Pub Date : 2025-12-14DOI: 10.1016/j.gaitpost.2025.110084
Mark S. Redfern
Background
There are numerous measures of standing balance using force plates presented in the literature. Two of the most common measures are the root-mean-square (RMS) and mean velocity (MV) of the Center of Pressure (CoP). The purpose of this short communication is to promote a greater understanding of the implications of these two common metrics.
Research question
What aspects of postural control do the RMS and MV of the CoP measure?
Methods
CoP time series measured with a force plate and CoM calculated from motion capture during quiet standing in the AP and ML directions were analyzed. The RMS and MV of the CoP, Center of Mass (CoM), and the difference between the CoP and the CoM (CoP-CoM) were calculated. The relationships among these measures are presented.
Results
The CoPRMS was highly correlated with the CoMRMS (r > .96), indicating that CoPRMS measures the amount of sway. The CoPMV was highly correlated with (CoP-CoM)RMS (r > .90). The (CoP-CoM)RMS is related to the torque generation used to maintain stability; therefore CoPMV is related to the control effort used. The AP and ML measures do have some different characteristics due to the mechanism by which stability is maintained.
Significance
The RMS and MV of CoP are effective at capturing two different fundamental aspects of stability: the amount of sway and control effort. This highlights the importance of reporting both CoPRMS and CoPMV to allow for a better understanding of standing balance.
{"title":"Interpreting common standing postural sway measures","authors":"Mark S. Redfern","doi":"10.1016/j.gaitpost.2025.110084","DOIUrl":"10.1016/j.gaitpost.2025.110084","url":null,"abstract":"<div><h3>Background</h3><div>There are numerous measures of standing balance using force plates presented in the literature. Two of the most common measures are the root-mean-square (RMS) and mean velocity (MV) of the Center of Pressure (CoP). The purpose of this short communication is to promote a greater understanding of the implications of these two common metrics.</div></div><div><h3>Research question</h3><div>What aspects of postural control do the RMS and MV of the CoP measure?</div></div><div><h3>Methods</h3><div>CoP time series measured with a force plate and CoM calculated from motion capture during quiet standing in the AP and ML directions were analyzed. The RMS and MV of the CoP, Center of Mass (CoM), and the difference between the CoP and the CoM (CoP-CoM) were calculated. The relationships among these measures are presented.</div></div><div><h3>Results</h3><div>The <em>CoP</em><sub><em>RMS</em></sub> was highly correlated with the <em>CoM</em><sub><em>RMS</em></sub> (r > .96), indicating that <em>CoP</em><sub><em>RMS</em></sub> measures the amount of sway. The <em>CoP</em><sub><em>MV</em></sub> was highly correlated with (<em>CoP-CoM)</em><sub><em>RMS</em></sub> (r > .90). The (<em>CoP-CoM)</em><sub><em>RMS</em></sub> is related to the torque generation used to maintain stability; therefore <em>CoP</em><sub><em>MV</em></sub> is related to the control effort used. The AP and ML measures do have some different characteristics due to the mechanism by which stability is maintained.</div></div><div><h3>Significance</h3><div>The RMS and MV of CoP are effective at capturing two different fundamental aspects of stability: the amount of sway and control effort. This highlights the importance of reporting both <em>CoP</em><sub><em>RMS</em></sub> and <em>CoP</em><sub><em>MV</em></sub> to allow for a better understanding of standing balance.</div></div>","PeriodicalId":12496,"journal":{"name":"Gait & posture","volume":"125 ","pages":"Article 110084"},"PeriodicalIF":2.4,"publicationDate":"2025-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145784092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-13DOI: 10.1016/j.gaitpost.2025.110083
Jianqi Pan , Zixiang Gao , Zhanyi Zhou , Diwei Chen , Fengping Li , Julien S. Baker , Yaodong Gu
Objective
Artificial intelligence (AI) methods have been widely applied in gait analysis, yet quantitative comparisons across models and their input–output specifications remain limited. This study aims to systematically review and synthesize the existing literature to evaluate the effectiveness of AI methods in predicting lower limb joint moments during typically developed (TD) gait.
Methods
Relevant studies published before July 1, 2025, were retrieved from five databases (PubMed, Scopus, IEEE Xplore, ScienceDirect, and Web of Science) using Boolean logic operations and were screened according to predefined criteria. Risk of bias and applicability were assessed with PROBAST. Meta-analyses were performed in R using a multilevel random-effects model to examine differences in predictive performance across AI model group, signal input type, and output joints.
Results
Eleven studies involving 371 TD participants met the inclusion criteria. Deep neural networks (DNN) showed the best performance for R2 (0.88, 95 %CI 0.52–1.24), while traditional machine learning (ML) models demonstrated relative superiority for nRMSE (0.11, 95 %CI 0.06–0.29). Among input types, surface EMG (sEMG) achieved the highest R2 (0.96, 95 %CI 0.04–1.89), whereas all inputs except “kinematic and speed and anthropometrics” performed well in the nRMSE analysis. For output joints, the ankle was significantly superior to both the knee (p < 0.001) and the hip (p < 0.001) in terms of R2 and nRMSE.
Conclusion
AI methods can effectively predict lower limb joint moments during TD gait, but differences exist across model group, input type, and output joints. DNN show advantages in fitting complex data, while traditional ML demonstrates greater robustness in small-sample settings. The sEMG, as a process-related input, exhibits high potential, and predictions for the ankle joint are generally superior. Future studies should expand sample size, explore multimodal inputs and advanced modeling strategies, and further validate the applicability of AI methods in pathological gait.
{"title":"Artificial intelligence in lower limb joint moment prediction during typically developed gait: A systematic review and multilevel random-effects meta-analysis","authors":"Jianqi Pan , Zixiang Gao , Zhanyi Zhou , Diwei Chen , Fengping Li , Julien S. Baker , Yaodong Gu","doi":"10.1016/j.gaitpost.2025.110083","DOIUrl":"10.1016/j.gaitpost.2025.110083","url":null,"abstract":"<div><h3>Objective</h3><div>Artificial intelligence (AI) methods have been widely applied in gait analysis, yet quantitative comparisons across models and their input–output specifications remain limited. This study aims to systematically review and synthesize the existing literature to evaluate the effectiveness of AI methods in predicting lower limb joint moments during typically developed (TD) gait.</div></div><div><h3>Methods</h3><div>Relevant studies published before July 1, 2025, were retrieved from five databases (PubMed, Scopus, IEEE Xplore, ScienceDirect, and Web of Science) using Boolean logic operations and were screened according to predefined criteria. Risk of bias and applicability were assessed with PROBAST. Meta-analyses were performed in R using a multilevel random-effects model to examine differences in predictive performance across AI model group, signal input type, and output joints.</div></div><div><h3>Results</h3><div>Eleven studies involving 371 TD participants met the inclusion criteria. Deep neural networks (DNN) showed the best performance for R<sup>2</sup> (0.88, 95 %CI 0.52–1.24), while traditional machine learning (ML) models demonstrated relative superiority for nRMSE (0.11, 95 %CI 0.06–0.29). Among input types, surface EMG (sEMG) achieved the highest R<sup>2</sup> (0.96, 95 %CI 0.04–1.89), whereas all inputs except “kinematic and speed and anthropometrics” performed well in the nRMSE analysis. For output joints, the ankle was significantly superior to both the knee (<em>p</em> < 0.001) and the hip (<em>p</em> < 0.001) in terms of R<sup>2</sup> and nRMSE.</div></div><div><h3>Conclusion</h3><div>AI methods can effectively predict lower limb joint moments during TD gait, but differences exist across model group, input type, and output joints. DNN show advantages in fitting complex data, while traditional ML demonstrates greater robustness in small-sample settings. The sEMG, as a process-related input, exhibits high potential, and predictions for the ankle joint are generally superior. Future studies should expand sample size, explore multimodal inputs and advanced modeling strategies, and further validate the applicability of AI methods in pathological gait.</div></div>","PeriodicalId":12496,"journal":{"name":"Gait & posture","volume":"125 ","pages":"Article 110083"},"PeriodicalIF":2.4,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145784038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-11DOI: 10.1016/j.gaitpost.2025.110082
Maxwell D. Smith, Rebecca L. Wong, Derek N. Pamukoff
Background
Bone responds to loading by accruing areal bone mineral density (BMD). Distance runners experience a ground reaction force (GRF) during exercise which contributes to bone loading. Sex differences in BMD reflect that males and females respond differently to running-imposed GRF.
Research question
What is the relationship between GRF and BMD in male and female runners?
Methods
Forty participants (20 male; age=25.1 ± 4.5 years; height=1.7 ± 0.1 m; mass=67.2 ± 11.5 kg) who routinely participated in distance running (44.0 ± 26.1 km/week over 4.5 ± 1.5 weekly sessions for the past 6.9 ± 5.2 years) underwent dual x-ray absorptiometry to calculate BMD and ran on a force-instrumented treadmill to measure vertical GRF characteristics at a self-selected (SS) and at a standardized pace (SP; 3.33 m/s). Independent samples t-tests compared outcomes between males and females. Pearson correlation examined associations between GRF and BMD separately based on sex.
Results
Absolute GRF and BMD outcomes were consistently lower in females compared with males (all p < 0.05). At SS, greater BMD in some sites was associated with greater vertical GRF (r = 0.582–0.793, p < 0.001–0.007), vertical loading rate (r = 0.459–0.626, p = 0.003–0.042), and vertical impulse (r = 0.518–0.759, p < 0.001–0.019) in males. Greater BMD in some sites was also associated with greater vertical GRF (r = 0.550–0.736, p < 0.001–0.012), vertical loading rate (r = 0.495–0.718, p < 0.001–0.026), and vertical impulse (r = 0.478–0.755, p < 0.001–0.033) in males at SP. There were no associations between BMD and GRF in females at either pace (r = -0.095–0.360, p = 0.130–0.983).
Significance
The associations between GRF and BMD in runners differ between males and females. Supplemental training methods may be necessary for female runners to influence BMD.
{"title":"Association between bone mineral density and ground reaction force in male and female runners","authors":"Maxwell D. Smith, Rebecca L. Wong, Derek N. Pamukoff","doi":"10.1016/j.gaitpost.2025.110082","DOIUrl":"10.1016/j.gaitpost.2025.110082","url":null,"abstract":"<div><h3>Background</h3><div>Bone responds to loading by accruing areal bone mineral density (BMD). Distance runners experience a ground reaction force (GRF) during exercise which contributes to bone loading. Sex differences in BMD reflect that males and females respond differently to running-imposed GRF.</div></div><div><h3>Research question</h3><div>What is the relationship between GRF and BMD in male and female runners?</div></div><div><h3>Methods</h3><div>Forty participants (20 male; age=25.1 ± 4.5 years; height=1.7 ± 0.1 m; mass=67.2 ± 11.5 kg) who routinely participated in distance running (44.0 ± 26.1 km/week over 4.5 ± 1.5 weekly sessions for the past 6.9 ± 5.2 years) underwent dual x-ray absorptiometry to calculate BMD and ran on a force-instrumented treadmill to measure vertical GRF characteristics at a self-selected (SS) and at a standardized pace (SP; 3.33 m/s). Independent samples t-tests compared outcomes between males and females. Pearson correlation examined associations between GRF and BMD separately based on sex.</div></div><div><h3>Results</h3><div>Absolute GRF and BMD outcomes were consistently lower in females compared with males (all p < 0.05). At SS, greater BMD in some sites was associated with greater vertical GRF (r = 0.582–0.793, <em>p</em> < 0.001–0.007), vertical loading rate (r = 0.459–0.626, <em>p</em> = 0.003–0.042), and vertical impulse (r = 0.518–0.759, <em>p</em> < 0.001–0.019) in males. Greater BMD in some sites was also associated with greater vertical GRF (r = 0.550–0.736, <em>p</em> < 0.001–0.012), vertical loading rate (r = 0.495–0.718, <em>p</em> < 0.001–0.026), and vertical impulse (r = 0.478–0.755, <em>p</em> < 0.001–0.033) in males at SP. There were no associations between BMD and GRF in females at either pace (r = -0.095–0.360, <em>p</em> = 0.130–0.983).</div></div><div><h3>Significance</h3><div>The associations between GRF and BMD in runners differ between males and females. Supplemental training methods may be necessary for female runners to influence BMD.</div></div>","PeriodicalId":12496,"journal":{"name":"Gait & posture","volume":"125 ","pages":"Article 110082"},"PeriodicalIF":2.4,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145776376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-06DOI: 10.1016/j.gaitpost.2025.110077
Chu-Fen Chang , Anne Dixie M. Lim , Shih-Wun Hong , Tung-Wu Lu , Kelly I.-Rong Lee
Introduction
Assessing the interaction between the body’s center of mass (COM) and center of pressure (COP) during gait provides valuable insights into dynamic balance control. However, traditional motion capture methods are costly and impractical in clinical settings, highlighting the need for accessible alternatives. This study utilizes force plate data to explore the use of ANNs in predicting the motion of the COM relative to the COP during walking.
Materials and Methods
Eighty-four healthy adults (50 young, 34 older) performed gait trials on a walkway with motion capture and force plate data collection. Ground reaction forces (GRFs) and COM-COP distances (dCOM) were computed for the stance phase. Multi-layer perceptron (MLP) artificial neural network (ANN) models were developed to predict dCOM in the anteroposterior (AP) and mediolateral (ML) directions as well as COM height based on GRFs and anthropometric inputs. Model performance was evaluated using root mean squared error (RMSE) and coefficient of determination (R2).
Results
ANN models achieved high predictive accuracy with optimal hidden layer sizes of 5 (AP, COM height) and 9 (ML). RMSE values ranged from 0.89 % to 7.77 %LL, with R2 values between 0.74 and 0.92. Significant age-related differences were observed in ML direction and COM height (p < 0.05), but not in AP.
Conclusion
This study highlights ANN models as accurate, low-cost tools for dynamic balance assessment, reliably predicting dCOM across directions. The consistency between calculated and predicted group differences supports their application in fall risk evaluation and personalized intervention planning for older adult populations.
{"title":"Predicting the distance between the center of mass and center of pressure during walking in the young and elder population based on ground reaction forces using artificial neural network","authors":"Chu-Fen Chang , Anne Dixie M. Lim , Shih-Wun Hong , Tung-Wu Lu , Kelly I.-Rong Lee","doi":"10.1016/j.gaitpost.2025.110077","DOIUrl":"10.1016/j.gaitpost.2025.110077","url":null,"abstract":"<div><h3>Introduction</h3><div>Assessing the interaction between the body’s center of mass (COM) and center of pressure (COP) during gait provides valuable insights into dynamic balance control. However, traditional motion capture methods are costly and impractical in clinical settings, highlighting the need for accessible alternatives. This study utilizes force plate data to explore the use of ANNs in predicting the motion of the COM relative to the COP during walking.</div></div><div><h3>Materials and Methods</h3><div>Eighty-four healthy adults (50 young, 34 older) performed gait trials on a walkway with motion capture and force plate data collection. Ground reaction forces (GRFs) and COM-COP distances (dCOM) were computed for the stance phase. Multi-layer perceptron (MLP) artificial neural network (ANN) models were developed to predict dCOM in the anteroposterior (AP) and mediolateral (ML) directions as well as COM height based on GRFs and anthropometric inputs. Model performance was evaluated using root mean squared error (RMSE) and coefficient of determination (R<sup>2</sup>).</div></div><div><h3>Results</h3><div>ANN models achieved high predictive accuracy with optimal hidden layer sizes of 5 (AP, COM height) and 9 (ML). RMSE values ranged from 0.89 % to 7.77 %LL, with R<sup>2</sup> values between 0.74 and 0.92. Significant age-related differences were observed in ML direction and COM height (p < 0.05), but not in AP.</div></div><div><h3>Conclusion</h3><div>This study highlights ANN models as accurate, low-cost tools for dynamic balance assessment, reliably predicting dCOM across directions. The consistency between calculated and predicted group differences supports their application in fall risk evaluation and personalized intervention planning for older adult populations.</div></div>","PeriodicalId":12496,"journal":{"name":"Gait & posture","volume":"125 ","pages":"Article 110077"},"PeriodicalIF":2.4,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-05DOI: 10.1016/j.gaitpost.2025.110066
Sara Mahmoudzadeh Khalili, Diané Brown, Caroline Simpkins, Feng Yang
Background
Perturbation-based training has emerged as a promising intervention to enhance balance recovery strategies.
Research Question
Can healthy young adults quickly adapt to repeated backward surface translations while standing on a treadmill?
Methods
In this cross-sectional study, 20 young adults completed five treadmill-induced backward surface translations during standing. The primary outcome was dynamic gait stability at perturbation onset (ON), recovery step liftoff (LO), and touchdown (TD). Secondary outcomes included center of mass (COM) position and velocity, recovery step performance (latency, duration, length, and speed), belt displacement at LO, trunk movements (angle and angular velocity), ankle angle at ON, and integrated electromyography (EMG) of bilateral leg muscles (tibialis anterior, TA, gastrocnemius, GA, rectus femoris, RF, and biceps femoris, BF).
Results
Participants were more stable at ON (p = 0.004), LO (p ≤ 0.001), and TD (p = 0.047) on later trials than on earlier trials. Recovery step latency (p ≤ 0.001), duration (p ≤ 0.001), speed (p = 0.006), and length (p = 0.015) improved across trials. Other secondary outcomes also showed significant improvements across trials: less forward-leaning and rotating trunk at LO and TD (p ≤ 0.001), increased integrated EMG for TA, GA, and RF on the stepping leg (p ≤ 0.017) and all muscles on the standing leg (p ≤ 0.033) before ON, and reduced integrated EMG for TA, RF, and BF on both legs (p ≤ 0.047) between ON and TD.
Significance
Repeated treadmill-induced backward surface translations during standing enhanced lower-limb muscle activation, recovery step performance, and trunk movement control, thereby improving dynamic stability proactively and reactively. The findings may elucidate mechanisms for balance recovery after a trip-like postural perturbation.
{"title":"Adaptation to repeated backward surface translations in healthy young adults: A kinematic elucidation of trip-based perturbation training for preventing falls","authors":"Sara Mahmoudzadeh Khalili, Diané Brown, Caroline Simpkins, Feng Yang","doi":"10.1016/j.gaitpost.2025.110066","DOIUrl":"10.1016/j.gaitpost.2025.110066","url":null,"abstract":"<div><h3>Background</h3><div>Perturbation-based training has emerged as a promising intervention to enhance balance recovery strategies.</div></div><div><h3>Research Question</h3><div>Can healthy young adults quickly adapt to repeated backward surface translations while standing on a treadmill?</div></div><div><h3>Methods</h3><div>In this cross-sectional study, 20 young adults completed five treadmill-induced backward surface translations during standing. The primary outcome was dynamic gait stability at perturbation onset (ON), recovery step liftoff (LO), and touchdown (TD). Secondary outcomes included center of mass (COM) position and velocity, recovery step performance (latency, duration, length, and speed), belt displacement at LO, trunk movements (angle and angular velocity), ankle angle at ON, and integrated electromyography (EMG) of bilateral leg muscles (tibialis anterior, TA, gastrocnemius, GA, rectus femoris, RF, and biceps femoris, BF).</div></div><div><h3>Results</h3><div>Participants were more stable at ON (<em>p</em> = 0.004), LO (<em>p</em> ≤ 0.001), and TD (<em>p</em> = 0.047) on later trials than on earlier trials. Recovery step latency (<em>p</em> ≤ 0.001), duration (<em>p</em> ≤ 0.001), speed (<em>p</em> = 0.006), and length (<em>p</em> = 0.015) improved across trials. Other secondary outcomes also showed significant improvements across trials: less forward-leaning and rotating trunk at LO and TD (<em>p</em> ≤ 0.001), increased integrated EMG for TA, GA, and RF on the stepping leg (<em>p</em> ≤ 0.017) and all muscles on the standing leg (<em>p</em> ≤ 0.033) before ON, and reduced integrated EMG for TA, RF, and BF on both legs (<em>p</em> ≤ 0.047) between ON and TD.</div></div><div><h3>Significance</h3><div>Repeated treadmill-induced backward surface translations during standing enhanced lower-limb muscle activation, recovery step performance, and trunk movement control, thereby improving dynamic stability proactively and reactively. The findings may elucidate mechanisms for balance recovery after a trip-like postural perturbation.</div></div>","PeriodicalId":12496,"journal":{"name":"Gait & posture","volume":"125 ","pages":"Article 110066"},"PeriodicalIF":2.4,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145717096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-04DOI: 10.1016/j.gaitpost.2025.110067
Tatsuya Igarashi , Shota Hayashi , Shingo Hirano , Kazusa Saisu , Hironobu Kakima , Yuta Tani , Hiroyuki Inooka
Background
The instrumented modified Clinical Test of Sensory Interaction on Balance (i-mCTSIB) assesses sensory contributions to postural control using Center of Pressure (CoP) data. Existing composite scores do not reflect task difficulty or sensory weighting across conditions.
Objectives
This study developed a regression-based new composite score and examined its ability to discriminate walking independence and its correlation with standard balance measures in subacute stroke.
Methods
This study included 54 patients with first-ever stroke. Postural control was evaluated under four i-mCTSIB conditions combining visual input and surface type. Total CoP path length was recorded, and a composite score was derived using regression analysis. Discriminative ability for walking independence was assessed via receiver operating characteristic analysis, and area under the curve (AUC) values were compared. Measures with AUC > 0.80 were further tested for construct validity using the Mini-Balance Evaluation Systems Test (Mini-BESTest).
Results
The i-mCTSIB composite score demonstrated an AUC of 0.84 (95 % CI: 0.69–0.98), exceeding the threshold of 0.80 and outperforming all individual test conditions, which showed AUCs below 0.80. The composite score also showed a moderate correlation with the Mini-BESTest (r̄ = 0.48, 95 % CI: 0.24–0.67, p < 0.001).
Conclusions
This study developed a novel composite score for the i-mCTSIB that quantitatively reflects sensory integration in postural control and demonstrated its superior ability to discriminate walking independence in patients with subacute stroke. Further investigations are required to evaluate whether these findings generalize to additional CoP parameters.
{"title":"Development and validity of composite scores for the instrumented-modified Clinical Test of Sensory Interaction in Balance in inpatients with subacute stroke","authors":"Tatsuya Igarashi , Shota Hayashi , Shingo Hirano , Kazusa Saisu , Hironobu Kakima , Yuta Tani , Hiroyuki Inooka","doi":"10.1016/j.gaitpost.2025.110067","DOIUrl":"10.1016/j.gaitpost.2025.110067","url":null,"abstract":"<div><h3>Background</h3><div>The instrumented modified Clinical Test of Sensory Interaction on Balance (i-mCTSIB) assesses sensory contributions to postural control using Center of Pressure (CoP) data. Existing composite scores do not reflect task difficulty or sensory weighting across conditions.</div></div><div><h3>Objectives</h3><div>This study developed a regression-based new composite score and examined its ability to discriminate walking independence and its correlation with standard balance measures in subacute stroke.</div></div><div><h3>Methods</h3><div>This study included 54 patients with first-ever stroke. Postural control was evaluated under four i-mCTSIB conditions combining visual input and surface type. Total CoP path length was recorded, and a composite score was derived using regression analysis. Discriminative ability for walking independence was assessed via receiver operating characteristic analysis, and area under the curve (AUC) values were compared. Measures with AUC > 0.80 were further tested for construct validity using the Mini-Balance Evaluation Systems Test (Mini-BESTest).</div></div><div><h3>Results</h3><div>The i-mCTSIB composite score demonstrated an AUC of 0.84 (95 % CI: 0.69–0.98), exceeding the threshold of 0.80 and outperforming all individual test conditions, which showed AUCs below 0.80. The composite score also showed a moderate correlation with the Mini-BESTest (r̄ = 0.48, 95 % CI: 0.24–0.67, p < 0.001).</div></div><div><h3>Conclusions</h3><div>This study developed a novel composite score for the i-mCTSIB that quantitatively reflects sensory integration in postural control and demonstrated its superior ability to discriminate walking independence in patients with subacute stroke. Further investigations are required to evaluate whether these findings generalize to additional CoP parameters.</div></div>","PeriodicalId":12496,"journal":{"name":"Gait & posture","volume":"125 ","pages":"Article 110067"},"PeriodicalIF":2.4,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145703629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-04DOI: 10.1016/j.gaitpost.2025.110070
Amy B. Zavatsky , Po-Hsiang Chan , Julie Stebbins
Background
Although there is general agreement about the longitudinal division of the foot into segments for clinical gait analysis, there is limited evidence on which to base decisions about mediolateral segmentation, particularly in the metatarsal region.
Research question
We investigate how best to divide the metatarsals mediolaterally by considering both segment rigidity and angular motion.
Methods
Motion capture data were collected on 45 healthy adults during barefoot walking. The rigidities of ten subunits of adjacent metatarsals were quantified. Segment axes were defined for a selection of subunits and their three-dimensional angular motions calculated relative to an Oxford Foot Model (OFM) hindfoot segment.
Results
Subunits of metatarsals 2–3 and 3–4 were equally the most rigid, followed by subunit 2–3–4. Medial metatarsal groups were more rigid than lateral groups. Model A (metatarsal subunits 1–2–3 & 4–5), Model B (1–2 & 3–4–5), and Model C (1& 2–3–4 & 5) all had angular motion significantly different from the OFM forefoot for most of the gait cycle. There were significant differences between the motions of the medial and lateral subunits of Models A and B. The central subunit of Model C moved more like the medial subunits in dorsiflexion and more like the lateral subunits in adduction.
Significance
The forefoot models examined represent the minimum complexity required to capture metatarsal motion during walking. A mediolateral division of the forefoot at or adjacent to the third metatarsal is one option. The alternative is a three-segment model with a central subunit and separate first and fifth metatarsals.
{"title":"Medio-lateral forefoot segmentation for clinical gait analysis based on metatarsal subunit rigidity and angular motion","authors":"Amy B. Zavatsky , Po-Hsiang Chan , Julie Stebbins","doi":"10.1016/j.gaitpost.2025.110070","DOIUrl":"10.1016/j.gaitpost.2025.110070","url":null,"abstract":"<div><h3>Background</h3><div>Although there is general agreement about the longitudinal division of the foot into segments for clinical gait analysis, there is limited evidence on which to base decisions about mediolateral segmentation, particularly in the metatarsal region.</div></div><div><h3>Research question</h3><div>We investigate how best to divide the metatarsals mediolaterally by considering both segment rigidity and angular motion.</div></div><div><h3>Methods</h3><div>Motion capture data were collected on 45 healthy adults during barefoot walking. The rigidities of ten subunits of adjacent metatarsals were quantified. Segment axes were defined for a selection of subunits and their three-dimensional angular motions calculated relative to an Oxford Foot Model (OFM) hindfoot segment.</div></div><div><h3>Results</h3><div>Subunits of metatarsals 2–3 and 3–4 were equally the most rigid, followed by subunit 2–3–4. Medial metatarsal groups were more rigid than lateral groups. Model A (metatarsal subunits 1–2–3 & 4–5), Model B (1–2 & 3–4–5), and Model C (1& 2–3–4 & 5) all had angular motion significantly different from the OFM forefoot for most of the gait cycle. There were significant differences between the motions of the medial and lateral subunits of Models A and B. The central subunit of Model C moved more like the medial subunits in dorsiflexion and more like the lateral subunits in adduction.</div></div><div><h3>Significance</h3><div>The forefoot models examined represent the minimum complexity required to capture metatarsal motion during walking. A mediolateral division of the forefoot at or adjacent to the third metatarsal is one option. The alternative is a three-segment model with a central subunit and separate first and fifth metatarsals.</div></div>","PeriodicalId":12496,"journal":{"name":"Gait & posture","volume":"125 ","pages":"Article 110070"},"PeriodicalIF":2.4,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145727807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-04DOI: 10.1016/j.gaitpost.2025.110069
Yu-Lin Yen, Yun-Ju Lee
Background
Gait intention is typically detected using electroencephalogram (EEG) and primarily focuses on recognizing the initiation of walking. Recently, wearable sensors have been extensively used to classify different walking patterns.
Research questions
The study was aimed to investigate the effectiveness of Inertial Measurement Units (IMUs) in recognizing directional change intentions during gait, hypothesizing that distinct patterns exist that indicate the initiation of turning before actual turning movements occur.
Methods
Twenty healthy participants performed one to two gait cycles before directional changes during straight walking, a 45-degree right turn, and a 90-degree right turn. Seven IMUs were attached to various body segments, and a matching network combined with sliding window bidirectional gated recurrent units was used to recognize turning intentions. The EEG data analysis was used by EEGLAB to determine the event-related desynchronization in the alpha (8–13 Hz) and beta (14–30 Hz) frequency bands.
Results
The results showed that the model using different combinations of IMU sensors achieved an optimal accuracy of 96.80 %, with several combinations exceeding 95 %. Subtle movements in different body segments were sufficient to predict upcoming turning intentions. The accuracy dropped to 83.79 % in the model that excluded data from the head segment, while the other models that included the head segment achieved over 94 % accuracy. Furthermore, angular acceleration data was notably more accurate, at 93.46 %, compared to 88.43 % for acceleration data alone.
Significance
Successfully highlighted the crucial role of sensing contralateral body and head segments, providing insights into the model's interpretability. The use of IMUs for gait turning intention recognition shows promise in replacing devices that rely on sensing brain waves. Furthermore, this approach opens possibilities for applications such as controlling exoskeletons, including assisting walking robots with strategically placed sensors.
{"title":"Recognizing intentions with body segmental cues of gait cycles before direction change during continuous walking","authors":"Yu-Lin Yen, Yun-Ju Lee","doi":"10.1016/j.gaitpost.2025.110069","DOIUrl":"10.1016/j.gaitpost.2025.110069","url":null,"abstract":"<div><h3>Background</h3><div>Gait intention is typically detected using electroencephalogram (EEG) and primarily focuses on recognizing the initiation of walking. Recently, wearable sensors have been extensively used to classify different walking patterns.</div></div><div><h3>Research questions</h3><div>The study was aimed to investigate the effectiveness of Inertial Measurement Units (IMUs) in recognizing directional change intentions during gait, hypothesizing that distinct patterns exist that indicate the initiation of turning before actual turning movements occur.</div></div><div><h3>Methods</h3><div>Twenty healthy participants performed one to two gait cycles before directional changes during straight walking, a 45-degree right turn, and a 90-degree right turn. Seven IMUs were attached to various body segments, and a matching network combined with sliding window bidirectional gated recurrent units was used to recognize turning intentions. The EEG data analysis was used by EEGLAB to determine the event-related desynchronization in the alpha (8–13 Hz) and beta (14–30 Hz) frequency bands.</div></div><div><h3>Results</h3><div>The results showed that the model using different combinations of IMU sensors achieved an optimal accuracy of 96.80 %, with several combinations exceeding 95 %. Subtle movements in different body segments were sufficient to predict upcoming turning intentions. The accuracy dropped to 83.79 % in the model that excluded data from the head segment, while the other models that included the head segment achieved over 94 % accuracy. Furthermore, angular acceleration data was notably more accurate, at 93.46 %, compared to 88.43 % for acceleration data alone.</div></div><div><h3>Significance</h3><div>Successfully highlighted the crucial role of sensing contralateral body and head segments, providing insights into the model's interpretability. The use of IMUs for gait turning intention recognition shows promise in replacing devices that rely on sensing brain waves. Furthermore, this approach opens possibilities for applications such as controlling exoskeletons, including assisting walking robots with strategically placed sensors.</div></div>","PeriodicalId":12496,"journal":{"name":"Gait & posture","volume":"125 ","pages":"Article 110069"},"PeriodicalIF":2.4,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145665544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-29DOI: 10.1016/j.gaitpost.2025.110063
Dyuti Deepta Rano , Love Kapoor , Venkatesan Sampath Kumar , Shamim Ahmed Shamim , Shah Alam Khan
Introduction
Patients undergoing proximal tibial endoprosthesis for bone tumors usually have a medial gastrocnemius flap for wound coverage, supposed to help in knee extension instead of normal flexor of the knee.
Objectives
1. Does medial gastrocnemius flap participates in knee extension during normal gait? 2. What are the gait changes following proximal tibial endoprosthesis?
Materials & methods
This cross-sectional observational study included 52 patients who had proximal tibial endoprosthesis between January 2008 to January 2020 for bone tumours and regained maximum function with independent ambulatory capacity. Instrumented gait analysis was done according to Helen-Hayes protocol with a special surface EMG probe placed over the flap. Tc 99 m three-phase bone scan was used to evaluate flap viability.
Results
Mean age was 27.92 ± 12.88 years and mean follow-up duration was 23.1 ± 4.2 months. Patients walked slower with mean velocity of 0.74 ± 0.23 m/s and mean cadence of 87.9 ± 10.3 steps/min. Mean knee flexion on the operated side was significantly decreased(89.42 ± 14.87° vs 125.38 ± 6.01°, p < 0.001). Mean swing time was significantly increased on the operated limb(0.56 ± 0.08 sec vs 0.46 ± 0.07 sec, p < 0.001) with consequent increase in mean single support phase on the normal limb(operated vs normal limb, 33.71 ± 5.05 % vs 40.81 ± 4.03 %, p < 0.001). Peak knee flexion in swing, total sagittal plane excursion, peak flexion loading response, peak knee extensor moment at early stance and peak ankle plantarflexion moment at stance decreased significantly on operated side. Electrical activity in the knee extensors decreased over the operated side. Bone scan confirmed flap viability in all.
Conclusion
The medial gastrocnemius flap primarily provides successful soft tissue coverage but does not consistently adopt a functional role in knee extension during gait. Patients' walking patterns remain slower and asymmetrical but well compensated post-reconstruction, adopting a stiff-knee gait pattern with features of quadriceps avoidance.
{"title":"Does transferred medial gastrocnemius flap help with knee extension during gait following proximal tibial endoprosthesis?","authors":"Dyuti Deepta Rano , Love Kapoor , Venkatesan Sampath Kumar , Shamim Ahmed Shamim , Shah Alam Khan","doi":"10.1016/j.gaitpost.2025.110063","DOIUrl":"10.1016/j.gaitpost.2025.110063","url":null,"abstract":"<div><h3>Introduction</h3><div>Patients undergoing proximal tibial endoprosthesis for bone tumors usually have a medial gastrocnemius flap for wound coverage, supposed to help in knee extension instead of normal flexor of the knee.</div></div><div><h3>Objectives</h3><div>1. Does medial gastrocnemius flap participates in knee extension during normal gait? 2. What are the gait changes following proximal tibial endoprosthesis?</div></div><div><h3>Materials & methods</h3><div>This cross-sectional observational study included 52 patients who had proximal tibial endoprosthesis between January 2008 to January 2020 for bone tumours and regained maximum function with independent ambulatory capacity. Instrumented gait analysis was done according to Helen-Hayes protocol with a special surface EMG probe placed over the flap. Tc 99 m three-phase bone scan was used to evaluate flap viability.</div></div><div><h3>Results</h3><div>Mean age was 27.92 ± 12.88 years and mean follow-up duration was 23.1 ± 4.2 months. Patients walked slower with mean velocity of 0.74 ± 0.23 m/s and mean cadence of 87.9 ± 10.3 steps/min. Mean knee flexion on the operated side was significantly decreased(89.42 ± 14.87° vs 125.38 ± 6.01°, p < 0.001). Mean swing time was significantly increased on the operated limb(0.56 ± 0.08 sec vs 0.46 ± 0.07 sec, p < 0.001) with consequent increase in mean single support phase on the normal limb(operated vs normal limb, 33.71 ± 5.05 % vs 40.81 ± 4.03 %, p < 0.001). Peak knee flexion in swing, total sagittal plane excursion, peak flexion loading response, peak knee extensor moment at early stance and peak ankle plantarflexion moment at stance decreased significantly on operated side. Electrical activity in the knee extensors decreased over the operated side. Bone scan confirmed flap viability in all.</div></div><div><h3>Conclusion</h3><div>The medial gastrocnemius flap primarily provides successful soft tissue coverage but does not consistently adopt a functional role in knee extension during gait. Patients' walking patterns remain slower and asymmetrical but well compensated post-reconstruction, adopting a stiff-knee gait pattern with features of quadriceps avoidance.</div></div>","PeriodicalId":12496,"journal":{"name":"Gait & posture","volume":"124 ","pages":"Article 110063"},"PeriodicalIF":2.4,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145662892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-29DOI: 10.1016/j.gaitpost.2025.110068
Hyeon-Deok Jo , Maeng-Kyu Kim
Background
Neuromuscular fatigue impairs force steadiness and alters motor unit (MU) behavior. However, it remains unclear how joint angle modulates the neuromuscular response to fatigue, especially in terms of MU characteristics and intermuscular coherence. This study examined the effects of fatigue and knee joint angle on MU behavior, force steadiness, and intermuscular coherence between the soleus (SOL) and gastrocnemius medialis (GM) during isometric plantarflexion.
Methods
Sixteen healthy males performed isometric plantarflexion at 30, 50, and 70 % of maximal voluntary isometric contraction (MVIC) in pre-and post-fatigue, under two knee joint conditions: straight leg (0°, STR) and bent leg (90°, BENT) positions, in a randomized order. Fatigue was induced via repeated sustained contractions at 60 % MVIC in each position. High-density surface electromyography from SOL and GM was decomposed to quantify MU parameters, including MU action potential amplitude (MUAP), firing rate (FR), recruitment threshold (ReTHR), and decruitment threshold (DeTHR). Intermuscular coherence between MU spike trains from SOL and GM was analyzed across frequency bands.
Results
Post-fatigue, MIVC decreased significantly in both the STR and BENT conditions (p < 0.01). Force steadiness significantly worsened post-fatigue in the BENT condition at 50 % (p < 0.01) and 70 % (p < 0.05). In SOL, MUAP and FR increased post-fatigue across all conditions, while GM showed more selective increases at higher intensities. SOL exhibited higher MUAP in the BENT condition, whereas GM showed greater activity in the STR condition. ReTHR in SOL and DeTHR in both muscles showed significant changes related to posture and fatigue. Notably, beta-band intermuscular coherence showed significant interaction effects at 50 % and 70 % (p < 0.05), with increased coherence in the BENT condition post-fatigue (p < 0.05).
Conclusions
Fatigue induces muscle-specific and posture-dependent neuromuscular adaptations, characterized by changes in MU properties and intermuscular coherence, particularly in the bent knee position.
{"title":"Fatigue-induced changes in motor unit behavior and intermuscular coherence across knee joint positions","authors":"Hyeon-Deok Jo , Maeng-Kyu Kim","doi":"10.1016/j.gaitpost.2025.110068","DOIUrl":"10.1016/j.gaitpost.2025.110068","url":null,"abstract":"<div><h3>Background</h3><div>Neuromuscular fatigue impairs force steadiness and alters motor unit (MU) behavior. However, it remains unclear how joint angle modulates the neuromuscular response to fatigue, especially in terms of MU characteristics and intermuscular coherence. This study examined the effects of fatigue and knee joint angle on MU behavior, force steadiness, and intermuscular coherence between the soleus (SOL) and gastrocnemius medialis (GM) during isometric plantarflexion.</div></div><div><h3>Methods</h3><div>Sixteen healthy males performed isometric plantarflexion at 30, 50, and 70 % of maximal voluntary isometric contraction (MVIC) in pre-and post-fatigue, under two knee joint conditions: straight leg (0°, STR) and bent leg (90°, BENT) positions, in a randomized order. Fatigue was induced via repeated sustained contractions at 60 % MVIC in each position. High-density surface electromyography from SOL and GM was decomposed to quantify MU parameters, including MU action potential amplitude (MUAP), firing rate (FR), recruitment threshold (ReTHR), and decruitment threshold (DeTHR). Intermuscular coherence between MU spike trains from SOL and GM was analyzed across frequency bands.</div></div><div><h3>Results</h3><div>Post-fatigue, MIVC decreased significantly in both the STR and BENT conditions (<em>p</em> < 0.01). Force steadiness significantly worsened post-fatigue in the BENT condition at 50 % (<em>p</em> < 0.01) and 70 % (<em>p</em> < 0.05). In SOL, MUAP and FR increased post-fatigue across all conditions, while GM showed more selective increases at higher intensities. SOL exhibited higher MUAP in the BENT condition, whereas GM showed greater activity in the STR condition. ReTHR in SOL and DeTHR in both muscles showed significant changes related to posture and fatigue. Notably, beta-band intermuscular coherence showed significant interaction effects at 50 % and 70 % (<em>p</em> < 0.05), with increased coherence in the BENT condition post-fatigue (<em>p</em> < 0.05).</div></div><div><h3>Conclusions</h3><div>Fatigue induces muscle-specific and posture-dependent neuromuscular adaptations, characterized by changes in MU properties and intermuscular coherence, particularly in the bent knee position.</div></div>","PeriodicalId":12496,"journal":{"name":"Gait & posture","volume":"125 ","pages":"Article 110068"},"PeriodicalIF":2.4,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}