Modular Organization of Exploratory Force Development Under Isometric Conditions in the Human Arm |
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| Authors: | Jinsook Roh Sang Wook Lee Kevin D. Wilger |
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| Affiliation: | 1. Department of Kinesiology, Temple University, Philadelphia, PA, USA;2. Neuromotor Science Program, Temple University, Philadelphia, PA, USA;3. Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA;4. Department of Biomedical Engineering, Catholic University of America, Washington, DC, USA;5. Center for Applied Biomechanics and Rehabilitation Research, MedStar National Rehabilitation Hospital, Washington, DC, USA;6. Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institute of Health, Bethesda, MD, USA |
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| Abstract: | Muscle coordination of isometric force production can be explained by a smaller number of modules. Variability in force output, however, is higher during exploratory/transient force development phases than force maintenance phase, and it is not clear whether the same modular structure underlies both phases. In this study, eight neurologically-intact adults isometrically performed target force matches in 54 directions at hands, and electromyographic (EMG) data from eight muscles were parsed into four sequential phases. Despite the varying degree of motor complexity across phases (significant between-phase differences in EMG-force correlation, angular errors, and between-force correlations), the number/composition of motor modules were found equivalent across phases, suggesting that the CNS systematically modulated activation of the same set of motor modules throughout sequential force development. |
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| Keywords: | electromyography force development motor coordination motor modules |
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