Search

We evaluated 18 methods capable of identifying initial contact (IC) and terminal contact (TC) gait events during human running using data from a single wearable sensor on the shank or sacrum. We adapted or created code to automatically execute each method, then applied it to identify gait events from 74 runners across different foot strike angles, surfaces, and speeds. To quantify error, estimated gait events were compared to ground truth events from a time-synchronized force plate. Based on our findings, to identify gait events with a wearable on the shank, we recommend the Purcell or Fadillioglu method for IC (biases +17.4 and −24.3 ms; LOAs −96.8 to +131.6 and −137.0 to +88.4 ms) and the Purcell method for TC (bias +3.5 ms; LOAs −143.9 to +150.9 ms). To identify gait events with a wearable on the sacrum, we recommend the Auvinet or Reenalda method for IC (biases −30.4 and +29.0 ms; LOAs −149.2 to +88.5 and −83.3 to +141.3 ms) and the Auvinet method for TC (bias −2.8 ms; LOAs −152.7 to +147.2 ms). Finally, to identify the foot in contact with the ground when using a wearable on the sacrum, we recommend the Lee method (81.9% accuracy).

We introduce WeAllWalk, a data set of inertial sensor time series collected from blind and sighted walkers using a long cane or a guide dog. Ten blind volunteers (seven using a long cane, one using a guide dog, and two alternating use of a long cane and of a guide dog) as well as ve sighted volunteers contributed the data collection. The participants walked through fairly long and complex indoor routes that included obstacles to be avoided and doors to be opened. Inertial data was recorded by two iPhone 6s carried by our participants in their pockets and carefully annotated. Ground truth heel strike times were measured by two small inertial sensor units clipped to the participants’ shoes. We also present an in-depth comparative analysis of various step counting and turn detection algorithms as tested on WeAllWalk. This analysis reveals interesting differences between the achievable accuracy of step and turn detection across di erent communities of sighted and blind walkers.

This study was conducted to determine running kinematics while using compression socks (CS) and smooth socks (SS) among 16 recreational runners. They were required to complete a maximal treadmill test with two different running sock conditions (smooth and compression). All kinematic parameters (ground contact time, heel strike, stride length and swing time) were reported in an average of the four stages of Bruce protocol. Results showed more significant correlations (p

Background and objective: Tightness of the gastroc–soleus muscle complex is one of the limiting factors of the ankle joint’s range of motion (ROM) during daily activities. The aim of this study was to investigate the effectiveness of functional and extra-functional stretching of the gastrocnemius–soleus complex on knee joint loading in athletes with limited ankle dorsiflexion. Material and methods: In this cross-sectional study, 30 male athletes with gastrocnemius–soleus shortness were recruited and randomly divided into three equal-size groups of functional stretching, extra-functional stretching, and a control group. The extra-functional stretching group performed stretching exercises three times per day for eight weeks. The functional stretching group was instructed to change their gait pattern via increased heel strike during daily activities. Results: None of the stretching programs reduced the knee flexion angle in heel contact (p > 0.05). The knee flexion angle was significantly increased in the stance phase in the functional group (p ≤ 0.05). Walking speed was increased significantly in the extra-functional group (p ≤ 0.05). The knee adductor moment and external rotation moment decreased significantly in the functional group (p ≤ 0.05). Conclusion: An eight-week functional stretching program in this study led to a reduction of knee loading in the frontal and horizontal planes in comparison to the extra-functional stretching group, demonstrating the effectiveness of functional stretching in improving knee joint biomechanics during walking.

To determine if anterior cruciate ligament (ACL) reconstruction (ACLR) with lateral extraarticular tenodesis (LET) is beneficial for restoring knee kinematics with concomitant meniscal pathology causing rotatory knee instability. Twenty patients with an ACL tear were randomized to either isolated ACLR or ACLR with LET. Patients were divided into four groups based on the surgery performed and the presence of meniscal tear (MT): ACLR without MT, ACLR with MT, ACLR with LET without MT, and ACLR with LET with MT. Kinematic data normalized to the contralateral, healthy knee were collected using dynamic biplanar radiography superimposed with high-resolution computed tomography scans of patients’ knees during downhill running. Anterior tibial translation (ATT) and tibial rotation (TR) as well as patient-reported outcome measures (PROMs) were analyzed at 6- and 12-months postoperatively. At 6 months, ACLR with LET resulted in significantly decreased ATT at heel strike compared to ACLR (ACLR without MT: 0.3 ± 0.8 mm and ACLR with MT: 1.4 ± 3.1 mm vs. ACLR with LET without MT: − 2.5 ± 3.4 mm and ACLR with LET with MT: − 1.5 ± 1.2 mm ATT, p = 0.02). At 6 months, at toe off ACLR with LET better restored ATT to that of the contralateral, healthy knee in patients with meniscal pathology, while in patients without meniscal pathology, ACLR with LET resulted in significantly decreased ATT (1.0 ± 2.6 mm ATT vs. − 2.6 ± 1.7 mm ATT, p = 0.04). There were no significant differences in kinematics or PROMs between groups at 12 months. For combined ACL and meniscus injury, ACLR with LET restores native knee kinematics at toe off but excessively decreases ATT at heel strike in the early post-operative period (6 months) without altering knee kinematics in the long term. Future large-scale clinical studies are needed to better understand the function of LET and ultimately improve patient outcomes. III.

Background Women are twice as likely as men to develop knee osteoarthritis (OA), and with it experience greater losses of physical function and disability. A change in the mechanical environment of the joint is a key initiating factor for knee OA. Differences in morphology, joint injury risk, and hormonal shifts in mid-life are often considered factors which increase OA risk for women. Pregnancy, a time of significant hormonal, morphological, and biomechanical change, has received comparably less attention. If morphological and biomechanical changes persist postpartum, this could increase OA risk for parous (childbearing) women. Research question Are lower limb gait mechanics different between healthy nulliparous (non-childbearing) and parous (childbearing) women? Methods Twenty-eight self-reported not pregnant female participants (14 parous, 14 nulliparous) were recruited for the study. Nulliparous participants had never given birth to a child. Parous participants had given birth to at least one full-term infant (37–42 weeks) without complications between one to five years before data collection. Motion capture of participants’ preferred, fast, and set (1.4 m/s) walking speeds was conducted. Repeated measures ANOVA were performed to test for significant group differences in joint kinematics and kinetics. Results There was a significant main effect of group indicating a larger knee flexion angle at toe off (p = 0.0002), smaller knee extension moment at heel strike (p = 0.0006), smaller first peak knee flexion moment (p = 0.040), and smaller peak hip adduction moment for the parous group compared to the nulliparous group (p = 0.003). Static Q-angle did not differ between groups. Significance Alteration in mechanics from the habitual loading pattern are thought to increase risk of OA. Smaller knee moments in post-partum women could alter the mechanical stimulus to cartilage, and should be investigated in conjunction with cartilage health measures to determine the link with OA initiation.

Tripping is accompanied by reduced minimum toe clearance (mTC) during the swing phase of gait. The risk of fall due to tripping among transfemoral amputees is nearly 67% which is greater than the transtibial amputees. Therefore, intervention to improve mTC can potentially enhance the quality of life among transfemoral amputees. In this paper, we first develop a real-time visual feedback system with center of pressure (CoP) information. Next, we recruited six non-disabled and three transfemoral amputees to investigate the effect on mTC while participants were trained to shift the CoP anteriorly/posteriorly during heel strike. Finally, to assess the lasting effect of training on mTC, retention trials were conducted without feedback. During feedback, posterior shift in the CoP improved the mTC significantly from 4.68 ± 0.40 cm to 6.12 ± 0.68 cm (p 0.05) from feedback condition in amputee, suggesting a positive effect of feedback training. The foot-to-ground angle (FGA) at mTC increased significantly (p < 0.025) during posterior shift feedback in non-disabled suggests active ankle dorsiflexion in increasing mTC. However, in amputees, FGA at mTC did not differ significantly during both anterior and posterior CoP shift feedback. The present findings suggest CoP feedback as a potential strategy during gait rehabilitation of transfemoral amputees.

This paper proposes a gait detection model that can recognize important gait events in real time. Human gaits are periodic, with each gait cycle containing the important gait events of mid-swing, heel-strike (HS), and toe-off. The correct identification of different gait patterns caused by stroke or progressive neurodegenerative Parkinson’s disease could ensure that the patients receive appropriate treatment and rehabilitation strategies. However, online detection of gait events can be challenging because each person has their own walking patterns and speeds. This paper applies recurrent neural networks (RNNs) to develop a model that can instantly detect important gait events in any subject. We collected clinical gait data and used them to develop an RNN model for real-time detection of HS. The model correctly recognized HS events with an average success rate of 98.84% and an average delay of 0.024 s in the laboratory environment. We then applied the model to three different groups of subjects: healthy elderly subjects, stroke patients, and patients with Parkinson’s disease. The developed RNN model also correctly recognized HS events in all three groups with an average accuracy of more than 99.65%, even though the subjects had very different walking patterns. In the future, the developed gait detection model can be integrated with real-time rehabilitation systems to provide patients with repetitive guidance using clinician-determined cures for enhanced clinical gait training.

Older adults with hyperkyphosis might have a high risk of falls since their whole body center of mass may shift to the boundary of the base of support. Body composition changes, such as low bone mineral content (BMC), decreased muscle mass, high body mass index (BMI), and increased fat mass are common in older adults with hyperkyphosis. This study aimed to investigate the relationship between body composition and balance performance using a biomechanical analysis in older adults with hyperkyphosis. Thirty older adults with hyperkyphosis were recruited. BMC, muscle mass, BMI, and fat mass were measured for body composition. Balance performances were determined with walking, quiet standing, and forward reach. Gait speed, step length, center of mass–center of pressure inclination angle of heel strike (Inc-HS) and toe off (Inc-TO) during walking, center of mass–center of pressure inclination angle during quiet standing (Inc-QS), and reaching distance were calculated. BMC had a moderately positive correlation with gait speed (r = 0.48, p

This paper presents a low-cost wireless gait event detection system that incorporates infra-red range sensors mounted laterally at a specific anatomical location on the shoe. This system uses foot clearance information to extract heel strike (HS) and toe-off (TO) events. A subject-specific algorithm based on signature curve matching was developed to estimate the HS and TO in six able-bodied subjects and three transfemoral amputees. The data were acquired in a real-life environment while the subject walked on level ground and ramp terrains, including the transitions. The HS and TO in the level ground were detected with an accuracy of 22.87± 9.93 ms and 10.42± 6.70 ms, respectively, in able-bodied participants. The accuracy of 37.91± 12.36 ms and 20.41± 11.23 ms in HS and TO, respectively, was observed in amputees during level ground walking. Further, within the ramp terrain, the HS and TO were detected with an accuracy of 23.33± 11.20 ms and 13.36± 9.5 ms respectively in able-bodied subjects and 40.35± 12.64 ms and 47.51± 19.23 ms in amputees. This method reports comparable accuracy, with minimal standard deviation, to other existing methods based on accelerometer, gyroscope, electromyography, and force myography. This system is robust, easy to operate, and avoids direct contact with the body. The developed system offers a movable sensor platform in two degrees of freedom that facilitates the adaptability of the proposed system for different heel height and shoe sizes.

Foot prosthetics is one of the needs of the disabled feet as a tool for activities. The ankle prosthetic model is proposed as an alternative prosthetic model that is affordable to people with disabilities. The model is designed and analyzed to be able to withstand the average weight of a human being in the heel strike, midstance, and toe-off position and has a safe safety factor value. The research method used is the model design and model analysis consisting of preprocessing, solution, and post-processing. The analysis results showed that the greatest deformation occurred in the toe-off position of 1.52 mm when given a load of 500 N and 0.036 mm when given a moment of 5000 Nmm. The greatest strain energy was located in the forefoot area at a toe-off position of 0.6 mJ. Maximum stress also occurred at the toe-off position of 5.71 MPa. With a safety factor of 4.7, this model is categorized as safe because the stress that occurs is still below the yield strength limit of the ABS material.

This paper concerns the issue of the dynamic impact of people running on footbridges with particular with attention to various footstrike patterns occurring during the running (i.e. heel strike pattern and forefoot strike pattern). The results of a series of laboratory tests of vertical ground reaction force (VGRF) measurements generated by running people are presented along with the characteristics of the VGRF curves. Based on the results of the tests, a new proposal for a dynamic load model generated by people classified as heel strike runners has been developed, and corrections of the input parameters of two load models proposed by other authors have been performed. Moreover, the VGRF modelling technique using the Gaussian functions is presented along with a set of equations describing the variability of the Gaussian function parameters as a function of the frequency of running. The presented methods of the VGRF modelling allow increasing the accuracy of determining the VGRF values and, consequently, increasing the accuracy of dynamic analyses of footbridges subjected to dynamic loads generated by people running.

This study proposes a system to detect the phases of gait. It consists of an intelligent shoe equipped with an inertial measurement unit (IMU) and force-sensitive resistors (FSRs), and it uses a compound method to recognize gait. The continuous wavelet transform is applied according to accelerations obtained via the IMU to identify heel strike and toe-off events. These events are used to calculate the pressure threshold and proportional factor via the Lopez–Meyer (LM) method by using minimal leave-one-out for training and validation. The LM method can identify the entire sub-phase of the stance of the gait based on ground contact forces measured by using the FSRs and rules of gait event detection. The proposed system was tested on five healthy volunteers who used the intelligent shoe. The results show that it can detect all sub-phases of the gait with an overall accuracy (96%) higher than the LM method. The proportional factor was adaptable to variable body weights, and the reported average errors of competing systems in the literature significantly exceeded the average variation of the proposed system for all phases of gait. The range of errors in the swing phase and sub-phases of stance was also acceptable for application purposes. When the size of the subject’s foot was close to that of the intelligent shoe, the error between normative data and phases of gait identified by the detection system was minimal. Furthermore, the proposed system detected abnormalities in the gait circle, and thus, it can be used to monitor the walking activity and measure the motor recovery.

Knee-stretched walking is considered to be a human-like and energy-efficient gait. The strategy of extending legs to obtain vertical center of mass trajectory is commonly used to avoid the problem of singularities in knee-stretched gait generation. However, knee-stretched gait generation utilizing this strategy with toe-off and heel-strike has kinematics conflicts at transition moments between single support and double support phases. In this article, a knee-stretched walking generation with toe-off and heel-strike for the position-controlled humanoid robot has been proposed. The position constraints of center of mass have been considered in the gait generation to avoid the kinematics conflicts based on model predictive control. The method has been verified in simulation and validated in experiment.

It has been proposed that during running, the greatest force occurs when the foot strikes the ground and simultaneously exhalation occurs at initial heel contact. As a result, breathing retraining has been used as a method to prevent lower extremity overuse injuries by modifying an individual's breathing pattern and consequently, reducing ground reaction forces. There is, however, little research exploring this link during walking. This study explored the interaction effect between the phase of respiration and foot strike pattern on measures of ground reaction forces while walking. The study also examined the correlation between the phase of respiration and peak forces. The research findings did not support the concept of breathing synchronization with higher ground reaction forces when exhalation occurred at heel strike during walking. The biomechanics of walking are very different than running and, therefore, the utility of breathing retraining may not be supported as has been proposed for running.

Steady state gait dynamics has been examined using the measures of regularity, local dynamic stability, and variability. This study investigates the relationship between these measures under increasing cognitive loads. Participants walked on an instrumented treadmill at 1 m/s under walk only and two dual-task conditions. The secondary tasks were visuomotor cognitive games (VCG) of increasing difficulty level. The center of pressure displacement in the mediolateral direction (ML COP-D) and cognitive game performance were recorded for analysis. The following measures were calculated: (1) sample entropy (SampEn) and quantized dynamical entropy (QDE) of the ML COP-D, (2) short-term largest Lyapunov exponent (LLE) of the ML COP-D, and (3) variability of inter-stride spatio-temporal gait variables. Entropy and variability measures significantly increased from walk only to both dual-task conditions. Whereas, the short-term LLE increased only during the easy VCG task. No measure was sensitive to the difficulty level of the VCG tasks. The variability of heel strike positions in the mediolateral direction was positively correlated with SampEn and QDE. However, there were no significant correlations between the short-term LLE and either variability measures or entropy measures. These findings confirm that each of these measures is representative of a different aspect of human gait dynamics.

Introduction Forefoot strike has been advocated for many runnersbecause of the relatively lower impact and push-off forces comparedto a heel strike. The purpose of this study was to explore the abilityof mature (> 30 years old), experienced runners to transition from aheel foot strike to a forefoot strike when first introduced to barefootrunning on a treadmill. We hypothesized: 1) mature runners who heelstrike while wearing traditional training shoes would persist in heelstriking immediately following a switch to barefoot, 2) mean shoeheel-to-toe drop would be significantly greater in runners who persistin heel striking when running barefoot compared to those who transitionto a forefoot strike pattern, and 3) there would be a significantdecrease in heel striking in the barefoot condition as running speedsincreased. Methods This was a controlled crossover laboratory study. Thirty-three experienced runners (average 23.4 miles per week) withan average age of 45.6 years were recruited for this study. The participantsfirst ran in their standard running shoes and subsequentlybarefoot. A motion capture system was utilized to detect and analyzeany transition from heel strike to forefoot strike made by study participants. Results Of the 26 participants who were classified as heel strikerunners in their running shoes, 50% (13/26, p = 0.001) transitionedto forefoot strike when changing from running in shoes to runningbarefoot. Conclusions The injuries associated with transition from standardrunning shoes to barefoot running or minimalist shoes may be influencedby the persistence of heel striking in mature runners. Olderexperienced runners may have limited ability to transition from heelto forefoot striking when first introduced to barefoot running. Maturerunners should be cautious when beginning a minimalist shoe orbarefoot running regimen.

PURPOSE High vertical ground reaction force (vGRF) loading rates are thought to contribute to lower extremity injuries in runners. Given that elevated lower extremity stiffness has been reported to be associated with increased GRFs, the purpose of the current study was to determine if overall lower extremity stiffness, individual joint angular excursions and/or torsional stiffness are predictive of the average vGRF loading rate during running. METHODS Forty heel strike runners (20 men and 20 women) ran overground at a speed of 3.4 m·s. Average vGRF loading rate, lower extremity stiffness, and hip, knee, and ankle joint excursions and torsional stiffness from initial contact to the first peak of the vGRF were quantified. Stepwise multiple linear regression was performed to determine the best predictor(s) of average vGRF loading rate. RESULTS Lower extremity stiffness was found to the best predictor of average vGRF loading rate (R = 0.68, P < 0.001). The second variable that entered the stepwise regression model of average vGRF loading rate was knee joint excursion (ΔR = 0.03, P = 0.023). CONCLUSIONS Increased lower extremity stiffness immediately after initial contact may expose heel strike runners to higher vGRF loading rates.

It is important to find objective biomarkers for evaluating gait in Parkinson’s Disease (PD), especially related to the foot and lower leg segments. Foot-switch signals, analyzed through Statistical Gait Analysis (SGA), allow the foot-floor contact sequence to be characterized during a walking session lasting five-minutes, which includes turnings. Gait parameters were compared between 20 PD patients and 20 age-matched controls. PDs showed similar straight-line speed, cadence, and double-support compared to controls, as well as typical gait-phase durations, except for a small decrease in the flat-foot contact duration (−4% of the gait cycle, p = 0.04). However, they showed a significant increase in atypical gait cycles (+42%, p = 0.006), during both walking straight and turning. A forefoot strike, instead of a “normal” heel strike, characterized the large majority of PD’s atypical cycles, whose total percentage was 25.4% on the most-affected and 15.5% on the least-affected side. Moreover, we found a strong correlation between the atypical cycles and the motor clinical score UPDRS-III (r = 0.91, p = 0.002), in the subset of PD patients showing an abnormal number of atypical cycles, while we found a moderate correlation (r = 0.60, p = 0.005), considering the whole PD population. Atypical cycles have proved to be a valid biomarker to quantify subtle gait dysfunctions in PD patients.

Background and Objectives: Acquiring knowledge about the magnitude and direction of induced joint forces during modifying gait strategies is critical for proper exercise prescription. The present study aimed to evaluate whether a heel-first strike pattern during gait can affect the biomechanical characteristics of ankle and knee joints among asymptomatic people. Materials and Methods: In this cross-sectional study performed in the biomechanics laboratory, 13 professional healthy male athletes walked on an instrumented walkway under two walking conditions. For the normal condition, subjects were instructed to walk as they normally would. For the heel-first strike condition, subjects were instructed to walk with heel-first strike pattern and increase heel contact duration as much as possible. Then, knee and ankle joint range of motions and moments, as well as vertical ground reaction force was measured by the Kistler force plate and Vicon motion analysis system. Results: Knee flexion angle at the initial contact and during stance phase was significantly lower when increasing the heel strike pattern. In addition, the mean values of the knee external rotation and adductor moments during heel strike condition were lower than those in normal walking. Further, the ankle dorsiflexion range of motion (ROM) during mid-stance increased significantly during heel-first strike pattern compared to the value in normal gait pattern. Conclusions: The modification of gait pattern including heel-first strike pattern can reduce the mechanical load applied to the knee, while improving the extensibility of gastro-soleus muscle complex.

PurposeThe purpose of the current study was to: 1) evaluate sex differences in peak hip adduction during the late swing and stance phases of running and 2) determine if peak hip adduction during late swing is predictive of peak hip adduction during stance.Methods15 female and 16 male heel strike runners ran over ground at a speed of 4 m/s. Hip joint kinematics during running were quantified using a 3D motion capture system. Sex differences in peak hip adduction during the late swing and stance phases were compared using independent sample t-tests. Linear regression analysis was used to determine the relationship between late swing and stance phase hip adduction.ResultsCompared to males, females exhibited significantly greater peak hip adduction during both the late swing (8.5 ± 2.6 vs 6.1 ± 2.8°, p = 0.019) and stance phases of running (13.3 ± 4.2 vs 9.6 ± 3.4°, p = 0.011). Furthermore, late swing peak hip adduction was predictive of subsequent stance phase peak hip adduction (r = 0.63, p < 0.001).ConclusionSex differences in hip adduction during stance are influenced in part by late swing phase hip adduction. Further studies are needed to identify potential causes of excessive hip adduction during the late swing phase of running.

Muscle synergy assessments are often employed to evaluate the modular organization of the spinal cord during a locomotion task. While they provide valuable insights into the pattern formation of the a-motoneurons at the spinal cord, by construction they cannot capture control from supra-spinal layers. We examined how locomotor muscle synergies are represented in the sensorimotor cortex, with particular focus on the cortico-synergy coherence as a measure of coupling along the cortico-spinal tract. Non-negative matrix factorization served to decompose multivariate electromyographic signals into muscle synergies. Their representations were localized in the cortex using coherence-based beamforming. Overall, the cortico-synergy coherence was maximal in sensorimotor areas especially in the beta-frequency band. However, only for the synergies timed to heel strike, that are related to the double support phases, the coherence was significant. These coherences were closely related to the timing of the activation patterns of the synergies, suggesting sensorimotor cortex to be strongly involved in emergence and control of these synergies.

(1) Background: The femoroacetabular impingement (FAI) type cam leads to a conflict between the acetabular rim and a bony thickening of the femoral neck junction. While maximal excursions in flexion, adduction and internal rotation provoke pain, the aim of this study was to analyze if a cam morphology shows an impact on gait pattern. (2) Methods: Fifty-five patients with end-stage hip osteoarthritis performed gait analysis before hip replacement as well as three, six and 12 months postoperatively. Thirty-three (60%) of them presented an FAI type cam. An ANOVA was used to compare the hip angles in sagittal, frontal and transversal planes between patients with a FAI type cam (group “+cam”) and without (group “−cam”). (3) Results: Before surgery the patients of the +cam-group showed a tendency towards a reduced flexion and internal rotation at the heel strike (p &gt, 0.05). Over time, the differences were adjusted by total hip arthroplasty. (4) Conclusions: We did not find any differences in the gait analysis of patients with a FAI type cam compared to patients without.

Background Back-support exoskeletons (BSEs) are a promising intervention to mitigate physical demands at work. Although growing evidence indicates that BSEs can reduce low-back physical demands, there is limited understanding of potential unintended consequences of BSE use, including the risk of falls. Research question Does using a BSE adversely affect gait performance and stability, and are such effects dependent on specific BSE external torque characteristics? Methods Twenty participants (10 M, 10 F) completed five level over-ground walking trials and a five-minute treadmill walking trial while wearing a BSE (backXTM) with three different levels of external torque (i.e., no torque, low torque, and high torque) and in a control (no-exoskeleton) condition. Spatiotemporal gait patterns, stride-to-stride gait variability measures, required coefficient-of-friction (RCoF), and minimum foot clearance (MFC) were determined, to assess gait performance. Gait stability was quantified using the maximum Lyapunov exponent (MLE) of trunk kinematics and the margin-of-stability (MoS). Results Using the backXTM with high supportive torque decreased slip risk (7% decrease in RCoF) and slightly improved trunk stability (3% decrease in MLE). However, it also decreased step length (1%), increased step width (10%) and increased gait variability (8-19%). Changes in MoS were complex: while MoS at heel strike decreased in the AP direction, it increased in the ML direction. There was a rather large decrease in MoS (26%) in the ML direction during the swing phase. Significance This is the first study to quantify the effects of wearing a passive BSE with multiple supportive torque levels on gait performance and stability during level walking. Our results, showing that the external torque of the BSE may adversely affect gait step width, variability, and dynamic stability, can contribute to better design and practice guidelines to facilitate the safe adoption of BSEs in the workplace.

Ground reaction force (GRF) is a key metric in biomechanical research, including parameters of loading rate (LR), first impact peak, second impact peak, and transient between first and second impact peaks in heel strike runners. The GRFs vary over time during stance. This study was aimed to investigate the variances of GRFs in rearfoot striking runners across incremental speeds. Thirty female and male runners joined the running tests on the instrumented treadmill with speeds of 2.7, 3.0, 3.3, and 3.7 m/s. The discrete parameters of vertical average loading rate in the current study are consistent with the literature findings. The principal component analysis was modeled to investigate the main variances (95%) in the GRFs over stance. The females varied in the magnitude of braking and propulsive forces (PC1, 84.93%), whereas the male runners varied in the timing of propulsion (PC1, 53.38%). The female runners dominantly varied in the transient between the first and second peaks of vertical GRF (PC1, 36.52%) and LR (PC2, 33.76%), whereas the males variated in the LR and second peak of vertical GRF (PC1, 78.69%). Knowledge reported in the current study suggested the difference of the magnitude and patterns of GRF between male and female runners across different speeds. These findings may have implications for the prevention of sex-specific running-related injuries and could be integrated with wearable signals for the in-field prediction and estimation of impact loadings and GRFs.

BackgroundDefinition and clinical diagnosis of instability in TKA is challenging. Sensitive and objective biomechanical tools to aid diagnosis are currently lacking. This proof-of-concept study evaluates the use of pressure mat analyses to identify abnormal biomechanical loading patterns associated with TKA instability within an outpatient clinical setting.MethodsTwenty participants were examined: 10 patients with suspected unilateral TKA instability and 10 healthy controls. Participants underwent bilateral stance and gait tests measuring time and limb loading pressure parameters. Gait was divided into three phases: heel strike, mid-foot and toe off. Pressure recordings are expressed relative to bodyweight. Between-limb loading discrepancies were calculated in TKA patients and controls, and these differences were then compared between groups. Statistical significance was accepted at p < 0.05.ResultsTKA patients consistently offloaded pressure away from the operated limb, whereas healthy controls exhibited more even limb loading throughout bilateral stance ( p < 0.05). TKA patients exhibited greater discrepancy in overall step contact time between limbs (−0.09 s ± 0.16 s; p = 0.016) compared to controls (0.06 s ± 0.08 s; p = 0.04). Post-hoc tests showed significant between-group differences during midfoot (−0.04 s ± 0.07 s; p = 0.03) and toe-off (0.05 s ± 0.14 s; p = 0.013). Between-group differences in limb loading discrepancy were evident at heel strike (−9.24% ± 2.11%; p = 0.0166) and toe-off (−10.34% ± 5.51%; p = 0.0496).DiscussionPedobarographic measurements demonstrated differences in mechanical loading patterns in patients with TKA instability compared to healthy controls during functional tasks and warrants further investigation. This may prove to be a useful clinical diagnostic tool in identifying patients that would benefit from revision surgery or physical therapy.

Background: Dravet Syndrome (DS) is a developmental and epileptic encephalopathy characterized by severe drug-resistant seizures and associated with cognitive and motor impairments. Walking problems are frequently observed. As the foot plays a key role during walking, compromised foot function can be a feature of deviant gait. Aim: To investigate foot function in DS by characterizing foot-floor contact patterns using pedobarography. Methods: A total of 31 children and adults were included in the DS group (aged 5.2–32.8 years, 17 female, 174 steps) and 30 in the control group (aged 6.0–32.9, 16 female, 180 steps). The foot-floor contact pattern was evaluated based on progression, length and smoothness (spectral arc length) of the center of pressure (CoP). Linear mixed models were used to identify differences between non-heel strikes and heel strikes and between the DS and control group. Results: Fifteen participants with DS showed inconsistency in the type of foot-floor contact (heel strikes and non- heel strikes). Heel strikes of participants with DS had significantly reduced time of CoP under the hindfoot and increased time under the midfoot region compared to the control group. Significant time and age effects were detected. Conclusions and implications: Deviant foot-floor contact patterns were observed in DS. Possible gait immaturity and instability as well as implications for interventions are discussed. ispartof: Gait and Posture vol:84 issue:December 2020 pages:315-320 ispartof: location:England status: Published online

In this paper, the investigation of human gait for normal and abnormal persons is done. It involves investigating different body joints, especially the foot while walking, on heel off and heel strike stage. The heel off and heel strike comes under phases of the gait cycle of a person. In a gait cycle, several features were calculated for different persons. The designed system is continuously monitoring the person’s features and can derive comprehensive body joints information of the gait cycle. In this study, a data set is constructed. Twenty-four persons (male and female) participated, including those who have a normal and abnormal gait. The persons are instructed to walk along a straight-line path of 8 ft in length. Data is recorded using Kinect Sensor v1.0, and several features are calculated, and the analysis of features is done using MATLAB. This investigation includes creating a GUI tool for feature extraction from the Microsoft Kinect Sensor and classification of feature set for the normal and abnormal gait of a person using the basic feature extraction model. 83.33% of accuracy is achieved for identifying that the person is a normal or an abnormal during walking.

Gait phase plays an important role in controlling wearable robot. This paper focuses on the continuous gait phase estimation by using capacitive sensing method for one transtibial amputee wearing robotic prosthesis. First, the capacitive sensing signals are used to record muscles’ contraction and relaxation to detect two gait events (heel strike and toe off) as the start points (reset 0 rad) of one gait cycle. Secondly, continuous gait phase estimation is conducted based on the detected gait events (heel strike and toe off, respectively) with adaptive oscillators. In this study, the heel strike and toe off in each gait cycle can be detected with 100% accuracy based on linear discriminant analysis algorithm. The delay ratios for heel strike and toe off are less than 1% within one gait cycle. The root-mean-square errors of continuous gait phase estimation based on the different reset timings (heel strike and toe off) are 0.15 rad and 0.19 rad. The results show the feasibility to estimate the gait phase for amputee based on the residual muscles’ capacitive signals.

Drop foot is a neuromuscular disorder that deteriorates patients’ walking ability by preventing them from raising their feet during the swing. This issue causes two main problems during walking: unrestrained declining of the forefoot after heel strike which subsequently makes foot slap and dragging of the toes when the pretentious leg starts fluctuation. An ankle foot orthosis (AFO) is a mechanical device worn by drop foot patients with paretic ankle dorsiflexor muscles, to support and improve the working of the foot and ankle joint. An AFO ought to never be awkward for a kid to wear, and kids ought to probably wear it cheerfully for the majority of their dynamic day. Once in a while, AFOs can rub on weight centers and make “sensitive areas”, so it’s vital to screen your tyke’s foot, particularly the impact point and lower leg.

The objective was to examine the interactive effects of load magnitude and locomotion pattern on lower-extremity joint angles and intralimb coordination in recruit-aged women. Twelve women walked, ran, and forced marched at body weight and with loads of +25%, and +45% of body weight on an instrumented treadmill with infrared cameras. Joint angles were assessed in the sagittal plane. Intralimb coordination of the thigh–shank and shank–foot couple was assessed with continuous relative phase. Mean absolute relative phase (entire stride) and deviation phase (stance phase) were calculated from continuous relative phase. At heel strike, forced marching exhibited greater (P P = .007) and ankle dorsiflexion (P = .04) increased with increased load magnitude for all locomotion patterns. Forced marching (P = .009) demonstrated a “stiff-legged” locomotion pattern compared with running, evidenced by the more in-phase mean absolute relative phase values. Running (P = .03) and walking (P = .003) had greater deviation phase than forced marching. Deviation phase increased for running (P = .03) and walking (P 25% of body weight, forced marching may increase risk of injury due to inhibited energy attenuation up the kinetic chain and lack of variability to disperse force across different supportive structures.

Most stroke patients with hemiplegia have difficulty on heel rocker function due to weak dorsiflexors at their paralyzed side. The proposed high-dorsiflexion assistive robotic technology (RT) supports ankle dorsiflexion during gait rehabilitation. Aside from the McKibben-type artificial muscle's contraction to assist swing phase dorsiflexion, a tension spring is aligned in series to support heel rocker function upon heel strike. Because of different requirements of dorsiflexion torque during loading response phase, selection of suitable spring for corresponding user could be important. Springs with either excessively large or small coefficients might the normal heel rocker function. In this research, an identification method based on observing tension on the spring in loading response phase was derived. We aim for simple clinical setting and availability on patients with various pathological gait patterns, especially gait asymmetry. A case study on a stroke patient with hemiplegia was conducted to evaluate effect with the identified spring. Increase of knee angle (before intervention: mean 2.118°, SD 0.418°; during intervention: mean 12.814°, SD 1.764°) and shank angular velocity to the ground (before intervention: mean 117.300°/s, SD 9.491°/s; during intervention: mean 255.875°/s, SD 34.130°/s) indicates sufficient heel rocker function could be supported during intervention of the identified tension spring in this specific case.

Human walking gait is much more natural looking and energy efficient compared with biped robots. This paper presents a bio-inspired approach to realizing more human-like biped robotic walking. For this purpose, a biped robot actuated coordinately by pneumatic artificial muscles and springs is developed, capable of exploiting passive compliance of the mechanical system in locomotion. And a control scheme for human-like walking is designed based on finite state machine. Experiments show that the biped robot can walk stably on the treadmill even with some small obstacles. The realized gait has the important features of human walking, including heel strike and toe off, stretched knees, and variation in the height of the body’s center of mass, which demonstrates the effectiveness of the proposed approach.

This study aimed to understand the ability of fixed-bearing posterior cruciate ligament (PCL)-retaining implants to maintain functionality of the PCL in vivo. To achieve this, elongation of the PCL was examined in six subjects with good clinical and functional outcomes using 3D kinematics reconstructed from video-fluoroscopy, together with multibody modelling of the knee. Here, length-change patterns of the ligament bundles were tracked throughout complete cycles of level walking and stair descent. Throughout both activities, elongation of the anterolateral bundle exhibited a flexion-dependent pattern with more stretching during swing than stance phase (e.g., at 40 degrees flexion, anterolateral bundle experienced 3.9% strain during stance and 9.1% during swing phase of stair descent). The posteromedial bundle remained shorter than its reference length (defined at heel strike of the level gait cycle) during both activities. Compared with loading patterns of the healthy ligament, postoperative elongation patterns indicate a slackening of the ligament at early flexion followed by peak ligament lengths at considerably smaller flexion angles. The reported data provide a novel insight into in vivo PCL function during activities of daily living that has not been captured previously. The findings support previous investigations reporting difficulties in achieving a balanced tension in the retained PCL., Journal of Clinical Medicine, 9 (7), ISSN:2077-0383

In this work, a new custom wireless capacitive step sensor and a real-time algorithm are proposed to detect the start and end of the swing phase of the gait to trigger the stimulation in Functional Electrical Stimulator devices (FES) for Drop Foot. For this, an array of capacitive pressure sensors was designed to detect patterns of the gait swing phase through the Heel Center of Pressure (HCOP). The proposed system recognized all the events with an average error of 20.86±0.02[ms] for the heel strike (initial contact) and 27.60±0.03[ms] for the heel-off (final contact) compared with lower-back accelerometer, constituting a viable, robust and promising alternative as a step sensor for functional electrical stimulators.

A previous study reported that habitually barefoot Kenyan distance runners tend to use a mid-foot strike or a forefoot-heel strike (FHS). Current findings indicate FHS helps enhance Kenyans’ running performance. However, no study has investigated how FHS modulates leg stiffness (kleg) and altered running velocity with changes in kleg. Because vertical displacement of the centre of mass and kleg during hopping are applicable to the running process, this study investigated how FHS affects kleg and hopping frequency (fhopping) during hopping. Subjects hopped at 2.2 Hz with normal hopping (NH-2.2Hz) and at a comfortable frequency with FHS (FHS-CF). According to each subject’s comfortable frequency at FHS-CF, they were divided into higher (HG, 2.49 ± 0.11 Hz) and lower (LG, 2.16 ± 0.19 Hz) groups. With FHS-CF, the flight duration in HG was significantly shorter than that in LG. kleg in HG was greater than that in LG. Negative work in the first half of the stance phase and positive work in the second half of the stance phase at all three joints were smaller in HG than in LG. The touchdown angle was larger and angular displacements at the joints were smaller in HG than in LG. The findings indicate that when hoppers used FHS, they increased their preferred fhopping by stiffening their leg joints during the stance phase and jumping with a lower height than in normal hopping; additionally, it is important to increase the touchdown joint angle for a stiffened joint.

Background and purpose Iliotibial Band Syndrome (ITBS) is the second leading cause of pain in runners and there are a number of theories related to its etiology. Multiple theories exist for the etiology of ITBS related symptoms including anterior-posterior friction of the IT band on the lateral femoral condyle during knee flexion and extension activities, compression of a layer of fat near the IT band distal attachment, and inflammation of the IT band bursa. The purpose of this literature review and clinical commentary was to explore the potential factors that contribute to ITBS development in runners. Description of topic with related evidence A literature review was performed to gather relevant evidence related to the topic and then categorized according to prospective and retrospective results. The electronic databases PubMed, EBSCOhost, CINAHL, and SportDiscus were utilized with the search terms iliotibial band, iliotibial band syndrome, iliotibial pain, and runners. The inclusion criteria included English-language, peer-reviewed journals; adult male or female runners, whether competitive or recreational with regard to mileage; subjects that either had a previous or existing diagnosis of ITBS or were at risk for developing ITBS; retrospective and prospective designs were included and the majority of studies reviewed were cohort or case-control designs. Discussion/relation to clinical practice The literature was either contradictory or inconclusive to support a link between ITBS and decreased muscle strength or endurance. A weak correlation existed between strain rate of the hip abductor muscles with hip adduction and knee internal rotation, increased knee internal rotation during the stance phase of gait, and a diminished rearfoot eversion angle at heel strike. Additionally, decreased hip adduction angles during stance phase were observed in individuals without active symptoms but who had a previous history of ITBS. Finally, the female gender may be a predisposing factor. Level of evidence 5.

Initial heel contact is an important attribute of gait, and failure to complete the heel rocker reduces gait stability. One common goal in treating toe-walking is to restore heel strike and prevent or reduce early heel rise. Foot floor angle (FFA) is a measure of toe-walking that is valuable for quantifying foot orientation at initial contact when using ankle dorsiflexion angle alone is misleading. However, no age-standardized FFA norms exist for clinical evaluation. Our objectives were to: (1) obtain normative FFA in typically developing children; and (2) examine its utility in the example of toe-walking secondary to unilateral cerebral palsy. Gait kinematics were acquired and FFA trajectories computed for 80 typically developing children (4-18 years). They were also obtained retrospectively from 11 children with toe-walking secondary to unilateral cerebral palsy (4-10 years), before and after operative intervention, and compared to 40 age-matched, typically developing children. FFA at initial contact was significantly different (P

Running shoe cushioning has become a standard method for managing impact loading and consequent injuries due to running. However, despite decades of shoe technology developments and the fact that shoes have become increasingly cushioned, aimed to ease the impact on runners’ legs, running injuries have not decreased. To better understand the shoe cushioning paradox, we examined impact loading and the spring-like mechanics of running in a conventional control running shoe and a highly cushioned maximalist shoe at two training speeds, 10 and 14.5 km/h. We found that highly cushioned maximalist shoes alter spring-like running mechanics and amplify rather than attenuate impact loading. This surprising outcome was more pronounced at fast running speed (14.5 km/h), where ground reaction force impact peak and loading rate were 10.7% and 12.3% greater, respectively, in the maximalist shoe compared to the conventional shoe, whereas only a slightly higher impact peak (6.4%) was found at the 10 km/h speed with the maximalist shoe. We attribute the greater impact loading with the maximalist shoes to stiffer leg during landing compared to that of running with the conventional shoes. These discoveries may explain why shoes with more cushioning do not protect against impact-related running injuries.

Variation in hip joint contact forces directly influences the performance of total hip replacements (THRs). Measurement and calculation of contact forces in THR patients has been limited by small sample sizes, wide variation in patient and surgical factors, and short-term follow-up. This study hypothesised that, at long-term follow-up, unilateral THR patients have similar calculated hip contact forces compared to controls walking at similar (self-selected) speeds and, in contrast, THR patients walking at slower (self-selected) speeds have reduced hip contact forces. It was further hypothesised that there is no difference in calculated hip contact forces between operated and non-operated limbs at long-term follow-up for both faster and slower patients. Gait analysis data for THR patients walking at faster (walking speed: 1.29 ± 0.12 m/s; n = 11) and slower (walking speed: 0.72 ± 0.09 m/s; n = 11) speeds were used. Healthy subjects constituted the control group (walking speed: 1.36 ± 0.12 m/s; n = 10). Hip contact forces were calculated using static optimisation. There was no significant difference (p > 0.31) in hip contact forces between faster and control groups. Conversely, force was reduced at heel strike by 19% (p = 0.002), toe-off by 31% (p < 0.001) and increased at mid-stance by 15% (p = 0.02) for the slower group compared to controls. There were no differences between operated and non-operated limbs for the slower group or the faster group, suggesting good biomechanical recovery at long-term follow-up. Loading, at different walking speeds, presented here can improve the relevance of preclinical testing methods.

We introduce WeAllWalk, a dataset of inertial sensor time series collected from blind and sighted walkers using a long cane or a guide dog. Ten blind volunteers (seven using a long cane, one using a guide dog, and two alternating use of a long cane and of a guide dog) as well as five sighted volunteers contributed to the data collection. The participants walked through fairly long and complex indoor routes that included obstacles to be avoided and doors to be opened. Inertial data were recorded by two iPhone 6s carried by our participants in their pockets and carefully annotated. Ground-truth heel strike times were measured by two small inertial sensor units clipped to the participants’ shoes. We also present an in-depth comparative analysis of various step counting and turn detection algorithms as tested on WeAllWalk. This analysis reveals interesting differences between the achievable accuracy of step and turn detection across different communities of sighted and blind walkers.

Osteoarthritis (OA) is a common occupational hazard for service members. This study quantified how body borne load impacts knee biomechanics for participants who do and do not present varus thrust (range of knee adduction motion exhibited from heel strike to mid-stance (0–51%)) during over-ground running. Eighteen (9 varus thrust and 9 control) military personnel had knee biomechanics recorded when running with three load conditions (light, ∼6 kg, medium, 15% BW, and heavy, 30% BW). Subject-based means for knee biomechanics were calculated and submitted to a RM ANOVA to test the main effects and possible interactions between load and varus thrust group. The varus thrust group exhibited greater varus thrust (p = .001) and peak stance (PS, 0–100%) knee adduction (p = .009) posture compared to the control group with the light load, but not for the medium (p = .741 and p = .825) or heavy loads (p = .142 and p = .429). With the heavy load, varus thrust group reduced varus thrust (p = .023), whereas, the control group increased varus thrust (p = .037) compared to the light load, and increased PS knee adduction moment compared to light (p = .006) and medium loads (p = .031). The varus thrust group, however, exhibited no significant difference in knee adduction moment between any load (p = .174). With the addition of body borne load, varus thrust participants exhibited a significant reduction in knee biomechanics related to OA; whereas, control participants adopted knee biomechanics, including greater varus thrust and knee adduction moment, related to the development of OA.

The foot strike angle (FSA) is a common biomechanical parameter in the analysis of human running. It can be used for shoe recommendation purposes by classifying runners into foot strike patterns (Z...

Kinematics at heel strike instant (HSI) has been used to quantify slip severity. However, methods to identify HSI remain ambiguous and have not been evaluated under slippery conditions. A glass force plate was used to observe the contact interface between shoe and floor under slippery conditions. HSIs identified from the video captured beneath the force plate and from the force plate and kinematics were compared. The results showed that HSIs identified with the video were closer to those identified with the normal force threshold (NFT) (9.0 ms ± 5.5 ms) than were most of those identified with kinematics. Slips with a longer distance travelled between NFT HSI and video HSI had a larger heel horizontal velocity (0.8 m/s) and a smaller foot angular velocity (100deg/s) at the NFT instant, and were still part of the forward swing. The results show that improved methods are needed over NFT to identify HSI, especially under slippery conditions.

The assumption that the morphology of the human calcaneus reflects high and cyclical impact forces at heel strike during adult human walking has never been experimentally tested. Since a walking step with a heel strike is an emergent behavior in children, an ontogenetic study provides a natural experiment to begin testing the relationship between the mechanics of heel strike and calcaneal anatomy. This study examined the ground reaction forces (GRFs) of stepping in children to determine the location of the center of pressure (COP) relative to the calcaneus and the orientation and magnitude of ground reaction forces during foot contact. Three-dimensional kinematic and kinetic data were analyzed for 18 children ranging in age from 11.5 to 43.1 months. Early steppers used a flat foot contact (FFC) and experienced relatively high vertical and resultant GRFs with COP often anterior to the calcaneus. More experienced walkers used an initial heel contact (IHC) in which GRFs were significantly lower but the center of pressure remained under the heel a greater proportion of time. Thus, during FFC the foot experienced higher loading, but the heel itself was relatively wider and the load was distributed more evenly. In IHC walkers load was concentrated on the anterior calcaneus and a narrower heel, suggesting a need for increased calcaneal robusticity during development to mitigate injury. These results provide new insight into foot loading outside of typical mature contact patterns, inform structure-function relationships during development, and illuminate potential causes of heel injury in young walkers.

In this study we investigated balancing responses to lateral perturbations during slow walking (0.85m/s). A group of seven healthy individuals walked on an instrumented treadmill while being perturbed at the level of waist at left heel strike in outward and inward lateral directions. Centre of mass (COM) and centre of pressure (COP), rotation of pelvis around vertical axis, step lengths, step widths and step times were assessed. The results have shown that beside control of COP in lateral direction, facilitated by adequate step widths, control of COP in sagittal direction, slowing down movement of COM was present after commencement of lateral perturbations. Sagittal component of COM was significantly retarded as compared to unperturbed walking for both inward (4.32±1.29cm) and outward (9.75±2.17cm) perturbations. This was necessary since after an inward perturbation first step length (0.29±0.04m compared to 0.52±0.02m in unperturbed walking) and step time (0.45±0.05s compared to 0.61±0.04s in unperturbed walking) were shortened while after an outward perturbation first two step lengths (0.36±0.05m and 0.32±0.11m compared to 0.52±0.03m in unperturbed walking) were shortened that needed to be accommodated by the described modulation of COP in sagittal plane. In addition pronounced pelvis rotation assisted in bringing swing leg to new location. The results of this study show that counteracting lateral perturbations at slow walking requires adequate response in all three planes of motion.

Wear and fatigue of polyethylene acetabular cups have been reported to play a role in the failure of total hip replacements. Hip simulator testing under a wide range of clinically relevant loading conditions is important. Edge loading of hip replacements can occur following impingement under extreme activities and can also occur during normal gait, where there is an offset deficiency and/or joint laxity. This study evaluated a hip simulator method that assessed wear and damage in polyethylene acetabular liners that were subjected to edge loading. The liners tested to evaluate the method were a currently manufactured crosslinked polyethylene acetabular liner and an aged conventional polyethylene acetabular liner. The acetabular liners were tested for 5 million standard walking cycles and following this 5 million walking cycles with edge loading. Edge loading conditions represented a separation of the centers of rotation of the femoral head and the acetabular liner during the swing phase, leading to loading of the liner rim on heel strike. Rim damage and cracking was observed in the aged conventional polyethylene liner. Steady‐state wear rates assessed gravimetrically were lower under edge loading compared to standard loading. This study supports previous clinical findings that edge loading may cause rim cracking in liners, where component positioning is suboptimal or where material degradation is present. The simulation method developed has the potential to be used in the future to test the effect of aging and different levels of severity of edge loading on a range of cross‐linked polyethylene materials.

The aims of this study were to investigate the ankle position, the changes and persistence of ankle kinematics after neuromuscular training in athletes with chronic ankle instability (CAI). A total of 21 national women’s field hockey players participated (CAI = 12, control = 9). Ankle position at heel strike (HS), midstance (MS), and toe touch (TT) in the frontal plane during walking, running and landing were measured using 3D motion analysis. A 6-week neuromuscular training program was undertaken by the CAI group. Measurements of kinematic data for both groups were measured at baseline and the changes in kinematic data for CAI group were measured at 6 and 24 weeks. The kinematic data at HS during walking and running demonstrated that the magnitude of the eversion in the CAI group (−5.00° and −4.21°) was less than in the control group (−13.45°and −9.62°). The kinematic data at MS also exhibited less ankle eversion in the CAI group (−9.36° and −8.18°) than in the control group (−18.52° and −15.88°). Ankle positions at TT during landing were comparable between groups. Following the 6-week training, the CAI participants demonstrated a less everted ankle at HS during walking and running (−1.77° and −1.76°) compared to the previous positions. They also showed less ankle eversion at MS (−5.14° and −4.19°). Ankle orientation at TT changed significantly to an inverted ankle position (from −0.26° to 4.11°). The ankle kinematics were restored back to the previous positions at 24 weeks except for landing. It appeared that athletes with unstable ankle had a relatively inverted ankle position, and that 6-week neuromuscular training had an immediate effect on changing ankle orientation toward a less everted direction. The changed ankle kinematics seemed to persist during landing but not during walking and running.

The purpose of this study was to examine whether wearing compression socks (CS) and smooth socks (SS) during running could change the kinematics parameters among experienced and novice runners. Kinematic parameters which include the ground contact time, stride length, swing time and heel strike were measured to compare the effects between compression and smooth socks. Eight experience and eight novice runners (Age 23.6 ± 1.4 years) were selected for this study. All participants were required to complete a laboratory-based Bruce protocol treadmill test with two different sock conditions (CS and SS) which being separated by seven days of washout periods. The kinematics parameters were determined during four constant submaximal speeds of stage 1, 2, 3 and 4 and were measured during last 30 s of each stage. Data on kinematic parameters were analysed using mixed-model ANOVA. Results revealed that there were significant differences (p < .05) only for the novice runners while wearing the CS as compared to SS (significantly higher values of swing time, stride length and heel strike). The findings of this study suggest that wearing compression socks seems to significantly alter running kinematics in novice runners.