Motor Control最新文献

{"title":"Control of Posture During Lifting: Effects of Weight Knowledge and Load Position Asymmetry.","authors":"Tippawan Kaewmanee, Huaqing Liang, Alexander S Aruin, Wit Wichaidit, Sirirat Tohpreecha","doi":"10.1123/mc.2026-0010","DOIUrl":"https://doi.org/10.1123/mc.2026-0010","url":null,"abstract":"<p><p>Lifting objects challenges postural stability and requires the generation of anticipatory (APA) and compensatory postural adjustments. This study investigated the combined effects of perturbation predictability and asymmetric load placement on postural control during a bimanual lifting task. Sixteen healthy adults completed a randomized crossover study involving repeated lifts of a box containing a load equal to 5% of their body weight that was positioned asymmetrically under three conditions: known, unpredictable, and predictable. Surface electromyography from trunk and lower limb muscles and center-of-pressure (COP) displacements were recorded. Electromyography integrals and COP displacements were analyzed separately for APA and compensatory postural adjustment phases using linear mixed-effects models. Explicit knowledge of load position resulted in larger and more direction-specific APAs, characterized by larger anticipatory trunk muscle activation and a proactive anterior shift of the COP (all p < .05). Predictability acquired through repeated exposure produced smaller APAs (p < .05). Under unpredictable conditions, participants exhibited reduced anticipatory COP shifts and larger compensatory responses for right-sided loads (all p < .05), whereas left-sided loads were characterized by a posterior COP shift before lift initiation. Postural adjustments during lifting are modulated by both explicit task information and experience-based predictability, and load position asymmetry alters anticipatory and compensatory control strategies. Enhancing information about load position may therefore improve postural stability and reduce reliance on compensatory mechanisms during manual material handling.</p>","PeriodicalId":49795,"journal":{"name":"Motor Control","volume":" ","pages":"1-16"},"PeriodicalIF":1.6,"publicationDate":"2026-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148892780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nonlinear Dynamical Measures in Assessing the Function of Plantar Tactile Feedback on Postural Sway During Quiet Standing Without Vision.","authors":"Yun Wang","doi":"10.1123/mc.2026-0002","DOIUrl":"https://doi.org/10.1123/mc.2026-0002","url":null,"abstract":"<p><p>This study aimed to use nonlinear dynamical measures to examine the function of plantar tactile feedback during quiet standing without vision in order to elucidate the stimulation effects on postural sway. Detrended fluctuation analysis, sample entropy, and rambling and trembling analysis were applied to analyze the dynamics of postural sway in the anterior-posterior and mediolateral directions. Twenty young adults stood on a force plate with eyes closed for 35 s under three conditions: no plantar stimulation, plantar stimulation under the forefoot, and plantar stimulation under the midfoot (MS). The results showed that postural dynamics were affected by the placement of plantar stimulation in the absence of visual information. In the anterior-posterior direction, increased detrended fluctuation analysis values for the center of pressure and rambling displacements were revealed in the MS condition than in the plantar stimulation under the forefoot condition, indicating greater adaptability in postural sway. There were also increased detrended fluctuation analysis values in the rambling displacement in the MS condition compared with the no plantar stimulation condition. In the mediolateral direction, the sample entropy in the trembling displacement was significantly greater in the MS condition than in the no plantar stimulation condition, indicating more automaticity in postural sway. These results suggest that plantar stimulation may contribute to balance regulation in an axis- and component-specific manner during quiet standing without vision.</p>","PeriodicalId":49795,"journal":{"name":"Motor Control","volume":" ","pages":"1-15"},"PeriodicalIF":1.6,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148763250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reliability and Diurnal-Fatigability Effects on Force-Time Characteristics During Maximal Voluntary Handgrip Contractions.","authors":"Modesto A Lebron, Justine M Starling-Smith, Grant E Norte, Jeffrey R Stout, David H Fukuda","doi":"10.1123/mc.2025-0075","DOIUrl":"10.1123/mc.2025-0075","url":null,"abstract":"<p><p>Single-effort isometric handgrip strength tests are widely used as a proxy of overall muscular strength. While using peak force (PF) is practical and meaningful, additional force-time characteristics could provide insight into muscle function. The purpose of this study was to assess test-retest reliability of force-time characteristics for maximal voluntary handgrip contractions (Analysis 1) and assess the influence of fatigability and time-of-day (Analysis 2). Nineteen participants completed Analysis 1 (23.5 ± 5.7 years, 168.7 ± 8.3 cm, 75.4 ± 14.0 kg) and 18 participants completed Analysis 2 (23.4 ± 5.9 years, 168.7 ± 10.4 cm, 77.6 ± 14.6 kg). For both analyses, participants completed three 4-s maximal voluntary handgrip contractions with 1-min rest periods. For Analysis 2, participants completed the maximal voluntary handgrip contractions before and after a fatiguing handgrip intervention at three separate times-of-day. Variables included PF, time to PF, time to 90% PF (TT90), area under the curve deficit (AUC Deficit), plateau force coefficient of variation, and plateau derivative root mean square. Using point estimates, all dependent variables demonstrated moderate-excellent relative reliability. A Time-of-day × Fatigability interaction was observed for TT90, AUC Deficit, and force coefficient of variation. Main effects of fatigability were observed for all variables, excluding plateau derivative root mean square. Time-of-day did not demonstrate an impact to any dependent variable. While task specific, an adequate warm-up may mitigate time-of-day impact to performance previously reported. TT90 and force maintenance variables, such as AUC Deficit, and force coefficient of variation, appear to be sensitive to the interaction between time-of-day and fatigability. Force maintenance variables may provide further insight beyond PF when examining maximal effort handgrip strength.</p>","PeriodicalId":49795,"journal":{"name":"Motor Control","volume":" ","pages":"182-200"},"PeriodicalIF":1.6,"publicationDate":"2026-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147327911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Restricting the Center of Mass Motion Via Multisegment Versus Localized Constraints: Its Impact on the Center of Pressure Behavior.","authors":"Lucas Michaud, Laurent Pommier, Valérie Grondin, Spencer Giddings, Brandon Paquet, Yves Lajoie","doi":"10.1123/mc.2025-0095","DOIUrl":"10.1123/mc.2025-0095","url":null,"abstract":"<p><p>Artificially restricting the center of mass (COM) motion during quiet standing through multisegment constraints has previously been shown to alter center of pressure (COP) dynamics. Increases in COP motion during such mechanically restricted stances have been interpreted as potential markers of exploratory behavior, whereby the central nervous system may generate movements to gather sensory input that would otherwise be limited by the imposed constraints. However, past studies relied on a plank-based apparatus that places participants in a nonecological posture, potentially limiting interpretations. This study compared the effects of the plank-based setup and a more ecologically valid belt-based apparatus that restricts COM movement without fully constraining the body. The analysis focused on both traditional measures of COP (i.e., variability) and dynamic measures (i.e., regularity and frequency components). Participants performed standing trials with both apparatuses, with eyes open and closed. Results revealed distinct COP behaviors between the two systems: compared with the unrestricted condition, the restricted condition with the plank-based apparatus yielded higher COP variability and regularity, whereas the belt-based system yielded lower COP variability and increased irregularity. These effects were not strongly influenced by visual input. The persistent COP motion observed under both conditions suggests that COP displacement may serve functions beyond merely stabilizing the COM, possibly reflecting exploratory behaviors. Overall, our findings support the use of belt-based systems as a more ecological alternative for restricting the COM motion, allowing for the study of the role of the COP in sensorimotor regulation without the limitations of a multisegment constraint.</p>","PeriodicalId":49795,"journal":{"name":"Motor Control","volume":" ","pages":"144-162"},"PeriodicalIF":1.6,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146114751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Investigation Into Finger Force Control Strategies in Relation to the Spin Efficiency of Fastball Pitching in Baseball.","authors":"Sungjune Lee, Hyeree Kim, Hyunwoo Park, Yoon-Seok Choi, Junkyung Song, Jaebum Park","doi":"10.1123/mc.2025-0068","DOIUrl":"10.1123/mc.2025-0068","url":null,"abstract":"<p><p>The objective of this study is to examine the relationship between the spin-related variables during real four-seam fastball pitching in baseball and the finger force production capability and its coordination in the laboratory test. Consequently, the sets of variables were derived from two distinct experiments: a field task and a laboratory task. The field task was designed to quantify the spin-related variables during actual pitching performance, and the laboratory task was designed to quantify the strength of the two fingers and the coordination-related variables of the index and middle fingers during the cyclic net finger force production task. The statistical test was implemented with the primary objective of ascertaining the significant correlation between the two metrics from the field and laboratory tests. The findings indicated a negative correlation between finger forces and spin-related variables (p < .05), suggesting that those who have greater finger force do not have a positive effect on spin-related variables. The strength of the synergy indices of moment stabilization was associated with a positive effect on spin-related variables (p < .05). The present experiment demonstrated that the stabilization of mechanical variables by the force production of the two fingers, that is, the net moment, indicates that the rotational effect of finger force production plays a critical role in determining the superior spin qualities of a fastball pitch in baseball.</p>","PeriodicalId":49795,"journal":{"name":"Motor Control","volume":" ","pages":"163-181"},"PeriodicalIF":1.6,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146087740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Placing the Dominant Foot Behind Reduces Postural Sway During Tandem Stance (Heel-to-Toe) Across Age Groups.","authors":"Anthi Angelou, Ioannis G Amiridis, Chrysostomos Sahinis, Zoi Tsampalaki, Konstantinos Salonikidis, Theodoros Kannas, Vassilia Hatzitaki, Roger M Enoka","doi":"10.1123/mc.2025-0084","DOIUrl":"10.1123/mc.2025-0084","url":null,"abstract":"<p><strong>Purpose: </strong>The present study explored the age-related influence of foot placement on balance control during quiet standing in tandem stance. Although tandem stance is widely used to assess postural control, foot dominance is rarely standardized in balance testing, even though it may influence stability outcomes. This study addressed this gap by examining whether dominant-foot placement affects postural control across the adult lifespan.</p><p><strong>Methods: </strong>One-hundred participants (53 women) were separated into five age groups: 21-30, 31-40, 41-50, 51-60, and 61-75 years. They stood upright on a force plate with the dominant foot placed either in the front or back in two visual conditions (eyes open vs. eyes closed). Postural control was assessed by measuring center-of-pressure displacement.</p><p><strong>Results: </strong>Analysis of variances indicated that center-of-pressure displacement increased across age groups (p < .01). For both visual conditions (eyes open or closed) and across all age groups, center-of-pressure displacement was reduced when the dominant foot was placed at the back during tandem stance (p < .05).</p><p><strong>Conclusion: </strong>This finding underscores the importance of considering foot dominance when assessing postural control during tandem stance. Standardizing foot placement relative to dominance may enhance the reliability and comparability of balance assessments across studies and age groups.</p>","PeriodicalId":49795,"journal":{"name":"Motor Control","volume":"30 2","pages":"129-143"},"PeriodicalIF":1.6,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147488132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beyond Quiet Stance: The Role of Levodopa in Prolonged Standing in Parkinson's Disease.","authors":"Ana Rita C Donati, Caroline Ribeiro de Souza, Thayna Magalhães, Mariana Freire Gonçalves, Victor Mantic Correia, Fabio Augusto Barbieri, Daniel Boari Coelho","doi":"10.1123/mc.2025-0080","DOIUrl":"10.1123/mc.2025-0080","url":null,"abstract":"<p><strong>Background: </strong>Prolonged standing demands continuous postural adjustments to redistribute weight and maintain comfort. People with Parkinson's disease (PwPD) may show impaired adaptability due to motor symptoms and rigidity. The effects of dopaminergic medication on postural control during prolonged standing are not well understood. This study aims to analyze the impact of dopaminergic medication on postural control during prolonged standing in PwPD, focusing on both global sway characteristics and discrete postural adjustments.</p><p><strong>Methods: </strong>Twenty-two PwPD (Hoehn and Yahr II-III) performed a 15-min standing task on a force plate in randomized ON (medicated) and OFF (unmedicated) sessions. Global sway parameters (sway area, root mean square, velocity, and frequency) and discrete postural adjustments (shifts, fidgets, and drifts) were calculated from center of pressure data. Nonparametric and parametric tests compared ON and OFF states.</p><p><strong>Results: </strong>In the ON state, participants showed significantly larger sway area, increased root mean square and velocity in anterior-posterior and mediolateral directions, and higher sway frequency (all p < .05). The number and amplitude of discrete adjustments were greater in the ON state, especially anterior-posterior drifts and mediolateral shifts. These changes indicate enhanced postural dynamics under dopaminergic medication.</p><p><strong>Conclusion: </strong>Dopaminergic therapy promotes a more dynamic and adaptable postural control strategy during prolonged standing in PwPD. Rather than reflecting instability, increased sway and frequent adjustments suggest adaptive behaviors facilitating comfort and stability over time. These findings underscore the value of prolonged standing tasks for assessing postural control and guiding rehabilitation strategies in PwPD beyond what short static tests capture.</p>","PeriodicalId":49795,"journal":{"name":"Motor Control","volume":" ","pages":"117-128"},"PeriodicalIF":1.6,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146031544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relationship Between Balance Automaticity and Dual-Task Interference in Older Adults.","authors":"Simona Kusleikiene, Kazimieras Pukenas, Margarita Drozdova Statkeviciene, Gal Ziv, Wouter A J Vints, Nerijus Masiulis, Tolga Tek, Lina Mickeviciene, Oron Levin, Vida Janina Cesnaitiene","doi":"10.1123/mc.2025-0014","DOIUrl":"https://doi.org/10.1123/mc.2025-0014","url":null,"abstract":"<p><strong>Background: </strong>Age-related decline can impair older adults' ability to perform tasks involving a mix of motor and cognitive goals in a dual-task (DT) paradigm. The amount of DT interference effects has typically been associated with the availability of attentional resources and the degree of balance automaticity. Older adults with mild cognitive impairment may lack sufficient sensorimotor capacity for \"automatic\" regulation of posture under demanding balance conditions, resulting in larger DT interference effects due to increasing attentional control.</p><p><strong>Research question: </strong>Does the degree of automaticity affect balance stability in older adults with mild cognitive impairment during dual tasking, and does this relationship vary with the difficulty of the balance task?</p><p><strong>Methods: </strong>Sixty-seven older adults, aged 60-80 years (23 mild cognitive impairmentss), were positioned barefoot on a single piezoelectric force plate in a double-support and tandem stance with eyes open. Each stance condition was tested as single task during performance of a mathematical counting task (i.e., DT). DT cost (DTC) scores of center-of-pressure sway velocity (DTCVcop) were calculated, and regression analyses were conducted to assess the unique contribution of baseline center-of-pressure sway entropy under single-task conditions to DTCVcop, with age, Montreal Cognitive Assessment scores, gender, and cognitive status included as covariates.</p><p><strong>Results: </strong>Baseline sway entropy accounted for only 0.25%-4% of the variance in DTC of Vcop. Gender and cognitive status accounted for 12%-20% of the variance under double-support but not in tandem stance.</p><p><strong>Significance: </strong>Our findings suggest that sway entropy has only minimal impact on DT interference while gender and cognitive status play a more substantial role, highlighting the importance of these factors in balance control of older adults.</p>","PeriodicalId":49795,"journal":{"name":"Motor Control","volume":"30 1","pages":"100-116"},"PeriodicalIF":1.4,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145866362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Impact of Cold-Water Immersion on Great Toe Flexor Strength and Postural Control.","authors":"Jeff A Nessler, Isabella O Martinez, Sarah Kruse, Ronald Dunn, Sean C Newcomer","doi":"10.1123/mc.2025-0025","DOIUrl":"https://doi.org/10.1123/mc.2025-0025","url":null,"abstract":"<p><strong>Background: </strong>The great toe contributes to healthy gait and balance but may be impacted by exposure to cold. The purpose of this study was to examine the effects of 60 min of cold-water immersion on great toe flexor force and single-limb balance.</p><p><strong>Methods: </strong>Forty-four healthy adults participated in one of two experiments. All participants placed one foot in water that was maintained at 10 °C and the other foot in water maintained at body temperature (37 °C) for 60 min. Both feet were submerged to a depth just above the malleolus. For the first experiment (n = 25), maximum voluntary great toe flexion force and control of submaximal force were measured while standing using a custom designed apparatus both before and immediately following immersion. For the second experiment (n = 19), postural sway was assessed before and after immersion while standing on an unstable surface with a single limb and eyes open.</p><p><strong>Results: </strong>Cold-water immersion resulted in a significant decrease in maximal flexor force of the great toe (332.6 ± 111.5 N vs. 235.1 ± 108.2 N, p < .001, Cohen's d = -0.89), but it did not impact the amount of error measured during control of submaximal flexor force (13.5 ± 4.4 N vs. 14.4 ± 5.6 N, p = .368). Further, exposure to cold resulted in significant increases to center of pressure rambling in the mediolateral direction (4.0 ± 0.9 mm vs. 4.8 ± 1.0 mm, p < .001, Cohen's d = 0.79) and trembling (3.2 ± 0.9 mm vs. 3.9 ± 1.4 mm, p = .002, Cohen's d = -0.63) and range of motion (49.6 ± 15.3 mm vs. 61.8 ± 21.9 mm, p = .007, Cohen's d = -0.62) in the anteroposterior direction.</p><p><strong>Conclusion: </strong>Cold-water immersion can impact force at the great toe and may adversely affect balance.</p>","PeriodicalId":49795,"journal":{"name":"Motor Control","volume":"30 1","pages":"82-99"},"PeriodicalIF":1.4,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145866349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Fatigue Induced by a Functional Task on Balance Control in Individuals With Multiple Sclerosis.","authors":"Mohan Ganesan, Neeta Kanekar, Ketaki Mehendale, Alexander S Aruin","doi":"10.1123/mc.2025-0024","DOIUrl":"10.1123/mc.2025-0024","url":null,"abstract":"<p><p>Fatigue experienced by individuals with multiple sclerosis (MS) during activities of daily living affects their balance and increases the risk of falls. The aim was to assess the effect of fatigue induced by a functional task on balance control in individuals with MS. The study involved 10 individuals with MS and 10 gender-matched healthy volunteers who performed a functional sit-to-stand task using a standardized chair and metronome until they reported an inability to continue. Motor Control and Sensory Organization tests were implemented using Dynamic Posturography three times: before, immediately after fatigue, and after a 30-min rest period. The Motor Control Test revealed that individuals with MS, compared to healthy controls, showed significantly longer latencies during small, medium, and large amplitudes of backward perturbation. Longer latencies were observed in the MS group after fatigue, specifically during small and large amplitudes of forward perturbations. The Sensory Organization Test discovered that following fatigue, the MS group demonstrated significantly lower equilibrium scores compared with healthy controls in the following conditions: eyes closed (p < .001), sway-referenced visual surround (p = .02), and sway-referenced support surface (p = .03). Functional fatigue induced by sit-to-stand tasks significantly impacted outcomes of both the Motor Control and Sensory Organization tests of balance control in individuals with MS. These findings lay the groundwork for future investigations into the role of fatigue in balance control in individuals with MS.</p>","PeriodicalId":49795,"journal":{"name":"Motor Control","volume":" ","pages":"21-36"},"PeriodicalIF":1.4,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145309815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}