Force-Time Dependent Characteristics of Dynamic and Isometric Muscle Actions

Abstract

Eight trained men were used to compare isometric and dynamic force-time variables. Subjects performed maximum isometric and dynamic pulls at 80% (DP80), 90% (DP90), and 100% (DP100) of their current 1-RM power clean from a standardized postion on a 61.0- × 121.9-cm AMTI force plate. Isometric peak force showed moderate to strong correlations with peak force during DP80, DP90, and DP100 (r = 0.66, 0.77, and 0.80, respectively). Isometric rate of force development showed moderate to strong correlations with dynamic peak force during DP80, DP90, and DP100 (r = 0.65, 0.73, and 0.75, respectively) and was strongly correlated with peak dynamic rate of force development during DP80, DP90, and DP100 (r = 0.84, 0.88, and 0.84, respectively). This suggests that the ability to exert both isometric and dynamic peak force shares some structural and functional foundation with the ability to generate force rapidly.