Abstract
Aim. The purpose of this study was to determine if a plyome-tric training program can affect the latency time of the qua-driceps femoris and gastrocnemius short-latency responses (SLRs) of the stretch reflex. Methods. Sixteen healthy subjects (12 female and 4 male) were randomly assigned to either a control or a plyometric training group. Maximum vertical jump height (VJ) and SLRs of both quadriceps femoris and gastrocnemius were measured before and after a four week plyometric training program. Results. Plyometric training significantly increased VJ (mean±SEM) by 2.38±0.45 cm (P<0.05) and non-significantly decreased the latency time of the quadriceps femoris SLR (mean±SEM) 0363±0.404 ms (P>0.05) and gastrocnemius SLR (mean±SEM) 0.392±0.257 ms (P>0.05). VJ results support the effectiveness of plyometric training for increasing VJ height. Conclusion. The non-significant changes in the latency time of the quadriceps femoris and gastrocnemius SLRs seen in the trai-ning group suggest that performance improvements following a four-week plyometric training program are not mediated by changes in the latency time of the short-latency stretch reflex.