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Fear of movement has been related to lower limb activation patterns in older adults. However, insight into consecutive perturbations on stepping strategy while considering fall-related confidence is unknown. Are there latency time delays following three consecutive slip perturbations between subjects with and without kinesiophobia when considering limb dominance and fall efficacy differences? There were 15 older adults with kinesiophobia and 15 age- and body mass index (BMI)-matched control subjects. The subjects stood on the platform during three consecutive perturbations (250, 300, and 400 msec excursions), which were produced by a Bertec device. The subjects completed questionnaires to evaluate the psychological features of their fall-related fear (Tampa Scale for Kinesiophobia: TSK) as well as the modified fall efficacy scale (FES). The latency times (msec) measured the time it took for a subject to respond to a translation. Overall, the results of the FES demonstrated a moderate negative association with the TSK (r = −0.52, p = 0.004). There was a significant group difference for the FES (t = 2.78, p = 0.01). The FES demonstrated significant positive correlation coefficients (ranging from 0.40 to 0.51) and significant negative correlation coefficients (ranging from −0.41 to −0.61), except for the slow perturbations. The groups demonstrated a significant interaction on consecutive latency times and limb side (F = 5.84, p = 0.02). The latency time during the fast perturbations on the dominant limb (F = 5.53, p = 0.02) was significantly shorter in the kinesiophobia group. The control group demonstrated confidence during fall-related activities, but the latency times were significantly different between groups when considering the dominant limb following repeated slip perturbations. The kinesiophobia group demonstrated shorter latency times on the dominant limb to protect against potential fall-risks from perturbations. The group interactions on limb side and consecutive perturbations need to be considered with fall-related confidence and improved standing balance in older adults with kinesiophobia. • Fear of movement on limb activation patterns was compared in older adults. • The group interactions on limb side and perturbations were evident for fall risks. • The kinesiophobia group demonstrated shorter dominant limb reactions. • The control group demonstrated confidence during fall-related perturbations. [ABSTRACT FROM AUTHOR]

Modern medical implants are characterized by non-circular shapes, which is often challenging for economic production. Non-Circular-Rotary-Turning (NCRT) is a newly developed process for manufacturing non-circular cross-sections at high productivity and a high degree of geometric freedom. In this work, the basic process kinematics of NCRT are presented. A process design method is proposed and validated. The fundamental cutting conditions are examined using simulation and the cutting forces are studied experimentally. In an example of application, NCRT enables to reduce machining time by a factor of more than ten compared to a conventional process chain, resulting even in better surface quality. [ABSTRACT FROM AUTHOR]

Introduction: The relationship between anterior pelvic tilt and overall sagittal alignment has been well-described previously. However, the relationship between pelvic tilt, frontal, and axial leg alignment remains unclear. The aim of the study was to analyze the relationship between pelvic tilt and frontal and axial leg alignment in healthy subjects.Material and Methods: Thirty healthy subjects (60 legs) without prior surgery underwent standing biplanar long leg radiograph. Pelvic parameters (pelvic tilt, pelvic incidence, sacral slope), hip-knee-ankle angle (HKA), femoral antetorsion and tibial torsion were measured using SterEOS (EOS Imaging) software. EOS was acquired with the feet directing straight anteriorly, which corresponds to a neutral foot progression angle (FPA). The influence of HKA, femoral antetorsion, tibial torsion and gender on pelvic tilt was analyzed in a univariate correlation and multiple regression model.Results: Sixteen female subjects and 14 male subjects with a mean age of 27.1 years ± 10 (range 20-67) were included. HKA, femoral antetorsion, and tibial torsion correlated with anterior pelvic tilt in univariate analysis (all p < 0.05). Anterior pelvic tilt increased 1.1° (95% CI: 0.7 to 1.5) per 1° of knee valgus (p < 0.001) and 0.5° (95% CI: 0.3 to 0.7) per 1° of external tibial torsion (p < 0.001). Overall, linear regression model fit explained 39% of variance in pelvic tilt by the HKA, femoral antetorsion and tibial torsion (R2 = 0.385; p < 0.001).Conclusion: Valgus alignment and increasing tibial torsion demonstrated a weak correlation with an increase in anterior pelvic tilt in healthy subjects when placing their feet anteriorly. The relationship between frontal, axial leg alignment and pelvic tilt needs to be considered in patients with multiple joint disorders at the hip, knee and spine. Alteration of the frontal, or rotational profile after realignment surgery or by implant positioning might influence the pelvic tilt when the FPA is kept constant. [ABSTRACT FROM AUTHOR]

Tendons play a crucial role allowing the storage and release of mechanical energy during the running cycle. Running kinematics, including duty factor, constitute a basic element of the runner's biomechanics, and can determine their performance. This study aimed to analyze the link between Achilles tendon and plantar fascia morphology and running parameters, considering the influence of wearing shoes versus running barefoot. Cross-sectional study. 44 participants (30 men and 14 women) engaged in two running sessions, one with shoes and one without, both lasting 3 min at a consistent speed of 12 km/h. We captured running kinematic data using a photoelectric cell system throughout the sessions. Before the trials, we measured the thickness and cross-sectional area of both the Achilles tendon and plantar fascia using ultrasound. The Pearson test revealed a significant correlation (p < 0,05) between Achilles tendon and plantar fascia morphology and contact time (r > − 0.325), flight time (r > − 0.325) and duty factor (ratio of ground contact to stride time) (r > − 0.328) during barefoot running. During the shod condition, no significant correlation was found between connective tissue morphology and kinematic variables. In barefoot running, greater size of the Achilles tendon and plantar fascia results in a reduced duty factor, attributed to longer flight times and shorter contact times. [ABSTRACT FROM AUTHOR]

Walking is the most important mode of human locomotion; however, the ability to walk often decreases with age. Age-related differences in lower-limb kinematics during gait may differ depending on sex. However, the question of the compounded effects of age and sex on gait kinematics remains unsolved. The present study aimed to clarify the interaction between age and sex in differences in gait kinematics of community-dwelling middle-age and older individuals. This study included 836 community-dwelling middle-age and older adults (61.8 % female). Joint motion during comfortable gait was measured using magnetic and inertial measurement units. Hip, knee, and ankle joint angles were calculated in the sagittal plane. Participants were divided into four groups according to age: 50–59, 60–69, 70–79, and 80–89 years. The interaction of sex and age on spatiotemporal gait parameters and the peak value of joint angles was analyzed using two-way analysis of variance (ANOVA) and Tukey's post hoc test. Gait speed (F = 43.92, P < 0.001), step length (F = 73.00, P < 0.001), hip extension (F = 12.89, P = 0.002), knee flexion (F = 39.99, P < 0.001), and ankle plantar flexion (F = 27.43, P < 0.001) significantly decreased with age. Significant differences according to sex were observed in all parameters except gait speed. Significant age and sex interaction effects were observed for knee flexion (F = 4.97, P = 0.002) and ankle dorsiflexion (F = 4.04, P = 0.007). A significant interaction effect of age and sex was observed for peak angle of knee flexion and ankle dorsiflexion during gait. In particular, the knee flexion angle among females during gait began to decrease from 60 years of age, and the decreasing trend was faster and more prominent than that among males. • Gait speed, step length and joint angle decreased with age, particularly among those >60 years old. • Significant age and sex interaction effects were observed in knee flexion and ankle dorsiflexion. • Females exhibited decreased knee flexion and increased ankle dorsiflexion with increases in age. [ABSTRACT FROM AUTHOR]

The optimal alignment technique for total knee arthroplasty (TKA) remains controversial. We previously reported 6-month and 2-year results of a randomized controlled trial comparing kinematically versus mechanically aligned TKA. In the present study, we report the mean 13-year (range, 12.6-14.4) follow-up results from this trial. The original cohort included 88 TKAs (44 kinematically aligned using patient-specific guides and 44 mechanically aligned using conventional instrumentation), performed from 2008 to 2009. After institutional review board approval, the health records of the original 88 patients were queried. Revisions, reoperations, and complications were recorded. There were 26 patients who died, leaving 62 patients for follow-up. Of these, 48 patients (77%) were successfully contacted via phone. Reoperations and complications were documented. Furthermore, a battery of patient-reported outcome measures (PROMs) (including Western Ontario and McMaster University Index, Oxford Knee Score, Knee Injury and Osteoarthritis Outcome Score Junior, Forgotten Joint Score, Modified-Single Assessment Numerical Evaluation, and patient satisfaction) were obtained. Of the original 88 patients in the study, 15 patients had at least one reoperation (17%) and 5 patients had undergone complete revision surgery (6%). There was no difference between the 2 alignment methods for major and minor reoperations (P =.66). The kinematically aligned total knees self-reported a nonstatistically significant (P =.16) improved satisfaction (96% versus 82%), but no difference in other PROMs compared to mechanically aligned TKAs. Kinematically aligned TKA demonstrates excellent mean 13-year results, comparable to mechanically aligned TKA with similar reoperations, complications, and PROMs. [ABSTRACT FROM AUTHOR]

A saddle joint enables the movement of two components relative to each other primarily about two axes of rotation and, to a limited extent, in translational direction. This type of joint is primarily found in nature, for example in the human thumb, in the ossicles and the cervical spine of owls. Motivated by the high degree of the owls' head mobility, the authors aim to make this high motion potential technically accessible by defining relevant design parameters and developing calculation methods for dimensioning the saddle joint components. First, an abstracted contact geometry model based on the owls' saddle joints is defined. A method for calculating the kinematics of the joint as a function of the previously introduced design parameters of the contact is derived mathematically. Regarding the implementation in a design process, this model is used to calculate the restoring forces required to stabilize the joint parts as well as the actuator torque needed for a specific rotational movement around those axes. Furthermore, the rotational stiffness of a specific joint geometry is calculated as an important design criterion. In summary, the defined contact geometry, the kinematics, and the computable forces serve as basis for designing technical saddle joints in the future. [ABSTRACT FROM AUTHOR]

To optimize the biomechanical outcomes in lateral ankle ligament reconstruction, avoid stiffness or residual laxity, aiming for an isometric reconstruction of the anterior lateral talofibular ligament (ATFL) and the calcaneofibular ligament (CFL) is mandatory. However, the localization of the optimal ligament insertion remains challenging to assess intraoperatively. Three-dimensional (3D) surface models from 10 healthy ankles were generated. 30 insertion points of the CFL were defined on the lateral side of the calcaneus each 10% of its total length in the dorsal-to-ventral and proximal-to-distal plane. 6 insertion points were defined at the ventral ridge of fibula from the malleolar tip and 5 insertions were defined along the lateral talar process. The ligament length variation of ATFL and CFL was assessed after a simulation of the flexion/extension around a simulated tibiotalar axis and inversion/eversion around a simulated subtalar axis in 36 different positions. The isometric point of CFL on the calcaneus is located at about 60% along the dorsal-to-ventral and between 60% and 70% along the proximal-to-distal plane. From maximal extension to flexion, these points present respectively a length variation of − 0.8 to − 1.1 mm (p = 0.46) and − 1.1 to − 0.8 mm (p = 0.56). A fibular insertion at 5 mm proximal to the malleolar tip present a length variation ranging from − 0.1–1 mm (p < 0.001) for ATFL and from − 0.7–0.5 mm (p < 0.001) for CFL. A talar insertion point of the ATFL located 5 mm proximal to the subtalar joint present the lowest variation, ranging from − 1.1–0.7 mm (p < 0.001), however an insertion at 20- or 25-mm present isometry (+0.1 to +0.9 mm p = 0.1, and +0.4 to +0.4 mm p = 1 respectively) if the fibular insertion is located at 5 mm proximal to the malleolar tip. This study provides anatomical references which are reproducible in daily practice. These insertion points allow to achieve a stable reconstruction while maintaining a tension-free mobilization of the ankle. [ABSTRACT FROM AUTHOR]

Located in eastern China, the Dongying Sag is characterized as a prototypical rift basin with intricate fault systems. While research efforts have traditionally honed in on the geometry and kinematics of the northern steep slope zone, the structural characteristic of the southern gentle slope zone (SGS) have received comparably less attention, with a notable gap in the understanding of the fault's geometry and kinematics. The sedimentary facies distribution of the rift basin is unequivocally linked to structural activity, but previous studies have treated sedimentary facies and structural characteristics in isolation, leading to an unclear comprehension of the factors influencing sedimentary facies distribution. This study leverages 3D seismic data encompassing 650 km2 along with 20 well logs, directing focus on the key fault zones within the SGS (i.e. Chenguanzhuang (CGZ) and Liangjialou (LJL) fault zone). Using methodologies such as seismic-well integration, planar attribute extraction, and throw-stripping, the research studies the geometric and kinematic characteristic of these fault zones, scrutinizes their activity features, and elucidates the interplay between structural and sedimentary processes in both temporal and spatial dimensions. The results show that (1) the CGZ fault zone is characterized by an array of east-west oriented, en-echelon faults, which nucleated during the nascent phases of rifting (Es 4). Within the fault zone, the F1 fault exhibits the greatest strike extension, which can be further segmented into three distinct sections: F1-1, F1-2, and F1-3. These segments have undergone a kinematic evolutionary process of "separation-connection-extension" during the Es. Concurrently, the SGS is subject to a supply of sources from an east-west orientation, leading to the development of a delta-gravity flow sedimentary system within the hanging wall of the CGZ fault zone. (2) Conversely, the LJL fault zone exhibits a broom-like , comprising a series of NEE-oriented faults. The predominant faults (i.e. F10, F11, and F13) nucleated during the late rifting phase (Es 3 u). Concurrent with the Es 3 u interval, the northern part of the study area developed shallow-water delta within the hanging wall of the LJL fault zone. (3) During the Es 3 m period, the expansion index of the CGZ fault zone attained its zenith, this has facilitated the formation of gravity flow deposits arising from slumping at the delta front. Subsequently, fault activity within the study area experienced an overall decline, the gentle paleo-topography promotes a large-scale shallow water delta developed in the Es 3 u. The decreasing activity of the CGZ fault zone and the increasing activity of the LJL fault zone in Es 3 u drove the depocenter shifting towards the NW. • The three-dimensional geometric characteristics of the fault zones were described. • The kinematic evolution process of the major fault in the CGZ fault zone was restored in the Shahejie Formation. • The distribution of sedimentary facies in key areas was described. • The coupling relationship between the intensity of active of faults and sedimentary characteristics was established. [ABSTRACT FROM AUTHOR]

Background: The effect of the Posterior X Taping (PXT) used for subjects with Tibiofemoral Varus Malalignment (TFRV) aimed to control excessive tibiofemoral rotations is still unclear. Further, it is critical to use evidence-based therapeutic exercises to prevent non-contact injuries, especially in repetitive movements.Objective: To investigate whether the PXT and real-time feedback (RTF) interventions would improve lower extremity functions during the pedaling task in subjects with TFRV.Methods: Twenty-four male recreational athletes with TFRV participated in this study; Kinematic and muscle activity were synchronously recorded on ten consecutive pedal cycles during the last 30 s of 2-min pedaling.Results: The present study indicated that the subjects at the post-intervention of the RTF group exhibited significant decreased hip adduction and internal rotation, significant decreased tibiofemoral external rotation between 144° and 216° of crank angle, significant increased vastus medialis activity between 144° and 288° of crank angle, and significant increased gluteus medius activity between 180° and 144° of crank angle; In contrast, the subjects at the post-intervention of the PXT group exhibited significant decreased tibiofemoral external rotation and increased ankle external rotation at all the crank angles. No between-group differences were observed in pre-and post-intervention.Significance: These results suggest that the PXT and RTF interventions are recommended to immediately improve the functional defects of the subjects with TFRV during the pedaling task. [ABSTRACT FROM AUTHOR]

Background: Computer use is associated with poor postures and increased risk of developing neck pain. Evaluating differences in working posture of individuals with and without chronic neck pain may assist the development of strategies to lessen or prevent pain.Objective: To identify if upper body kinematics differs between individuals with and without chronic idiopathic neck pain during four conditions (tablet, laptop, and desktop computer sitting and standing).Methods: Three-dimensional (3D) motion capture measured upper body kinematics in 44 individuals with chronic idiopathic neck pain > 90 days (Cases n = 22) and without pain (Control n = 22), during a typing task under four conditions: tablet, laptop, desktop computer (sitting and standing). Differences between groups were evaluated using generalised linear mixed models.Results: Across all conditions and compared to controls, cases had significantly less flexion between their head-neck and upper trunk segments (between group mean difference 7.15°, 2.1, 12.2, p = .006), greater upper trunk flexion relative to the laboratory (-6.15°, -10.9, -1.3, p = .012), greater shoulder flexion bilaterally (left 12.35°, 6.7, 17.9, p < .001; right 13.49°, 7.9, 19.1, p < .001) and less right elbow flexion (-6.87°, -12.1, -1.7, p = .010). Approaching significance, the case group had less left elbow flexion (between group mean difference -5.36°, -10.9, 0.1, p = .056) and a smaller mean craniocervical angle for the seated desktop condition (group x condition interaction -6.37°; 95% CI -12.7, -0.1, p = .052).Significance: Individuals with neck pain consistently used different upper body postures compared to individuals without pain when working on computerised devices under varying workstation conditions. This finding suggests that people with neck pain work in potentially aggravating postures that may be associated with their pain. [ABSTRACT FROM AUTHOR]

• A natural pectin film was constructed on Zn anodes as a protective layer. • A unique hydrogen bond network endows pectin layer with excellent self-healing ability. • Pectin hydrogel layer possesses kinematic response ability from robust coordination forces. • Pectin protective film can sustain the complete structure and fit closely on Zn surface. • Zn@pectin symmetric cell can stably cycle for 2500 h at 2 mA cm−2 and 2 mAh cm−2. Zinc (Zn) dendrite growth and hydrogen evolution corrosion reaction of Zn metal anodes greatly affect the cycling performance and hinder the commercial application of high safety aqueous Zn ion batteries. Building an excellent protective layer to perfectly solve the above problems is still a big challenge, resulting from its high-cost raw materials and complicated preparation processes. Herein, in this work, natural pectin biopolymer with galacturonic acid structure was adopted as a functional coating on Zn anodes (Zn@pectin) to realize the excellent cycling properties. Abundant oxygen-containing groups endow pectin films with self-healing ability and response kinematic via multiple intermolecular hydrogen bonds and ligand binding with Zn metal after in-situ gelation with Zn2+ ions, which can sustain the complete structure and fit closely on Zn surface to address the fracture and separation of protective layers with Zn electrode. Functional pectin coatings can serve as a physical barrier to reduce the corrosion effects of H 2 O molecules in aqueous electrolyte and regular the deposition behavior of Zn2+ ions to hamper the dendrite growth. Zn@pectin symmetric cell can stably cycle for 2500 h at a current density of 2 mA cm−2 and a constant capacity of 2 mAh cm−2. Zn-iodine full batteries possess the high capacity retention of 95 % after 4500 cycles at 1 A g−1. This work provides a new strategy for the protection of Zn metal anodes and realizes the resource utilization of renewable biomass. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: The freezing episode (FE) management during gait in Parkinson's disease is inefficient with current medications, neurosurgery, and physical interventions. Knowing the biomechanical change patients suffer preceding FE would be the ultimate goal to measure, predict, and prevent these events.Objective: We performed a systematic review to summarize the kinematic, kinetic, electromyographic, and spatio-temporal characteristics of the events that precede the FE during gait in Parkinson's disease.Literature Survey: Databases searched included PubMed, Embase, and Cochrane and between 2001 to August 2021.Methodology: The present study was a systematic review registered in the PROSPERO database (CRD42021255082). Three reviewers searched and selected studies with methodologies involving biomechanical changes and kinetic, kinematic, electromyography, and spatiotemporal changes before FE in a patient with Parkinson's disease. The relevant articles that show the events preceding FE in patients with PD were identified. We excluded studies that describe or compare methods or algorithms to detect FE. Studies may include participants with all PD severity, time of disease, and age.Synthesis: We selected ten articles for final evaluation. The most consistent results indicate a dramatic reduction of movement excursions with (1) decrease in stride length; (2) decreased gait speed; (3) postural instability with the increased double support phase; (4) incoordination of anterior tibial and gastrocnemius; (5) larger amplitude in the EMG of biceps femoris; (6) decreased range of motion in the sagittal plane at the ankle and hip joints; and (7) anterior pelvic tilt.Conclusion: FE is characterized by complex motor patterns than normal gait and mismatched gains in the perception and execution of the ongoing movement. [ABSTRACT FROM AUTHOR]

Background: Individuals with nonspecific chronic neck pain (NP) walk with a stiffer spine. However, there is a lack of understanding on kinematic similarities on the limbs during gait between individuals with and without NP.Research Question: Are there differences in gait parameters and the kinematic similarity index (SI) between individuals with and without NP?Methods: Eighteen individuals with NP and 17 controls participated in this study. A three-dimensional motion capture system and two force plates were utilized to measure kinematic changes of the upper and lower limbs during gait. The gait parameters included cadence, speed, stride length, and step width. The SI calculations were compared based on the response vectors from the NP group and the prototype response vectors from the control participants. The SI values at 5% intervals of the entire gait cycle were compared between groups.Results: Although the gait parameters were not significantly different between groups, the SI values of the control group were significantly higher than the NP group during gait (0.98 ± 0.02 vs. 0.95 ± 0.03), especially at the midstance (10-30 %) and swing (80-90 %) phases. Also, the standard deviation of the SI decreased in the control group when compared to the NP group (0.02 ± 0.01 vs. 0.04 ± 0.02).Significance: The SI was a useful measure to differentiate similarities between groups in the gait cycle at specific phases. These results indicated that the NP group demonstrated a greater variation of walking patterns during the midstance and swing phases and displayed altered compensatory gait. Clinicians need to consider the similarities of the kinematic changes for the NP group to aid in detection of limb motion differences and the resulting gait dysfunction. [ABSTRACT FROM AUTHOR]

• A new algorithm for automatic stride detection during walking and stair climbing. • A new algorithm based on combined data of foot and shank-mounted IMUs. • Performance advance during ascending and descending stairs of the new algorithm. Stride detection, or the identification of the initial (IC) and terminal contact (TC) of the feet while walking, is important for gait analysis. Automatic stride detection based only on kinematic data is challenging, even when using portable, low-cost, user-friendly Inertial Measurement Units (IMUs). Although there are algorithms for straight walking available, they are often not applicable to other movement patterns. Furthermore, these algorithms are based on the use of different IMUs placed on different locations of the body with different pre-processing filters and rely on analyzing different measurement signals. Therefore, it is difficult to apply existing algorithms for specific study settings. To achieve a new algorithm, thirty-five healthy participants were analyzed during walking and stair climbing while kinematic motion data was measured using the IMU system MyoMotion. Based on the analysis of different published methods for IC and TC detection, a new robust stride detection algorithm was developed and validated in comparison with two different algorithms. From this, it was determined that the newly developed algorithm was successful in automatic stride detection during walking and ascending/ descending stairs with 100% detected gait events, while the other algorithms failed during stair climbing with only 44% and 91% detected gait events. [ABSTRACT FROM AUTHOR]

Lift technique training programs have been implemented to help reduce injury risk, but the underlying content validity of cues used within these programs is not clear. The objective of this study was to determine whether biomechanical variables, that commonly used lifting cues aim to elicit, are associated with resultant low back extensor moment exposures. A sample of 72 participants were recruited to perform 10 repetitions of a floor-to-waist height barbell lift while whole-body kinematics and ground reaction forces were collected. Kinematic, kinetic, and energetic variables representative of characteristics commonly targeted by lifting cues were calculated as predictor variables, while peak and cumulative low back moments were calculated as dependent measures. Multiple regression revealed that 56.6–59.2% of variance in low back moments was explained by predictor variables. From these regression models, generating motion with the legs (both greater hip and knee work), minimizing the horizontal distance of the body to the load, maintaining a stable body position, and minimizing lift time were associated with lower magnitudes of low back moments. These data support that using cues targeting these identified variables may be more effective at reducing peak low back moment exposures via lift training. [ABSTRACT FROM AUTHOR]

This study quantified sex-specific biomechanical adaptations to fatigue in asymmetric lifting. Twenty-one females and fifteen males performed a prolonged asymmetric lifting protocol while upper body, trunk and pelvis kinematics were collected. Features of movement identified with principal component analysis, and peak joint angular velocities and moments were calculated. Sex-specific kinematic adaptations to fatigue included females adopting a 'stoop-like' lifting strategy to a greater extent than males. Additionally, females exhibited higher vertical elbow positions during load rotation, moved their body toward the destination for load deposit, and did not reduce peak right shoulder flexion velocities, in contrast to male participants. Females also had greater low back and shoulder peak normalized joint moments. When fatigued, females adopted an asymmetric lifting strategy that minimized metabolic demand as supported by smaller decreases in maximum voluntary contractions. However, females' fatigue-related adaptations increased biomechanical exposures associated with injury risk. • Sex-specific kinematic adaptations to fatigue in asymmetric lifting were seen. • Higher low back loads in females may explain sex differences in injury rates. • Ergonomic interventions for asymmetric lifting should consider sex differences. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Shillong plateau in northeast India records Archean/Proterozoic to Cenozoic histories. • Shillong group of rocks present as a supracrustal unit within the plateau which preserves multiple deformation events. • Microstructural investigations on shear zone rocks suggest a deformation sequence for the study area. • Kinematic and vorticity analyses indicate the transpressive nature of the Barapani Shear Zone (BSZ). • The BSZ is represented here as an intraterrane shear zone that is restricted within the plateau only. The analysis of shear zone kinematics plays a crucial role in understanding the tectonics at micro-, meso-, and regional scales within a given terrane. This study focuses on investigating the kinematics of prominent asymmetric structural features preserved within the Barapani Shear Zone (BSZ). These features are utilized to establish vorticity numbers in relation to the reference frames of the BSZ. Typically, shear zones provide finite values for kinematics and vorticity numbers. The BSZ is identified as an intraterrane, multiply deformed shear zone within the Shillong Plateau, which exhibits varying kinematics and vorticity numbers measured across different deformation zones. The research reveals that the BSZ underwent successive D 1 , D 2 , D 3 , and D 4 events, resulting in preserved S 1 , S 2 , and S 3 planar fabrics, with D 4 evidenced by brittle deformation features. However, determining shear zone kinematics purely based on the orientation of these planar fabrics and mineral lineation with respect to the external reference frame is insufficient. Consequently, this study calculates vorticity numbers and kinematics by considering both the external and internal reference frames of the BSZ. The study suggests that superposed transpressional tectonics prevailed during D 2 and D 3 events. [ABSTRACT FROM AUTHOR]

• Compact transplanting unit fitted on semi-automatic transplanter. • Hopping dibber planter with bearing attachment. • Novel and simple system for opening and closing of the planter. • Zero-speed seedling picking and releasing. The most important operation in the vegetable cultivation is transplanting of vegetable seedling which can be acomplished efficiently by transplanters. A transplanting unit is a crucial component of the vegetable transplanter since it can substantially impact its overall effectiveness. The current study designed and developed a transplanting unit of a two-row tractor-mounted semi-automatic type vegetable seedling (plug type) transplanter. It includes a 5-bar planting mechanism, a hopping dibber planter with a bearing-fitted lever, and a half-open double-door planter opening mechanism. The planting geometry of 0.60×0.45 m was considered during the design process. To evaluate the functional viability and basic machine settings, the transplanting unit underwent preliminary laboratory testing. The field testing investigated the impact of the two types of germination tray cavities, three feeding systems, soil-covering wheel tilt angle, and plant age on the upright plant percentage. For the tomato and eggplant crops, the mean value of the upright plants transplanted by machine ranging from 89.35-94.21 % and 91.32-94.91 % across all treatment combinations; at a 5 % significance level, the differences were not statistically significant. However, the main effect of the soil-covering wheel tilt angle and the plant age on the upright plant percentage was statistically significant at a 5 % significance level in both crops. The mechanism has the ability to significantly raise transplanting quality, which may satisfy the mechanism's design and manufacturing requirements. [ABSTRACT FROM AUTHOR]

The chip thickness is often used to characterize abrasive processes, particularly grinding. Unfortunately, because of the seemingly random nature of the geometrically undefined cutting points and difficulty in estimating the cutting-point density, chip thickness is notoriously difficult to quantify. Recently, the dimensionless Aggressiveness number has gained popularity because it circumvents the need to quantify the wheel topography and is applicable to any geometry in abrasive contact. This paper shows how the concept of dimensionless Aggressiveness number applies to the most common abrasive geometries and how it can be used to achieve practical results in a variety of applications. [ABSTRACT FROM AUTHOR]

The modeling of modern high performance machining with intermittent cut and varying effective cutting parameters requires a flexible local cutting force prediction. Due to complex tool geometries and varying cutting conditions without a rigid reference system new approaches for the local cutting force decomposition are applied, investigated and compared. The force decompositions are based on the separation of the effective cutting speed into normal and tangential components to adequately consider the locally acting mechanisms. Regression models based on the effective cutting parameters are defined to compare and validate the local force decomposition. A high feed peripheral milling experiment with specific cutting force measurement is presented to develop the regression models. An extensive cutting force database for AISI 5115 is created by tool geometry and process control variable variations. The effective cutting conditions are calculated through geometric penetration simulation. Considering the tool deflection in the simulation achieves a high regression accuracy even with low chip thicknesses. This is especially important for the cutting force prediction of finishing processes. The resulting regression cutting force models and force decompositions are rated based on the applicability to different tool geometries, like a ball end mill. [ABSTRACT FROM AUTHOR]

Background: Backward walking and fast walking have distinctive gait patterns in adults; however, there is minimal literature describing these gait modifications in typically developing children. Additionally, most of previous research focused on overground backward walking, but not on a treadmill.Research Question: How do typically developing children adapt their gait patterns, including spatiotemporal parameters, joint kinematics, and muscle activation, to changes in direction and speed during treadmill walking?Methods: We recruited 19 children (10 M/9 F) aged 6-12 years. Treadmill conditions included forward and backward walking at three speeds: slow (75 % of normal speed), normal speed, and fast (125 % of normal speed). Subjects completed a 2-minute trial under each condition. Spatiotemporal, kinematic, kinetic and electromyography data were collected and analyzed. Correlations between forward and time-reversed backward walking were calculated for joint angles and vertical ground reaction force.Results: During backward walking, children (a) decreased step lengths and increased step widths and foot clearance, (b) decreased peak hip and knee flexion and increased peak ankle dorsiflexion, and (c) increased muscle activity at the vastus lateralis, rectus femoris, and tibialis anterior. At faster speeds, children increased step lengths and inconsistently increased overall muscle activity. Both the hip and knee showed high correlation between forward and time-reversed backward walking, while correlation at the ankle was low.Significance: Overall, children adapt their gait to changes in direction and speed of treadmill walking in similar ways to adults. However, notable differences emerged in that children limited their ankle range of motion. Our results suggest that, while many aspects of gait are mature enough by this age to adapt to backward walking on a treadmill, neuromuscular control at the ankle may still be lacking in children while walking backward on a treadmill. [ABSTRACT FROM AUTHOR]

Reverse total shoulder arthroplasty (RTSA) procedures have significantly increased in the last decade as an alternative to the current treatments for cuff-tear arthropathy. Since Grammont's theory in 1987, few data about the in vivo kinetics of the shoulder-girdle musculature in patients with RTSA have been available. The goals of this study are to (1) describe the contribution of principal muscles around the shoulder by electromyography and (2) access the range of motion of 5 movements of patients with RTSA compared with normal shoulders. This is an observational prospective cohort study of 21 patients divided into 11 patients with RTSA and 10 controls. The muscular activity was recorded with bipolar cutaneous electrodes, whereas the range of motion was synchronized and recorded by 8 motion cameras. Five movements (flexion, abduction, neutral external rotation, external rotation in 90° of abduction, and internal rotation in 90° of abduction) were studied. The upper trapezius is the main activator in all directions with early and constant activity (P <.01). The latissimus dorsi demonstrates increased muscular activity in internal rotation (P <.01) as well as the posterior deltoid in external rotation in the RTSA group compared with control (P <.01). RTSA shoulder muscle activation is significantly different than in normal shoulders. The significant contribution of the trapezius in all directions, latissimus dorsi in internal rotation, and posterior deltoid in external rotation has never been described within the same study until today. New rehabilitation protocols targeting those muscles could demonstrate better and more homogeneous results and increase patient satisfaction. [ABSTRACT FROM AUTHOR]

Background: Change in the lower extremity alignments in the frontal plane and muscle activation patterns have been associated with lower extremity injuries. Therefore, to prevent injuries, many therapeutic protocols focus on find ways to correct dynamic knee valgus (DKV).Methods: Thirty-one recreational male cyclists with DKV (26.4 ± 4.5 years, 176.63 ± 7.51 cm, 75.81 ± 9.29 kg, 23.20 ± 4.15 kg/m2) volunteered to participate in this study. Simultaneous recordings of kinematic and electromyography data were performed on ten consecutive pedal cycles which began during the last 30 seconds of each four test condition: with band at 0.5 kg workload, with band at 2 kg workload, without band at 0.5 kg workload, and without band at 2 kg workload. The paired t-test was used for statistical analysis (p < 0.05).Results: The results indicated significant differences in VM (band = 0.029, no band = 0.031) and VL (band = 0.015, no band = 0.035) activation between workloads in each condition. Also there were significant differences in Gmed activation (0.5kg = 0.001, 2kg = 0.037), onset of Gmed (0.5kg = 0.048, 2kg = 0.012), offset of Gmed (0.5kg = 0.048, 2kg = 0.015), TFL activation (0.5kg = 0.001, 2kg = 0.041) and offset of TFL (0.5kg = 0.078, 2kg = 0.005) between the band and no band conditions. There was no different significant in VM/VL ratio between in each of four testing conditions (p > 0.05). The Gmed/TFL ratio was significantly greater in band condition than no band at both 0.5 (p = 0.045) and 2 kg (p = 0.001) workload. Knee abduction angle was affected by the band loop during the pedaling at two different workloads (0.5 kg: p = 0.047, 2 kg: p = 0.021) but mean (p = 0.027) and peak (p = 0.033) knee abduction angle significantly increased with increasing workload during the pedaling with band loop.Conclusions: pedaling with the band loop can be considered as an effective method to increase the Gmed, Gmed/TFL ratio and control of DKV but increasing the workload during pedaling must be done with caution to prevent DKV. [ABSTRACT FROM AUTHOR]

Background: Randomized controlled trials of kinematic alignment (KA) and mechanical alignment (MA) in primary total knee arthroplasty (TKA) have to date demonstrated at least equivalence of KA in terms of clinical outcomes. No trial of bilateral TKA has been conducted so patient preference for one technique over the other is unknown.Methods: Forty-one participants underwent computer-assisted bilateral TKA. The outcome measures were as follows: (1) joint range of motion and functional scores including the KOOS, the KOOS JR, Oxford Knee Score, and the Forgotten Joint Score at a minimum of 2 years; (2) preference and perception of limb symmetry; (3) intraoperative alignment data; (4) release and gap balance data; and (5) postoperative radiographic joint angles.Results: There were no significant differences with respect to flexion range (P = .970) or functional scores (mean KOOS, P = .941; KOOS JR, P = .685; Oxford Knee Score, P = .578; FJS, P = .542). Significantly more participants who favored one knee preferred their KA TKA (P = .03); however, half of the patients had no preference and the overall numbers were small. Only 3 participants perceived any limb asymmetry (P < .001). More releases were required in the MA group (P = .018). Standing hip-knee-ankle angle means and frequency distributions were similar (P = .097 and P = .097, respectively).Conclusion: Clinical outcomes were equivalent at 2 years. Significantly more participants preferred their KA joint. Fewer releases were required using a KA technique. Participants were visually insensitive to modest hip-knee-ankle angle asymmetry.Level Of Evidence: Level 1. [ABSTRACT FROM AUTHOR]

Background: Instrumented treadmills that incorporate pressure platforms are increasingly used to characterize gait in children. Although footprint size is known to influence the measurement performance of pressure platforms, published evidence on the reliability of such systems for children's gait is lacking.Research Question: This study evaluated the test-retest reliability of temporospatial gait parameters and vertical ground reaction forces measured in healthy children during barefoot walking and running on a capacitance-based treadmill system.Methods: Temporospatial gait parameters, including cadence, stride length, stride duration, stance and swing phase durations and the magnitude and timing of conventional vertical ground reaction force peaks were determined on two occasions in 17 healthy children (mean age, 11 ± 2 years; height, 148.4 ± 9.3 cm; and mass, 43.3 ± 10 kg) during walking and running at preferred speed on an instrumented treadmill. Reliability was assessed using Intra Class Correlation Coefficients (ICC) and the standard error of measurement (SEM). The minimum detectable change (MDC95%) was also calculated.Results: ICC values ranged from 0.91-0.99 for all variables. When expressed as a percentage of the mean, the SEM was <5% for all gait parameters assessed during walking and running. The MDC95% values for gait parameters were typically higher during running than walking, and were ±4% of the gait cycle for temporal parameters, ±55 cm for stride length and ±0.1 bodyweights for peak vertical ground reaction force.Significance: Children's gait parameters varied by <5% between test occasions and were more consistent during walking than running. These findings provide clinicians and researchers with an index of the reliability and sensitivity of the treadmill to detect changes in common spatiotemporal gait parameters and vertical ground reaction forces in children. [ABSTRACT FROM AUTHOR]

Changes in spinal kinematic variability have been observed in people with chronic non-specific LBP (CNSLBP) during the performance of various repetitive functional tasks. However, the direction of these changes (i.e., less or more kinematic variability) is not consistent. This study aimed to assess differences in kinematic variability of the 3D angular displacement of thoracic and lumbar spinal segments in people with CNSLBP compared to asymptomatic individuals during a repetitive lifting task. Eleven people with CNSLBP and 11 asymptomatic volunteers performed 10 cycles of multi-planar lifting movements while spinal kinematics were recorded. For the three planes of motion, point-by-point standard deviations (SDs) were computed across all cycles of lifting and the average was calculated as a measure of kinematic variability for both segments. People with CNSLBP displayed higher thoracic (F = 8.00, p = 0.010, ηp2 = 0.286) and lumbar kinematic variability (F = 5.48, p = 0.030, ηp2 = 0.215) in the sagittal plane. Moreover, group differences were observed in the transversal plane for thoracic (F = 7.62, p = 0.012, ηp2 = 0.276) and lumbar kinematic variability (F = 5.402, p = 0.031, ηp2 = 0.213), as well as in the frontal plane for thoracic (F = 7.27, p = 0.014, ηp2 = 0.267) and lumbar kinematic variability (F = 6.11, p = 0.022, ηp2 = 0.234), all showing higher variability in those with CNSLBP. A significant main effect of group was not detected (p > 0.05) for spinal range of motion (ROM). Thus, people with CNSLBP completed the lifting task with the same ROM in all three planes of motion as observed for asymptomatic individuals, yet they performed the lifting task with higher spinal kinematic cycle-to-cycle variation. [ABSTRACT FROM AUTHOR]

• Rhythmic Auditory Stimulation (RAS) instantly improves parkinsonian gait, regardless of the dopaminergic drug. • A frequency of 110% of the preferred walking cadence is the most effective stimulus. • RAS improves spatio-temporal parameters and gait phases distribution, but leaves joint kinematics unaltered. Gait impairment is a highly disabling symptom for Parkinson's disease (PD) patients. Rhythmic auditory stimulation (RAS), has shown to improve spatio-temporal gait parameters in PD, but only a few studies have focused on their effects on gait kinematics, and the ideal stimulation frequency has still not been identified. We enrolled 30 PD patients and 18 controls. Patients were evaluated under two conditions (with (ON), and without (OFF) medications) with three different RAS frequencies (90%, 100%, and 110% of the patient's preferred walking cadence). Spatial-temporal parameters, joint angles and gait phases distribution were evaluated. A novel global index (GPQI) was used to quantify the difference in gait phase distribution. Along with benefits in spatial-temporal parameters, GPQI improved significantly with RAS at a frequency of 110% for both ON and OFF medication conditions. In the most severe patients, the same result was observed also with RAS at 100%. RAS administration, at a frequency of 110% of the preferred walking frequency, can be beneficial in improving the gait pattern in PD patients. When rhythmic auditory stimulation is provided to patients with PD, the selection of an adequate frequency of stimulation can optimize their effects on gait pattern. [ABSTRACT FROM AUTHOR]

This study evaluated three-dimensional kinematic parameters of the front crawl stroke in physically impaired swimmers across a range of functional classification levels. Eight highly-trained competitive swimmers (5 male and 3 female) from IPC classes S5 to S9 performed 50 m maximal front crawl trials while being video-taped by six cameras (four under- and two above water). The most distal point of the right upper limb was manually digitised at 50 Hz to allow three-dimensional reconstruction of the limb's trajectory through the water. The stroke presented large inter-swimmer variability, reflecting individual characteristics and severity of the impairment. The swimmers who combined shallow and narrow stroke movements produced a shorter trajectory. This study provides swimmers and coaches with an overview of the kinematic characteristics of a range of physically impaired swimmers. [ABSTRACT FROM AUTHOR]

• Gait patterns in amputees differ from those of speed-matched healthy subjects. • Transtibial and transfemoral amputees show a common and specific gait pattern. • Gait in transfemoral amputees is more asymmetric than in transtibial amputees. • Transfemoral amputees with several types of prosthesis have different gait patterns. • The type of prosthesis influences gait in terms of performance and adaptation. The present study's aim was to identify the kinematic and kinetic gait patterns and to measure the energy consumption in people with amputation according to both the anatomical level of amputation and the type of prosthetic components in comparison with a control group matched for the gait speed. Fifteen subjects with unilateral transtibial amputation (TTA), forty with unilateral transfemoral amputation (TFA) (9 with mechanical, 17 with CLeg and 14 with Genium prosthesis) and forty healthy subjects were recruited. We computed the time-distance gait parameters; the range of angular motion (RoM) at hip, knee and ankle joints, and at the trunk and pelvis; the values of the 2 peaks of vertical force curve; the full width at half maximum (FWHM) and center of activity (CoA) of vertical force; the mechanical behavior in terms of energy recovery (R-step) and energy consumption. The main results were: i) both TTA and TFA show a common gait pattern characterized by a symmetric increase of step length, step width, double support duration, pelvic obliquity, trunk lateral bending and trunk rotation RoMs compared to control groups. They show also an asymmetric increase of stance duration and of Peak1 in non-amputated side and a decrease of ankle RoM in amputated side; ii) only TFA show a specific gait pattern, depending on the level of amputation, characterized by a symmetric reduction of R-step and an asymmetric decrease of stance duration, CoA and FWHM and an increase of Peak1 in the amputated side and of hip and knee RoM, CoA and FWHM in the non-amputated side; iii) people with amputation with Genium prosthesis show a longer step length and increased hip and knee RoMs compared to people with amputation with mechanical prosthesis who conversely show an increased pelvic obliquity: these are specific gait patterns depending of the type of prosthesis. In conclusion, we identified both common and specific gait patterns in people with amputation, either regardless of, or according to their level of amputation and the type of prosthetic component. [ABSTRACT FROM AUTHOR]

Children with cerebral palsy perform small displacements during the anterior reach movement from standing position without loss of balance. There are two possible reasons for their decreased performance: the difficulty to stabilize their lower limbs during forward body inclination to reach greater distances or to control the movement of forward reaching. The objective of this study is to identify and compare the motor performance of children with CP and typically developing children, during anterior reach. This is a cross-sectional study, composed of 28 children, 14 with spastic cerebral palsy and 14 typical children, who were all evaluated by the Pediatric Reach Test and three-dimensional motion analysis. The decreased performance was shown by the lower movement control by children with cerebral palsy. The bilateral and unilateral cerebral palsy children showed lower range of motion of shoulder and trunk than typical children. Children with cerebral palsy show lower anterior displacement and movement control and difficulty bending the trunk and flexing shoulders while reaching forward, suggesting poor postural balance. • Children with mild cerebral palsy show lower performance in the anterior reaching. • Children with mild cerebral palsy showed difficult to flex trunk and shoulder. • Children with cerebral palsy performed anterior reaching with lower speed • Children with cerebral palsy needed a greater time to control their reaches. • Difference on postural orientation in cerebral palsy may justify lower displacement in reaching. [ABSTRACT FROM AUTHOR]

This study aimed to explore the influence of different onset thresholds on the between-session reliability and magnitude of squat jump (SJ) performance. Twenty men were tested on two sessions separated by 48 h against external loads of 0.5, 30 and 60 kg. The initiation of the jump was defined as the first instant in which the vertical ground reaction force exceeded system weight by 10 N (10 N), 50 N (50 N), 1% of system weight (1%SW), 10% of system weight (10%SW) and five standard deviation of system weight minus 30 ms (5SDSW). The following variables were calculated from the force-time signal collected on a force platform: mean, peak and time to peak values of force, power and velocity, average rate of force development, peak rate of force development, rate of force development index, impulse, jump height, and push-off time. The 50 N, 10%SW and 5SDSW thresholds generally revealed a higher reliability than the 10 N and 1%SW thresholds (97 and 21 out of 252 comparisons for the coefficient of variation and intraclass correlation coefficient, respectively). The magnitude of most of the variables calculated using the 50 N and 10%SW thresholds significantly differed with respect to the 10 N, 1%SW and 5SDSW thresholds (P < 0.05). These results suggest that both the reliability and magnitude of SJ performance variables are influenced by the jump starting threshold. The 50 N, 10%SW and 5SDSW thresholds maximise the reliability of SJ performance variables, while the 5SDSW should be recommended since it considers more force signal than the 50 N and 10%SW thresholds. [ABSTRACT FROM AUTHOR]

Objectives: Performance factors in the volleyball spike jump are well known for male players; however, technical-coordinative differences for female players are known only marginally. The objective of this study was to investigate the relationship between movement characteristics and female' spike jump performance and to identify the most relevant aspects of jump height and ball velocity.Design: Single group correlation and regression.Methods: Fifteen elite female volleyball players performed spike jumps by striking a stationary ball at maximal jump height. Data were collected via twelve MX13 Vicon cameras (250Hz), two AMTI force plates (2000Hz), and controlled via Visual3D software.Results: Ten out of 42 characteristics correlated with jump height and none of 22 correlated with ball velocity. A stepwise regression model (adjusted R2=0.82, p<0.001) predicted jump height based on orientation step length and maximal angular velocity of dominant knee extension. For ball velocity, stepwise regression analysis was not feasible; however, an alternative model yielded adjusted R2=0.55, p<0.01.Conclusions: Key aspects for jump height were (1) optimised approach and energy conversion, (2) wide dynamic arm swing allowing for a forceful countermovement and, thus, increased range of motion in lower limbs, and (3) large angular velocities in ankles and knees, especially on the dominant side. These aspects strongly determined jump height in females and should be included in technical and strength-related training. For ball velocity, upper body anthropometrics and angular joint velocities emerged as the most important criteria. The importance of specific joints may depend on variations in striking technique. [ABSTRACT FROM AUTHOR]

Process planning for multi-axis forming presses is a particular challenge. This process provides the option to actively influencing the material flow in the forming process by defining a six dimensional tool motion path and the tool velocity. By comprehending this interaction, it is possible to control and thereby tailor the induced local material properties of the workpiece. Experiments were conducted with a multi-axis press, which is based on a Stewart platform. A simple plane workpiece geometry is chosen to analyse the flow behaviour and the temperature evolution of the glass mat thermoplastics (GMT) during the forming process. Subsequently, a numerical simulation of the multi-axis forming process is carried out and validated with the experimental data. The numerical analysis focuses on the material modelling as well as the prediction of the flow characteristics. Regarding material modelling of GMT, an extensive material characterization is performed to describe the flow behaviour. A prediction of the flow behaviour of GMT with reference to tool motion is enabled. For the FE simulation the element-free Galerkin method (EFG) is applied for modelling the fluid structure interaction and adaptive procedures. [ABSTRACT FROM AUTHOR]

Residual stresses through plastic deformation during the assembly operation of a rail car can cause cracks, distortion or other associated welding flaws if not checked. This study considers the use of analytical and numerical methods involving the simulation of isotropic hardening models for the prediction of AISI 1035 weld residual stresses during the arc welding assembly of the lower brackets of a rail car. Using the isotropic hardening model as well as the ABAQUS simulation software, the dynamic simulation of the gas metal arc welding process was performed at ambient temperature of 25oC over varying temperatures. The thermal modelling of the weld pass was carried out followed by the determination of the stress and strain values from the combined thermal elastic-plastic analysis. The results obtained indicated that the predictive ability of the isotropic model is highly significant, with the values of the weld stress and corresponding strain agreeing closely with the experimental values over varying ranges of temperatures. Hence, the isotropic hardening model can be used for weld residual stress simulation and prediction. Future work can consider the combination of both the isotropic and kinematic models. [ABSTRACT FROM AUTHOR]

The shoulder complex (SC) consists of joints with little congruence and its active and passive structures ensure its stability. Stability of the SC rotation centre during upper arm movements can be estimated through the analysis of Helical Axes (HAs) dispersion. The aim of this study was to describe shoulder HAs dispersion during upper limb movements performed with dominant and non-dominant arms by young and elderly subjects. Forty subjects participated in the study (20 young: age 24.8 ± 2.8 years and 20 elderly: age 71.7 ± 6.3 years). Subjects were asked to perform four cycles of 15 rotations, flexions, elevations and abductions with one arm at a time at constant speed. Reflective markers were placed on participants' arms and trunk in order to detect movements and the HAs dispersion with an optoelectronic system. Mean Distance (MD) from the HAs barycenter and Mean Angle (MA) were used as HAs dispersion indexes. Young subjects showed significant lower MD compared to the elderly during all motion ranges of rotation, flexion and elevation (p < 0.001). Moreover, the MD was lower in the dominant arm compared to the contralateral for rotation (p = 0.049) and flexion (p = 0.019). The results may be due to joint degeneration described in elderly subjects and differences in neuromuscular control of SC stability. [ABSTRACT FROM AUTHOR]

Highlights • The kinematic properties of movements being generated unimanually and bimanually were compared. • Parameters estimated using the Delta- and Sigma-Lognormal model were analyzed in addition to kinematic variables. • Bimanual Movements result in an overall delayed, slower, and less efficient movements. • The findings were overall similar when using the Delta- and Sigma-lognormal model. • The Sigma-lognormal model suggested additionally that the two hands contribute differently to the manual conditions. Abstract The use of large digitizers, allowing users to interact using both hands simultaneously, are getting more and more popular in applications requiring human computer interaction. In most of these applications, gesture commands are used and these commands to activate specific actions can provide also information about the neuromuscular system of the user. As shown for single hand interactions, understanding of the neuromotor coordination processes using both hands could improve interface design. In the present paper, we address this topic with a first study aimed to characterize the bimanual and unimanual coordination. We compare the kinematic properties of movements performed unimanually and bimanually. Rapidly drawn lines are assessed using kinematic features in addition to the parameters estimated by two models, i.e., the Delta-Lognormal model and Sigma-Lognormal model. Sixteen right-handed participants were instructed to conduct 120 rapid drawing actions with the dominant hand, non-dominant hand, and both hands simultaneously. Kinematic variables (i.e. reaction time (RT) and movement time (MT)) together with parameters of the Delta-Lognormal model and Sigma-Lognormal model were extracted from the movements. The latter parameters estimate the agonist and antagonist synergies that contribute to the overall movement production of the rapid drawn lines. A 2 × 2 repeated measures ANOVA was applied to all dependent variables with manual condition (uni- vs bimanual) and hand used (dominant vs non-dominant) as independent factors. Parameters of the Delta-Lognormal model and Sigma-Lognormal model revealed that the prolonged preparation time of the bimanual task had both a central and peripheral origin, i.e., it originated at the CNS and neuromuscular levels. Furthermore, findings from the Sigma-lognormal model suggested that the dominant and non-dominant hand contribute differently to the manual conditions, which may lead to new heuristics for implementing command systems for computer interaction systems requiring bimanual manipulation as well as designing automatic systems for rehabilitative training. [ABSTRACT FROM AUTHOR]

To improve the accuracy of an industrial 6-DOF robot, this paper proposes a new calibration method based on a line structured light measurement system. The line structured light measurement system mounted on the end-effector is used as a tool to acquire the three-dimensional coordinate information of the centre of a standard sphere. Hand-eye calibration is used to establish the transformation between the robot and the measurement system. A combined kinematic model that includes both the kinematic parameters of the robot and the initial hand-eye relationship is established by applying the modified Denavit and Hartenberg (MDH) model. An error model is derived based on the principle that the coordinate of the sphere centre is invariant in the base frame of the robot. Consequently, the errors in the kinematic parameters of the robot and the hand-eye relationship can be identified by substituting the measurement results and the original parameters of the robot into the error model. The results of the simulations and experiments show that the accuracy of the robot is significantly improved by implementing the proposed calibration method. The proposed method is effective, simple, time-saving and low-cost and is therefore a suitable candidate for on-site calibration of industrial robots. [ABSTRACT FROM AUTHOR]

Highlights • An additional ultra-soft grid method is developed for deployable structures. • Kinematic of deployable structures can be computed. • Deformation of deployable structures can be computed. Abstract An additional ultra-soft grid method is developed to compute the deformation and kinematic of scissor-type deployable structures. By theoretical derivation, in the developed method the additional ultra-soft grid will not affect numerical results of the deployable structures. Based on the numerical and theoretical analysis of a ring array scissor-type deployable structure, it shows that the method is effective to deformation and kinematic analysis of deployable structures. As a case study, the developed method is used to analyze a complex scissor-type inspired net system. It shows that the developed method can also be used to compute the deformation and kinematic of complex deployable structures. [ABSTRACT FROM AUTHOR]

Honing is a precise machining process with high standards for the resulting form, dimension and surface quality. Additionally, tolerances can even be further reduced by honing processes. Essential for the adherence of high quality is the interaction of the honing tool and the workpiece. The following work investigates the fundamental kinematic and dynamic process during the internal long-stroke honing process. The focus of the investigation lies on a simulation for low and high oscillation and rotation speeds. Two experiments are set up to determine simulation parameters such as the path excitation of the tool as well as friction states in the gimbal. [ABSTRACT FROM AUTHOR]

Abstract Background The cleats-surface interaction has been described as a possible risk factor for lateral ankle sprain. However, their interaction is still unknown in individuals with chronic ankle instability. The purpose of this study was to determine the influence of different soccer cleats on kinematic, kinetic and neuromuscular ankle variables on artificial grass in soccer players with and without chronic ankle instability. Methods Eighty-two amateur athletes divided in two groups: 40 with chronic ankle instability and 42 without chronic ankle instability. All subjects performed 2 series of 6 consecutive crossover jumps with dominant foot, each one with one of the four models of cleats (Turf, Artificial grass, Hard and Firm ground). Cleat and group main effect and interactions of kinematic, kinetic and neuromuscular variables were analyzed according to factorial repeated measures ANOVA. Findings No statistically significant cleat and group main effect and interactions were identified in kinematic, kinetic and electromyographic magnitude of the peroneal muscles. A main effect of the group was observed for peroneus longus activation time for TF model (p = 0.010). Interpretation In soccer players, the contributor variables for ankle sprain were not influenced by the kind of soccer cleat used in a functional jump test on artificial grass. However, players with chronic ankle instability present delayed postural adjustments in peroneus longus with the TF model compared to players without chronic ankle instability. Highlights • The cleat model doesn't interfere with ankle sprain predisposing factors. • Turf cleats delayed peroneal activation in ankle instability athletes compared to controls. • These results should be only considered in dry 3rd generation artificial grass conditions. [ABSTRACT FROM AUTHOR]

Abstract Background The variation of the anterolateral ligament (ALL) length during knee motion is still unclear, and the knee position in which a reconstruction graft should be tensioned remains controversial. The objective of this study was to determine the variation of the ALL length during knee motion using a three-dimensional optoelectronic system. Methods Kinematic analyses of 20 cadaveric knees were performed using a Motion Analysis® system. The variability of the measurements made during the five acquisition cycles was studied. Reliability was evaluated by two separate measurement sessions, with complete system reinstallation, using different cadavers and a new operator. The ALL length was analysed from extension to full flexion in three rotational conditions. Findings When analysing the reliability of the five cycles, 82% of the measurements we found to have an Intra Class Correlation (ICC) >0.85. The reproducibility of inter-sessional measures by different operators and different cadavers was either good (ICC >0.75) or excellent (ICC >0.85). The ALL length was maximum in full internal rotation with the knee at 25° of flexion. Interpretation This three-dimensional optoelectronic protocol allowed us to analyse the variation of the ALL length during intact knee motion with good reliability and the required accuracy to analyse this variable. The maximal length and highest tension of the ALL was reported at 25° of knee flexion in internal rotation, suggesting this as the optimal position for the knee joint when tensioning an ALL reconstruction. Highlights • Knee motion can be accurately assessed using 3D optoelectronic motion capture. • The protocol established is reliable, allowing accurate ALL length analysis. • The ALL length is maximum in full internal rotation with the knee in 25° of flexion. [ABSTRACT FROM AUTHOR]

Background: Injury to the anterior cruciate ligament (ACL) is common among young athletes and can impact knee stability and control. Wearing proprioceptive knee braces can improve knee control and may reduce the risk factors associated with injury and re-injury, although the effect of such braces after ACL reconstruction (ACLR) is unclear.Research Question: This study aimed to determine the effect of proprioceptive knee bracing on knee control and subjective rating of participants post ACLR during three dynamic tasks.Methods: Fifteen participants 2-10 years post ACLR performed a slow step down, single leg drop jump, and pivot turn jump with and without a proprioceptive knee brace. Knee kinematics in the sagittal (flexion - extension), coronal (abduction - adduction), and transverse (internal - external rotation) planes were collected using a 3D infrared system. Paired t-tests were performed to explore differences in knee angles and angular velocities between the no brace and brace conditions during the three tasks. After each task, subjective ratings regarding ease of the task were recorded.Results: The brace reduced the peak knee external rotation angle and range of motion in the transverse plane during the pivot turn jump task, and significantly increased the maximum knee flexion angular velocity during the single leg drop jump task. The majority of participants reported that tasks were easier to perform with the proprioceptive brace than without.Significance: This study confirms that proprioceptive knee braces can significantly influence knee kinematics during dynamic tasks post ACLR. The observed effects were clinically relevant. [ABSTRACT FROM AUTHOR]

Goal: The main objective was to use the inertial sensor integrated into a smartphone to collect quantitative data on lower limb functioning during execution of the timed up and go test and sit to stand test by people in the acute stage of stroke. The secondary objective was to analyze whether smartphones provide reliable quantitative data on performance of these functional tests.Material and Methods: Cross-sectional analytical study involving 8 elderly people (M age = 67.50 years). Both tests were performed to parametrize and analyze the functionality, balance, and strength of lower limbs using an inbuilt inertial sensor of the smartphone. Time, difference in trunk position, angular displacement, angular velocity, and angular acceleration were measured and calculated for each stage at which both functional tests were divided.Results: The obtained results highlight the similarity in the angular displacement during the 2 stages into which the sitting-standing (flexion: 38.85° and extension: 38.10°) and the standing-sitting (flexion: 36.42° and extension: 36.45°) phases were divided. Mean velocities of .59 m/s and .61 m/s were registered during outward and return walking phases. The intra- and interobserver reliability of variables recorded with the inbuilt inertial sensor ranged from .860 to .897.Conclusions: Balance and muscle strength problems of stroke patients gave rise to the use of compensatory mechanisms when getting up from or sitting down in a chair and resulted in a reduction in walking speed that is sufficient to make walking in community contexts difficult. Smartphones has excellent reliability when used to quantify lower limb functioning in stroke patients. [ABSTRACT FROM AUTHOR]

Every orogenic belt is marked by a fault system, the nature of which depends on the orogenic processes and formation mechanisms at play. The Chengkou Fault separates the Qinling Orogen from the Yangtze Block and played an important role in the formation of the arcuate Dabashan fold-and-thrust belt. Therefore, it is a very good place to improve our understanding of plate collisions and intra-continental orogenies. We collected detailed field data along the Chengkou Fault to clarify its structural features and develop a reconstruction of the Dabashan fold-and-thrust belt. Based on our study and previous studies, we believe that the Chengkou Fault experienced complex deformations, in at least three stages, before the Cenozoic. The Chengkou Fault first developed as a normal fault with some curvature on the passive continental margin of the Yangtze Block during the Early Paleozoic. NEE-directed compression related to the collision of the North China and South China plates during the Triassic resulted in the Chengkou Fault being thrust southward. With the development of curvature on the Chengkou Fault, sinistral strike-slip movement on its eastern segment and dextral strike-slip movement on its western segment gradually appeared. The fault was reactivated under a NNW-directed compressive stress field during the following intracontinental orogeny, which spanned the Late Jurassic and Early Cretaceous. The obvious decrease in the plunge angle of the fold hinge as one moves east along the fault, as well as a few strike-slip indicators on the eastern segment of the Chengkou Fault, reveal that both reverse and dextral strike-slip components occur on the western segment, while the reverse movement progressively dominates the eastern segment. This change may be attributable to the increasing angle between the regional compressive stress and the Chengkou Fault. [ABSTRACT FROM AUTHOR]

Background: Functional knee braces are extensively used for partially and completely torn anterior cruciate ligament (ACL) patients and those who have undergone ACL graft reconstruction, in order to support the healing ACL, improve the joint's functional stability, and restore the normal joint kinematics.Research Question: Does wearing braces alter the arthrokinematics of the ACL deficient knees during lung exercise?Methods: For ten male unilateral ACL deficient subjects, 3D knee models were reconstructed from CT images, acquired in rest position. Sagittal plane fluoroscopy was then performed throughout a complete cycle of lunge in braced and non-braced conditions. The 3D kinematics of the knees were obtained using a 2D-3D registration method in which six anatomical bony landmarks on the fluoroscopic images were matched with those on the 3D models.Results: No significant difference was found between the tibial anterior-posterior translations and abduction-adduction motions of the braced and non-braced knees. A significant decrease, however, was observed after bracing in the tibial internal rotation at 45° flexion during eccentric (non-braced: 5.9° (±6.7°) vs. braced: 2.4° (±7.0°); p = 0.045), and at 30° flexion during concentric (non-braced: 2.3° (±6.9°) vs. braced: -1.6° (±8.1°); p = 0.001) phases of the lunge cycle.Significance: The immediate effect of knee bracing is limited to controlling the tibial rotation of the ACL deficient individuals during the lunge exercise. Hence, care should be taken in prescribing the lunge exercise for rehabilitation of ACL injured patients with high anterior-posterior knee instability, even when wearing knee braces. [ABSTRACT FROM AUTHOR]

Robotics is the engineering branch which deals with robots and its technologies. Developing new technologies that exhibit unique, versatile, user friendly, redundant data, instrument and software is the prime motive behind robotics. Researchers who work in this area focus on automating a particular task by conferring information about the environment to the robotic arm through sensors, while others are concerned in implementing analytical concepts in robotics. Present day the industries are mainly working with the help of robotic machineries, which is used in all kind of manufacturing factories. This paper introduces a master slave robotic arm-‘SAKSHA’. SAKSHA is a controller for an industrial robotic arm which can be used in factories, medical field and manufacturing companies. The device can replace the present version of controllers which are used in industries, make them easy to use and precise. The design removes the complexity of programming a robotic arm in doing multiple tasks at a time. The main intention on developing this device is to reduce the gap between robots and humans. [ABSTRACT FROM AUTHOR]

Background In case of people suffering from chronic low back pain, specific movements of the hip, pelvis, and trunk are associated with pain. Comparing range of motion measurements for multiple planes and from different segments and lines in reference to those of healthy individuals seems interesting but present interpretations challenge in relation to important number of variables and correlation with clinical data. Methods The proposed index is based on using principal component analysis to quantify differences in trunk mobility between patients with chronic low back pain and a control group. Kinematic data were recorded for the cervical and thoracic vertebrae, the lumbar spine, and the pelvic and scapular belts during repeated trials (hip flexion and extension, hip bending, and trunk twists). Angular motion values were calculated. Principal component analysis was used to convert 10 discrete variables (kinematical data) extracted from control data into 10 independent variables. Findings The proposed index comprises the sum of the variables. Initial demonstration of its clinical utility and statistical tests of this index validity were revealed. It establishes correlations between the psychosocial impact of chronic low back pain, trunk mobility (as summarized by the index) and the positive effects of functional restoration program. Interpretation This index let to assess the absolute potential benefits of rehabilitation in term of kinematic motion. Functional restoration program promotes the physical functioning of patients by increasing their range of motion. This index uses kinematic motion to assess the potential benefits of such rehabilitation program. [ABSTRACT FROM AUTHOR]

Severe Typhoon Vicente was the strongest tropical cyclone (TC) that has attacked Hong Kong (HK) since 1999. This paper presents a comprehensive observational study on this windstorm during its landfall, based on in-situ measurements from weather radars, radiosonde balloons, wind profilers and other ground-based devices at various meteorological stations in HK. Both its thermodynamic and kinematic structures are investigated to explore the TC characteristics at landfall. The results of this study reflected that the vortex extended to the tropopause around 16 km. Vertical profiles of pressure deficit below TC outflow layer depicted a linear distribution pattern with respect to isobar-expressed altitude, with a slope increasing almost linearly with increasing surface pressure deficit. The inner and outer rainband regions were respectively dominated by stratiform and convective precipitations, and the inner region was vertically separated into two discriminatory layers by the melting layer located at 5.4 km. The sea-air contrast temperature varied noticeably during the landfall process, with an increase of 1–1.5 °C in the TC inner region where sea-air flux exchange strengthened distinctly compared to that at outer areas. Vertical wind profiles from balloons showed that horizontal wind speed and wind direction experienced a sharp change around the tropopause, above which flow motions were dominated by the anti-cyclone of Tibetan high. The inflow layer depth was found on the order of 2 km, compared to 1–2 km for the atmospheric mixing layer depth. The gradient height, recognized via the maximum horizontal wind, was in the range of 0.5–2.5 km which decreased with decreasing radii prior to landfall. Examination of the results from wind profilers over marine, urban and rugged terrain showed that the wind structures in the TC boundary layer (TCBL) depended upon storm-relative position and underlying terrain features. Vertical profiles of marine winds in the inner rainband region demonstrated a jet feature, with mean speed being logarithmical with height in the lowest 1 km. TCBL winds above rugged areas were influenced severely by topographic effects. The low-level wind maximum, or the gradient speed, changed insignificantly above different sites. [ABSTRACT FROM AUTHOR]

Objective: The study aimed to analyze the differences between kinematic parameters in the single-leg stance (SLS) in patients with stroke and in healthy elderly people measured with 2 inertial sensors-1 in the trunk and 1 in the lumbar region.Methods: Two groups of participants were measured: the first group consisted of 5 healthy elderly people over 65 years of age; the second group consisted of 5 patients with stroke over 65 years of age, recovering for more than 6 months after suffering a stroke, and who had been undergoing rehabilitation treatment for at least 6 months. Two inertial sensors were located in the participants: in the trunk region (T7-T8) and in the lumbar region (L5-S1). The SLS test was performed in 4 conditions: right-dominant leg, open eyes; right-dominant leg, closed eyes; left-nondominant leg, open eyes; and left-nondominant leg, closed eyes.Results: Significant differences in displacement in the lumbar and trunk sensors are highlighted in 6 of 36 variables. In the velocity variables, significant differences were only found in 1 variable. Differences during SLS between the affected and the nonaffected legs in patients with stroke were found in 5 of the 36 analyzed variables and in 1 variable in velocity. The intraclass correlation coefficients were higher than .866 (95% confidence interval: .828-.857) for all variables.Conclusions: Only significant differences were found in 7 of the 128 kinematic variables analyzed in both groups, so that it could be confirmed that there are no significant differences in the static balance between healthy elderly people and people with stroke who undergo the rehabilitative treatment. [ABSTRACT FROM AUTHOR]