The Differences Between CMJ & Squat Jump Performance: A Review... скачать в хорошем качестве

The Differences Between CMJ & Squat Jump Performance: A Review...

ABSTRACT - Two movements that are widely used to monitor athletic performance are the countermovement and squat jump. Countermovement jump performance is almost always better than squat jump performance, and the difference in performance is thought to reflect an effective utilization of the stretch-shortening cycle. However, the mechanisms responsible for the performance enhancing effect of the stretch-shortening cycle are frequently undefined. Uncovering and understanding these mechanism(s) is essential to make an inference regarding the difference between the jumps. Therefore, we will review potential mechanisms that explain the better performance in a countermovement jump as compared to a squat jump. It is concluded that the difference in performance may primarily be related to the greater uptake of muscle slack and the buildup of stimulation during the countermovement in a countermovement jump. Elastic energy may also have a small contribution to enhanced countermovement jump performance. Therefore, a larger difference between the jumps is not necessarily a better indicator of high-intensity sports performance. Although a larger difference may reflect the utilization of elastic energy in a small amplitude countermovement jump as a result of a well-developed capability to co-activate muscles and quickly buildup stimulation, a larger difference may also reflect a poor capability to reduce the degree of muscle slack and buildup stimulation in the squat jump. Because the capability to reduce the degree of muscle slack and quickly buildup stimulation in the squat jump may be especially important to high-intensity sports performance, training protocols might concentrate on attaining a smaller difference between the jumps.