Recovery of fine motor control after submaximal wrist fatigue

This study investigated how a repeated submaximal hand tracking task affects fine motor performance and short-term recovery. Nineteen males traced a 2:3 Lissajous curve using a haptic wrist robot both pre- and post-fatigue. The fatigue protocol was the same task with resistance applied to the handle of the robot at 40% maximal voluntary isometric wrist force. Performance was measured at baseline and at seven intervals during recovery (0, 1, 2, 4, 6, 8, and 10 minutes). The fatigue protocol led to a 12% decrease in grip force and remained below baseline at 10 minutes. Movement quality, quantified by tracking error, figural error, and jerk ratio, increased by 23%, 19%, and 27%, immediately following fatigue but normalised by 4 minutes. This work highlights how submaximal forearm muscle fatigue can temporarily compromise hand tracking ability but suggests that movement accuracy and smoothness recover rapidly with rest.