Neuromuscular Adaptations in Isokinetic, Isotonic, and Agility Training Programs

Weight training is an integral part of most athletic con ditioning programs; yet, the effect of these programs on neuromuscular function remains unclear. To exam ine the neuromuscular effects of training and condition ing at the knee joint, 32 volunteers (16 men and 16 women; average age, 25.4 years) were placed into one of four groups: isokinetic, isotonic, agility, or control. Each group trained 3 days per week for 6 weeks. The knee function of all participants was evaluated just before and after the 6-week training period. The agility- trained group significantly improved the spinal reflex times of the lateral and medial quadriceps muscles in response to anterior tibial translation. The cortical re sponse time of the agility group also significantly im proved in the gastrocnemius, medial hamstring, and the lateral quadriceps muscles. Interestingly, the corti cal response time of the medial hamstring and the medial quadriceps muscles in the isokinetic group slowed significantly, by 39.1 and 32.4 msec, respec tively, after 6 weeks of training. Isotonic and isokinetic strength training of the lower extremities do not appear to improve muscle reaction time to anterior tibial trans lation, whereas agility exercises potentially improve this parameter.