Perceived Submaximal Force Production in Young Adults

Abstract

The purpose of this investigation was to examine the force production patterns using perceived stimulus cues from 10% to 90% of maximal force. In Experiment 1, 54 men (age: 19-34 years) and 53 women (age: 18-37 years) performed leg extensions on a dynamometer at a speed of 60°/s. Participants produced actual forces perceived to be 10-90% of maximal force in 10% increments followed by a maximal force. A 2-min rest interval was maintained between each increment. Participants rested 5 min and repeated the protocol. Desired forces were calculated as the required percentage of the produced maximal force. In Experiment 2, 40 men (age: 18-30 years) followed the protocol of Experiment 1, but the submaximal stimuli were randomly presented. In Experiment 1, test-retest results indicated consistency between the trials for actual and maximal force (r = .90). The correlations between actual and desired forces were moderately high (r > .76). Actual forces trended above desired forces at 10% of maximal, with median errors ranging 33-40% for men and 60-73% for women. From 30% to 90% of maximal forces, actual trended below desired forces, with median errors ranging from a low of 1.5% to a high of 37%. A power function analysis relating the change in actual force with desired force stimuli produced exponents of 0.68 (.95 CI = 0.62-0.74) for men and 0.57 (.95 CI = 0.52-0.62) for women. Findings were similar in Experiment 2, indicating that individuals tended to overshoot and then undershoot desired force production through perceptual force ranges of 10-90% of maximal forces and that force production grew more slowly than perceptual stimulus cues. The results of the present study, along with findings from past research, indicate that production of submaximal force using perceptual cues or stimuli display a great deal of specificity. This specificity is related to type of contraction, amount of muscle mass involved, and number and types of stimuli.