Relationship between strength parameters and squat jump performance in trained athletes

Abstract

Squat jump (SJ) has been extensively used in training, yet analysis in trained athletes is scarce. Therefore, main research question was: what strength parameters can better explain the best SJ performance in trained athletes? Thirty five athletes performed 3 maximal SJ (using a 17kg bar) weighted jumps while ground reaction forces were sampled using a force platform synchronized with a linear transducer. Only the best attempt was taken for analysis. For the purpose of this paper the SJ was divided into the following two segments: the concentric segment 1 was defined from the initiation of movement until maximum positive velocity occurred; and the Concentric segment 2 was defined from the moment following the end of the Concentric segment 1 until take off velocity was achieved. No relationship was observed between SJ performance and impulse for concentric segment 1. However, a moderate but significant correlation (r = .63) was found between SJ height and impulse for Concentric segment 2. Additionally, a moderate significant association (r = .56) was observed between the SJ and the maximum rate of force development produced during the Concentric segment 1. The SJ showed important relations with peak and average power only for Concentric segment 1 (r = .57). As predictors, it’s important that the force, power, and rate of force development must be maintained with high values of correlation to the height of the SJ but only during the concentric segment 1.