Effect of Grip Force on Wrist Range of Motion

Abstract

This study investigated the effect of a constant grip exertion on wrist range-of-motion (ROM). Seven different levels of grip force were investigated, including two levels of zero exertion, 25%, 50%, 75%, 90%, and 100% MVC. Both hands were tested for each of three forearm positions (pronation, halfway between pronation and supination (neutral), and supination). Twenty student subjects (10 males and 10 females) were tested. Subjects held a particular grip force level constant while simultaneously moving their wrist. The maximum angles of flexion and extension were recorded to measure range-of-motion (ROM). ANOVA analysis was performed for the dependent variables of flexion angle, extension angle, and total ROM. Independent variables were gender, hand, forearm position, and exertion level. Exertion level was a significant factor for extension, flexion, and ROM. Forearm posture was a significant factor for extension and ROM. Tukey-Kramer analysis revealed similar groupings of exertion levels and forearm positions for flexion, extension, and ROM. The data show a significant decrement in wrist ROM as grip force exertion level increased.