PURPOSE The present study addressed the lack of data on the effect of different types of stretching on diurnal variations in vertical jump height - i.e., squat-jump (SJ) and countermovement-jump (CMJ). We hypothesized that dynamic stretching could affect the diurnal variations of jump height by producing a greater increase in short-term maximal performance in the morning than the evening throug...

We present the results of a combined theoretical and experimental investigation of the influence of surface tension σ on the laminar circular hydraulic jump. An expression is deduced for the magnitude of the radial curvature force per unit length along a circular jump, Fc =−σ (s − R)/Rj , where Rj is the jump radius, and s and R are, respectively, the arclength along the jump surface and radial...

Background: The purpose of this study was to examine the effect of a cognitive task on jump-landing biomechanics and performance. Methods: 26 recreational athletes participated in the study. Participants jumped forward off of a 30cm box a distance equal to one half of their body height, then immediately performed a countermovement jump. This movement was performed in a control condition, while ...

This study aimed to investigate the contributions of kinetic and kinematic parameters to inter-individual variation in countermovement jump (CMJ) performance. Two-dimensional kinematic data and ground reaction forces during a CMJ were recorded for 18 males of varying jumping experience. Ten kinetic and eight kinematic parameters were determined for each performance, describing peak lower-limb j...

A force platform can be an excellent teaching aid in undergraduate physics classes and laboratories. Recently, Cross showed how to increase student interest and understanding of elementary mechanics by using a force platform to study everyday human movement such as walking, running, and jumping. My experiences with using a force platform in undergraduate classes have also been highly favorable....

Ankle braces in sports are used for prevention of ankle sprains. Besides restricting inversion and eversion, it is possible that an ankle brace also reduces the functional range of motion of the ankle joint. Consequently, their use could also impair athletic performance. It is unlikely that prophylactic ankle bracing will gain wide acceptance if bracing hinders athletic performance. The purpose...

The aim of this study was to assess changes in indirect markers of muscle damage and type I collagen degradation, as well as, patellar and Achilles tendon morphological differences during nine daily drop-jumps sessions with constant load alternated with rapid increases in load to test the hypothesis that frequent drop-jump training results in negative muscular and tendon adaptation. Young men (...