Effects of a Short-Term Conditioning Intervention on Knee Flexor Sensorimotor and Neuromuscular Performance in Men.

Abstract

Long-term conditioning programs for enhanced sensorimotor performance have been causally linked to reduced risk of serious ligamentous injury. However, the efficacy of brief, short-term conditioning interventions has not been established. To assess the effects of short-term sensorimotor conditioning on the knee flexors. Randomized controlled trial. University research laboratory. 23 males randomly assigned to conditioning (n = 12; age: 20.5 ± 1.8y; height: 1.80 ± 0.05m; body mass: 74.3 ± 6.0kg [mean ± SD]) and no-conditioning control (n = 11; age: 20.6 ± 1.9y; height: 1.79 ± 0.05m; body mass: 73.6 ± 6.3kg) groups. Sensorimotor conditioning of the nondominant leg (4 sessions/wk; 3wk). Sensorimotor (blind force and limb-position-replication errors) and neuromuscular (peak force, electromechanical delay [volitional and magnetically evoked]) performance of the knee flexors of both legs were assessed. The contralateral limb and an antecedent period of no conditioning were controls. The conditioned leg showed decreased force error to 3.8% (3.8 ± 6.9% vs6.3 ± 3.7% [mean ± SD], post- vspreconditioning, respectively; F1,21 = 5.4; P = .04) and a trend towarddecreased positional error to 2.0% (2.0 ± 6.9% vs4.7 ± 7.7%, post- vspreconditioning; F1,21 = 2.7; P = .06). Performances were not altered in the control conditions. Modest improvements were noted for volitional electromechanical delay following conditioning (39.8 ± 4.3ms vs42.3 ± 5.2ms [F1,21 = 7.2; P = .01]), but peak force (overall, 202 ± 78N) and magnetically evoked electromechanical delay (24.7 ± 4.2ms) were not influenced. Short-term conditioning offered improved sensorimotor performance and positively affected neuromuscular determinants of knee flexor performance in men.