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Background: Currently, training of the gait function for patients with cerebral stroke using the biofeedback technology is an independent, effective, and promising method. The most common training and exposure parameters are the gait speed, cycle length, and cadence. However, the application of basic and more complex types of selective training using wearable sensor technology is rare due to the technological complexity of their use for biofeedback. Aims: To study the possibility of using the biofeedback training technology with a targeted effect on one of the basic parameters characterizing the symmetry of walking, the duration of the support period, in patients in the early recovery period of cerebral stroke. Methods: We examined 12 patients who underwent a course of biofeedback training to harmonize the period of support during the early recovery period of hemispheric cerebral stroke in the middle cerebral artery basin. The biomechanics of voluntary walking was investigated before and after the training. The spatio-temporal parameters of walking, kinematics of movements in the hip, knee, and ankle joints, and the maximum EMG amplitudes of the main muscle groups responsible for walking were recorded. The classical clinical scales were also used. The biofeedback training on a treadmill consisted of 10 sessions; the duration of the support period was the training parameter. Results. As a result of the treatment, a significant improvement was noted according to the UpGo clinical scale and Hausers walking index. The differences in the trained support phase after the treatment are not significant and demonstrate positive changes. The kinematics of movements in the joints also demonstrates relatively small, but significant changes for the knee joint. For the hip joint, no dynamics in the parameters values is observed; the joint function does not change significantly, and the amplitude asymmetry remains unchanged. For the knee joint, the greatest dynamics is observed for the main swing amplitude and its phase. Conclusion: The study has shown that the purposeful biofeedback training of the gait function using the support period to reduce the functional asymmetry in this parameter, and also has a positive effect on other gait parameters.

Context Quadriceps weakness is associated with disability and aberrant gait biomechanics after anterior cruciate ligament reconstruction (ACLR). Strength-sufficiency cutoff scores, which normalize quadriceps strength to the mass of an individual, can predict who will report better function after ACLR. However, whether gait biomechanics differ between individuals who meet a strength-sufficiency cutoff (strong) and those who do not (weak) remains unknown. Objective To determine whether vertical ground reaction force, knee-flexion angle, and internal knee-extension moment differ throughout the stance phase of walking between individuals with strong and those with weak quadriceps after ACLR. Design Case-control study. Setting Laboratory. Patients or Other Participants Individuals who underwent unilateral ACLR >12 months before testing were dichotomized into strong (n = 31) and weak (n = 116) groups. Main Outcome Measures Maximal isometric quadriceps strength was measured at 90° of knee flexion using an isokinetic dynamometer and normalized to body mass. Individuals who demonstrated maximal isometric quadriceps strength ≥3.0 N·m·kg−1 were considered strong. Three-dimensional gait biomechanics were collected at a self-selected walking speed. Biomechanical data were time normalized to 100% of stance phase. Vertical ground reaction force was normalized to body weight (BW), and knee-extension moment was normalized to BW × height. Pairwise comparison functions were calculated for each outcome to identify between-groups differences for each percentile of stance. Results Vertical ground reaction force was greater in the weak group for the first 22% of stance (peak mean difference [MD] = 6.2% BW) and less in the weak group between 36% and 43% of stance (MD = 1.4% BW). Knee-flexion angle was greater (ie, more flexion) in the strong group between 6% and 52% of stance (MD = 2.3°) and smaller (ie, less flexion) between 68% and 79% of stance (MD = 1.0°). Knee-extension moment was greater in the strong group between 7% and 62% of stance (MD = 0.007 BW × height). Conclusions Individuals with ACLR who generated knee-extension torque ≥3.0 N·m·kg−1 exhibited different biomechanical gait profiles than those who could not. More strength may allow for better energy attenuation after ACLR.

Purpose History of an anterior cruciate ligament reconstruction (ACLR) and high body mass index (BMI) are strong independent risk factors for knee osteoarthritis (KOA) onset. The combination of these risk factors may further negatively affect joint loading and KOA risk. We sought to determine the combined influence of BMI and ACLR on walking speed and gait biomechanics that are hypothesized to influence KOA onset. Methods Walking speed and gait biomechanics (peak vertical ground reaction force [vGRF], peak vGRF instantaneous loading rate [vGRF-LR], peak knee flexion angle, knee flexion excursion [KFE], peak internal knee extension moment [KEM], and peak internal knee abduction moment [KAM]) were collected in 196 individuals with unilateral ACLR and 106 uninjured controls. KFE was measured throughout stance phase, whereas all other gait biomechanics were analyzed during the first 50% of stance phase. A 2 × 2 ANOVA was performed to evaluate the interaction between BMI and ACLR and main effects for both BMI and ACLR on walking speed and gait biomechanics between four cohorts (high BMI ACLR, normal BMI ACLR, high BMI controls, and normal BMI controls). Results History of an ACLR and high BMI influenced slower walking speed (F1,298 = 7.34, P = 0.007), and history of an ACLR and normal BMI influenced greater peak vGRF-LR (F1,298 = 6.56, P = 0.011). When evaluating main effects, individuals with an ACLR demonstrated lesser KFE (F1,298 = 7.85, P = 0.005) and lesser peak KEM (F1,298 = 6.31, P = 0.013), and individuals with high BMI demonstrated lesser peak KAM (F1,297 = 5.83, P = 0.016). Conclusion BMI and history of ACLR together influence walking speed and peak vGRF-LR. History of an ACLR influences KFE and peak KEM, whereas BMI influences peak KAM. BMI may need to be considered when designing interventions aimed at restoring gait biomechanics post-ACLR.

Anterior cruciate ligament reconstruction (ACLR) incurs a high risk of posttraumatic knee osteoarthritis (PTOA). Aberrant gait biomechanics contribute to PTOA and are attributable in part to quadriceps dysfunction. Vibration improves quadriceps function following ACLR, but its effects on gait biomechanics are unknown. The purpose of this study was to evaluate the effects of whole-body vibration (WBV) and local muscle vibration (LMV) on gait biomechanics in individuals with ACLR. Seventy-five volunteers (time since ACLR 27 ± 16 months) were randomized to WBV, LMV, or Control interventions. Walking biomechanics were assessed prior to and following a single exposure to the interventions. Outcomes included pre-post change scores in the ACLR limb for the peak vertical ground reaction force (vGRF) and its loading rate, peak internal knee extension (KEM) and abduction moments, and peak knee flexion and varus angles. LMV produced a significant decrease in the vGRF loading rate (-3.6 BW/s) that was greater than the changes in the WBV (-0.3 BW/s) and Control (0.5 BW/s) groups. Additionally, WBV produced an increase in the peak KEM (0.27% BW × Ht) that was greater than the change in the Control group (-0.17% BW × Ht) but not the LMV group (0.01% BW × Ht). Lower KEM and greater loading rates have been linked to declines in joint health following ACLR. WBV acutely increased the peak KEM and LMV decreased loading rates. These data suggest that vibration has the potential to mitigate aberrant gait biomechanics, and may represent an effective approach for reducing PTOA risk following ACLR.

Introduction/Clinical Scenario: Ankle sprains are highly common within the population and can lead to chronic ankle instability (CAI). Individuals with CAI have both functional and mechanical impairments, which are thought to contribute to maladaptive gait biomechanics. Neuromuscular control and balance training are frequently incorporated into rehabilitation programs, however the effect of balance training on gait biomechanics remains unknown. Focused Clinical Question: Does balance or neuromuscular training improve gait biomechanics in individuals with CAI? Summary of Key Findings: Three studies assessed 4–6 weeks of progressive neuromuscular control training and found no improvements in gait biomechanics. One study found a worsening of eversion position at midstance upon program completion. However, when training was augmented with destabilizing shoes, improvements in dorsiflexion were noted. Clinical Bottom Line: Cumulative findings suggest that neuromuscular control training does not improve gait biomechanics in those with CAI. However, augmentation of programs may be beneficial. Strength of Recommendation: There is high-quality evidence(Grade B) that balance training does not alter gait biomechanics in patients with CAI.

NEW FINDINGS What is the central question of this study? The aim was to compare the cost of transport and mechanical work between obese and non-obese children at different walking speeds. What is the main finding and its importance? Our data show that the cost of transport, mechanical efficiency and work are similar and directly mass dependent in obese and non-obese children. The optimal walking speed (most economical walking speed) is reduced in obese children. ABSTRACT Although studies have shown the influence of gait biomechanics on the metabolic economy in obese adults and adolescents, little is known regarding obese children. We compared the metabolic cost of transport, apparent mechanical efficiency and gait biomechanics (assessed by mechanical energy fluctuations) in obese children (n = 12; mean ± SD: 8.6 ± 0.51 years of age, 1.38 ± 0.04 m, 44.6 ± 6.65 kg, 24.1 ± 3.50 kg m-2 ) and age- and sex-matched non-obese children (n = 12, 7.8 ± 0.90 years of age, 1.31 ± 0.08 m, 26.8 ± 2.24 kg, 16.4 ± 1.40 kg m-2 ) while walking at different speeds (from 1 to 5 km h-1 ) on a treadmill. We found that the mechanical efficiency was higher at 3 km h-1 compared with the remaining speeds for both groups (P

(1) Background: Semi-active prosthetic feet can provide adaptation in different circumstances, enabling greater function with less weight and complexity than fully powered prostheses. However, determining how to control semi-active devices is still a challenge. The dynamic mean ankle moment arm (DMAMA) provides a suitable biomechanical metric, as its simplicity matches that of a semi-active device. However, it is unknown how stiffness and locomotion modes affect DMAMA, which is necessary to create closed-loop controllers for semi-active devices. In this work, we develop a method to use only a prosthesis-embedded load sensor to measure DMAMA and classify locomotion modes, with the goal of achieving mode-dependent, closed-loop control of DMAMA using a variable-stiffness prosthesis. We study how stiffness and ground incline affect the DMAMA, and we establish the feasibility of classifying locomotion modes based exclusively on the load sensor. (2) Methods: Human subjects walked on level ground, ramps, and stairs while wearing a variable-stiffness prosthesis in low-, medium-, and high-stiffness settings. We computed DMAMA from sagittal load sensor data and prosthesis geometric measurements. We used linear mixed-effects models to determine subject-independent and subject-dependent sensitivity of DMAMA to incline and stiffness. We also used a machine learning model to classify locomotion modes using only the load sensor. (3) Results: We found a positive linear sensitivity of DMAMA to stiffness on ramps and level ground. Additionally, we found a positive linear sensitivity of DMAMA to ground slope in the low- and medium-stiffness conditions and a negative interaction effect between slope and stiffness. Considerable variability suggests that applications of DMAMA as a control input should look at the running average over several strides. To examine the efficacy of real-time DMAMA-based control systems, we used a machine learning model to classify locomotion modes using only the load sensor. The classifier achieved over 95% accuracy. (4) Conclusions: Based on these findings, DMAMA has potential for use as a closed-loop control input to adapt semi-active prostheses to different locomotion modes.

Because dementia is difficult to treat, the best way is to detect the prodromal stage, this can identify those at high risk of dementia and help to delay its onset. It is a well-known fact that gait has a high correlation with cognitive function. Considering that dementia starts with cognitive decline, investigating the association between cognitive decline and gait may contribute to the detection of elderly individuals at high risk of dementia and even the prevention of dementia. The purpose of the present study was to investigate the gait cycle and biomechanics of elderly people with and without cognitive decline. A three-dimensional motion analysis system was used, and older adults over 65 participated in this study. K-MoCA was used to assess cognitive function and, according to the results of a cognition function assessment, they were classified into two groups. Spatiotemporal variables, subdivisions of the gait cycle, joint angle, joint moment, joint power, and support moment were investigated. Significant differences between both groups appeared in the subdivisions of the gait cycle, and parameters of gait biomechanics were established. These results provide insight into the mechanism dictating the gait of elderly individuals with cognitive decline.

OBJECTIVE: The aim of this study was to investigate the differences in temporal and spatial parameters in patients with and without knee osteoarthritis (OA) during different phases of gait cycle. MATERIALS AND METHODS: In this study, two groups were taken, OA group and healthy group. OA group consisted of 25 females suffering from knee OA (mean age 60.04 ± 5.74 years; mean height 150.44 ± 5.88 cm; mean weight 63.76 ± 7.28 kg), and healthy group consisted of 25 females (mean age 50.56 ± 7.03 years; mean height 155.16 ± 4.08 cm; mean weight 61.77 ± 12.03 kg). Both OA and healthy groups were assessed for temporal and spatial gait parameters by Zebris FDM Treadmill analysis system. RESULTS: Mann–Whitney U-test was used to compare the results of the study groups. Significant differences were found in the following variables – left stance phase (%), right stance phase (%), right load response (%), right mid stance (%), right preswing (%), left swing phase (%), right swing phase(%), double stance (%), right and left foot rotation (degrees), and cadence (steps/min). CONCLUSION: The spatial and temporal differences between patients with knee OA and healthy elderly females suggest that patients with knee OA adopt different strategies to reduce impact on knees. Gait dysfunction can be evaluated by assessing the various gait parameters, and treatment progression can be done in patients with knee OA. The assessment of gait by Zebris FDM Treadmill analysis system is a simple way which is done objectively.

Background The utilized coefficient of friction (uCOF) and the risk of slipping are known to increase as the heel height of shoes increases. The heel base area of shoes can also affect the uCOF. Objective The purpose of this study is to investigate the effect of the heel base area of high heels and walking speed on the uCOF during walking and their interaction effect. Methods The walking experiment was conducted at the speed of 1.0 m/s and 1.25 m/s using four 9-cm high heels having different heel areas (narrow, moderate, wide, and wedge heels). Results The peak uCOF was significantly lower when wearing the wide heels than when wearing the other heels. Wearing the narrow and moderate heels reduced the vertical ground reaction force (GRF) owing to the early timing of the peak anterior-posterior GRF and increased the peak uCOF. As the walking speed became faster, the peak uCOF became greater with more increases by the interaction effect when wearing the narrow and moderate heels than when wearing the wide and wedge heels. Conclusions These results imply that wearing narrow high heels should be considered carefully, as the potential for a slip could be high owing to the increase in the peak uCOF. If it is inevitable to wear narrow high heels, it is critical to walk at a slower speed than usual. It is better to wear high heels with a wide heel area, e.g., 3 cm*3 cm, rather than narrow high heels or even wedge heels to reduce the possibility of slipping.

The present study aimed to identify movement patterns most related to running performance among highly trained middle-distance runners. Eleven male runners performed overground running trials on an indoor running track, and three-dimensional analyses techniques were used to measure running kinematics and kinetics. Performance was measured as season and personal best time over 1500 m. The average velocity during the running trials was 7.2 ± 0.3 m/s. The average season and personal best 1500 m race times were 3:49.7 ± 0:05.8 and 3:46.0 ± 0:08.3 minutes, respectively. Regression analysis revealed that a smaller range of sagittal-plane hip motion during swing, less thorax flexion at toe-off and a smaller ankle plantarflexion angle at contact accounted for 95.7% (p < 0.001) of the variation in season best running performance. Less sagittal-plane hip motion during swing and a smaller ankle plantarflexion angle at contact also explained 79% of the variance in personal best time. Slower middle-distance runners make initial ground contact with a more plantarflexed ankle and greater forward lean of the trunk. We recommend that coaches and runners pay attention to ankle, shank and thorax angles during technical development and training to identify opportunities to optimise middle-distance running mechanics and performance.

Reduced daily stepping in stroke survivors may contribute to decreased functional capacity and increased mortality. We investigated the relationships between clinical and biomechanical walking measures that may contribute to changes in daily stepping activity following physical interventions provided to participants with subacute stroke. Following ≤40 rehabilitation sessions, 39 participants were categorized into three groups: responders/retainers increased daily stepping >500 steps/day post-training (POST) without decreases in stepping at 2–6 month follow-up (F/U); responders/non-retainers increased stepping at POST but declined >500 steps/day at F/U; and, non-responders did not change daily stepping from baseline testing (BSL). Gait kinematics and kinetics were evaluated during graded treadmill assessments at BSL and POST. Clinical measures of gait speed, timed walking distance, balance and balance confidence were measured at BSL, POST and F/U. Between-group comparisons and regression analyses were conducted to predict stepping activity from BSL and POST measurements. Baseline and changes in clinical measures of walking demonstrated selective associations with stepping, although kinematic measures appeared to better discriminate responders. Specific measures suggest greater paretic vs non-paretic kinematic changes in responders with training, although greater non-paretic changes predicted greater gains (i.e., smaller declines) in stepping in retainers at F/U. No kinetic variables were primary predictors of changes in stepping activity at POST or F/U. The combined findings indicate specific biomechanical assessments may help differentiate changes in daily stepping activity post-stroke.

Acknowledgments: This research work was supported by the Portuguese Foundation for Science and Technology (FCT) and Centro2020 through Project References UID/Multi/04044/2013; PAMI – ROTEIRO/0328/2013 (Nº 022158) and BioMaTE project - A novel bio-manufacturing system to produce bioactive scaffolds for tissue engineering reference PTDC/EMS-SIS/7032/2014. In recent years, sheep have been reported as the ideal animal model to study osteoporosis, hence it is important to identify instruments, tools and ideal parameters needed to assess the effects of different treatments. In previous studies conducted in other animal models with osteoporosis, the most common parameters used for evaluation concerned primarily bone properties, such as the dual X-ray absorptiometry. However, biomechanical gait analysis as an integrative functional parameter and a non-invasive method, will be an important tool in research and clinical applications. This research review was performed using the PubMed database and included studies related to sheep with outcome measures concerning functional performance assessed during gait in vivo; and excluded studies related with cardiovascular disease and sperm properties, which include other animal species, with outcomes not related with functional locomotor evaluation. Only studies related with bone properties were analyzed. The most frequent and relevant included parameters were the following: mean peak vertical ground force reaction, gait cycle and stance/swing phase duration, percentage of stance/swing phase in a gait cycle, stride length and the stifle joint angles during a gait cycle. Gait biomechanical parameters have been established for the assessment of some clinical orthopedic condition using sheep models but not currently for osteoporosis. info:eu-repo/semantics/publishedVersion

Background Mechanical axis malalignment contributes to abnormal forces across the knee joint. Genu varum, or increased medial mechanical axis deviation (MAD), increases force transmission and contact pressures to the medial compartment. With increasing MAD and femoral-tibial mechanical axis angle (MAA), contact forces within the medial or lateral compartment of the knee significantly increase with increasing deformity. This may lead to knee pain, further deformity, and medial compartment degenerative joint disease, which can interfere with participation in sports and diminish quality of life. Purposes/Questions We sought to evaluate patients with knee pain with bilateral genu varum and determine the effect of bilateral proximal tibial osteotomies on knee biomechanics, deformity correction, and functional outcomes. Methods This was a single-center, prospective study of eight limbs in four patients. Consecutive patients presenting with knee pain and bilateral genu varum originating from the proximal tibia were included. All patients underwent staged bilateral proximal tibial osteotomies with gradual deformity correction with an external fixator. Subjects underwent a three-dimensional (3D) instrumented motion analysis during level walking. A 3D lower extremity model was built and bilateral knee frontal plane kinematics and kinetics during the stance phase of gait were determined. Radiographic analysis was performed including assessment of MAD, MAA, and medial proximal tibial angle (MPTA). Functional outcomes were assessed with the Knee Injury and Osteoarthritis Outcome Score (KOOS), the 36-item Short-Form Survey (SF-36), the Lower Limb Questionnaire (LLQ), and a visual analog scale (VAS) for pain. Results The average time in the external fixator for a single limb was 97 days. The average follow-up period was 310 days. All biomechanical outcomes significantly improved, including knee adduction angle (7.8° to 1.8°), knee adduction moments (first peak, − 0.450 to − 0.281 nm/kg, and second peak, − 0.381 to − 0.244 nm/kg), and knee adduction moment impulse (− 0.233 to − 0.150 nm s/kg). There was a significant improvement in MAA, MAD, and MPTA. All patients showed qualitative improvement in mean scores on VAS (11.8 to 0.0), LLQ (77 to 93), KOOS (64 to 84), and SF-36 (71 to 88). Conclusion These findings suggest that bilateral proximal tibial osteotomy may be effective in improving knee biomechanics during gait and correcting mechanical alignment in patients with bilateral genu varum. Patients also demonstrated improvement in functional outcome scores. This technique should thus be considered in patients with varus knee osteoarthritis in the setting of genu varum to alleviate symptoms and potentially decrease further clinical deterioration.

The goal of this research was to investigate functional and biomechanical symptoms in patients with chondromalacia patella. Material and Methods — Gait biomechanics was assessed in 35 patients with diagnosed unilateral chondromalacia patella and in 20 healthy adult controls. We recorded hip and knee movements, impact loads and temporal characteristics of the gait cycle (GC) during self-paced walking. Results — The temporal characteristics of gait and the impact loads remained normal in the patient population. Hip flexion amplitude decreased both on the affected (p=0.002) vs. unaffected (p=0.016) sides, compared to healthy control, whereas the amplitude phase increased on the affected (p=0.012) vs. unaffected (p=0.001) sides, versus healthy control. Hip extension and adduction-abduction amplitudes did not change significantly. Stance-phase and swing-phase knee flexion amplitudes did not change significantly. Knee extension amplitude on the affected limb increased (p=0.015), and knee rotation on the unaffected limb decreased versus control (p=0.016). The so-called stairstep symptom defined in the study was found in 83% of patients: in 23 patients bilaterally and in 6 patients unilaterally. Conclusion — Chondromalacia patella affected the gait biomechanics on both sides. The changes in the kinematic patterns during the flat-surface walking were not substantial. The only pathognomonic functional symptom of the condition was the stairstep symptom.

Summary Objective To compare gait biomechanics 6 months following anterior cruciate ligament (ACL) reconstruction (ACLR) between patients with the highest and lowest concentrations of synovial fluid (SF) interleukin-6 (IL-6) and matrix metalloproteinase-3 (MMP-3), as well as compared to uninjured controls. Design SF concentrations of IL-6 and MMP-3 were collected 7 ± 4 days post injury in 38 ACL injured patients (55% female, 21±4yrs, 25.3 ± 5.2BMI). ACL injured individuals were stratified into the lowest and highest quartiles based on IL-6 (IL-6Lowest and IL-6Highest) and MMP-3 (MMP-3Lowest and MMP-3Highest) concentrations. Gait biomechanics were collected on the injured limb 6 months post-ACLR and in 38 uninjured controls (50% female, 21±3yrs, 23.8 ± 2.8BMI). Functional analyses of variance were used to compare vertical ground reaction force (vGRF), knee flexion angle (KFA), and internal knee extension moment (KEM) waveforms throughout stance phase of gait to determine the proportions of stance differing between limbs and groups. Results Compared to uninjured controls, IL-6High and MMP-3High ACL subgroups demonstrated lesser vGRF (largest differences: IL-6, 7.88%BW; MMP-3, 11.05%BW) during early-stance and greater vGRF (largest differences: IL-6, 6.21%BW; MMP-3, 5.85%BW) in mid-stance, lesser KFA (largest differences: IL-6, 3.11°; MMP-3, 3.72°) and lesser KEM (largest differences: IL-6, 0.96%BW•m; MMP-3, 1.07%BW•m) in early-stance, as well as greater KFA in mid-stance (largest differences: IL-6, 1.5°; MMP-3, 2.95°). Conclusions High SF concentrations of a proinflammatory cytokine and a degradative enzyme early post-ACL injury are associated with aberrant gait biomechanics in the injured limb at 6 months post-ACLR (i.e., lesser vGRF, KFA and KEM) linked to posttraumatic osteoarthritis development.

The objective of this study is to present conventional manufacturing process of chopart socket prosthesis using polypropylene and carbon fiber composite, and test their feasibility using finite element analysis (FEA). The accepted understanding suggest that prosthesis stiffness influence the gait biomechanics in amputees. Finite element analysis is becoming more feasible in biomechanical applications because it can provide better insights under complex boundary and load conditions. In the present study, FEA analysis was conducted to test the feasibility of chopart socket prosthesis with two different materials, viz. polypropylene and carbon fiber with three laminations. Results showed that carbon fibers give a higher strength-to-weight ratio and provide greater stiffness in the distal region. A distinct advantage of using these materials in the fabrication of prostheses is the availability of additive manufacturing processes which could be used to significantly reduce the time to manufacture the prosthesis with fit dimensions.

Walking is the most basic form of human activity for achieving mobility. As an essential function of the human body, the examination of walking is directed towards the assessment of body mechanics in posture and during movement. This work proposes a wearable smart system for the monitoring and objective evaluation of foot biomechanics during gait. The proposed solution assumes the cross-correlation of the plantar pressure with lower-limb muscular activity, throughout the stance phase of walking. Plantar pressure is acquired with an array of resistive pressure sensors deployed onto a shoe insole along the center of gravity progression line. Lower-limb muscular activity is determined from the electromyogram of the tibialis anterior and gastrocnemius lower limb muscles respectively. Under this scenario, physiological gait assumes the interdependency of plantar pressure on the heel area with activation of the tibialis anterior, as well as plantar pressure on the metatarsal arch/toe area with activation of the gastrocnemius. As such, assessment of gait physiology is performed by comparison of a gait map, formulated based on the footprint&ndash, lower-limb muscle cross-correlation results, to a reference gait template. A laboratory proof of concept validates the proposed solution in a test scenario which assumes a normal walking and two pathological walking patterns.

Traumatic injuries to the musculoskeletal system are the most prevalent of those suffered by United StatesMilitary Service members and accounts for two-thirds of initial hospital costs to the Department of Defense. These combat-related wounds often leave survivors with life-long disability and represent a significant impediment to the readiness of the fighting force.There are immense opportunities for the field of tissue engineering and regenerative medicine (TE/RM) to address these musculoskeletal injuries through regeneration of damaged tissuesas a means to restore limb functionalityand improve quality of life for affected individuals.Indeed, investigators have made promising advancements in the treatment for these injuries by utilizing small and large preclinical animalmodels to validate therapeutic efficacy of next generation TE/RM based technologies. Importantly, utilization of a comprehensive suite of functional outcome measures, particularly those designed to mimic data collected within the clinical setting, is critical for successful translation and implementation of these therapeutics.To that end, the objective of this review is to emphasizethe clinical relevance and applicationof gait biomechanics as a functional outcome measure for preclinical research studies evaluating the efficacy of TE/RM therapies to treat traumatic musculoskeletal injuries. Specifically, common musculoskeletal injuries sustained by Service members - including volumetric muscle loss, post-traumatic osteoarthritis, and composite tissue injuries - are examined as case examples to highlight the use of gait biomechanics as an outcome measure usingsmall and large preclinical animal models. This article is protected by copyright. All rights reserved.

Quadriceps dysfunction is a common, chronic complication following anterior cruciate ligament reconstruction (ACLR) that contributes to aberrant gait biomechanics and poor joint health. Vibration enhances quadriceps function in individuals with ACLR, but the duration of these effects is unknown. This study evaluated the time course of the effects of whole body vibration (WBV) and local muscle vibration (LMV) on quadriceps function. Twenty-four volunteers with ACLR completed 3 testing sessions during which quadriceps isometric peak torque, rate of torque development, and EMG amplitude were assessed prior to and immediately, 10, 20, 30, 45, and 60 min following a WBV, LMV, or control intervention. WBV and LMV (30 Hz, 2g) were applied during six one-minute bouts. WBV increased peak torque 5–11% relative to baseline and control at all post-intervention time points. LMV increased peak torque 6% relative to baseline at 10 min post-intervention and 4–6% relative to control immediately, 10 min, and 20 min post-intervention. The interventions did not influence EMG amplitudes or rate of torque development. The sustained improvements in quadriceps following vibration, especially WBV, suggest that it could be applied at the beginning of rehabilitation sessions to “prime” the central nervous system, potentially improving the efficacy of ACLR rehabilitative exercise.

In persons with calf muscle weakness, walking energy cost is commonly increased due to persistent knee flexion and a diminished push-off. Provided ankle-foot orthoses (AFOs) usually lower walking energy cost. To maximize the reduction in energy cost, AFO bending stiffness should be individually optimized, but this is not common practice. Therefore, we aimed to evaluate whether individually stiffness-optimized AFOs reduce walking energy cost compared to conventional AFOs in persons with non-spastic calf muscle weakness and, secondarily, whether stiffness-optimized AFOs improve walking speed and gait biomechanics. Thirty-seven persons with non-spastic calf muscle weakness using a conventional AFO were included. Participants were provided a new, individually stiffness-optimized AFO. Walking energy cost, speed and gait biomechanics were assessed, at delivery and 3-months follow-up. Stiffness-optimized AFOs reduced walking energy cost with 9.2% (-0.42J/kg/m, 95%CI: 0.26 to 0.57) compared to the conventional AFOs while walking speed increased with 5.2% (+0.05m/s, 95%CI: 0.03 to 0.08). In bilateral affected persons the effects were larger compared to unilateral affected persons (difference effect energy cost: 0.31J/kg/m, speed: +0.09m/s). Although individually gait biomechanics changed considerably, no significant group differences were found (p > 0.118). We demonstrated that individually stiffness-optimized AFOs considerably and meaningfully reduced walking energy cost compared to conventional AFOs, which was accompanied by an increase in walking speed. Especially in bilateral affected persons large effects of stiffness-optimization were found. The individual differences in gait changes substantiate the recommendation that the AFO bending stiffness should be individually tuned to minimize walking energy cost.

Background Autism spectrum disorder, a neurodevelopmental disorder, is difficult to characterize from a gait biomechanics perspective, possibly due to increased inter and intra-individual variability. Previous research illustrates increased gait variability in young children with autism, but assessments in older adolescents or at varying speeds are unavailable. The purpose of this study was to determine if adolescents with autism demonstrate increased intra-limb and inter-limb coordination variability during walking compared to age, sex, and body mass index matched controls. Methods Seventeen adolescents with autism (age 13–18 years) and seventeen matched controls performed walking at two matched speeds: self-selected of adolescents with autism and at 1.3 m/s. Modified vector coding was used to determine the patterns of movement for foot-shank, left/right thigh, and contralateral thigh-arm coupling. Coordination variability, a measure of cycle-to-cycle variability, was determined across the full stride. Mixed-model analyses of variance were used to determine if group by speed interactions and/or main effects existed for coordination variability. Findings A significant interaction existed for foot-shank variability (p = 0.039). Adolescents with autism had greater variability at self-selected speeds (p = 0.018), but not at 1.3 m/s (p = 0.593) compared to controls. Thigh-thigh coordination was greater for adolescents with ASD compared to controls at both speeds (p = 0.021). Variability was decreased at 1.3 m/s for both foot-shank (p = 0.016) and thigh-thigh (p = 0.021) coupling. Interpretation This study illustrates that adolescents with autism perform walking with increased coordination variability at both proximal and distal segments. Thus, it is likely intra-individual variability drives the disparity of movement patterns in this population.

Objective: This study is a literature review aimed at synthesizing information regarding the relationship between body posture, gait biomechanics, and the use of sensory insoles, as well as contributing to the investigations on this topic. Methodology: We have collected the research data from the databases Science Direct, MEDLINE/PubMed, Web of Science and Scielo. We used the following descriptors in the search for the articles: body posture, running, injury, plantar pressure, sensors, and sensory insoles; we have also associated these terms with one another in our search. Results: We have selected the articles that contained literature reviews, treatment, or on-site surveys, published up to 2020. This review has identified the existence of several commercially available pressure sensors, with technologies such as capacitive, resistive, piezoelectric, and piezoresistive sensors. This study has also identified several advantages in the use of the insole technology: improvements in balance and speed rates in the anteroposterior region; redistribution of plantar pressure during walking for diabetic patients; alteration of the pressure over time relationship throughout the entire plantar region. Conclusion: The progress obtained by the use of these sensors over the past few years has been motivating researchers to aim for improvements in its performance and practicality, allowing for its use in diagnosing balance disorders, which can be related to body posture and gait biomechanics. Objetivo: El objetivo de este estudio fue realizar una revisión de la literatura, buscando sintetizar informaciones sobre la relación entre postura corporal, biomecánica de carrera y el uso de plantillas sensoriales, así como contribuir a las investigaciones que se han llevado a cabo sobre este tema. Metodología: La investigación se realizó en las siguientes bases de datos: Science Direct, MEDLINE/PubMed, Web of Science y Scielo. Los descriptores utilizados para buscar los artículos fueron: postura corporal, carrera, lesiones, presión plantar, sensores y plantillas sensoriales; estos términos también se usaron en asociación entre sí. Resultados: Entre las publicaciones, se seleccionaron artículos que incluían revisiones de literatura, tratamientos o investigaciones in vivo, hasta 2020. Esta revisión identificó la existencia de varios sensores de presión disponibles en el mercado, con tecnologías de sensores piezoeléctricos capacitivos, resistivos. y piezoresistivos. Este trabajo también identificó varios beneficios de usar la tecnología de la plantilla: mejoras en el equilibrio y la velocidad de oscilación, en la dirección anteroposterior; redistribución de la presión plantar durante la marcha en pacientes diabéticos; y cambio en la relación de presión en función del tiempo, a través del área plantar. Conclusión: El progreso realizado por el uso de estos sensores en los últimos años ha motivado a los investigadores a buscar mejoras en el rendimiento y la practicidad de esta tecnología, que puede utilizarse para el diagnóstico de trastornos del equilibrio, un factor relacionado con la postura corporal y la biomecánica del funcionamiento. Objetivo: O objetivo deste estudo foi realizar uma revisão de literatura, buscando sintetizar informações sobre a relação entre postura corporal, biomecânica de corrida e o uso de palmilhas sensoriais, bem como contribuir com as investigações que vêm sendo realizadas acerca desta temática. Metodologia: A pesquisa foi realizada nos bancos de dados: Science Direct, MEDLINE/PubMed, Web of Science e Scielo. Os descritores utilizados para a busca dos artigos foram: postura corporal, corrida, lesão, pressão plantar, sensores e palmilhas sensoriais; esses termos também foram usados em associação entre si. Resultados: Dentre as publicações, foram selecionados artigos que incluíssem revisões de literatura, tratamentos ou pesquisas in vivo, até o ano de 2020. Esta revisão identificou a existência de diversos sensores de pressão disponíveis no mercado, com tecnologias de sensores capacitivos, resistivos, piezoelétricos e piezoresistivos. Este trabalho também identificou diversas vantagens do uso da tecnologia da palmilha: melhorias no equilíbrio e na velocidade de oscilação, na direção ântero-posterior; redistribuição da pressão plantar durante a caminhada em pacientes diabéticos; e mudança na relação pressão em função do tempo, em toda a área plantar. Conclusão: O progresso feito pelo uso desses sensores, durante os últimos anos, tem motivado pesquisadores a buscar melhorias no desempenho e na praticidade desta tecnologia, podendo ser utilizados para o diagnóstico dos distúrbios do equilíbrio, fator relacionado à postura corporal e à biomecânica de corrida.

Summary Objective Although mechanically-induced inflammation is an appealing explanation linking different etiologic factors in osteoarthritis (OA), clinical research investigating changes in both biomechanics and joint inflammation is limited. The purpose of this study was to evaluate the association between change in surrogate measures of knee load and knee effusion-synovitis in patients with medial compartment knee OA undergoing high tibial osteotomy (HTO). Methods Thirty-six patients with medial compartment knee OA and varus alignment underwent 3D gait analysis and 3T magnetic resonance imaging (MRI) preoperatively and 1 year after medial opening wedge HTO. Primary outcome measures were the change in the external knee adduction moment impulse during walking and change in knee suprapatellar effusion-synovitis volume manually segmented on MRI by one blinded assessor. Results Mean (SD) knee adduction moment impulse [24.0 (6.5) Nm•s] and knee effusion-synovitis volume [8976.7 (8016.9) mm3] suggested substantial preoperative medial knee load and inflammation. 1-year postoperative changes in knee adduction moment impulse [−10.1 Nm•s (95%CI: −12.7, −7.4)], and knee effusion-synovitis volume [−1856 mm3 (95%CI: −3830, 117)] were positively correlated [r = 0.60 (95% CI 0.34, 0.78)]. Simple linear regression suggested a 448 mm3 (95%CI: 241, 656) reduction in knee effusion-synovitis volume per 1 Nm•s reduction in knee adduction moment impulse. Change in knee adduction moment impulse explained 36% (R2 = 0.36) of the variance of change in knee effusion-synovitis volume. Conclusions Reduction in medial knee load is positively associated with reduction in knee inflammation after HTO, suggesting the phenomenon of mechano-inflammation in patients with knee OA.

Multi-centre gait biomechanics studies provide the opportunity to increase sample size and the confidence in results, yet differences between centres may introduce additional error. While previous investigations have compared gait biomechanics from different laboratories assessed by different raters, estimates of relative reliability, measurement error, and thresholds for real change are still unknown. These metrics are imperative to interpret multi-centre study results. Therefore, we examined the reliability of gait biomechanics assessed in two different laboratories, by two different raters, and using the same study sample. Twelve healthy participants underwent gait assessments by two raters in two laboratories at different institutions. Identical protocols were used to collect five walking trials per participant. Discrete data were examined for knee joint angles and moments, gait speed, and stride length. Reliability was assessed using the intraclass correlation coefficient (ICC), standardized error of the measurement (SEM), minimum detectable difference (MDD), and Bland and Altman plots. All spatiotemporal, joint angle, and joint moment measures had ICCs = 0.83-0.94, except for the knee adduction moment peak in late stance (ICC = 0.69 and 0.72). The knee adduction moment SEMs indicate that measurement errors due to the laboratory effect are between 0.19% and 0.31% body weight times height (0.03-0.05 Nm/kg). Meanwhile, measurement error for the knee flexion-extension angle is2°. Our results are similar to previous test-retest reliability results from a single laboratory, and multiple laboratories, while adding previously unreported reliability metrics necessary for interpreting multi-centre study results.

Clinical Question: Is it beneficial to utilize feedback motion retraining in improving gait biomechanics, pain, and self-reported function on patients with patellofemoral pain (PFP)? Clinical Botto...

Introduction. Equino-plano-valgus deformity of the feet (EPvDS) in patients with cerebral palsy is one of the most common and functionally significant pathologies of the lower extremities, which leads to changes in the shape of the feet, decreased support, and disturbance of gait biomechanics. An important task is to determine the effective methods of treating this pathology (and their combinations) to correct or reduce the severity of these disorders. The evaluation of the radiological changes occurring with the foot is also important. Aim. The paper assesses the changes in the main X-ray significant indicators of the foot by using rammed implants in the treatment of mobile EPvDS in children with cerebral palsy. Materials of the study. The assesses of radiological results of treatment of 64 patients from 6 to 17 years with mobile EPvDS and cerebral palsy have been analyzed using subtalar implants. The results of study showed that 94% of cases showed good and satisfactory indicators, whereas 6% of patients showed unsatisfactory results. Conclusion. High efficiency was shown by using subtalar implants combined with tenodesis and transposition of the anterior tibial muscle tendon in the treatment of mobile EPvDS in children with cerebral palsy of early and middle childhood.

Background Gait asymmetry is frequently observed following anterior cruciate ligament reconstruction (ACLR). Psychological readiness to return to sport is associated with functional and activity-re...

To examine knee and hip biomechanics during walking and jogging in groups of ACLR patients at early, mid, and late time frames postsurgery and healthy controls.Participants included individuals with a history of primary, unilateral ACLR, stratified into early (1.4 ± 0.4 yr post, n = 18), mid (3.3 ± 0.6 yr post, n = 20), and late (8.5 ± 2.8 yr post, n = 20) ACLR groups based on time postsurgery, and a healthy control group (n = 20). Walking and jogging motion capture analysis of knee and hip kinetics and kinematics were measured in the sagittal and frontal planes. Interlimb (within groups) and between-group comparisons were performed for all gait variables. Statistical comparisons were made across the gait cycle by plotting graphs of means and 90% confidence intervals and identifying regions of the gait cycle in which the 90% confidence intervals did not overlap.Early ACLR group demonstrated reduced knee flexion, knee extension, knee adduction, and hip adduction moments on the ACLR limb. Mid ACLR group demonstrated no gait differences between limbs or other groups. Late ACLR group demonstrated reduced knee flexion moments, and greater knee and hip adduction moments in their ACLR limb. Control group demonstrated no interlimb differences.Walking and jogging gait biomechanics presented differently in patients at different stages in time after ACLR surgery. The early ACLR group demonstrated lower sagittal and frontal plane joint loading on the ACLR limb compared with contralateral and control limbs. The mid ACLR group did not demonstrate any gait differences compared with the contralateral or control limb. The late ACLR group demonstrated lower sagittal plane joint loading compared with control limbs and greater frontal plane joint loading compared to contralateral and control limbs.

Patients with peripheral artery disease (PAD) experience significant leg dysfunction. The effects of PAD on gait include shortened steps, slower walking velocity, and altered gait kinematics and kinetics, which may confound joint torques and power measurements. Spatiotemporal parameters, joint torques and powers were calculated and compared between 20 patients with PAD and 20 healthy controls using independent t-tests. Separate ANCOVA models were used to evaluate group differences after independently adjusting for gait velocity, stride length and step width. Compared to healthy controls, patients with PAD exhibited reduced peak extensor and flexor torques at the knee, and hip. After adjusting for all covariates combined, differences between groups remained for ankle power generation in late stance, and knee flexor torque. Reduced walking velocity observed in subjects affected by PAD was closely connected with reductions in joint torques and powers during gait. Gait differences remained, at the knee and ankle, after adjusting for the combined effect of spatiotemporal parameters. Improving muscle function through exercise or with the use of assistive devices needs to be a key tool in the development of interventions that aim to enhance the ability of PAD patients to restore spatiotemporal gait parameters.

Lower limb amputees (LLAs) are at increased risk of falling due to the inherent asymmetry resulting from their limb loss, muscle weakness and other neuro-musculoskeletal limitations.The aim of this study was to evaluate the effects of a personalised exercise programme on falls prevention and gait parameters in LLAs.Fifteen LLAs, recruited from their local prosthetic services centre, were block randomised, by age and level of amputation, into two groups: exercise group (transfemoral, n = 5; transtibial, n = 2) and control group (transfemoral, n = 5; transtibial, n = 3). The exercise group completed a 12-week programme, focusing on strength, balance, flexibility and walking endurance, delivered in group sessions at the University, and combined with a personalised home exercise programme. Temporal-spatial, 3D kinematic and kinetic gait parameters were collected at baseline and post-intervention. Falls incidence was also followed up at 12 months.The exercise group experienced significantly fewer falls in the one-year period from baseline, compared with the average annual falls rate, obtained at baseline (P = 0.020; d = 1.54). Gait speed in the exercise group increased by 0.21 m∙sThis is the first study to document the clinically meaningful benefits of an exercise intervention for falls prevention and gait performance in LLAs. Specialised exercise programmes for community-dwelling LLAs should be implemented as a method to reduce falls and improve walking performance in this population.

The aim of this study was to determine the influence of schoolbag carriage on pattern changes in plantar pressure during walking among schoolchildren of first grade. The sample consisted of 127 schoolchildren, 48.8% male (n = 62) and 51.2% female (n = 65), aged 6.7 (±0.5) years. The mean schoolbag weight was 4.2 kg (±0.7), which represented 16.9% (±3.9) of children’s body weight, thus exceeding the upper limit of the recommended 15% of the body weight and generally affecting their posture. The study has shown the statistically significant influence of the schoolbag on changes in plantar pressure pattern when walking in relation to walking without the schoolbag. Using a t-test for large dependent samples and by setting statistical significance at p≤.05, the significant increase was noticed in peak pressure for the forefoot (p=.000; 17.1%), midfoot (p=.000; 5.7%) and hindfoot (p=.004; 3.9%) as well as in average pressure for the midfoot (p=.005; 6.2%). Also, due to the compensatory mechanisms activated while the bag was being carried, the statistically significant increase in the contact surface at the forefoot (p=.000; 3.6%) and midfoot (p=.000, 8.8%) occurred. Changes in the distribution of pressure between different parts of the foot are a source of potential foot problems which is why the results of this study have a high applicability in the prevention of foot pathology in the future

Limb salvage surgeries are performed to treat a variety of lower limb pathologies and traumatic injuries. Individuals who have undergone limb salvage surgeries may require an ankle foot orthosis (AFO) to compensate for limb impairments and restore walking ability. Understanding the effects of AFO design parameters on gait biomechanics is important to refine AFO prescription criteria. In this study sagittal plane kinematic and kinetic data, muscle activity and alignment preference were examined as individuals treated for traumatic lower extremity injuries (N=12) walked over level ground with Plantarflexed (PF), Neutral, and Dorsiflexed (DF) aligned AFOs. A PF alignment resulted in earlier center of pressure progression (p0.007) and a resulting decrease in both internal knee extensor moment (p0.001) and quadriceps and soleus muscle activity (p0.014) compared to the Neutral and DF alignments without affecting the lower limb support moment. A clear alignment preference was observed, with eight participants preferring the PF over the Neutral and DF alignments. The increase in internal knee extensor moment between the PF and DF alignments in the present study is consistent with previous investigations in other patient populations, suggesting a more DF aligned AFO may affect the knee joint moment similarly across patient populations. The results of this study suggest AFO alignment is an important design parameter that affects ankle and knee joint moments and muscle activity and should be carefully considered during AFO design and clinical fitting.

Background Surgical advances have substantially improved outcomes for individuals sustaining traumatic lower extremity injury. Injuries once requiring lower limb amputation are now routinely managed with limb reconstruction surgery. However, comparisons of functional outcomes between the procedures are inconclusive. Purpose To compare gait biomechanics after lower limb reconstruction and transtibial amputation. Methods Twenty-four individuals with unilateral lower limb reconstruction wearing a custom ankle-foot orthosis (Intrepid Dynamic Exoskeletal Orthosis), 24 with unilateral, transtibial amputation, and 24 able-bodied control subjects underwent gait analysis at a standardized Froude speed based on leg length. Lower extremity joint angles, moments, and powers, and ground reaction forces were analyzed on the affected limb of patients and right limb of able-bodied individuals. ANOVA with Tukeys post-hoc tests determined differences among groups and post-hoc paired t -tests with Bonferroni-Holm corrections determined differences between limbs. Results The ankle, knee, and hip exhibited significant kinematic differences between amputated, reconstructed and able-bodied limbs. The reconstruction group exhibited less ankle power and range of motion while the amputee group exhibited lower knee flexor and extensor moments and power generation. Conclusion Gait deficiencies were more pronounced at the ankle following limb reconstruction with orthosis use and at the knee following transtibial amputation with prosthesis use. Although both groups in the cohorts tested can replicate many key aspects of normative gait mechanics, some deficiencies still persist. These results add to the growing body of literature comparing amputation and limb reconstruction and provide information to inform the patient on functional expectations should either procedure be considered.

Category: Ankle Arthritis, Basic Sciences/Biologics Introduction/Purpose: Adjacent joint disease often occurs after many orthopaedic surgical interventions. Specifically in the foot and ankle, subtalar arthritis has been demonstrated as a long term sequelae after ankle arthrodesis. The purpose of this study was to evaluate real time qualitative and quantitative motion differences in the hindfoot and midfoot during simulated gait, both before and after ankle fusion in a cadaveric model. Data recorded from each cadaveric trial is used in conjunction with a CT scan of each specimen, allowing creation of a three-dimensional, real time, anatomic model of motion of the foot and ankle. Methods: Three human cadaveric specimens (lower leg and foot) were obtained and prepared for testing. Taking care to preserve the ligamentous and tendinous attachments, radiopaque fiducial makers were placed in each bone (tibia, fibula, talus, calcaneus, navicular, all cuneiforms, 1st metatarsal). CT scan of each specimen was then performed, and used to develop a three dimensional anatomic model of the specimen. Each specimen was then mounted into a custom built apparatus, and load was applied to the construct using a follower load model. Each specimen was taken through two full cycles of the simulated stance phase. Kinematic data of the individual bones/joints were measured in real time, using optoelectronic targets, and saved for later comparison. Next, tibiotalar fusion was performed on each of the previously tested specimens using an anterior plate and screw construct. The specimens were again cycled in the same fashion and data was recorded in the same manner. Results: Tibiotalar fusion successfully eliminated motion between the talus and tibia, directly altering the normal kinematics of the foot ankle complex. Quantitatively, the motion at the subtalar and talonavicular joints increased only slightly with fusion. However, this represents a relative increased motion demand at each joint that exceeds what was observed in the non-fusion condition. Qualitatively, the motion curves for the talocalcaneal and talonavicular joints were altered when compared to the non-fusion state (Figure 1). The qualitative change in motion revealed a relative linkage of motion between the subtalar and talonavicular joints and this was consistently observed across all specimens. Conclusion: Simulated ankle fusion via an anterior plate and screw construct directly alters the kinematics of the downstream (talocalcaneal and talonavicular) joints. Real time observation demonstrates a relative linkage of the motion occurring in the subtalar and talonavicular joints. This linkage resulted in alteration from the observed physiologic motion that occurred in these joints during the non-fusion condition. These findings may provide insight into the etiology of adjacent segment disease seen in the subtalar and talonavicular joints after ankle fusion.

Background To reduce gait problems in individuals with non-spastic calf muscle weakness, spring-like ankle-foot orthoses (AFOs) are often applied, but they are not individually optimized to treatment outcome. The aim of this proof-of-concept study was to evaluate the effects of modifying the stiffness for two spring-like AFO types with shoes-only as reference on gait outcomes in three individuals with calf muscle weakness due to polio. Methods We assessed 3D gait biomechanics, walking speed and walking energy cost for shoes-only and five stiffness conditions of a dorsal-leaf-spring AFO and a spring-hinged AFO. Outcomes were compared between stiffness conditions in the two AFOs and three subjects. Results Maximum ankle dorsiflexion angle decreased with increasing stiffness in both AFOs (up to 6–8°) and all subjects. Maximum knee extension angle changed little between stiffness conditions, however different responses between the AFOs and subjects were observed compared to shoes-only. Walking speed remained unchanged across conditions. For walking energy cost, we found fairly large differences across stiffness conditions with both AFOs and between subjects (range 3–15%). Conclusions Modifying AFO stiffness in individuals with non-spastic calf muscle weakness resulted in substantial differences in ankle biomechanics and walking energy cost with no effect on speed. Our results provide proof-of-concept that individually optimizing AFO stiffness can clinically beneficially improve gait performance. Electronic supplementary material The online version of this article (10.1186/s13047-019-0348-8) contains supplementary material, which is available to authorized users.

Background: Literatures indicate a strong association between biomechanical factors, i.e., increased knee adduction moment (KAM) and knee osteoarthritis. Laboratory studies showed that yoga exercises and medial thrust (MT) gait pattern could reduce the KAM. However, there is a lack of clinical evidence to support their efficacy compared to current exercise therapy regimens. Objectives: This randomized control trial will compare the effects of combined yoga and the MT gait training and conventional knee exercises on gait biomechanics, pain, and function in people with knee OA. Methods: Forty patients with knee OA will be randomly allocated to two treatment groups: (1) the yoga and MT gait group (YogaMT), and (2) the conventional physiotherapy group. Exercise therapy for the YogaMT group includes the MT gait training, and the yoga exercises, and for the conventional physiotherapy group, conventional knee strengthening exercises. The amount of KAM during gait, pain severity, and the functional score will be assessed at baseline, two days and one month after 12 sessions of treatment. Conclusions: Physiotherapists should explore etiology-based interventions targeting the contributing factors to the development and progression of OA. The results of this RCT may help suggest a more effective treatment for patients with knee OA.

This work proposes a new methodology to investigate the potential for disconnection (Type III endoleak) of pairs of overlapped endoprostheses in a popliteal model vessel after a cyclic physiologic load, for three different overlap lengths. Multiaxial fatigue accelerated testing was designed to mimic the physiological loads and movements to which the peripheral arteries are submitted during gait. The experiment design was based on principles from technical standards ASTM F2477-07, Standard Test Methods for In Vitro Pulsatile Durability Testing of Vascular Stents (Superseded), and ASTM F2942-13, Standard Guide for In Vitro Axial, Bending, and Torsional Durability Testing of Vascular Stents (Superseded). Migration and disconnection were monitored by digital image correlation for three different overlap lengths (20, 30, and 40 mm). The testing method proposed in this work was efficient to provide a simulated environment to evaluate the influence of gait biomechanics on overlapped endoprosthesis disconnection. Obtained results demonstrated minimal or absence of relevant migration between the endoprostheses, range −0.06 to 0.34 millimeters. The proposed methodology was verified as a valuable tool to investigate the influence of the biomechanical environment that the devices are subjected to on the migration of overlapped endoprostheses. It may become a new alternative to study the preclinical in vitro performance of single endoprosthesis or multiple connected devices with different overlapped regions.

Materials and methods. The authors studied gait biomechanics in respect of time, velocity and dynamics in 34 patients with verified ACL rupture including 11 patients (first group) before the surgery and 23 patients (second group) after the surgery. Patients of the first group were followed in the period from 1 week up to 6 years (mean – 18 months), of the second group – from 1.5 months up to 5.5 years (mean – 13 months). Patients of the second group underwent standard arthroscopic ACL reconstruction with semitendinous and gracillis tendon autograft. Biomechanical gait examination was performed using strap down inertial motion sensors that register rotation angles in space. The authors measured time phases of gait cycle, movements in hip and knee joints in three mutually perpendicular planes as well as walking shock load.Results. Time phases of gait cycle in both groups demonstrated normal values both on healthy and affected limbs. Movements in hip and knee joints were within the normal range, no reliable differences in the analogous indices for each limb were reported. Shock load in walking was registered within 1.6 g, symmetrical on both sides; shock load dynamics was absent in the group of patients after the surgery. Study results did not identify functional disorders during random flat surface waking that would be specific for ACL lesion as compared to normal values and to intact limb. However, a certain tendency was observed towards an increase of flexion-extension movement range in the knees following ACL reconstruction. The reported differences were not credible.Conclusion. The authors did not observe any specific functional knee joint instability during normal activities in the first group of patients with ACL rupture. On the one hand, that means that ACL lesion does not manifest in such circumstances, on the other - knee joint instability does not progress during flat surface walking at a random pace. The obtained results give certain ground to reconsider the concept of “knee joint instability”.