Motor Control最新文献

{"title":"Working Together: Synergistic Predictors of Dyadic Performance in a Shared Force-Production Task.","authors":"Amutha De Silva, Nicole S Carver, Francis M Grover, Tehran Davis, Amanda Haskell, Paula L Silva","doi":"10.1123/mc.2025-0076","DOIUrl":"https://doi.org/10.1123/mc.2025-0076","url":null,"abstract":"<p><p>A core feature of joint action is task-sharing-the dynamic coordination of individual efforts to produce and stabilize a shared outcome. Yet, it remains unclear which features of task-sharing dynamics relate to stable performance. In this study, we address this gap by identifying behavioral markers that capture the organization and robustness of task-sharing in a joint force-production task. Thirty dyads performed a continuous force-production task in which each partner independently applied force to jointly match a target total force. Real-time visual feedback was provided on their combined output. The task was completed under low-force (10% maximum voluntary contraction) and high-force (30% maximum voluntary contraction) conditions to manipulate difficulty. Trials revealed qualitatively distinct patterns of force contribution, including cases in which a single partner carried most of the output, patterns in which partners contributed with distinct temporal roles, and fully synergistic task-sharing in which both partners continuously shaped total force fluctuations. We used within-trial uncontrolled manifold (UCM) analysis to characterize the dominant, synergistic mode along two dimensions. The first is the degree of variation in task-sharing patterns that leaves performance unchanged (VUCM). The second is the degree of irregularity-computed as sample entropy-of these patterns (SampEnUCM). Dyads with lower VUCM and lower SampEnUCM demonstrated greater performance stability. VUCM and SampEnUCM thus serve as indices of robust task-sharing patterns, offering behavioral access to the control mechanisms that enable stable joint performance, particularly under more challenging conditions.</p>","PeriodicalId":49795,"journal":{"name":"Motor Control","volume":" ","pages":"1-19"},"PeriodicalIF":1.4,"publicationDate":"2026-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147786861","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":"Between a Rock and a Hard Place in Science: A Biographical Account of One Discovery.","authors":"Anatol G Feldman","doi":"10.1123/mc.2025-0123","DOIUrl":"https://doi.org/10.1123/mc.2025-0123","url":null,"abstract":"","PeriodicalId":49795,"journal":{"name":"Motor Control","volume":" ","pages":"1-17"},"PeriodicalIF":1.4,"publicationDate":"2026-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147730537","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}

{"title":"Relationship Between Vision and Postural Control in Children With Autism Spectrum Disorder: Is It Time to Move Forward? A Scoping Review.","authors":"Giulio Valagussa, Alessandra Mari, Elisa Redaelli, Enzo Grossi, Cecilia Perin, Giulia Purpura","doi":"10.1123/mc.2024-0131","DOIUrl":"10.1123/mc.2024-0131","url":null,"abstract":"<p><p>Despite the main clinical criteria for Autism Spectrum Disorder (ASD) diagnosis being the dysfunction of socio-communicative interaction abilities and the presence of restricted interests and repetitive behaviors, sensory-motor dysfunctions are also frequently observed in this population. Moreover, among sensory-motor issues, both postural control and visual processing may be impaired. The main aim of this scoping review is to synthesize the evidence on the relationship between visual behavior and postural control dysfunctions in children and adolescents with ASD. This scoping review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol, Extension for Scoping Reviews guidelines, and was registered a priori on the Open Science Framework. PubMed, CINAHL, Embase, PsycINFO, Scopus, and Web of Science databases were consulted. Primary studies with any study design were included. No time, geographical, or study setting limitations or language restrictions were applied. A total of 646 articles were found in the initial search, but only 14 studies met the full inclusion criteria. Findings highlighted that studies on the relationship between vision and posture in ASD children and adolescents are scarce, and their results are contrasting because of the significant heterogeneity in the methods. This scoping review carried out a relevant survey of the literature considering the relationship between vision and posture in ASD. Nonetheless, the characteristics of the included sample and the methodology used in the analyzed studies were highly variable. Thus, rigorous study methods with population-specific objective outcome measures are needed to draw generalizable conclusions.</p>","PeriodicalId":49795,"journal":{"name":"Motor Control","volume":" ","pages":"37-66"},"PeriodicalIF":1.4,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145309818","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":"Differential Impact of Cognitive Tasks on Postural Stability in Individuals Following Anterior Cruciate Ligament Reconstruction Compared With Healthy Controls: A Cross-Sectional Study.","authors":"Amir Mohammad Rajaee-Nejad, Hossein Negahban, Ehsan Sinaei, Neda Mostafaee, Fatemeh Emami, Salman Nazary-Moghadam, Hadi Makhmalbaf","doi":"10.1123/mc.2025-0031","DOIUrl":"10.1123/mc.2025-0031","url":null,"abstract":"<p><p>Anterior cruciate ligament reconstruction (ACLR) can result in persistent deficits in postural stability particularly under dual-task conditions involving cognitive demands. This study investigated the effects of cognitive tasks from different domains on postural control among individuals with ACLR compared with healthy controls. Twenty-five individuals with ACLR and 25 asymptomatic matched controls performed three cognitive tasks of backward counting (working memory), Stroop Color-Word Test (executive function), and Benton's Judgment of Line Orientation (visuospatial perception) under single- (seated) and dual-task (single-leg stance on rigid and foam surfaces) conditions. Postural stability was quantified by measuring center-of-pressure sway area and sway velocity in anterior-posterior and medial-lateral directions. Cognitive performance was evaluated by counting task errors. Results indicated significantly greater postural sway in the ACLR group compared with controls across all tasks (p < .01), with the Stroop Color-Word Test significantly increasing mean sway velocity compared with the no-task condition (p < .01) in only the ACLR group. ACLR participants also demonstrated consistently greater cognitive errors under all conditions. However, cognitive errors were not significantly affected by increased postural difficulty. Findings suggest that executive function tasks uniquely exacerbate postural control deficits following ACLR, highlighting the clinical importance of incorporating targeted cognitive-postural training focusing on executive control into rehabilitation protocols.</p>","PeriodicalId":49795,"journal":{"name":"Motor Control","volume":" ","pages":"67-81"},"PeriodicalIF":1.4,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145259764","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":"External Attention Focus Enhances Standing Long Jump Performance by Modulating Muscle Dynamics Compared With Internal Focus.","authors":"Xinxin Liu, Jian Chen, Zhengye Pan, Zhizhong Geng","doi":"10.1123/mc.2025-0002","DOIUrl":"10.1123/mc.2025-0002","url":null,"abstract":"<p><p>Different attentional focus strategies are commonly employed in sports training, with the external focus of attention (EF) strategy shown to enhance performance in the standing long jump. However, the underlying muscular dynamics responsible for this improvement remain unclear. In this study, we utilized a Latin square design to recruit 12 healthy male participants, each undergoing standing long jump testing under EF, internal focus (IF), and control conditions. During the take-off phase, we synchronously recorded kinematic and dynamic data. Inverse dynamics calculations were performed on the dynamic and kinematic data. Compared with IF and control, the EF condition exhibited longer jump distances, lower projection angles, and higher peak horizontal take-off velocities and impulses alongside increased center of mass displacement during the eccentric phase and decreased center of mass displacement during the concentric phase (p < .05). The peak muscle force and rate of muscle force development of the vastus lateralis, vastus medialis, vastus intermedius, and gluteus maximus during the take-off phase were also higher in the EF group (p < .05). These results indicate that the EF strategy optimizes standing long jump mechanics by enhancing the efficiency of eccentric muscle contractions, thereby increasing stored elastic potential energy in the muscles. Consequently, this leads to greater muscle force and rate of muscle force development during the concentric phase, ultimately resulting in increased jump distances.</p>","PeriodicalId":49795,"journal":{"name":"Motor Control","volume":" ","pages":"1-20"},"PeriodicalIF":1.4,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145259742","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":"Individuals With Transtibial Amputation Using a Prescribed Prosthesis and a Portable Bionic Prosthesis Under Myoelectric Control During a Stepping Activity.","authors":"Nicole Stafford, Eddie B Gonzalez, Daniel Ferris","doi":"10.1123/mc.2024-0059","DOIUrl":"10.1123/mc.2024-0059","url":null,"abstract":"<p><p>Navigating changes in surface height is a component of daily living, requiring different musculoskeletal demands compared with level-ground walking. Individuals with transtibial amputation commonly adopt a hip-dominant strategy to compensate for the absence of active ankle plantar flexor power. Recent tests of overground walking with a direct control myoelectric bionic prosthesis found that participants exhibited similar prosthesis torques and powers to their passive devices, likely due to persistent motor memory. We tested six individuals with transtibial amputation performing a noncyclic stepping activity simulating a curb with the Open Source Leg prosthesis under direct proportional myoelectric input. We measured step time, prosthetic preference, lower limb muscle activity, kinematics, and kinetics. Similar to the overground walking study, we found participants chose to perform the task with bionic prosthesis mechanics similar to their passive prosthesis. No significant differences were observed in peak prosthetic ankle power (bionic: 1.5 W/kg, passive: 1.3 W/kg, p = .268), despite the bionic prosthesis being capable of generating 2.5 W/kg. This suggests participants chose a less powerful movement strategy that resembled movement dynamics similar to their passive prosthesis. As a result, there were no significant differences in step time (p = .345) or prosthetic ankle work (p = .062) between prostheses. Stepping with the powered prosthesis led to significantly increased intact limb hip work (p = .026) and residual limb quadriceps activity (p = .011). Four of six participants preferred the powered prosthesis. These results align with prior studies, indicating that extended training or visual biofeedback may be required to retrain amputees to increase mechanical power and adjust movement strategies.</p>","PeriodicalId":49795,"journal":{"name":"Motor Control","volume":" ","pages":"340-362"},"PeriodicalIF":1.4,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144976706","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":"Real-Time External Focus of Attention Biofeedback During a Forward Hop-To-Stabilization on Dynamic Postural Stability in Individuals With Chronic Ankle Instability.","authors":"Danielle M Torp, Matthew C Hoch, Kyle B Kosik, Ke'La H Porter, Stacey Slone, Kyeongtak Song","doi":"10.1123/mc.2024-0124","DOIUrl":"10.1123/mc.2024-0124","url":null,"abstract":"<p><strong>Introduction: </strong>Chronic ankle instability (CAI) is a common sequela of lateral ankle sprains that impairs postural stability during functional tasks. External biofeedback may be an appropriate rehabilitation tool to improve functional movement; however, more research is needed to determine its effectiveness in dynamic tasks in individuals with CAI. This study aimed to assess the effect of real-time external biofeedback via laser on dynamic postural stability indices during a single-limb forward hop-to-stabilization task in participants with CAI.</p><p><strong>Methods: </strong>Eighteen participants with CAI completed five successful forward hop-to-stabilization jumps with and without external biofeedback using a single-dot laser attached to the distal tibia. A single inertial measurement unit fastened to the lower back captured dynamic postural stability indices in the vertical, anterior-posterior, medial-lateral, and the resultant of each plane during the 5 s after landing. The mean difference between biofeedback and no biofeedback was assessed using independent t tests.</p><p><strong>Results: </strong>Our results indicate no significant differences were observed between forward hop-to-stabilization tasks with and without real-time external biofeedback in individuals with CAI.</p><p><strong>Discussion: </strong>More research is needed to determine the appropriate biofeedback tool location and modality type of external biofeedback in addition to the minimum amount of training exposure to improve dynamic postural stability during a single-limb landing task.</p>","PeriodicalId":49795,"journal":{"name":"Motor Control","volume":" ","pages":"291-302"},"PeriodicalIF":1.4,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144334318","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}