Possibilities and Limitations in the Biomechanical Analysis of Countermovement Jumps: A Methodological Study

TLDR

The study examined the possibilities and limitations of biomechanical analysis of countermovement jumps using force plate data. Four male and four female sport students were assessed with force plate recordings processed by custom software to compute net velocity and displacement of the center of gravity, and compared with a film-based Dempster center‑of‑gravity model while evaluating error sources in data acquisition and numerical computations. Numerical integration reliably estimates net velocity and displacement for detailed jump analysis, whereas Dempster‑like center‑of‑gravity models introduce errors that preclude their use as validation criteria.

Abstract

Possibilities and limitations in the biomechanical analysis of countermovement jump performance were examined using force plate data. Four male and 4 female sport students participated in the study. Software designed to test jumping performance was used to evaluate recordings from a force plate and to compute net velocity and net displacement measures for the center of gravity. In parallel, a film analysis incorporating Dempster's center of gravity model was used for a comparison. Validity of the computed kinetic measures was evaluated with a general analysis of the major error sources including the data acquisition and numerical computations. Numerical integration procedures were found to be a reasonable tool for calculating net velocity and net displacement parameters for a more detailed analysis of athletic jumping performance. On the other hand, it appeared that Dempster-like center of gravity models can cause errors that disqualify their use as validation criteria for kinetic parameters.