Search

The biomechanical impact of undergoing a single-event multilevel surgery (SEMLS) for children with cerebral palsy (CP) presenting an intoeing gait pattern has been widely documented. However, past studies mostly focused on gait quality rather than efficiency. Thus, there is a need to determine the impact of undergoing a SEMLS on gait quality and efficiency in children with CP presenting an intoeing gait pattern.Data from 16 children with CP presenting an intoeing gait pattern who underwent a SEMLS were retrospectively selected. Gait kinematics was quantified before (baseline) and at least 1 year after the surgery (follow-up). Gait quality was investigated with the Gait Profile Score (GPS), hip internal rotation angle and foot progression angle (FPA). Gait efficiency was analysed using clinically accessible variables, namely the normalised gait speed and medio-lateral and vertical centre of mass excursions (COMp). Dependent variables were compared between sessions with paired t-tests.At the follow-up, children with CP exhibited a more outward FPA and GPS as well as a decreased hip internal rotation angle. No changes in normalised gait speed and vertical COMp excursion were observed, and medio-lateral COMp excursion was slightly decreased.Children with CP presenting an intoeing gait pattern who underwent a SEMLS exhibited an increased gait quality, but gait efficiency was only minimally improved at the follow-up compared to baseline. Further studies are needed to identify contributors of gait efficiency in children with CP, and the best treatment modalities to optimise both their gait quality and efficiency.

Background: There is a paucity of data on mid to long-term gait outcomes after total knee arthroplasty. The aims of this longitudinal study were: to assess the evolution of both clinical and gait outcomes before and up to seven years after primary total knee arthroplasty (TKA) in a cohort of patients with knee osteoarthritis.Methods: This study included 28 patients evaluated before and up to seven years after primary TKA with both gait analysis and patient reported outcomes; of these, 20 patients were evaluated one year after surgery as well. Kinematic outcomes during gait (gait velocity, dimensionless gait veolicity, maximal knee flexion and knee range of motion), pain relief, Western Ontario and MacMaster Osteoarthritis Index (WOMAC), quality of life and patient satisfaction were assessed and compared at each visit with the paired Wilcoxon signed rank test (p < 0.05).Results: The significant improvement achieved at one year after TKA was stable up to seven years after surgery, with all clinical and kinematic outcomes unchanged, except for gait velocity, with a significant decrease over time (1.3 (1.1-1.4) m/s one year after TKA versus 1.0 (0.9-1.1) m/s, p < 0.05 up to seven years after).Conclusion: Patients with knee osteoarthritis significantly improve their clinical and kinematic outcomes at one year postoperatively and maintain the gain up to seven years after primary TKA, except for gait velocity which decreases over time, most likely along with ageing.

Inertial measurement units (IMUs) have shown promising outcomes for estimating gait event detection (GED) and ground reaction force (GRF). This study aims to determine the best sensor location for GED and GRF prediction in gait using data from IMUs for healthy and medial knee osteoarthritis (MKOA) individuals. In this study, 27 healthy and 18 MKOA individuals participated. Participants walked at different speeds on an instrumented treadmill. Five synchronized IMUs (Physilog®, 200 Hz) were placed on the lower limb (top of the shoe, heel, above medial malleolus, middle and front of tibia, and on medial of shank close to knee joint). To predict GRF and GED, an artificial neural network known as reservoir computing was trained using combinations of acceleration signals retrieved from each IMU. For GRF prediction, the best sensor location was top of the shoe for 72.2% and 41.7% of individuals in the healthy and MKOA populations, respectively, based on the minimum value of the mean absolute error (MAE). For GED, the minimum MAE value for both groups was for middle and front of tibia, then top of the shoe. This study demonstrates that top of the shoe is the best sensor location for GED and GRF prediction.

Many individuals with a transtibial amputation (TTA) exhibit balance deficits after limb loss. However, limited evidence exists on balance deficits of individuals with a TTA using hip, knee, and ankle kinematics and center of mass outcomes.To identify balance control deficits in individuals with a TTA and determine to what extent they are accentuated without visual inputs.Cross-sectional.Ten individuals with TTA and 10 healthy controls undertook a biomechanical assessment during a 30-s quiet standing task with eyes open (EO) and eyes closed (EC). The mean trunk, hip, knee, and ankle angles and center of pressure (COP) and center of mass excursions were calculated.More ankle dorsiflexion was observed for amputated limbs compared with intact lower limbs (mean difference: 5.8-degree, P = 0.031). Less anteroposterior (mean difference: 26.5 mm, P0.001) and mediolateral (ML) (mean difference: 4.2 mm, P = 0.042) COP excursions were found for amputated limbs compared with intact lower limbs and for control limbs compared with intact limbs (mean difference: 18.8 mm, P = 0.019). Greater ML COP excursion was found during EC than during EO condition (mean difference: 1.1 mm, P = 0.037).Individuals with a TTA presented a greater reliance on the intact lower limb, as highlighted by the greater ankle plantarflexion and anteroposterior and ML COP excursions for intact limbs compared with amputated limbs during quiet standing tasks. During EC condition, both groups exhibited greater ML COP excursions compared with EO condition, suggesting less postural stability. These differences may place them at greater risk of falling.

Gait parameters are altered and asymmetrical in individuals with transtibial amputation. The purpose of this study was to evaluate and compare the effect of four different prosthetic feet on lower-limb biomechanics during gait. A 34-year-old man with transtibial amputation performed four gait analysis sessions with four foot–ankle prostheses (Variflex, Meridium, Echelon, and Kinterra). Kinematic and kinetic parameters and gait symmetry were analyzed in different prosthetic conditions. The type of prosthesis had little effect on the participant’s spatiotemporal parameters. Throughout the stance phase, increased hip angle, reduced knee flexion and ankle dorsiflexion were observed in the amputated leg. For kinetic parameters, reduced propulsive force (SI = 0.42–0.65), reduced knee extension moment (mainly during Echelon and Kinterra conditions, SI = 0.17 and 0.32, respectively), and increased knee abduction moment (mainly during the Variflex and Meridium, SI = 5.74 and 8.93, respectively) were measured in the amputated leg. Lower support moments were observed in the amputated leg as compared to the unaffected leg, regardless of the type of prosthesis (SI = 0.61–0.80). The prostheses tested induced different lower-limb mechanical adaptations. In order to achieve the clinical goal of better gait symmetry between lower limbs, an objective gait analysis could help clinicians to prescribe prosthetic feet based on quantitative measurement indicators to optimize gait rehabilitation.

Inertial measurement units and normative values enable clinicians to quantify clinical walking tests and set rehabilitation goals. Objectives of this study were (1) to compare time- and distance-based walking tests in individuals with lower limb amputation (iLLA) and normative values following rehabilitation discharge (T1) and 6 weeks after discharge (T2) and (2) to investigate spatiotemporal and foot kinematic parameters over a 6-minute walk test using inertial measurement units. Twelve iLLA participated in this study. Distance, cadence, stance ratio, loading rate ratio, push-up ratio, path length, and minimum toe clearance were analyzed during 6-minute walk test. Nonparametric repeated-measures analysis of variance tests, Bonferroni corrections, were performed. Time of distance-based walking tests diminished at T2 (P P = .026). Stance ratio increased in both legs at T2 (P P = .0003). Variability of path length and minimum toe clearance at T2 were less than at T1 in the nonamputated leg (P

Background Most previous studies reported biomechanical deficits in individuals with a trans-tibial amputation (TTA) during gait using zero-dimensional analyses. However, these analyses do not allow to precisely determine during which part of the gait cycle these deficits occur. There is a need to use more appropriate methods to map the differences, such as one-dimensional statistical parametric mapping. Research question What are the most relevant phases of the gait cycle during which the biomechanical deficits in TTA occur? Methods Eight TTA and 15 healthy counterparts (CON) underwent one biomechanical gait analysis. Pelvis, hip, knee and ankle kinematics, total support moment (TSM) and gastrocnemius lateralis, vastus lateralis and tibialis anterior muscle activity were compared between the amputated (AmLL), the intact (InLL) and the control (CnLL) lower limbs using one-dimensional statistical parametric mapping. Results More ankle dorsiflexion and knee flexion were observed for the AmLL compared to the InLL and CnLL (ankle only) from the end of the stance phase to the beginning of the swing phase. Less knee flexion was also found for the AmLL during early stance phase. More pelvis posterior tilt and rotation toward the contralateral limb was observed during most of the gait cycle for the AmLL compared to the InLL. TSM was smaller for the AmLL compared to the CnLL during early stance phase. Significance Using a one-dimensional statistical parametric mapping approach for TTA gait analysis, this study provides novel insights on their biomechanical gait deficits compared to CON. Greater reliance on the InLL was observed in TTA as suggested by the asymmetric kinematic and kinetic profiles.

PurposeGait parameters are altered and asymmetrical in individual with transtibial amputation. The purpose of this study was to evaluate and compare the effect of four different prosthetic feet on lower-limb biomechanics during gait.MethodsOne young adult with transtibial ampution performed four gait analysis sessions with four foot-ankle prosthesis (Variflex, Meridium, Echelon, Kinterra). Kinematic, kinetic parameters and gait symmetry were analyzed during different prosthesis conditions.ResultsThe type of prosthesis had little effect on amputee’ spatiotemporal parameters. Throughout the stance phase, an increase hip angle and a reduced knee flexion and ankle dorsiflexion were observed in the amputated leg. For kinetic parameters, a reduced propulsive force (SI=0.42–0.65), reduced knee extension moment (mainly during Echelon and Kinterra conditions, SI=0.17 and 0.32, respectively) and an increased knee abduction moment (mainly during the Variflex and Meridium, SI=5.74 and 8.93, respectively) in the amputated leg. Lower support moments were observed in the amputated leg compared to the unaffected leg, regardless of the type of prosthesis (SI=0.61–0.80).ConclusionsThe prostheses tested induced different lower-limb mechanical adaptations. If better gait symmetry between lower limbs is one of the clinical goals, an objective gait analysis could help clinicians to prescribe prosthetic feet based on quantitative measurement indicators.

Diabetes peripheral neuropathy (DPN) leads to balance impairment among diabetes mellitus (DM). The aims of this study were to (1) distinguish between DM patients who have/do not have DPN and to (2) compare quadriceps’ strength and balance performance of DM, DPN, and healthy groups. Fifteen healthy females and 33 females with type 2 diabetic patients participated. The electrodiagnostic method was used to classify diabetic patients into DM and DPN. A dynamometer was used to measure quadriceps’ strength. Single-leg standing on a force plate was also used to quantify participants’ balance. Smaller conduction velocity and amplitude and greater distal latency of all nerves were observed in the DPN compared with the DM in particular for sensory nerve. In DPN, conduction velocity was asymmetrical. The quadriceps’ strength of both legs in DPN and the right leg in DM was smaller than in the control group. The root mean square of the center of pressure was similar between DM and DPN. But it was larger in DPN than in the control group. DPN is associated with asymmetrical conduction velocity, smaller quadriceps’ strength, and weaker balance performance that is suggestive of higher risk of falling. Balance training is recommended for the DPN group during their rehabilitation to reduce their falling risk.

Background: The 6-minute walk test (6MWT) is one of the common clinical tests to assess rehabilitation progress and needs in individuals with lower-limb amputation (iLLAs). However, the analysis of this test is mostly limited to the distance parameter. The first aim was to investigate effort intensity and spatiotemporal parameters of 6MWT in iLLAs using inertial measurement units (IMUs) and heart rate (HR) monitor, and second, to assess physical, physiological, and pain-related aspects of fatigue over 6MWT. Methods: Eleven unilateral iLLAs (57.91±15.63 years old) participated in this study. To evaluate HR and spatiotemporal parameters over 6MWT, data were classified using 6 intervals of 1 minute each (I1-I6). The pain level of participants was estimated using the visual analog scale (VAS). Results: Our results showed that the means of normalized HR gradually increased over 6MWT (I1: 61.59±10.73 HRmax%, I6: 70.15±12.26 HRmax%, P = .003). Variability of HR during the first interval of 6MWT was higher than the others ( P < .05). The stance ratio of the gait cycle increased over 6MWT ( P < .05). Cadence and speed decreased over 6MWT ( P < .05). VAS score after 6MWT was significantly higher than before 6MWT ( P = .016). Conclusion: In this preliminary study, effort intensity over 6MWT gradually increased because of enhancement of HR. Deterioration of speed and cadence and enhancement of stance ratio over 6MWT imply potential physical aspects of fatigue and instability. Level of Evidence: Level III, retrospective comparative study.

Individuals with a lower limb amputation use compensatory strategies during essential tasks such as sit-to-stand and stair ascent leading to secondary physical conditions. The ensuing biomechanical parameters outlining the motion strategies they put in place need to be identified and described.We searched three databases (Embase, IEEE Xplore and PubMed) for articles on the spatiotemporal, the kinematics and the kinetics that compared the amputated, the intact lower limbs, or the trunk of individuals with a unilateral transtibial or transfemoral amputation with the limbs of a control group.We found twenty articles. During sit-to-stand, individuals with a lower limb amputation increased the trunk inclination angle toward the intact lower limb, explaining higher ground reaction forces and peak knee sagittal power generation. During stair ascent, individuals with a lower limb amputation increased the stance phase duration on the intact lower limb. Moreover, individuals with a lower limb amputation increased both lower limbs hip extension moment and power, and the amputated lower limb knee extension moment. In both tasks, the individuals with a transfemoral amputation presented larger differences than those with transtibial compared to the control group.Both lower limbs intact joint moment and power were increased to compensate for the prosthesis passive joint and to ensure stability. Stair gait studies mainly focused on the lower limbs' biomechanical changes in the sagittal plane, while sit-to-stand studies focused on asymmetries without comparing the lower limbs independently. Better methodological descriptions are essential to enhance the external validity of previous results.

Background A recent amputation leads to decreased functional capacities in the lower limb amputees (LLA), especially during walking. Assessments of LLA’s gait in clinical settings are used to provide feedback on their evolution without quantifying gait parameters distinctly, unlike new technologies, such as inertial sensors (IMUs), which have demonstrated their effectiveness in different environments and populations. Research question How do the spatial-temporal gait parameters and kinematics of the LLA evolve quantitatively over a six-minute walk test (6MWT) and is the use of inertial sensors relevant in clinical practice to quantify those parameters? Methods Fifteen LLA from a study cohort performed a 6MWT post-rehabilitation, wearing inertial sensors on both feet to provide gait parameters (i.e., minimum toe clearance (minTC), speed, cadence, stance time and foot flat ratio (FFr)) over this test. A non-parametric ANOVA was conducted comparing the evolution of each parameter over the 6MWT (12 intervals of 30 s). Significance level was set at P ≤ 0.05. Post-hoc Wilcoxon signed-rank tests were performed if a main effect was detected. Results MinTC and stance phase variability along the 6MWT were significantly different over time. Cadence variability and speed variation were significantly different between both feet (amputated and non-amputated leg). Significance The increased variability in gait parameters along the 6MWT suggests a greater risk of future mobility problems following a return in community. The data provided by the IMUs reflect the potential of the clinical rehabilitation programme and could, therefore, help clinicians to refine their interventions.

Background: Toe-out foot positioning is increasingly analyzed as a compensatory body-mechanical strategy to reduce pain and joint constraints in people with degenerative joint disease during gait. However, its influence during functional tasks, such as sit-to-stand, has not been reported. Research question: How uni- and bilateral toe-out foot positioning influence body-dynamics during a STS task? Methods: The study was conducted on 15 healthy participants. Seven feet conditions were tested: neutral (N); right toe-out angle of 10° (U10), 20° (U20), and 30° (U30); bilateral toe-out angle of 10° (B10), 20° (B20), and 30° (B30). Execution time, trunk kinematic, vertical ground reaction force ratio as well as maximal knee and hip joint moments were analyzed and compared. Results: A significant difference was found across conditions in the STS execution time (p = 0.036) showing a main effect on temporal parameters using both uni- and bilateral toe-out foot positioning. A significant difference between conditions was also obtained for the vertical force ratio (p = 0.018) and the maximal knee flexion moment (p = 0.008). Post-hoc tests demonstrated a significant difference on force ratio and on knee flexion moment only while using a more pronounced unilateral toe-out foot positioning. Significance: The influence of toe-out foot positioning on body-dynamics during STS supports the idea of an alteration of body-mechanical strategy, as reported in literature gait studies. The results could have an impact on the management of patients using these strategies in order to reduce the onset of secondary joint diseases such as osteoarthritis.

Background The purpose of this prospective study was to understand the relation between gait outcomes and patient satisfaction one year after total knee arthroplasty (TKA). Methods Seventy-nine patients were evaluated before and one year after TKA using clinical gait analysis. Specific gait outcomes were analyzed: gait speed, stance phase, range of motion (ROM) knee flexion and maximal knee flexion. The parameters of interest selected for the statistical analysis were: gait speed and maximal knee flexion during gait. The Western Ontario and MacMaster Osteoarthritis Index (WOMAC) and patient satisfaction were also assessed. The satisfaction was evaluated using a questionnaire and was splited in five categories: very unsatisfied, unsatisfied, neutral, satisfied or very satisfied. To assess associations between patient satisfaction and maximal knee flexion during gait and gait speed, an unadjusted ordinal logistic regression analysis was used. The analysis was then adjusted for covariates: age and Body Mass Index (BMI) before surgery and WOMAC pain one year after surgery. Results All gait outcomes after TKA had significantly improved. The ordinal logistic regression analysis found significant associations between patient satisfaction and maximal knee flexion after TKA (unadjusted and adjusted) but not for gait speed. Conclusion These findings show that all patients improved their gait outcomes one year after TKA but only a higher maximal knee flexion during gait may influence the level of patient satisfaction.

Background Total knee arthroplasty (TKA) is the operation of choice in patients with end-stage knee osteoarthritis (OA). Up to 1 in 5 patients still encounter functional limitations after TKA, partly explaining patient dissatisfaction. Which gait ability to target after TKA remains unclear. To determine whether Minimal Clinical Important Improvement (MCII) or Patient Acceptable Symptom State (PASS) values could be derived from gait parameters recorded in patients with TKA. And, if so, to define those values. Methods In this ancillary study, we retrospectively analyzed gait parameters of patients scheduled for a unilateral TKA between 2011 and 2013. We investigated MCII and PASS values for walking speed and maximal knee flexion using anchor-based methods: 5 anchoring questions based on perceived body function and patients’ satisfaction. Results Over the study period, 79 patients performed a clinical gait analysis the week before and 1 year after surgery, and were included in the present study. All clinical and gait parameters improved 1 year after TKA. Nevertheless, changes in gait outcomes were not associated with perceived body function or patients’ satisfaction, precluding any MCII estimation in gait parameters. PASS values, however, could be determined as 1.2 m/s for walking speed and 50° for maximal knee flexion. Conclusion In this study, we found that MCII and PASS values are not necessarily determinable for gait parameters after TKA in patients with end-stage OA. Using anchor questions based on perceived body function and patient’s satisfaction, MCII could not be defined while PASS values were potentially useful. Level of evidence Level III

Gait retraining as a non-invasive prospective approach to restore mechanical loading at the knee joint and slowing down knee osteoarthritis (OA) progression shows great promise. However, the impact of gait modifications such as an increase in foot progression angle (FPA) or lateral trunk lean (LTL) on the ankle and hip is not yet well understood. Thus, the goal of this study is to provide insight on the impact of FPA and LTL on the sagittal and frontal external moments at the ankle and hip of healthy participants. We hypothesize that there is an optimum, for which an increase in FPA and/or LTL minimize the knee adduction moment (KAM) without increasing significantly the frontal and sagittal external moments at the ankle and hip during gait. To test this hypothesis, 23 participants performed walking trials with modified FPA and/or LTL angles following a real-time visual feedback. The hypothesis was not confirmed and while not all the gait modifications performed by the participants in this study reduced the KAM, they significantly increased the sagittal moment at the ankle and the frontal moment at the hip. This study highlights the importance to consider the biomechanical consequences of gait modifications on the ankle and hip before considering a clinical application of gait retraining approaches.

Individuals with knee osteoarthritis (OA) show variability during the sit-to-stand (STS) task, so they may not perform the STS in the same way. This study aimed to determine whether individuals with knee OA have different strategies in performing the STS.Participants with knee OA and able-bodied individuals underwent STS evaluation at a self-selected pace with use of a motion measurement system consisting of 12 cameras and 2 force plates.In total, 101 participants (57 women) with knee OA showed 3 main STS strategies. As compared with the 27 controls (14 women), 24 OA participants, compensated STS, showed greater trunk flexion (47.1° vs. 38.3°; P0.01) and trunk obliquity (4.6° vs. -0.8°; P0.001) when completing the STS task in the same amount of time as controls (2.4 vs. 2.7s; P=0.999). The second group (n=59), inadequately compensated STS, also compensated with trunk flexion (47.7° vs. 38.3°; P0.01) and trunk obliquity (1.6° vs. -0.8°; P0.001) but took longer than controls (3.4 vs. 2.7s; P=0.001). The third group (n=18), severe impaired STS, took an extended amount of time to execute the STS (6s), with marked trunk flexion (59.2°) and obliquity (4.1°), so participants in this group were perhaps severely impaired in completing the STS.This study identified 3 groups STS trunk strategies among participants with STS. Moreover, the data reveal a concise representation of the relations among strategy variables. The findings could be used to simplify the characterization of the STS among patients with knee OA and aid with follow-up.

The purpose of this prospective study was to investigate the influence of body mass index (BMI) on gait parameters preoperatively and 1 year after total knee arthroplasty (TKA).Seventy-nine patients were evaluated before and 1 year after TKA using clinical gait analysis. The gait velocity, the knee range of motion (ROM) during gait, their gains (difference between baseline and 1 year after TKA), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), quality of life, and patient satisfaction were assessed. Nonobese (BMI30 kg/mAt baseline, gait velocity and knee ROM were significantly lower in obese compared with those in the nonobese patients (0.99 ± 0.27 m/s vs 1.11 ± 0.18 m/s; effect size, 0.53; P = .021; and ROM, 41.33° ± 9.6° vs 46.05° ± 8.39°; effect size, 0.52; P = .022). Univariate and multivariate linear regressions did not show any significant relation between gait speed gain or knee ROM gain and BMI. At baseline, obese patients were more symptomatic than nonobese (WOMAC pain: 36.1 ± 14.0 vs 50.4 ± 16.9; effect size, 0.9; P.001), and their improvement was significantly higher (WOMAC pain gain, 44.5 vs 32.3; effect size, 0.59; P = .011).These findings show that all patients improved biomechanically and clinically, regardless of their BMI.

Some studies have used load cells (LC) to measure the force applied to horizontal handrails, but no work has validated an inclined set-up that can be used to bring new insights into handrail use during staircase gait. The aim of this study was to validate the accuracy of an inclined handrail set-up instrumented with LC. A handrail set-up designed to be easily reconstructed and integrating two commercial LC is proposed. Twenty points were tested along the handrail, with four reference weights in the three orthogonal directions of the sensors (Medio-Lateral, Antero-Posterior, Vertical). For each direction, the percentage (%) of error and the cross-talk between the known and recorded forces were calculated. A linear regression of the % error was performed to evaluate measurement accuracy in relation to point of application along the handrail. The current easily replicated set-up of an inclined handrail showed accurate measures with low cross-talk. The percentage of error and cross-talk were below 3.7% and 3.7%, respectively, consistent with previous studies evaluating inclined handrail with other methods. The error and cross-talk were greater in the Medio-Lateral and Antero-Posterior directions. The error in the Antero-Posterior direction was larger over the upper part of the handrail.

Mechanical alignment in total knee arthroplasty (TKA) can be achieved using dependent bone cuts. The hypothesis is that patients have a better balanced TKA, as a result. The aim of this study was to determine if this technique is superior to an independent bone cut technique in terms of gait parameters, patient-reported outcome measures (PROMs), and satisfaction assessed before surgery and at 1-year follow-up. A total of 58 patients were evaluated before and 1 year following TKA, using the Press Fit Condylar (PFC) Sigma posterior stabilizer (PS) design; 39 (70 ± 8 years; 27 women) with independent bone cuts and 19 (71 ± 7 years; 12 women) with dependent bone cuts using the Specialist TRAM. Gait was evaluated with a three-dimensional motion analysis system for spatiotemporal and kinematics parameters. Pain and functional levels were assessed using the Western Ontario and McMaster Universities arthritis index (WOMAC); general health was assessed by the short form (SF)-12. Global satisfaction, as well as patient satisfaction, related to pain and functional levels were assessed using a five-point Likert's scale. No significant difference was found between both groups in terms of age, body mass index, pain, and functional levels at baseline. At 1-year follow-up, despite an overall improvement in gait, WOMAC, SF-12 physical score and pain, none of the patients showed gait parameters comparable to a healthy control group. No surgical technique effect was observed on gait, clinical outcomes, and satisfaction level. While observing an overall improvement at 1-year follow-up, we did not find any significant difference between the two surgical techniques in terms of gait parameters, patients' outcomes, and satisfaction.

Background We evaluated the influence of the body-mass index (BMI) on the estimation of the static frontal knee alignment (FKA) using three-dimensional (3D) reconstruction method based on movement analysis. Methods Two-hundred nineteen knees (120 individuals with end-stage osteoarthritis) were analyzed. The validity of the 3D method was evaluated under comparison with a reference method based on weight bearing full-leg length radiography. Extensive statistical analyses (Pearson's correlation, one-way ANOVA, linear regression, boxplot diagram) over four groups of BMI (normal, overweight, obese class I and obese classes II and III) were performed. Results For BMI below 25 kg/m2, the validity of the 3D method was confirmed. For BMI over 25 kg/m2, there was an increasing error of the 3D method, especially for the obese groups affected with a large varus alignment. Conclusions In a biomechanical context of movement analysis, the results of the study suggest that the 3D method may represent a satisfying alternative to the full-leg radiograph method with limitations regarding to BMI over 25 kg/m2.

Introduction Le passage assis-debout (PAD) est une tâche importante pour l’independance. Chez les individus amputes, le PAD est modifie par une inclinaison laterale du tronc (ILT) pour mettre en charge le membre inferieur (MI) non-ampute. Le but de cette etude est de comprendre l’influence d’lLT sur la cinetique du MI et l’activite musculaire en absence d’affection. Materiel et methodes Dix individus sains devaient effectuer 5 PAD dans 3 conditions standardisees : sans contrainte (N), 5°d’ILT (ILT5) et 10° (ILT10). La cinematique du corps entier etait collectee par 10-cameras VICON a 100 Hz. Les forces de reaction au sol (FRS) etaient recueillies par 2 plateformes de forces (AMTI) a 1000 Hz. L’activite musculaire des muscles ilio-costalis (IC) et vastus lateralis (VL) etaient enregistrees par des capteurs Trigno (Delsys) a 2000 Hz. La duree du PAD, le ratio des FRS (homolateral a l’ILT/controlateral), l’activite musculaire et les moments de force sagittaux des MI ont ete compares entre chaque condition avec une ANOVA a mesures repetees. Resultat L’ILT augmente la duree du PAD ([p = 0,007] N : 1,45 ± 0,16 s ; ILT5 : 1,54 ± 0,32 ; ILT10 : 1,74 ± 0,35 s). On note aussi une augmentation significative du ratio des FRS ([p Discussion/conclusion Le tronc influence le ratio des FRS et l’activation des muscles VL et IC controlateraux. Cependant, l’augmentation de la duree semble limiter l’influence des FRS sur les moments de force.

The aim of this study was to describe the evolution of kinematic and clinical outcomes of a large patient cohort with knee osteoarthritis from before surgery (V1) to 3 months (V2) and 1 year (V3) after a total knee arthroplasty (TKA).The patients were evaluated at each visit (118 patients at V1, 93 patients at V2, and 79 patients at V3) during a clinical gait analysis and were compared with a matched control group of healthy adults (CG). The kinematic parameters, the Western Ontario and MacMaster Osteoarthritis Index (WOMAC), quality of life, and patient satisfaction were assessed. Gait velocity and knee range of motion (ROM) as well as clinical parameters were compared at each visit with CG was based on the unpaired samples t-test. To determine changes in the data at baseline, 3 months, and 1 year after surgery in the patient groups, repeated-measure analysis of variance was conducted (P.05). Pearson correlation was used to examine relationships between clinical and biomechanical outcomes.One year after TKA (V3) compared to V1 and V2, the ROM of the operated knee during gait was significantly improved (V1: 44.2 ± 8.8° vs V3: 47.5 ± 7.1°, P.001, and V2: 42.2 ± 9.3° vs V3: 47.5 ± 7.1°, P = .001), as was the gait velocity (V1: 1.0 ± 0.2 and V2: 1.1 ± 0.2 m/s vs V3: 1.3 ± 0.2 m/s, P.001). The WOMAC and knee pain were significantly better 1 year after TKA. No strong relationships have been found between clinical parameters and knee kinematics.This study showed that 1 year after TKA, patients exhibited improved gait velocity and ROM and experienced a significant decrease in the level of pain and an increased clinical score (although different from CG).

The objective of this study was to investigate how gait and clinical outcomes contribute to patients' satisfaction three months following a total knee arthroplasty (TKA). Seventy-eight patients with knee osteoarthritis (OA) and a control group of twenty-nine subjects were evaluated. The gait parameters, Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain and functional levels, quality of life and patients' satisfaction following TKA were assessed. A multiple linear regression model shows that the WOMAC functional score explained 39% of the global satisfaction and 37% of the satisfaction related to pain relief following TKA. Finally, the model shows that 65% of the satisfaction related to the functional improvement was explained by a combination of clinical and gait parameters. This study demonstrated the contribution of both gait and clinical outcomes to patients' satisfaction following TKA.

Objective To compare the well-recognized solid ankle cushion heel (SACH) foot with the prosthetic foot developed by the International Committee of the Red Cross (CR Equipements SACH) during gait. Design Double-blind study was conducted to compare the influence on the biomechanics of gait of the CR Equipements SACH foot and the SACH foot. Setting University hospital research center. Participants Participants with unilateral transtibial amputation (N=15) were included. Interventions Three-dimensional motion analysis system and 2 forceplates were used to capture body motion and ground reaction forces during gait at a self-selected speed and at 1.2m/s. Main Outcome Measures Nonparametric Wilcoxon matched-pairs tests were used to compare the 2 prosthetic feet with respect to their spatiotemporal (gait velocity, stride length, and percentage of stance phase), kinematic (range and peak angles of the pelvis, hip, knee, and ankle), and kinetic (peak moment and power of the hip, knee, and ankle) parameters. Results Compared with the SACH foot, the CR Equipements SACH foot demonstrated a significantly greater stance phase symmetry ratio (SACH: 94% vs CR Equipements SACH: 97%), a more extensive ankle range of motion in the sagittal plane (SACH: 7° vs CR Equipements SACH: 12°), a greater maximal dorsiflexion angle during the terminal stance phase (SACH: 10° vs CR Equipements SACH: 13°), and a higher ankle power (SACH: .31W/kg vs CR Equipements SACH: .40W/kg). No significant difference was found for the examined knee, hip, and pelvis parameters. Conclusions The CR Equipements SACH foot provides more symmetry and improves ankle kinematics and kinetics in the sagittal plane compared with the SACH foot. This study suggests that individuals using the CR Equipements SACH foot improve their gait biomechanics compared when using the SACH foot.

Background Given the complexity of the gait of patients with knee osteoarthritis, a multiple correspondence analysis may be helpful to optimise the extraction of relevant gait and clinical information. Therefore, the aims of this study are to identify the main associations with clinical and gait biomechanical parameters and to evaluate whether there are more specific knee osteoarthritis groups with different gait profiles. Methods Ninety patients with severe knee osteoarthritis and twenty-six healthy individuals participated in this study. Pain and function were assessed with the WOMAC Index; knee joint deformity was assessed by the hip-knee-ankle angle on full-limb radiography; and full body gait analysis was performed with a motion analysis system and force plates. Findings Using multiple correspondence analysis, two categories of gait parameters that best explain the gait variance of patients with knee osteoarthritis were highlighted. The forward displacement category is composed of the parameters speed, stride length, hip flexion and knee flexion. The frontal category is composed of the parameters thorax obliquity and knee adductor moments. Moreover, based on these parameters, four distinct gait profiles were identified: two gait profiles were associated with knee varus deformities, increased thorax obliquity and different forward displacements, while two gait profiles were associated with valgus deformities and different forward displacements. Interpretation These gait parameters can be used to simplify the characterisation of the gait of the knee osteoarthritis population. Patients in varus profiles increase thorax obliquity on the stance limb and may reduce forward displacement. Patients in valgus profiles, however, only reduce forward displacement.

The International Committee of the Red Cross supports a worldwide program of prosthetic fitting and rehabilitation. In this context, a prosthetic foot was developed and widely distributed in least developed countries.Prospective, randomized, double-blind, controlled study.To compare patient satisfaction and energy expenditure during ambulation between a low-cost prosthetic foot designed with a polypropylene keel (CR-EquipementsA total of 15 participants with unilateral transtibial amputation were evaluated using the two prosthetic feet in a randomized prospective double-blind crossover study. Main outcomes were patient satisfaction questionnaires (Satisfaction with Prosthesis Questionnaire and prosthetic foot satisfaction) and energy expenditure (oxygen consumption-mL/kg/min, oxygen cost-mL/kg/m, and heart rate-bpm).There were no significant differences between the two prosthetic feet for satisfaction and energy expenditure.The low-cost solid ankle cushion heel foot with polypropylene keel provides comparable satisfaction and similar energy expenditure as the solid ankle cushion heel foot with wooden keel. Clinical relevance The results of this study support the application and widespread use of the CR-Equipements

The aim of this study is to quantify the changes in the sagittal alignment of the cervical spine in patients with adolescent idiopathic scoliosis following posterior spinal fusion. Patients eligible for study inclusion included those with a diagnosis of mainly thoracic adolescent idiopathic scoliosis treated by means of posterior multisegmented hook and screw instrumentation. Pre and post-operative anterior-posterior and lateral radiographs of the entire spine were reviewed to assess the changes of cervical sagittal alignment. Thirty-two patients (3 boys, 29 girls) met the inclusion criteria for the study. The average pre-operative cervical sagittal alignment (CSA) was 4.0° ± 12.3° (range -30° to 40°) of lordosis. Postoperatively, the average CSA was 1.7° ± 11.4° (range -24° to 30°). After surgery, it was less than 20° in 27 patients (84.4%) and between 20° and 40° in 5 patients (15.6%). The results of the present study suggest that even if rod precontouring is performed and postoperative thoracic sagittal alignment is restored, improved or remains unchanged after significant correction of the deformity on the frontal plane, the inherent rigidity of the cervical spine limits changes in the CSA as the cervical spine becomes rigid over time.

The aim of this study is to describe the radiological changes in rib-vertebral angles (RVAs), rib-vertebral angle differences (RVADs), and rib-vertebral angle ratios (RVARas) in patients with untreated right thoracic adolescent idiopathic scoliosis and to compare with the normal subjects. The concave and convex RVA from T1 to T12, the RVADs and the RVARas were measured on AP digital radiographs of 44 female patients with right convex idiopathic scoliosis and 14 normal females. Patients were divided into three groups: normal subjects (group 1), scoliotic patients with Cobb's angle equal or

Turcot K, Aissaoui R, Boivin K, Hagemeister N, Pelletier M, de Guise JA. Test-retest reliability and minimal clinical change determination for 3-dimensional tibial and femoral accelerations during treadmill walking in knee osteoarthritis patients. Objective To determine the test-retest reliability and the minimal clinical change determination for accelerometric parameters, estimated by a new accelerometric-based method that estimates 3-dimensional (3D) linear accelerations of the tibia and femur during comfortable and fast walking speeds. Design Test-retest study. Setting Gait laboratory in a research center. Participants Patients (N=25; 6 men, 19 women) with symptomatic knee osteoarthritis (OA). Interventions Not applicable. Main Outcomes Measures Subjects attended 2 walking sessions in which accelerometers were rigidly fixed by means of an exoskeleton to the femoral and tibial segments. In both sessions, 3D accelerations were collected for 25 seconds for each of the walking speeds. Mean accelerometric pattern was calculated using 15 gait cycles. From each mean pattern, maximal, minimal, and range values were extracted from the loading phase period. The root mean square (RMS) value was also calculated for every pattern. Relative and absolute reliability were determined using intraclass correlation (ICC) and standard error (SE) of measurement, respectively. Minimal detectable change was calculated for each parameter as the least significant difference. Results Tibial and femoral accelerations showed reliable values across sessions 1 and 2 with ICCs greater than or equal to .75 for 96% and 88% of the parameters at comfortable and fast speeds, respectively. The SE of measurement ranged from .01 to .05 g for the RMS value and from .05 to .35 g for maximal, minimum, and range point parameters. Conclusions The proposed method is the first to have determined the reliability and the minimal detectable change for tibial and femoral acceleration parameters in knee OA patients during a treadmill walking evaluation. The minimal detectable change determined in this study will be used to determine improvement or deterioration of knee OA patients after rehabilitation.

The purpose of this study is twofold: (1) to develop a classification method to distinguish between asymptomatic (AS) and knee osteoarthritis (OA) gait patterns using ground reaction force (GRF) measurements, and (2) to investigate OA severity within OA gait patterns. Features were first extracted from the GRF vectors to be used for classification. We investigated a two-level hierarchical classification and analysis method using the nearest neighbor rule. At the first level, the GRF data were classified into two classes: AS and OA. At the second level, the GRF data of OA patients were classified according to the pathology severity. The OA patients were grouped into two OA severity categories according to the Kellgren and Lawrence (KL) scale: KL 1 and KL 2 for one category, and KL 3 and KL 4 for the other. Experiments were conducted using data of 42 cases, 16 AS and 26 pathological. The method discriminated between AS and OA subjects with an accuracy of 38 of 42 cases, and assessed the severity correctly with an accuracy of 20 of 26 cases. These results demonstrated the validity of both, the feature and the classifier, for automatic classification of AS and knee OA gait patterns and for analysis of OA severity.

Background Previous studies have demonstrated balance impairment in patients with knee osteoarthritis (OA). Although it is currently accepted that postural control depends on multi-joint coordination, no study has previously considered this postural strategy in patients suffering from knee OA. The objectives of this study were to investigate the multi-joint postural behavior in patients with knee OA and to evaluate the association with clinical outcomes. Methods Eighty-seven patients with knee OA and twenty-five healthy elderly were recruited to the study. A motion analysis system and two force plates were used to investigate the joint kinematics (trunk and lower body segments), the lower body joint moments, the vertical ground reaction force ratio and the center of pressure (COP) during a quiet standing task. Pain, functional capacity and quality of life status were also recorded. Results Patients with symptomatic and severe knee OA adopt a more flexed posture at all joint levels in comparison with the control group. A significant difference in the mean ratio was found between groups, showing an asymmetric weight distribution in patients with knee OA. A significant decrease in the COP range in the anterior–posterior direction was also observed in the group of patients. Only small associations were observed between postural impairments and clinical outcomes. Conclusion This study brings new insights regarding the postural behavior of patients with severe knee OA during a quiet standing task. The results confirm the multi-joint asymmetric posture adopted by this population.

International audience; BACKGROUND:Evolution; Gait; Hereditary spastic paraplegia; Longitudinal study; WalkingThe degree of disability in patients with hereditary spastic paraplegia has been reported variable even in members of the same family (same gene mutation). Moreover, it has been established that patients with hereditary spastic paraplegia should be treated differently from cerebral palsy patients due to the progressive nature of this disease. However, the gait evolution of hereditary spastic paraplegia showing onset symptoms at an early age has been described as stable. Therefore, this study aims to evaluate the walking ability and the influence of treatments on gait evolution in a family with hereditary spastic paraplegia.METHODS:Clinical gait analyses were performed in six hereditary spastic paraplegia patients from the same family with a follow-up of 4-15 years.RESULTS:Based on the gait deviation index, results showed a large variation of walking ability in these patients and no statistical difference between the first and last examination. In fact, three patients have improved their gait (from childhood to adolescence) whereas three patients worsened their gait.CONCLUSIONS:Gait alterations in a family with hereditary spastic paraplegia are heterogeneous. Gait evolution in hereditary spastic paraplegia with early symptoms had a tendency to improve gait until adolescence with adapted treatments and to decline in the adulthood.

Objectif : Determiner les strategies de compensation utilisees par les individus atteints de gonarthrose pour accomplir une tâche de transition assis-debout. Methode : Soixante-treize individus atteints de gonarthrose (âge moyenne : 69 ans) et 27 individus sains (âge moyenne : 66 ans) ont ete evalues lors d’une tâche de transition assis-debout a l’aide d’un systeme d’analyse de mouvement en trois dimensions. Des correlations ont ete calculees afin d’evaluer les differentes associations entre les parametres biomecaniques. Resultat : Les moments articulaires a la hanche et au genou montrent des correlations avec le temps d’execution de la tâche. Ces resultats suggerent que la hanche et le genou sont associes pour creer le moment specifique lors de l’execution de cette tâche. Le moment a la cheville et la flexion du tronc sont egalement correles. Ceci suggere une strategie de compensation pour atteindre la position debout. Si l’on compare les deux membres inferieurs, les moments aux hanches, aux genoux et aux chevilles sont asymetriques. Conclusion : D’apres les associations faibles a moderees obtenues entre les parametres biomecaniques lors de la tâche de transition assis-debout, il semble que des interactions plus complexes doivent probablement etre impliquees dans le developpement de strategies pour executer cette tâche par les individus atteints de gonarthrose.

■ La comprehension du mouvement humain normal et pathologique est un sujet complexe qui fascine et qui demeure un enjeu majeur pour la sante. ■ Notre vie est etablie autour du mouvement. Nous realisons chaque jour autour de 10 000 pas et 60 levers de chaise. La realisation de ces mouvements permet de garder l'independance et une bonne qualite de vie. ■ La vitesse de marche est meme consideree comme un signe vital. ■ Le mouvement necessite l'integrite du systeme neuro-musculosquelettique (figure 1.1). En effet, les systemes proprioceptif, visuel, vestibulaire donnent les informations necessaires aux systemes nerveux central et peripherique qui transmettent la commande aux muscles lesquels vont s'activer pour deplacer les segments autour des articulations afin de creer un mouvement. Etant donne le nombre de systemes impliques dans la realisation du mouvement, la comprehension fine de ce dernier est complexe. ■ Si un element de ces systemes est altere, le mouvement souhaite ne pourra pas etre effectue ou sera effectue avec difficulte et/ou avec douleur. Selon l'atteinte, le role du clinicien sera alors de permettre, de restaurer ou de sauve garder un mouvement efficient et sans douleur. Avant d'etablir la strategie therapeutique, le clinicien devra comprendre l'origine des troubles du mouve ment. Devant la complexite du mouvement et de ses troubles, il pourra faire appel a un modele « integratif » comme la Classification internationale du fonctionnement, du handicap et de la sante (CIF) qui permettra de definir les differents elements alteres du mouvement et ainsi aider a comprendre les troubles du mouvement et le handicap cree par ses troubles (figure 1.2). ■ Une partie de l'examen clinique en orthopedie consiste a evaluer le mouvement du patient et ses troubles eventuels lors de la marche ou d'autres activites de la vie quotidienne. ■ Le mouvement peut etre analyse de differentes manieres, a l'œil nu ou a l'aide de divers instruments de mesures plus au moins precis. Si en clinique il existe un consensus sur la necessite d'analyser le mouvement, la maniere dont il va etre enregistre dependra de divers facteurs : de l'instrumentation, de la precision de la mesure, du temps disponible, des moyens a disposition, de l'expertise du clinicien ou de l'equipe therapeutique et enfin des possibilites du patient. 1

Objective The aim of this study was to evaluate the effectiveness of unstable shoes in reducing low back pain in health professionals. Methods Of a volunteer sample of 144 participants, 40 with nonspecific chronic low back pain were eligible and enrolled in this study. Participants were randomized to an intervention group, who wore unstable shoes (model MBT Fora), or a control group, who wore conventional sports shoes (model Adidas Bigroar). The participants had to wear the study shoes during their work hours, and at least 6 hours per workday, over a period of 6 weeks. The primary outcome was low back pain assessed on a Visual Analog Scale. The secondary outcomes were patient satisfaction, disability evaluated using Roland-Morris questionnaire and quality of life evaluated using EQ-VAS. Results The intervention group showed a significant decrease in pain scores compared to the control group. The rate of satisfaction was higher in the intervention group (79%) compared to the control group (25%). There was no significant difference for the Roland-Morris disability questionnaire score and the EQ-VAS scale. Conclusions The results of this clinical trial suggest that wearing unstable shoes for 6 weeks significantly decreases low back pain in patients suffering from chronic low back pain but had no significant effect on quality of life and disability scores.

The aim of this work is to develop an automatic computer method to distinguish between asymptomatic (AS) and osteoarthritis (OA) knee gait patterns using 3-D ground reaction force (GRF) measurements. GRF features are first extracted from the force vector variations as a function of time and then classified by the nearest neighbor rule. We investigated two different features: the coefficients of a polynomial expansion and the coefficients of a wavelet decomposition. We also analyzed the impact of each GRF component (vertical, anteroposterior, and medial lateral) on classification. The best discrimination rate (91%) was achieved with the wavelet decomposition using the anteroposterior and the medial lateral components. These results demonstrate the validity of the representation and the classifier for automatic classification of AS and OA knee gait patterns. They also highlight the relevance of the anteroposterior and medial lateral force components in gait pattern classification.

Context:Decreased flexibility in muscles and joints of lower extremities is commonly observed in runners. Understanding the effect of decreased flexibility on knee walking kinematics in runners is important because, over time, altered gait patterns can make runners vulnerable to overuse injuries or degenerative pathologies.Objectives:To compare hamstring and iliotibial-band (ITB) flexibility and knee kinematics in runners and nonrunners.Design:A descriptive, comparative laboratory study.Setting:Hamstring and ITB flexibility were measured with the active knee-extension test and the modified Ober test, respectively, in both groups of participants. Three-dimensional (3D) walking kinematic data were then recorded at the knee using a motiontracking system.Participants:18 runners and 16 nonrunners.Main Outcome Measures:Knee-extension angle (hamstring flexibility) and hip-adduction angle (ITB flexibility). Knee kinematic parameters of interest included knee angle at initial contact, peak knee angles, and knee-angle range in all planes of movement.Results:The runners had a significantly less flexible ITB than the nonrunners (hip adduction [−] and adduction [+] angles, 3.1° ± 5.6° vs −6.4° ± 4.5°; P < .001). The runners demonstrated a greater mean tibial external-rotation angle at initial contact (7.3° ± 5.8° vs 2.0° ± 4.0°; P = .01) and a smaller mean peak tibial internal-rotation angle (−1.6° ± 3.0° vs −4.2° ± 3.2°; P = .04) than the nonrunners.Conclusion:This study provides new insight into the relationship between muscle flexibility and 3D knee kinematics in runners. This supports the premise that there is an association between muscle flexibility and transverse-plane knee kinematics in this population.

Background Patients with knee osteoarthritis present an altered gait pattern. Amongst many factors, the lower limb alignment (varus, valgus) has been identified as an important risk factor for the progression of knee osteoarthritis. Among the large number of studies on knee osteoarthritis gait, only a few have included patients with a valgus deformity. The aims of this study were to determine how knee alignment influences full-body gait in patients with knee osteoarthritis and if knee malalignment is associated with pain and functional capacity. Methods Sixty patients with severe knee osteoarthritis scheduled for a total knee arthroplasty were included in this study. Twenty-six subjects were recruited as the control group. The spatio-temporal parameters, three-dimensional full-body kinematics, and lower body kinetics were evaluated during a comfortable gait and compared between the groups. Pain and function were assessed with the WOMAC questionnaire. Findings The full-body gait analysis demonstrated substantially different gait patterns and compensation mechanisms between the three groups. Patients with varus knee alignment significantly augmented their trunk movements in sagittal and frontal planes compared to patients with a valgus knee. In addition, patients with a valgus knee reported lower pain and lower functional deficits compared to patients with a varus knee. Interpretation We found that gait compensations were significantly influenced by lower limb alignment. These new insights related to different knee osteoarthritis gait patterns might help in the understanding of gait compensation behaviours prior to total knee arthroplasty and better manage the strategies of rehabilitation following surgery.