The Coordination of Digit Forces during Natural Precision Grasping with Five Digits

  • 陳 柏村

Student thesis: Doctoral Thesis


The precision grasp requiring the subtle force coordination among digits plays a critical role in the daily activity The cylindrical grasps have drawn much attention to investigate the force control during five-digit grasping Besides the capacity of force control has been shown to be disturbed by the impaired sensory such as in the patients with carpal tunnel syndrome (CTS) In addition to CTS the trigger digit (TD) may also impact the control of digit force However the previous findings may not be generalized exactly to the reality due to ignoring the natural configuration and functional tasks To realize the applied force with regards to the functional performance the dynamic analysis should be conducted rather than the static observations or a representative mean variable Therefore the purposes of this study were to (1) examine the continuous waveform repeatability of digit force during the functional five-digit grasping; (2) investigate the alteration in applied forces during grasping tasks with five digits in patients with TD and the controls; (3) compare the control characteristics of digit forces during five-digit grasping by patients with CTS and control group We found that the waveform repeatability of digit force was related to the force direction and the task Although the performance consistence was considered as the control capacity the fair to good repeatability of force waveform may be due to the high flexibility in the force control of each digit Since the applied force of each digit was contributed by several muscles and coordinated with other digits it can be controlled subtly to compensate for various task demands As for the TD patients with only one digit affected the force coordination of five digits was altered The abnormal patterns in TD patients may be associated with the role of the affected digit during functional grasping The CTS patients with sensory impairment adopted compensatory strategies by augmenting the digits forces associated with predominant force variability which may lead to the cumulative overloading injuries The decreased force correlation with less adjustment to the changes of task in CTS may retard the performance of an advanced precise task
Date of Award2015 May 13
Original languageEnglish
SupervisorFong-chin Su (Supervisor)

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