The Effects of Gender, Wrist and Forearm Position on Maximum Isometric Power Grasp Force, Wrist Force, and their Interactions

Abstract

The interaction of power grasp force and wrist force has not been previously examined. This research not only examined the effect of task (wrist force in flexion and extension with and without simultaneous power grasp force), but the effects of gender, wrist position, and forearm position on maximal static exertions. Gender, wrist position, and task were found to significantly affect both power grasp and wrist forces. Females averaged 59.5% of male power grasp force and 51% of male wrist force. Power grasp force was significantly greater in neutral and extended wrist positions than flexed wrist positions while a neutral wrist position generated significantly greater wrist forces than both extended and flexed wrist positions. Due to synergistic conflicts, grasp force during simultaneous wrist extension force was significantly less than grasp force during simultaneous wrist flexion force (60%) and grasp force only tasks (58%). Wrist extension forces were found to exceed flexion forces which contrasts with previous research studies. In addition, wrist forces during simultaneous grasp force did not differ from wrist forces with fingers relaxed.