Acute Effects of Stretching Are Not Evident in the Kinematics of the Vertical Jump

TLDR

The study examined whether a single bout of stretching alters vertical jump kinematics in 20 young adults. Using sagittal‑plane videography at 60 Hz, participants performed vertical jumps after two randomized warm‑up routines—one control and one involving stretching—on two separate occasions. Stretching did not produce significant changes in vertical velocity, knee angle, or phase durations, and only 55 % of participants showed a modest decrease in peak velocity, indicating that any performance reduction is likely due to neuromuscular inhibition rather than altered muscle stiffness.

Abstract

The acute effect of stretching on the kinematics of the vertical jump was investigated in a sample of 20 young adults. Sagittal plane videography (60 Hz) was used to measure the kinematics of vertical jumps after 2 warm-up routines, control and stretching. Subjects were tested on 2 occasions with warm-up routine randomized. There were no significant changes in vertical velocity, knee angle, or the durations of the eccentric and concentric phases as a result of stretching despite good statistical power for the tests. Fifty-five percent of the subjects had lower vertical velocities (-7.5%) after stretching, while 45 percent of the subjects had no change (10%) or higher vertical (35%) velocities (2.4%) after stretching. Stretching prior to stretch-shortening cycle activities like the vertical jump results in small decreases in performance in some subjects, but the nonsignificant biomechanical changes suggest that neuromuscular inhibition may be the mechanism rather than changes in muscle stiffness.