title: The influence of wrist position on individual finger forces during forceful grip.
abstract: Nine healthy subjects sustained maximum grip of an instrumented handle while voluntarily moving the wrist joint within their available range of motion of the wrist in a continuous and random manner. Individual finger forces and wrist angular positions in flexion/extension and radial/ulnar deviation were recorded simultaneously. Wrist position had a significant effect on individual finger force and total force production. Peak finger forces were produced at 20 degrees of wrist extension and 5 degrees of ulnar deviation. At this position, a mean total grip force of 114.9 (+/-12.8) N was produced with force-sharing percentages of 32.2% (+/-3.8%), 32.6% (+/-4.3%), 23.5% (+/-4.5%), and 11.7% (+/-4.9%) among the index, middle, ring, and small finger, respectively. As the wrist was moved farther away from this position, the forces produced by individual fingers decreased incrementally; however, the decreases in individual finger forces were not proportional, leading to a dependence of finger force-sharing patterns on wrist position.
authors.affiliation: Division of Physical Therapy, Walsh University, North Canton, OH , USA.
authors.forename: Zong-Ming
authors.initials: ZM
authors.lastname: Li
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D003198:Computer Simulation; D004594:Electrophysiology; D005385:Fingers / Q000502:physiology*; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D008954:Models, Biological; D016059:Range of Motion, Articular / Q000502:physiology; D014953:Wrist / Q000033:anatomy & histology*