic a healthy knee. This study aims to provide a comprehensive analysis of the kinematics and kinetics of a medially stabilising knee implant, comparing it to a healthy control group, as well as to its pre-operative state and the contralateral limb. Sixteen total knee replacement patients and ten healthy participants were recruited. Patients underwent testing 4–6 weeks before surgery and repeated the same tests 12 months after surgery. Healthy participants completed the same tests at a single time point. All participants completed three walking trials: kinematics was captured with eight cameras; kinetics with in-ground force plates. Subject-specific musculoskeletal models were developed in OpenSim. Inverse kinematics and inverse dynamics were used to determine gait parameters. Joint angles and joint moments were evaluated using Statistical Parametric Mapping. Patient-reported outcome measures were also collected at both time points. Spatiotemporal results indicate significant differences in velocity and step length between pre-operative patients and control participants. Differences are observed in the adduction angles between the contralateral and ipsilateral limbs pre-operatively. Postoperatively, there was an increase in the 1st peak flexion moment, reduced adduction moment and reduced internal rotation moment. In PROMs, patients all report improvements in pain levels and high satisfaction levels following surgery. Following medial stabilising total knee arthroplasty, patients displayed improved clinical parameters and joint moments reflecting a shift towards more normal, healthy gait. • No significant changes are seen in knee joint angles for walking after knee replacement surgery. • The medial pivot knees resulted in reduced knee adduction moments. • Patient body mass potentially contributes to the speed of osteoarthritis progression. • Post-operatively, patient reported outcomes measures are superior. [ABSTRACT FROM AUTHOR]

Lower limb amputation does not affect only physical and psychological functioning but the use of a prosthetic device can also lead to increased cognitive demands. Measuring cognitive load objectively is challenging, and therefore, most studies use questionnaires that are easy to apply but can suffer from subjective bias. Motivated by this, the present study investigated whether a mobile eye tracker can be used to objectively measure cognitive load by monitoring gaze behavior during a set of motor tasks. Five prosthetic users and eight able-bodied controls participated in this study. Eye tracking data and kinematics were recorded during a set of motor tasks (level ground walking, walking on uneven terrain, obstacle avoidance, stairs up and ramp down, as well as ramp up and stairs down) while the participants were asked to focus their gaze on a visual target for as long as possible. Target fixation times and increase in pupil diameters were determined and correlated to subjective ratings of cognitive load. Overall, target fixation time and pupil diameter showed strong negative and positive correlations, respectively, to the subjective rating of cognitive load in the able-bodied controls (−0.75 and 0.80, respectively). However, the individual correlation strength, and in some cases, even the sign, was different across participants. A similar trend could be observed in prosthetic users. The results of this study showed that a mobile eye tracker may be used to estimate cognitive load in prosthesis users during locomotor tasks. This paves the way to establish a new approach to assessing cognitive load, which is objective and yet practical and simple to administer. Nevertheless, future studies should corroborate these results by comparing them to other objective measures as well as focus on translating the proposed approach outside of a laboratory. • Eye-tracking can provide objective measures of cognitive load for lower limb prosthetic users. • Target fixation time and pupil diameter correlate with subjective ratings of cognitive load. • The strength of the correlation between the eye tracking measures and cognitive load is, however, subject-specific. • This work can lead to a practical and simple way to assess the cognitive load, both inside and outside the lab. [ABSTRACT FROM AUTHOR]

Peripheral neuropathy due to chemotherapeutic drugs causes alterations in ankle movement during gait. This study aimed to describe the spatiotemporal parameters and ankle kinematics during gait in schoolchildren with acute lymphoblastic leukemia with clinically suspected peripheral neuropathy. In children with acute lymphoblastic leukemia in the maintenance phase, we calculated spatiotemporal and kinematic parameters of the ankle during gait using Kinovea® software. Furthermore, we identified alterations in the parameters obtained considering the values of the normality data from a stereophotogrammetry system as the reference values. Finally, we represented the kinematic parameters of the ankles calculated with Kinovea® compared to the normality values of the stereophotogrammetry. We evaluated 25 schoolchildren; 13 were male (52.0%) with a median age of 88.0months and a median of 60.0 weeks in the maintenance phase, and 54.8% were classified as standard risk. Spatiotemporal parameters: cadence (steps/min), bilateral step length (m), and average gait speed (m/s) in ALL children were significantly lower than reference values (p < 0.001). Except for right mid-stance and bilateral foot strike, initial swing showed that both ankles maintained plantar flexion values during gait, significantly lower in ALL patients (p < 0.05). We identified spatiotemporal and kinematics alterations in schoolchildren with acute lymphoblastic leukemia during all phases of the gait suggestive of alteration in ankle muscles during movement, probably due to peripheral neuropathy; nevertheless, our results should be taken with caution until the accuracy and reliability of Kinovea® software as a diagnostic test compared to the stereophotogrammetric system in children with ALL and healthy peers is proven. • Movement disorders of the ankle during gait in acute lymphoblastic leukemia are common. • Plantar flexion pattern was observed during gait in acute lymphoblastic leukemia children. • Gait cadence and speed were low in children with acute lymphoblastic leukemia. • Early identification of ankle kinematic disorders in acute lymphoblastic leukemia is necessary. [ABSTRACT FROM AUTHOR]

This study investigated the most accurate method for estimating the hip joint center position in clinical 3D gait analysis for young individuals with high amounts of soft tissue. We compared position estimates of five regression-based and two functional methods to the hip joint center position obtained through 3D free-hand ultrasound. For this purpose, the data of 14 overweight or obese individuals with a mean age of 13.6 (SD 2.1 yrs) and a BMI of 36.5 (SD 7.1 kg/m2, range 26–52 kg/m2) who underwent standard clinical 3D gait analysis were used. The data of each participant were processed with five regression-based and two functional methods and compared to the hip joint center identified via 3D free-hand ultrasound. The absolute location errors to 3D free-hand ultrasound for each anatomical plane and the Euclidean distances served as outcomes next to their effects on gait variables. The data suggest that regression-based methods are preferable to functional methods in this population, as the latter demonstrated the highest variability in accuracy with large errors for some individuals. Based on our findings we recommend using the regression method presented by Hara et al. due to its superior overall accuracy of <9 mm on average in all planes and the lowest impact on kinematic and kinetic output variables. We do not recommend using the Harrington equations (single and multiple) in populations with high amounts of soft tissue as they require pelvic depth as input, which can be massively biased when a lot of soft tissue is present around the pelvis. • We tested various hip joint center estimation methods' accuracy in obese individuals. • We recommend using regression rather functional methods for this population. • Functional methods demonstrated lower accuracy and overall highest variability. • Hara's regression performed best in all planes with errors <8.2 (SD 7.6 mm). • Do not use pelvic depth in regression methods due to a bias related to soft tissue. [ABSTRACT FROM AUTHOR]

Unicompartmental knee arthroplasty is an effective treatment for knee osteoarthritis, but it has the risk of failure, and the installation position of the prosthesis is one of the factors affecting the failure. There are few biomechanical studies on the installation angle of unicompartmental knee prosthesis. Constructed a finite element model of a normal human knee joint, and the validity of the model was verified by stress and front anterior methods. The mobile-bearing unicompartmental knee arthroplasty femoral prosthesis was placed at 3° intervals from 0° sagittal plane to 15° flexion, and − 2° and 17°were established, and observing the biomechanical changes of components. Maximum peak stresses occurred at a sagittal mounting angle of −2° for the insert and the contralateral meniscus, with the tibia showing a maximum at 17° sagittal and the tibial prosthesis stress maximum occurring at 6° sagittal. As the sagittal plane angle of the femoral prosthesis increases and the osteotomy distance extends posteriorly, more bone is amputated during the osteotomy. The ratio of the distance from the tip of the anterior intramedullary nail to the anterior end of the osteotomy to the total anteroposterior length of the sagittal osteotomy ranged from 43.2% to 44.6%. In this paper, the more appropriate sagittal mounting position for the femoral prosthesis is between 9 and 12°, based on the amount of osteotomy and the peak stress of each component in a standing position. • Material assignment to the skeletal model based on the grey scale • Biomechanical effects of sagittal angles of femoral prostheses • Recommended femoral prosthesis angles in terms of Mises stresses and osteotomies • Anterior intramedullary nail and anterior end of the femoral osteotomy distance [ABSTRACT FROM AUTHOR]

Perceived instability is a primary symptom among individuals with chronic ankle instability. However, the relationship between joint kinematics during landing remains unclear. Therefore, we investigated the relationships between landing kinematics and perceived instability in individuals with chronic ankle instability. In 32 individuals with chronic ankle instability, we recorded ankle, knee, and hip joint angles during a single-leg drop landing. Joint angle waveforms during 200 ms before and after initial contact were summarized into single values using two methods: peak joint angles and principal component scores via principal component analysis. Using Spearman's rank correlation coefficient (ρ), we examined the relationships of peak joint angles and principal component scores with the Cumberland Ankle Instability Tool score, with a lower score indicating a greater perceived instability (α = 0.05). The second principal component scores of ankle angle in the horizontal and sagittal planes significantly correlated with the Cumberland Ankle Instability Tool score (Horizontal: ρ = 0.507, P = 0.003; Sagittal: ρ = −0.359, P = 0.044). These scores indicated the differences in the magnitude of angles before and after landing. Significant correlations indicated a greater perceived instability correlated with smaller internal rotation and plantarflexion before landing and smaller external rotation and dorsiflexion after landing. In contrast, no peak joint angles correlated with the Cumberland Ankle Instability Tool score (P > 0.05). In individuals with chronic ankle instability, ankle movements during landing associated with perceived instability may be a protective strategy before landing and potentially cause ankle instability after landing. • We examined the relationships between perceived instability and landing kinematics. • Ankle kinematic patterns in the horizontal plane correlated to perceived instability. • Sagittal plane ankle kinematic patterns were associated with perceived instability. • Peak joint angles were not correlated with perceived instability. [ABSTRACT FROM AUTHOR]

Obesity impacts a child's ability to walk with resulting biomechanical adaptations; however, existing research has not comprehensively compared differences across the gait cycle. We examined differences in lower extremity biomechanics across the gait cycle between children with and without obesity at three walking speeds. Full gait cycles of age-matched children with obesity (N = 10; BMI: 25.7 ± 4.2 kg/m2) and without obesity (N = 10; BMI: 17.0 ± 1.9 kg/m2) were analyzed at slow, normal, and fast walking speeds. Main and interaction effects of group and speed across hip, knee, and ankle joint angles and moments in sagittal, frontal, and transverse planes were analyzed using one-dimensional statistical parametric mapping. Compared to children without obesity, children with obesity had greater hip adduction during mid-stance, while also producing greater hip extensor moments during early stance phase, abductor moments throughout most of stance, and hip external rotator moments during late stance. Children with obesity recorded greater knee flexor, knee extensor and knee internal rotator moments during early stance, and knee external rotator moments in late stance than children without obesity; children with obesity also demonstrated greater ankle plantarflexor moments throughout mid and late stance. Interaction effects existed within joint kinetics data; children with obesity produced greater hip extensor moments at initial contact and toe-off when walking at fast compared to normal walking speed. While few kinematic differences existed between the two groups, children with obesity exhibited greater moments at the hip, knee, and ankle during critical periods of controlling and stabilizing mass. • Gait kinematics and kinetics were analyzed with statistical parametric mapping. • Greater lower extremity joint moments in children with obesity during transitions. • Kinetic differences occur during phases that could increase osteoarthritis risk. [ABSTRACT FROM AUTHOR]

The nose is a viable pathway for topical drug delivery to the olfactory cleft for treatment of obstructive smell loss and nose-to-brain drug delivery. This study investigates how variations in nasal vestibule morphology influence intranasal spray drug transport to the olfactory cleft and olfactory roof/bulb regions. The unilateral nasal vestibule morphology in three healthy subjects with healthy normal nasal anatomy was classified as Elongated (Subject DN001), Notched (Subject DN002), and Standard (Subject DN003). Computational fluid and particle dynamics modelling were used to simulate nasal airflow and drug particle transport to the olfactory cleft and olfactory roof/bulb regions in each subject-specific nasal cavity. To evaluate highest drug depositions in these regions, the particle transport simulations involved extensive parameter combination analyses: 6 inspiratory flow rates mimicking resting to sniffing (10-50 L/min); 5 spray release locations (Top, Bottom, Central, Lateral, and Medial); 5 head positions (Upright, Tilted Forward, Tilted Back, Supine, and Mygind); 3 particle velocities (1, 5, and 10 m/s); 350,000 μm-particles (1-100 μm) and 346,500 nanoparticles (10-990 nm). Particle size groups with highest depositions in olfactory cleft: DN001 left = 28.4% at 11–20 μm, right = 75.3% at 6-10 μm; DN002 left = 16.8% at 1-5 μm, right = 45.3% at 30-40 nm; DN003 left = 29.1% at 21-30 μm, right = 15.9% at 6-10 μm. Highest depositions in olfactory roof/bulb: DN001 left = 6.5% at 11–20 μm, right = 26.4% at 11–20 μm; DN002 left = 3.6% at 1-5 μm, right = 2.6% at 1-5 μm; DN003 left = 2.8% at 21-30 μm, right = 1.7% at 31-40 μm. DN001 (Elongated nasal vestibule) had the most deposition in the olfactory regions. Micron-particles size groups generally had better deposition in the olfactory regions. • Delivery characteristics to target drugs to olfactory varied by nasal morphology. • The Elongated nasal vestibule morphology had superior olfactory deposition. • Micron particles had better deposition in olfactory than nanoparticles. [ABSTRACT FROM AUTHOR]

Obesity and knee osteoarthritis adversely affect activities of daily living in older adults. Together, the complexities of their interaction on mobility, including stair negotiation, are unresolved. The purpose of this study was to determine the relationship between obesity, pain, and stair negotiation in older adults with knee osteoarthritis. Older adults with symptomatic knee osteoarthritis and overweight or obesity participated in the study (n = 28; age range = 57.0–78.0 yrs.; body mass index range = 26.6–42.8 kg•m−2). The Western Ontario and McMaster Universities Osteoarthritis Index pain subscale was used to measure knee pain. Measurements included a three-dimensional biomechanical analysis during descent on a set of force plate-instrumented stairs and a timed stair descent test. Pearson's r was used to determine associations between body mass index and pain, stair descent weight-acceptance phase vertical ground reaction force (vGRF) variables and lower extremity joint kinematics and kinetics, and timed stair descent performance. Significant correlations existed between body mass index and pain (r = 0.41; p = 0.03), peak vGRF (r = 0.39; p = 0.04), vertical impulse (r = 0.49; p = 0.008), and peak ankle plantar flexor moments (r = 0.50; p = 0.007) in older adults with knee osteoarthritis. Greater obesity in older adults with knee osteoarthritis was associated with greater knee pain and higher ankle joint loads during stair descent. These results support the recommendations of osteoarthritis treatment guidelines for weight-loss as a first-line of treatment for older adults with obesity and knee osteoarthritis. • Obesity predicts pain in older adults with knee osteoarthritis. • Obesity predicts stair descent forces in older adults with knee osteoarthritis. • Obesity predicts stair descent ankle-joint load in people with knee osteoarthritis. [ABSTRACT FROM AUTHOR]

Characterization of motor deficits after brain injury is important for rehabilitation personalization. While studies reported abnormalities in the kinematics of paretic and non-paretic elbow extension for patients with brain injuries, kinematic analysis is not sufficient to explore how patients deal with musculoskeletal redundancy and the energetic aspect of movement execution. Conversely, interarticular coordination and movement kinetics can reflect patients' motor strategies. This study investigates motor strategies of paretic and non-paretic upper limb after brain injury to highlight motor deficits or compensation strategies. 26 brain-injured hemiplegic patients and 24 healthy controls performed active elbow extensions in the horizontal plane, with both upper limbs for patients and, with the dominant upper limb for controls. Elbow and shoulder kinematics, interarticular coordination, net joint kinetics were quantified. Results show alterations in kinematics, and a strong correlation between elbow and shoulder angles, as well as time to reach elbow and shoulder peak angular velocity in both upper limbs of patients. Net joint kinetics were lower for paretic limb and highlighted a fragmented motor strategy with increased number of transitions between concentric and eccentric phases. In complement to kinematic results, our kinetic results confirmed patients' difficulties to manage both spatially and temporally the joint degrees of freedom redundancy but revealed a fragmented compensatory motor strategy allowing patients upper limb extension despite quality alteration and decrease in energy efficiency. Motor rehabilitation should improve the management of this fragmentation strategy to improve the performance and the efficiency of active movement after brain injury. • Brain-injured patients have difficulties to manage musculoskeletal redundancy. • Upper limb interarticular coordination is altered temporally and spatially. • Kinetic analysis revealed a fragmented motor strategy to perform active movement. • Alterations are present for both paretic and non-paretic patients' upper limbs. [ABSTRACT FROM AUTHOR]

Knee osteoarthritis causes structural joint damage. The resultant symptoms can impair the ability to recover from unexpected gait perturbations. This study compared balance recovery responses to moderate gait perturbations between individuals with knee osteoarthritis and healthy individuals. Kinematic data of 35 individuals with end-stage knee osteoarthritis, and 32 healthy individuals in the same age range were obtained during perturbed walking on a treadmill at 1.0 m/s. Participants received anteroposterior (acceleration or deceleration) or mediolateral perturbations during the stance phase. Changes from baseline in margin of stability, step length, step time, and step width during the first two steps after perturbation were compared between groups using a linear regression model. Extrapolated center of mass excursion was descriptively analyzed. After all perturbation modes, extrapolated center of mass trajectories overlapped between individuals with knee osteoarthritis and healthy individuals. Participants predominantly responded to mediolateral perturbations by adjusting their step width, and to anteroposterior perturbations by adjusting step length and step time. None of the perturbation modes yielded between-group differences in changes in margin of stability and step width during the first two steps after perturbation. Small between-group differences were observed for step length (i.e. 2 cm) of the second step after mediolateral and anteroposterior perturbations, and for step time (i.e. 0.01–0.02 s) of first step after mediolateral perturbations and the second step after outward and belt acceleration perturbations. Despite considerable pain and damage to the knee joint, individuals with knee osteoarthritis showed comparable balance recovery responses after moderate gait perturbations to healthy participants. • Knee osteoarthritis may contribute to an increased risk of falling. • We studied responses to moderate gait perturbations in individuals with knee osteoarthritis. • Individuals with knee osteoarthritis showed few limitations in balance recovery responses. [ABSTRACT FROM AUTHOR]

Individuals with cerebral-palsy commonly present with altered kinematics and selective-motor-control during gait, and may also experience musculoskeletal pain. This pilot study aims to investigate if the immediate experience of musculoskeletal pain during gait influences kinematics and selective-motor-control in individuals with spastic cerebral-palsy. Retrospective treadmill-based gait-analysis data for 145 individuals with spastic cerebral-palsy were screened. Participants were asked about experiencing lower-extremity musculoskeletal pain immediately during gait, with 26 individuals (18%) reporting this was the case (pain-group; mean 11.55 ± 3.15 years, Gross-Motor-Function-Classification-System levels I/II/III n = 5/13/8, Uni/bilateral involvement n = 11/15). Of the 77 individuals who did not report any pain, a no-pain group (n = 26) was individually matched. Kinematics were evaluated using the Gait-Profile-Score and spatiotemporal parameters (dimensionless-walking-speed, single-leg-support percentage and step-time). Selective-motor-control was assessed using the Walking-Dynamic-Motor-Control index. In the pain-group, 58% reported experiencing pain in their more-involved leg, 8% in the less-involved leg and 34% in both legs. Regarding the pain location, 38% of the pain-group reported experiencing pain in multiple locations. On a more specific level, 35%, 46% and 54% reported pain around the hip/thigh, knee/calf and ankle/ft, respectively. No significant differences were observed between the pain and no-pain groups for any of the outcome measures, in each leg or bilaterally. No significant differences in kinematics and selective-motor-control during gait were found between individuals with spastic cerebral-palsy, with and without musculoskeletal pain. This suggests that the individuals in this study may not present with obvious antalgic gait patterns, which may relate to the pre-existing altered kinematics and selective-motor-control. • 18% of patients with cerebral palsy experienced musculoskeletal pain during gait. • Kinematics and selective motor control were similar between the pain/no pain groups. • The pain-group did not exhibit obvious changes in gait patterns. [ABSTRACT FROM AUTHOR]

The use of movement screens as a clinical tool for injury risk assessment requires variables to be extracted across specific phases of interest. While manually selecting task events is the traditional method, automated event detection is an effective technique that maintains consistency across a cohort. This study aimed to examine variations in event identification, comparing manual detection and the application of an automated algorithm, with a specific focus on a drop vertical jump task. Thirty participants cleared to return-to-play after anterior cruciate ligament reconstruction and thirty controls were tested. For the automated event detection, normalized vertical ground reaction force and the velocity of the sacrum marker were used to identify five events during the drop vertical jump: initial contact, end of loading, end of propulsion, second contact, and end of second loading. Two raters manually selected events and were compared to the event times of the automated algorithm. Manual event detection exhibited excellent reliability Significant differences between manual and automated detection were observed, particularly at events indicating the lowest squat position (Event2 and Event5). Participants who had undergone anterior cruciate ligament reconstruction demonstrated larger differences than controls at Event5, correlating with significant squat depth disparities. While manual event detection demonstrated reliability, automated algorithms revealed differences, specifically in events of the drop vertical jump involving the lowest squat position. The automated algorithm presents potential benefits in reducing processing time and enhancing accuracy for event identification, offering valuable insights for motion capture applications in clinical settings. • Automating event detection of injury risk assessment could improve accuracy. • The least agreement was between two raters during manual placement of the events. • The least agreement between raters was for events with no ground reaction force. • Lower accuracy of manual placement was observed in the group that squatted lower. • This discrepancy reveals the need for an automated event detection method. [ABSTRACT FROM AUTHOR]

In total knee arthroplasty, unrestricted kinematic alignment aims to restore pre-arthritic lower limb alignment and joint lines. Joint line orientations of the contralateral healthy proximal tibia might be used to evaluate accuracy of tibial component alignment post-operatively if asymmetry is minimal. Our objective was to evaluate left-to-right asymmetry of the proximal tibial epiphysis in posterior tibial slope and varus-valgus orientation as related to unrestricted kinematic alignment principles. High resolution CT images (0.5 mm slice thickness) were acquired from bilateral lower limbs of 11 skeletally mature subjects with no skeletal abnormalities. Images were segmented to generate 3D tibia models. Asymmetry was quantified by differences in orientations required to shape-match the proximal epiphysis of the mirror 3D tibia model to the proximal epiphysis of the contralateral 3D tibia model. Systematic and random differences (i.e. mean ± standard deviation) in tibial slope and varus-valgus orientation were − 0.8° ± 1.2° and − 0.2° ± 0.8°, respectively. Ninety five percent confidence intervals on the means included 0° indicating that systematic differences were minimal. Since random differences due to asymmetry are substantial in relation to random surgical deviations from pre-arthritic joint lines previously reported, post-operative computer tomograms of the contralateral healthy tibia should not be used to directly assess accuracy of tibial component alignment on a group level without correcting for differences in tibial slope and varus-valgus orientation due to asymmetry. • Accuracy of tibial baseplate alignment in unrestricted kinematic alignment is of interest. • Baseplate alignment is defined by the posterior tibial slope and varus-valgus orientation. • Opposite healthy knee might be used to determine alignment deviations if asymmetry is minimal. • Using a new shape matching algorithm, asymmetry was determined. • Asymmetry was due to random differences and should be corrected on a group level. [ABSTRACT FROM AUTHOR]

Leg extensions should be avoided in the early stages after anterior cruciate ligament reconstruction because the force exerted by the quadriceps muscle leads to anterior tibial displacement. To allow for safe quadriceps training in the knee extension range during this period, we devised the leaf spring exercise, which involves placing subjects in the prone position with their knee slightly flexed and instructing them to perform maximum isometric quadriceps contractions while supporting the proximal region of the lower leg's anterior surface and immobilizing the femur's posterior surface to prevent lifting. The current study aimed to examine the safety of Leaf spring exercise by determining the femur–tibia relationship using ultrasound imaging. This controlled laboratory study included patients with unilateral anterior cruciate ligament-deficient knees (8 men and 8 women; age, 24.2 ± 8.3 years) who were instructed to perform Leaf spring exercise of both lower limbs. We measured the femur–tibia-step-off, which indicates the distance between the last point of the medial and lateral condyles of the femur and posterior margin of the tibial plateau, as a parameter to evaluate anterior tibial displacement via ultrasound diagnostic device. Further, peak torque of the quadriceps muscle was calculated using force measurement device. No difference in anterior tibial displacement and peak torque was observed between the uninjured and injured sides during Leaf spring exercise. Leaf spring exercise may add some strain on the reconstructed anterior cruciate ligament; hence, it can be considered a safe quadriceps exercise in the knee extension range. • Training quadriceps is difficult after anterior cruciate ligament reconstruction. • Leaf spring exercise controlled anterior tibial displacement during knee extension. • Patients performed leg extensions supported the lower leg in the prone position. • No difference in anterior tibial displacement and peak torque was observed. • Safe quadriceps exercise places less strain on the anterior cruciate ligament. [ABSTRACT FROM AUTHOR]

We compared the effects of whole-body vibration training and proprioceptive neuromuscular facilitation on the biomechanical characteristics of the lower limbs in functional ankle instability patients during cutting movement to ascertain the superior rehabilitation method. Twenty-two male College students with unilateral functional ankle instability volunteered for this study and were randomly divided into whole-body vibration training group and proprioceptive neuromuscular facilitation group. Kinematics data and ground reaction forces were collected using infrared motion capture system and 3-D force plates synchronously during cutting. Repeated measures two-way ANOVA was performed to analyze the data. Both training methods reduced the maximum hip abduction angle (p = 0.010, effect size: proprioceptive neuromuscular facilitation = 0.69; whole-body vibration training = 0.20), maximum knee flexion angle (p = 0.008, effect size: proprioceptive neuromuscular facilitation = 0.39, whole-body vibration training = 1.26) and angular velocity (p = 0.014, effect size: proprioceptive neuromuscular facilitation = 0.62, whole-body vibration training = 0.55), maximum ankle inversion angular velocity (p = 0.020, effect size: proprioceptive neuromuscular facilitation = 0.52, whole-body vibration training = 0.81), and knee flexion angle at the time of maximum vertical ground reaction forces (p = 0.018, effect size: proprioceptive neuromuscular facilitation = 0.27, whole-body vibration training = 0.76), and increased the maximum ankle dorsiflexion moment (p = 0.049, effect size: proprioceptive neuromuscular facilitation = −0.52, whole-body vibration training = −0.22). Whole-body vibration training reduced the maximum ground reaction forces value in the mediolateral directions (p = 0.010, effect size = 0.82) during cutting movement. These findings suggested that the two types of training might increase neuromuscular conduction function around the ankle. After these two types of training, functional ankle instability patients showed a similar risk of injury to the lateral ankle ligaments during cutting. • Proprioceptive neuromuscular facilitation improved neuromuscular control ability. • Whole body vibration training may increase neuromuscular conduction function. • The risk of lateral ankle ligament injury was comparable after both trainings. [ABSTRACT FROM AUTHOR]

Despite the existence of evidence-based rehabilitation strategies that address biomechanical deficits, the persistence of recurrent ankle problems in 70% of patients with acute ankle sprains highlights the unresolved nature of this issue. Artificial intelligence (AI) emerges as a promising tool to identify definitive predictors for ankle sprains. This paper aims to summarize the use of AI in investigating the ankle biomechanics of healthy and subjects with ankle sprains. Articles published between 2010 and 2023 were searched from five electronic databases. 59 papers were included for analysis with regards to: i). types of motion tested (functional vs. purposeful ankle movement); ii) types of biomechanical parameters measured (kinetic vs kinematic); iii) types of sensor systems used (lab-based vs field-based); and, iv) AI techniques used. Most studies (83.1%) examined biomechanics during functional motion. Single kinematic parameter, specifically ankle range of motion, could obtain accuracy up to 100% in identifying injury status. Wearable sensor exhibited high reliability for use in both laboratory and on-field/clinical settings. AI algorithms primarily utilized electromyography and joint angle information as input data. Support vector machine was the most used supervised learning algorithm (18.64%), while artificial neural network demonstrated the highest accuracy in eight studies. The potential for remote patient monitoring is evident with the adoption of field-based devices. Nevertheless, AI-based sensors are underutilized in detecting ankle motions at risk of sprain. We identify three key challenges: sensor designs, the controllability of AI models, and the integration of AI-sensor models, providing valuable insights for future research. [Display omitted] • Application of sensors and artificial intelligence to analyse ankle biomechanics. • Lab sensors predict parameters, paving the way for post-modern rehabilitation. • Field devices show potential for ankle injury prediction. • Focus on streamlined smart sensors and effective data management in the future. [ABSTRACT FROM AUTHOR]

Kinematic analysis has been recommended to quantify the upper limb motor function after stroke. However, previous studies have rarely reported the kinematic data of the post-stroke patients with moderate to severe upper limb paresis due to the poor accomplishment of the complex tasks. 27 post-stroke individuals and 20 non-disabled people participated in the study. The trunk and upper limb movements during the Hand-to-mouth task were captured by the motion capture system and upper extremity kinematic analysis software automatically. The subgroup analysis within stroke group were conducted layering by the Fugl-Meyer Assessment for Upper Extremity scores (severe: 16–31; moderate: 32–50). The paretic upper limbs in the stroke group tended to use more trunk and shoulder compensatory strategies to offset the impact of spasticity and weakness compared with non-disabled controls. The less-affected limbs in the stroke group also showed abnormal kinematic data. There were significant differences between the kinematic metrics of severe and moderate subgroups. The Hand-to-mouth task is a good and feasible option for kinematic analysis of these patients. It is essential to layer the severity of the paresis and put more emphasis on trunk movements in the future kinematic studies. • Both upper limbs in the stroke group showed significant kinematic abnormalities. • The dominant and non-dominant limbs in the non-disabled group performed highly similar. • The two subgroups within the stroke group showed different kinematic characteristics. [ABSTRACT FROM AUTHOR]

Progressive tendon loading programs for patellar tendinopathy typically include single-leg squats with heavy weights either on level ground or on a decline board. Changes in patellar tendon force due to variations of the heavy load single-leg squat have not yet been objectively quantified. The objective of this study was to investigate the influence of the mass of an external weight and the use of a decline board on the peak patellar tendon force during a heavy load single-leg squat. Twelve healthy participants performed single-leg back squats on a decline board and level ground at 70%, 80% and 90% of their one repetition maximum. Three-dimensional kinematics and ground reaction forces were measured and the peak patellar tendon force was calculated using musculoskeletal modelling. A two-way repeated measures ANOVA determined the main effects for the mass of the external weights and the use of a decline board as well as their interaction effect. Peak patellar tendon forces were significantly higher on the decline board compared to level ground (p < 0.05). Neither on the decline board, nor on level ground did the peak patellar tendon force increase significantly when increasing the external weights (p > 0.05). Progression in peak patellar tendon forces during a heavy load single-leg squat can only be obtained with a decline board. Increasing the mass of the external weight from 70% to 90% of the one repetition maximum does not result in a progressively higher peak patellar tendon force. • Increasing an external weight's mass does not increase peak patellar tendon forces. • Peak patellar tendon forces are higher on a decline board than on level ground. • High peak patellar tendon forces on a decline board are reached at lower weights. [ABSTRACT FROM AUTHOR]

Foot orthoses are therapeutic insoles designed to induce various effects on lower limb biomechanics. However, conflicting findings in previous research, highlight the need to better understand how foot orthoses with different features affect lower limb biomechanics during challenging tasks, particularly during unilateral drop jump landings. Seventeen participants with flat feet were recruited to participate in this cross-sectional descriptive study that examined the effects of thin-flexible foot orthoses and medially wedged foot orthoses on lower limb biomechanics during unilateral drop jump landings on level and valgus inclined surfaces. Midfoot, ankle, knee, and hip angles and moments were calculated and compared across conditions with repeated measures ANOVAs, using a statistical parametric mapping approach. Medially wedged and thin-flexible foot orthoses reduced ankle pronation and arch flattening during unilateral drop jump landings on level and valgus inclined surfaces. Medially wedged foot orthoses further decreased midfoot dorsiflexion and ankle eversion angles compared to thin-flexible foot orthoses. Medially wedged foot orthoses also generated greater effects on ankle kinetics and hip kinematics during unilateral drop jump landings. Medially wedged foot orthoses are more effective than thin-flexible foot orthoses in optimizing lower limb biomechanics during unilateral drop jump landings. While the biomechanical effects did not increase on inclined surfaces, medially wedged foot orthoses generated greater effects on proximal joints, highlighting their potential to improve hip stability and enhance overall lower limb function. Personalized foot orthoses selection based on specific biomechanical profiles should be further explored to optimize orthotic interventions benefiting individuals with musculoskeletal conditions. • Medially wedged foot orthoses generated the greatest biomechanical effects. • Similar foot orthoses' effects were observed during landing on both surfaces. • Foot orthoses mainly effected the distal segments of the lower limb. [ABSTRACT FROM AUTHOR]

A decrease in knee flexion excursion during the loading response may affect not only quadriceps muscle weakness, pain, and inflammatory symptoms, but also lead to physical function decline and activity limitation. The aim of this investigation was to clarify the relationship between knee flexion excursion during the loading response and mechanical stress on the knee joint, muscle strength, pain, and physical function in patients with knee osteoarthritis. Twenty patients diagnosed with medial knee osteoarthritis. The participants walked along a 10 m corridor in the laboratory at a comfortable pace. The kinematic and kinetic data were collected using a 3D motion analysis system. We employed to control for gait speed and age while examining the relationship between knee flexion excursion during the loading response and mechanical stress on the knee joint, muscle strength, pain, and physical function. Knee flexion excursion showed a significant positive correlation with the peak and angular impulse of knee flexion moment. In the partial correlation coefficients controlling for age and gait speed, significant negative correlations were found between knee flexion excursion and knee adduction moment angular impulse. It can be inferred that gait with reduced knee flexion movement during the loading response in patients with knee osteoarthritis may result in increased mechanical stress on the knee joint in the frontal plane. Exercise interventions aimed at increasing knee flexion excursion may result in a reduction in disease progression. • Studied knee flexion's impact on gait's mechanical stress. • Limited knee flexion may lower frontal-plane stress. • Exercises boosting knee flexion may curb disease spread. [ABSTRACT FROM AUTHOR]

Analyzing sports injuries is essential to mitigate risk for injury, but inherently challenging using in vivo approaches. Computational modeling is a powerful engineering tool used to access biomechanical information on tissue failure that cannot be obtained otherwise using traditional motion capture techniques. We extrapolated high-risk kinematics associated with ACL strain and cartilage load and stress from a previous motion analysis of 14 uninjured participants. Computational simulations were used to induce ACL failure strain and cartilage failure load, stress, and contact pressure in two age- and BMI-matched participants, one of each biological sex, during single-leg cross drop and single-leg drop tasks. The high-risk kinematics were exaggerated in 20% intervals, within their physiological range of motion, to determine if injury occurred in the models. Where injury occurred, we reported the kinematic profiles that led to tissue failure. Our findings revealed ACL strains up to 9.99%, consistent with reported failure values in existing literature. Cartilage failure was observed in all eight analyzed conditions when increasing each high-risk kinematic parameter by 2.61 ± 0.67 times the participants' natural landing values. The kinematics associated with tissue failure included peak hip internal rotation of 22.48 ± 19.04°, peak hip abduction of 22.51 ± 9.09°, and peak lumbar rotation away from the stance limb of 11.56 ± 9.78°. Our results support the ability of previously reported high-risk kinematics in the literature to induce injury and add to the literature by reporting extreme motion limits leading to injurious cases. Therefore, training programs able to modify these motions during single-leg landings may reduce the risk of ACL injury and cartilage trauma. • Exaggerated hip and lumbar kinematics in single-leg landings led to soft tissue failure in models. • Excessive hip and lumbar non-sagittal kinematics should be avoided during single-leg landings. • Medial knee side bears higher loads in single-leg landings with increased hip and lumbar rotations. [ABSTRACT FROM AUTHOR]

An inertial measurement unit is small and lightweight, allowing patient measurements without physical constraints. This study aimed to determine the differences in kinematic parameters during gait using an insole with a single inertial measurement unit in healthy controls and on both sides in patients with knee osteoarthritis. Twenty patients with knee osteoarthritis and 13 age-matched controls were included in this study. The participants walked at a self-selected speed and foot kinematics were measured during gait using an insole with a single inertial measurement unit. The right side of the healthy controls and both the affected and contralateral sides of patients with KOA were analyzed separately. The foot extension angular velocity at toe-off was significantly reduced on the affected side than on the contralateral side (P < 0.001) and in healthy controls (P < 0.001). During the swing phase, foot posterior-anterior acceleration was significantly lower on the affected side than on the healthy controls (P = 0.005). Furthermore, despite a decrease in walking speed, foot superior-inferior acceleration at initial contact in patients was significantly lower on the contralateral side than in healthy controls (P = 0.0167), but not on the affected side (P = 0.344). An insole with a single inertial measurement unit can detect differences in foot kinematics during gait between healthy controls and patients with knee osteoarthritis. Our findings indicate that patients with knee osteoarthritis exhibit dysfunction of push-off at toe-off and shock absorption at initial contact on the affected side. • A single inertial measurement unit can detect foot kinematics during gait. • Foot kinematic showed differences between healthy control and knee osteoarthritis. • The foot extension angular velocity at toe-off showed a side-to-side difference. • The single insole sensor helps assess gait in patients with knee osteoarthritis. [ABSTRACT FROM AUTHOR]

Most total disc replacements provide excessive mobility and not reproduce spinal kinematics, inducing zygapophyseal joint arthritic changes and chronic back pain. In cadaveric lumbosacral spines, we studied if a new lumbar disc prosthesis kinematics mimics the intact intervertebral disc. In eight cold preserved cadaveric lumbosacral spines, we registered the movement ranges in flexion, extension, right and left lateral bending, and rotation in the intact status, post-discectomy, and after our prosthesis implantation, comparing them for each specimen. Comparing the intact lumbosacral spine with the L 4 -L 5 prosthesis implanted specimens, we saw statistically significant differences in lateral bending and right rotation but not in the full range of rotation. Analyzing segments, we also noticed statistically significant differences at L 4 -L 5 in flexion-extension and rotation. On the other hand, the L 4 -L 5 discectomy, compared to the baseline spine condition, showed a statistically significant mobility increase in flexion, extension, lateral bending, and axial rotation, with an abnormal instantaneous center of rotation, which destabilizes the segment partly due to anterior annulus surgical removal. Disc prosthesis implantation reversed these changes in instantaneous center of rotation, but the prosthesis failed to restore the initial range of motion due to the destabilization of the ligaments in the operated disc. The ADDISC total disc replacement reproduces the intact disc kinematics and Instantaneous Center of Rotation, but the prosthesis fails to restore the initial range of motion due to ligament destabilization. More studies will be necessary to define a technique that restores the damaged ligaments when implanting the prosthesis. • Total disc replacements provide excess mobility, not reproducing instantaneous rotation center. • We created a new design based on the intact disc movement range and instantaneous rotation center. • Our implant reproduces intact disc kinematics and instantaneous rotation center. • This feature should provide less stress on the index and adjacent level zygapophyseal joints. [ABSTRACT FROM AUTHOR]

Reaching behind the back is painful for individuals with rotator cuff tears. The objectives of the study were to determine changes in glenohumeral kinematics when reaching behind the back, passive range of motion (RoM), patient reported outcomes and the relationships between kinematics and patient reported outcomes following exercise therapy. Eighty-four individuals with symptomatic isolated supraspinatus tears were recruited for this prospective observational study. Glenohumeral kinematics were measured using biplane radiography during a reaching behind the back movement. Passive glenohumeral internal rotation and patient reported outcome measures were collected. Depending on data normality, appropriate tests were utilized to determine changes in variables. Spearman's correlations were utilized for associations, and Stuart-Maxwell tests for changes in distributions. Maximum active glenohumeral internal rotation increased by 3.2° (P = 0.001), contact path length decreased by 5.5% glenoid size (P = 0.022), passive glenohumeral internal rotation RoM increased by 4.9° (P = 0.001), and Western Ontario Rotator Cuff Index and American Shoulder and Elbow Surgeons scores increased by 29.8 and 21.1 (P = 0.001), respectively. Changes in Western Ontario Rotator Cuff Index scores positively associated with changes in maximum active glenohumeral internal rotation and negatively associated with changes in contact path lengths (P = 0.008 and P = 0.006, respectively). The reaching behind the back movement was useful in elucidating in-vivo mechanistic changes associated with patient reported outcomes. Glenohumeral joint function and patient reported outcomes improved, where changes in Western Ontario Rotator Cuff Index scores were associated with kinematics. These findings inform clinicians of functional changes following exercise therapy and new targetable treatment factors. • The reaching behind the back movement is useful to assess dynamic joint function. • Improved in-vivo kinematics when reaching behind the back following exercise therapy. • Reaching behind the back kinematics are associated with patient reported outcomes. • Future rotator cuff studies should utilize the reaching behind the back movement. [ABSTRACT FROM AUTHOR]

Turning while walking is a complex component of locomotor capacity, which can be challenging in the daily lives of people with Parkinson's disease. The aim of the study was to compare biomechanical strategies during turning of gait in individuals with Parkinson's disease and its different clinical subtypes. A cross-sectional study, comprising of 43 individuals with idiopathic Parkinson's disease, divided in subgroups: akineto-rigid, dominant tremor and mixed. Motor impairment was assessed using the Unified Parkinson's Disease Rating Scale. The gait biomechanical parameters (number of steps, step length, cadence, amplitude, velocity and radius of the turn) were analyzed during turning in a kinematics laboratory. In the statistical analysis, a comparison was made between subgroups, and correlations between biomechanical parameters. There was no statistically significant difference between the subgroups. In the correlation analysis, notable correlations were found between the anticipatory step length and the following variables: number of steps (r = −0.418), step length while turning (r = 0.805), step length after turning (r = 0.644), average velocity (r = 0.830), average velocity while turning (r = 0.755), and maximum velocity (rho = 0.835). The difficulties primarily occur during the anticipatory phase of the turn, which affects the entire task. The greater the length of the anticipatory step, the greater the length of the step taken to turn as well as the step taken after turning. And the greater the velocity, the greater the step length, and to fewer steps taken to perform the task. • Individuals with Parkinson's disease have some compensatory strategies to turn. • There are not biomechanical differences in turning between subtypes of disease. • Anticipatory step length is correlated with step length during and after turning. • Rehabilitation that emphasizes attention to movement initiation are very important. [ABSTRACT FROM AUTHOR]

Patients with acetabular dysplasia have an abnormal acetabular geometry which results in insufficient coverage of the femoral head. This coverage deficiency reduces contact surfaces within the joint, accelerating the wear of the articular cartilage and predisposing patients to early osteoarthritis. Periacetabular osteotomy is a surgical treatment of acetabular dysplasia that aims to reorient the acetabulum relative to the femoral head, increasing coverage. Pelvic kinematics and lower limbs joint kinematics and kinetics during the stance phase of gait were recorded using a 3D motion capture system and force plates, then compared pre- to post- and between limbs with a repeated measures 2-way ANOVA. Radiographic measurements and gait parameters were compared pre- to post-surgery using a t -test for dependant samples. To identify predictors of pelvic symmetry improvements during gait, a multivariate analysis was performed using a forward stepwise linear regression. Radiographic measurements improved for all participants while gait parameters remained unchanged. Hip flexion symmetry was improved following surgery. The external rotation moment of the healthy hip was reduced after surgery (−29%) resulting in increased asymmetry. Pelvic tilt was significantly greater on the affected side (+0.5°) during the loading response, and the difference tended to be greater after surgery (+0.8°). Unilaterally affected dysplastic patients have an asymmetrical gait pattern that is only partially corrected by periacetabular osteotomy even when radiographic and clinical targets are met. Differences between the limbs could be explained in part by a learned antalgic pattern and muscle weaknesses leading to complex compensation mechanisms. • Gait parameters remain unchanged after periacetabular osteotomy. • Periacetabular osteotomy has mixed effect on limbs kinetics and kinematics symmetry during gait. • Dynamic pelvic tilt increases following surgery. [ABSTRACT FROM AUTHOR]

Challenging children with Down syndrome to walk fast and with external ankle load has demonstrated acute adjustments, such as increased step length and decreased step width, and improved joint stability. However, it is unknown to what extent these task constraints affect gait stability. Assessing dynamic gait stability through margin-of-stability not only quantifies adjustments related to balance control, but also informs safety considerations. Twenty-four children with and without Down syndrome participated in this study. Subjects walked overground at two speed conditions: self-selected (normal) and as fast as possible (fast); and two ankle load conditions: no load and ankle load of 2% body mass. We assessed margin-of-stability in the anteroposterior and mediolateral directions, separately, at three gait events of toe-off, mid-swing, and heel strike. Children with Down syndrome walked with greater mediolateral margin-of-stability than typically developing children. Children with Down syndrome demonstrated less anteroposterior margin-of-stability than typically developing children only before heel-strike at normal speed but increased anteroposterior margin-of-stability at fast speed. The ankle load increased the mediolateral margin-of-stability in both groups but did not impact the anteroposterior margin-of-stability. In addition, children with Down syndrome took shorter and wider steps for more lateral placement of mediolateral margin-of-stability. Children with Down syndrome were capable of adjusting their margin-of-stability for fast walking and ankle-load conditions. However, children with Down syndrome walked with less mediolateral stability and anteroposterior mobility than typically developing children. Children with Down syndrome overcompensate the mediolateral foot placement to recapture their margin-of-stability and maintain gait stability. • Children with Down syndrome walked with a distinct joint pattern compared to peers. • Increased walking speed improved ankle kinematics, but challenged knee kinematics. • Ankle load improved hip and knee kinematics, but challenged ankle plantarflexion. • Intervention design can consider the manipulation of walking speed and ankle load. [ABSTRACT FROM AUTHOR]

Cross-slopes are often encountered by manual wheelchair users propelling within an urban setting. While propulsion over cross-slopes is more difficult than on level surfaces, little is known about how the users counter the downhill turning tendency of the wheelchair over cross-slopes. This study aimed to identify the adaptations of the manual wheelchair users to the presence of cross-slopes and examine how these might impact shoulder injury. Nine manual wheelchair users propelled themselves across a cross-slope and over a level surface. The trunk and glenohumeral joint kinematics, as well as the handrim contact tangential force were compared between both conditions for the uphill and downhill limbs. The uphill arm technique used to counter the downhill turning tendency varied greatly in terms of potential injury risk and efficiency between participants. Trunk flexion increased the turning tendency of the manual wheelchair, yet only one participant decreased his flexion when rolling over the cross-slope. Various potential pathomecanisms related to the trunk lateral flexion and the glenohumeral kinematics over a cross-slope were identified. Both the uphill arm technique and trunk kinematics are important to propel over a cross-slope both efficiently and safely. Accordingly, tips about posture and kinematics are needed to teach this skill to manual wheelchair users. Additionally, as wheelchair positioning seems to influence the cross-slope skill, more research is needed to explore the impact of positioning devices (e.g., lateral supports) and wheelchair modifications (e.g., power assist wheels, handrim projections) on this skill. • Upper limb and trunk kinematics are important for an efficient and safe cross-slope propulsion. • Glenohumeral kinematics and trunk lateral flexion could explain shoulder pathomecanisms. • Subject-specific tips on posture and kinematics are needed to teach cross-slope propulsion. [ABSTRACT FROM AUTHOR]

The interplay between the medial gastrocnemius muscle and the Achilles tendon is crucial for efficient walking. In cerebral palsy, muscle and tendon remodelling alters the role of contractile and elastic components. The aim was to investigate the length changes of medial gastrocnemius belly and fascicles, and Achilles tendon to understand their interplay to gait propulsion in individuals with cerebral palsy. Twelve young individuals with cerebral palsy and 12 typically developed peers were assessed during multiple gait cycles using 3D gait analysis combined with a portable ultrasound device. By mapping ultrasound image locations into the shank reference frame, the medial gastrocnemius belly, fascicle, and Achilles tendon lengths were estimated throughout the gait cycle. Participants with cerebral palsy were classified into equinus and non-equinus groups based on their sagittal ankle kinematics. In typically developed participants, the Achilles tendon undertook most of the muscle-tendon unit lengthening during stance, whereas in individuals with cerebral palsy, this lengthening was shared between the medial gastrocnemius belly and Achilles tendon, which was more evident in the equinus group. The lengthening behaviour of the medial gastrocnemius fascicles resembled that of the Achilles tendon in cerebral palsy. The findings revealed similar length changes of the medial gastrocnemius fascicles and Achilles tendon, highlighting the enhanced role of the muscle in absorbing energy during stance in cerebral palsy. These results, together with the current knowledge of increased intramuscular stiffness, suggest the exploitation of intramuscular passive forces for such energy absorption. • Gastrocnemius muscle-Achilles tendon function is altered in cerebral palsy gait. • Both muscle and tendon contribute to muscle-tendon unit lengthening in stance phase. • Muscle fascicles and Achilles tendon resembled a similar behaviour in stance phase. • Intramuscular passive force transmission may be enhanced in cerebral palsy. [ABSTRACT FROM AUTHOR]

Children with developmental coordination disorder show difficulties in making rapid online corrections, and this has been demonstrated in experiments where reaching/pointing movements were employed. However, typical hand movements in real-life contexts involve subsequent movements, such as grasping and manipulating objects after reaching. This study aimed to reinvestigate online correction of reaching movements that were connected with grasping and object manipulation and to explore its impact on the coordination of subsequent hand movements in children with developmental coordination disorder. Five children with developmental coordination disorder and five children with typical development were recruited. Their reach-to-manipulate movements in a double-step task were recorded using motion analysis. The manipulative movements included simple and complex forms of pencil rotation. Movement time, movement velocity, and correlation coefficients between finger joints were derived to quantify their motor performances. Children with developmental coordination disorder showed longer movement time and deceleration phases during online correction of reaching movement than children without developmental coordination disorder. In subsequent grasping and manipulation movements after online correction, they also exhibited lower correlation coefficients in four to five finger joint couplings that are essential for movement completion, compared to children without developmental coordination disorder. Our findings from the current pilot study suggest that children with developmental coordination disorder have impairments in online correction when reaching for objects and may also have reduced coordination of some finger movements that are important for subsequent grasping and object manipulation. Future studies with larger sample sizes are warranted to confirm these findings. • Children with developmental coordination disorder had impaired online correction. • Atypical finger joint coordination after online correction was found. • Impaired internal model control of complex movements was revealed. [ABSTRACT FROM AUTHOR]

To assess the in-field walking mechanics during downhill hiking of patients with total knee arthroplasty five to 14 months after surgery and an age-matched healthy control group and relate them to the knee flexor and extensor muscle strength. Participants walked on a predetermined hiking trail at a self-selected, comfortable pace wearing an inertial sensor system for recording the whole-body 3D kinematics. Sagittal plane hip, knee, and ankle joint angles were evaluated over the gait cycle at level walking and two different negative slopes. The concentric and eccentric lower extremity muscle strength of the knee flexors and extensors isokinetically at 50 and 120°/s were measured. Less knee flexion angles during stance have been measured in patients in the operated limb compared to healthy controls in all conditions (level walking, moderate downhill, steep downhill). The differences increased with steepness. Muscle strength was lower in patients for both muscle groups and all measured conditions. The functional hamstrings to quadriceps ratio at 120°/ sec correlated with knee angle during level and downhill walking at the moderate slope in patients, showing higher ratios with lower peak knee flexion angles. The study shows that even if rehabilitation has been completed successfully and complication-free, five to 14 months after surgery, the muscular condition was still insufficient to display a normal gait pattern during downhill hiking. The muscle balance between quadriceps and hamstring muscles seems related to the persistence of a stiff knee gait pattern after knee arthroplasty. LoE: III. • Patients showed more extended knee during loading response than controls in downhill hiking. • Differences seem to be more pronounced with rising impact (steeper slope). • Ratio of hamstrings and quadriceps strength correlated with knee flexion in patients. • First study that shows a stiff knee gait pattern in patients with knee arthroplasty in-field. [ABSTRACT FROM AUTHOR]

Latissimus dorsi transfer is a surgical procedure that can be used for treating posterosuperior rotator cuff tears. The procedure leads to improved shoulder function via alterations in the force vector couple around the shoulder. However, there is still no consensus on the biomechanical changes resulting from latissimus dorsi transfer. We performed a systematic review of the literature on 3D motion analysis studies evaluating the effects of latissimus dorsi transfer on shoulder kinematics. The available data on segment and joint range of motion was extracted and subject to meta-analysis when consistent across the studies. Our meta-analysis of pre- and post-operative studies revealed a significant improvement in forward flexion and abduction following latissimus dorsi transfer. When comparing the latissimus transferred shoulder with an uninjured contralateral side the meta-analysis found no significant difference in flexion range of motion, while abduction and external rotation was significantly higher in the uninjured shoulders. The overall risk of bias was moderate to high. High heterogeneity was found in the reporting of data, which limited our ability to perform a meta-analysis across the studies for all interest outcomes. Our findings suggest that latissimus dorsi transfer for posterosuperior rotator cuff tears effectively improves shoulder flexion and abduction. External rotation is also expected to improve but at inferior levels as compared to the unaffected side. However, the heterogeneity of the reported data on 3D motion analysis studies highlights the need for better standardization in research and reporting as to conclude the impact of different joints. • Latissimus dorsi transfer improves shoulder flexion and abduction. • Abduction does not reach uninjured level range of motion while flexion may. • Future studies should focus on larger samples and standardized reporting. • Internal/external rotation, and scapular kinematics require further investigation. • Standardization of research and reporting on 3D motion analysis studies is needed. [ABSTRACT FROM AUTHOR]

Dance-based exergaming has exhibited efficacy in people with chronic stroke, it is beneficial to advance towards independent self-training to increase long-term compliance, and cost effectiveness through safety harness devices. Thus, the purpose of the study was to investigate people with chronic stroke's dance-movement kinematics to different types of assistance, namely no assistance, safety harness assistance, and contact guard assistance with gait belt. Community-dwelling people with chronic stroke (n = 10) participated in the study. Seven inertial sensors were used to capture their dance movements with three songs slow, medium, and fast pace. Three trials were recorded for each dance and the mean values of variables were used for analysis. A customized MATLAB code generated joint angle excursions (difference between the maximum and minimum angle peaks) of the hip, knee, and ankle in the sagittal plane. The results exhibited decreased joint angle excursions in no assistance condition in comparison to safety harness assistance and contact guard assistance conditions for all song paces (p < 0.05). The safety harness , and contact guard assistance condition exhibited similar levels of joint angle excursions for the all the conditions, except significantly higher hip (slow, and fast pace) (p < 0.05), and ankle (medium pace) (p < 0.05) joint angle excursions in contact guard assistance in comparison to safety harness assistance . The study represents the joint angle excursions that are influenced by different conditions in chronic stroke. Future studies, should evaluate feasibility of safety harness augmented dance-based exergaming in home-setting among chronic stroke. [Display omitted] • Lower extremity kinematics with safety harness exhibits safety and feasibility. • Safety harness, and contact guard assistance conditions facilitated equal levels of joint angle excursions. • Safety harness helps implement dance-based exergaming in home-setting in stroke. [ABSTRACT FROM AUTHOR]

The patellofemoral joint is an important source of pain in knee osteoarthritis. Most biomechanical research in knee osteoarthritis has focused on the tibiofemoral joint during level walking. It is unknown what happens during stair negotiation in patients with patellofemoral joint osteoarthritis, a task commonly increasing pain. Conservative therapy for patellofemoral joint osteoarthritis includes the use of a sleeve knee brace. We aimed to examine the effect of a sleeve knee brace on knee biomechanics during stair negotiation in patellofemoral joint osteoarthritis patients. 30 patellofemoral joint osteoarthritis patients (40–70 years) ascended and descended an instrumented staircase with force plates under two conditions – wearing a Lycra flexible knee support (Bioskin Patellar Tracking Q Brace) and no brace (control condition). Knee joint kinematics (VICON) and kinetics were recorded. During stair ascent, at the knee, the brace significantly reduced the maximal flexion angle (2.70, P = 0.002), maximal adduction angle (2.00, P = 0.044), total sagittal range of motion (2.00, P = 0.008), total frontal range of motion (1.70, P = 0.023) and sagittal peak extension moment (0.05 Nm/kg, P = 0.043) compared to control. During stair descent, at the knee, the brace significantly reduced the maximal flexion angle (1.80, P = 0.039) and total sagittal range of motion (1.50, P = 0.045) compared to control. The small changes in knee joint biomechanics during stair negotiation observed in our study need to be investigated further to help explain mechanisms behind the potential benefits of a sleeve knee brace for painful patellofemoral joint osteoarthritis. • Knee brace may reduce pain in patellofemoral osteoarthritis. • Knee biomechanics of stair negotiation in patellofemoral osteoarthritis is unknown. • We examined knee brace effect on knee biomechanics during stair negotiation. • Small changes in knee biomechanics were found during stair ascent and descent. • Knee brace could be beneficial in patellofemoral osteoarthritis. [ABSTRACT FROM AUTHOR]

Children with cerebral palsy experience movement disorders that influence gait stability. It is likely that gait stability further decreases when walking on uneven compared to even ground. Therefore, the aim of this study was to investigate gait on uneven ground in children with unilateral cerebral palsy. Twenty children with unilateral cerebral palsy and twenty typically developing children performed a three-dimensional gait analysis when walking on even and uneven ground. Spatio-temporal parameters, full-body joint kinematics and centre of mass displacements were compared. On uneven versus even ground, both groups showed decreased cadence, increased stance phase and double support time, increased toe clearance height, and increased knee and hip flexion during swing phase. Whereas only the typically developing children walked slower and had increased dorsiflexion and external foot progression during stance phase, only the patients showed increased stride width, increased elbow flexion (affected and non-affected side), and kept the centre of mass more medial when standing on the affected leg. Patients and healthy children use similar adaptation mechanisms when walking on uneven ground. Both groups increased the toe clearance height by increasing knee and hip flexion during swing. However, whereas patients enlarge their base of support by increasing stride width, healthy children do so by increasing their external foot progression angle. Furthermore, patients seem to feel more insecure and hold their arms in a position to prepare for falls on uneven ground. They also do not compensate with their non-affected side for their affected side on uneven ground. • Adaptive mechanisms when walking on uneven ground in patients with unilateral cerebral palsy • Patients and healthy children show similar adaptive mechanisms on uneven ground. • Different strategies to maintain dynamic stability on uneven ground were discovered. • Patients do not compensate with their non-affected side for their affected side on uneven ground. [ABSTRACT FROM AUTHOR]

Repetitive glenohumeral joint movement during manual wheelchair propulsion has been associated with shoulder pain in individuals with spinal cord injury. Clinical guidelines for shoulder health maintenance encourage semi-circular over arc propulsion to reduce loading frequency. This study aimed to determine the difference in estimated supraspinatus to acromion compression risk, and shoulder, thorax kinematics between (1) arc and semi-circular propulsion; and (2) self-selected and coached strategies. Shoulder and thorax kinematics were captured during wheelchair propulsion, noting individually self-selected styles. Participants were then coached to perform the other style(s) of interest, arc and/or semi-circular. CT bone models of the humerus and scapula were animated using glenohumeral kinematics to estimate the minimum distance between the supraspinatus humeral attachment and the acromion. Compression risk was defined as the proportion of each propulsion phase where the minimum distance fell below 5 mm. Comparisons were made between conditions evaluating compression risk, minimum distances and kinematics at events throughout propulsion. Ten individuals with spinal cord injury (9 male) participated. Arc and semi-circular propulsion did not significantly differ in compression risk or minimum distance across propulsion phases. Self-selected styles yielded lower compression risk and larger proximity values compared to coached styles. Glenohumeral horizontal abduction and thorax flexion differed between arc and semi-circular propulsion. Multiple glenohumeral and humerothoracic differences emerged between self-selected and coached conditions. Supraspinatus compression was observed during both arc and semi-circular propulsion, suggesting risk may be unavoidable in this task. Self-selected styles yield less risk, likely related to coached style unfamiliarity. • Compression risk between the supraspinatus and acromion occurs during wheelchair propulsion. • No differences in compression risk were found between arc and semi-circular propulsion. • Self-selected propulsion styles showed less compression risk than coached styles. • Results support adoption of semi-circular propulsion style to maintain shoulder health. [ABSTRACT FROM AUTHOR]

The aim of this systematic review with meta-analysis was to determine the change in gait biomechanics after total ankle replacement and ankle arthrodesis for end-stage osteoarthritis. Electronic databases were searched up until May 2019. Peer-reviewed journal studies including adult participants suffering from end-stage ankle osteoarthritis and reporting pre- and post-operative kinematics, kinetics and spatio-temporal effects of total ankle replacement and ankle arthrodesis during walking were included with a minimum of 12 months follow-up. Seventeen suitable studies were identified and assessed according to methodological and biomechanical qualities. Meta-analysis was performed by calculating the effect size using standard mean differences between pre- and post-operative gait status. Seventeen studies with a total of 883 patients were included. Meta-analysis revealed moderate evidence of an improvement in lower limb kinematics, kinetics and spatio-temporal parameters after total ankle replacement. Moderate evidence indicated an increase in ankle moment, hip range of motion and walking speed after ankle arthrodesis. The currently available evidence base of research papers evaluating changes in gait biomechanics after total ankle replacement and ankle arthrodesis is limited by a lack of prospective research, low sample sizes and heterogeneity in the patho-etiology of ankle osteoarthritis. Following total ankle replacement, improvements were demonstrated for spatio-temporal, kinematic and kinetic gait patterns compared to the pre-operative measures. Improvements in gait mechanics after ankle arthrodesis were limited to walking speed and ankle moment. Increased hip range of motion after ankle arthrodesis could represent a sign of compensation for the lack of ankle motion. • Moderate evidence to suggest that lower extremity biomechanics improved after total ankle replacement. • Moderate evidence to suggest that total ankle replacement improves pre-operative ankle range of motion by 3°. • No difference in outcomes between fixed- versus mobile-bearing prosthesis • Ankle moment, hip range of motion and walking speed increased after ankle arthrodesis. [ABSTRACT FROM AUTHOR]