Journal article
Adaptation of Transcortical Responses in Upper Extremity Movements During an Elbow Visuomotor Tracking Task in Humans
Journal of functional morphology and kinesiology, Vol.10(4), 368
09/26/2025
DOI: 10.3390/jfmk10040368
PMCID: PMC12551022
PMID: 41133558
Abstract
Background: Precise upper limb movements are essential for daily tasks and motor function. Feedforward responses enable anticipatory movement planning, while feedback responses utilize sensory information for real-time corrections. Long-latency reflexes (LLRs) represent rapid feedback responses during unexpected perturbations and are integral in maintaining motor control, yet the factors governing LLRs in the upper extremity remain unclear. Methods: Forty healthy participants with ages ranging from 20 to 45 years (mean = 26.75, and SD = 5.6), performed a unilateral visuomotor elbow flexion and extension task with one arm while following a sinusoidal target at varied resistances and speeds. Task performance was quantified and communicated to participants after each bout. Resistance was randomly released during the flexion phase to trigger a perturbation. Electromyography data from the biceps and triceps muscles were analyzed for the long-latency reflex (LLR) and secondarily for the short-latency reflex (SLR), and voluntary response (VR) phases. Results: In response to unexpected upper extremity perturbations, participants relied on two core strategies. Inhibitory LLRs within the biceps were prominent, emphasizing inhibition to maintain movement stability 50–150 ms post-disturbance. Additionally, volitional control through the triceps allowed participants to regain precision starting from over 150 ms. Participants’ responses to perturbations were dependent on speed and resistance but were not modified with learning across repeated attempts. Conclusions: This study reveals that participants demonstrate both long-latency and volitional responses to counteract perturbations during an upper extremity visuomotor task. These findings highlight that a predominant agonist inhibition strategy emerged during the during unpredictable perturbations of the upper extremity. Understanding these responses may inform rehabilitation and pharmaceutical interventions when treating individuals with neurological conditions that influence motor control.
Details
- Title: Subtitle
- Adaptation of Transcortical Responses in Upper Extremity Movements During an Elbow Visuomotor Tracking Task in Humans
- Creators
- Olga Dubey - University of IowaMichael A. Petrie - University of IowaRichard K. Shields - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Journal of functional morphology and kinesiology, Vol.10(4), 368
- DOI
- 10.3390/jfmk10040368
- PMID
- 41133558
- PMCID
- PMC12551022
- NLM abbreviation
- J Funct Morphol Kinesiol
- ISSN
- 2411-5142
- eISSN
- 2411-5142
- Publisher
- MDPI
- Grant note
- National Institute of Child Health and Human Development, Department of Physical Therapy and Rehabilitation Sciences: R01HD084645, R01HD082109
National Institute of Child Health and Human Development, Department of Physical Therapy and Rehabilitation Sciences, R01HD084645 and R01HD082109 (to RKS).
- Language
- English
- Date published
- 09/26/2025
- Academic Unit
- Orthopedics and Rehabilitation; Physical Therapy and Rehabilitation Science
- Record Identifier
- 9984969112902771
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