Forearm muscle activation during power grip and release
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Updated: Oct 28, 2026

Intracortical Inhibition Within the Primary Motor Cortex Can Be Modulated by Changing the Focus of Attention
Published on: September 11, 2017
M E Johanson1, M A James, S R Skinner
1Orthopaedic Biomechanics Laboratory, Shriners Hospital for Children, Northern California, Sacramento 95817, USA.
Abstract:
The position of the hand during power grip is well-described, but the normal phasic activity of the extrinsic forearm muscles during power grip and release is unknown. People with neurologic impairment may have inadequate power grip or release because of abnormal muscle timing. This study describes the timing of the forearm muscles in 10 normal subjects during power grip and release, which was evaluated using electromyography. During power grip, subjects had consistent timing patterns for extrinsic finger motors and different but individually consistent patterns for wrist motors. This finding supports our hypothesis that different individuals habitually use a specific motor strategy and an intact central nervous system allows them to change their motor strategy to adapt to new environmental parameters.
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