Fractionated reaction time and the rate of force development

The relationship between the rate of force development and components of fractionated reaction time were investigated in the present study. Subjects (N=9) were administered extensive practice before being required to produce 98N of isometric force on a hand dynamometer at a maximal rate, at 20% slower than maximal, and at 40% slower than maximal. Repeated measures analysis of variance followed by non-orthogonal Dunn planned comparisons demonstrated that pre-motor time and reaction time increased as similar peak forces were produced over longer durations. No significant differences in motor times were revealed. These data suggested that the manner in which force is expressed relates to the complexity of motor programming. The increased requirement of coordinating alpha-gamma coactivation, as well as the increased need for rate coding as a process underlying force development at slower contraction rates, are discussed in relation to programming complexity.