A simple method for measuring power, force, velocity properties, and mechanical effectiveness in sprint running

TLDR

The study validated a simple field method to assess force‑, power‑, and velocity‑relationships and mechanical effectiveness in sprint running. Using an inverse‑dynamic approach on the body center of mass, the method estimates step‑averaged ground‑reaction forces from anthropometric and spatiotemporal data during overground sprint acceleration, and was tested on nine sprinters against force plates and on six others for inter‑trial reliability. The method showed high concurrent validity, with less than 5 % bias and narrow limits of agreement for maximal horizontal force, velocity, power, force‑velocity slope, and mechanical effectiveness, and high reliability, with standard errors below 5 % across trials.

Abstract

This study aimed to validate a simple field method for determining force- and power-velocity relationships and mechanical effectiveness of force application during sprint running. The proposed method, based on an inverse dynamic approach applied to the body center of mass, estimates the step-averaged ground reaction forces in runner's sagittal plane of motion during overground sprint acceleration from only anthropometric and spatiotemporal data. Force- and power-velocity relationships, the associated variables, and mechanical effectiveness were determined (a) on nine sprinters using both the proposed method and force plate measurements and (b) on six other sprinters using the proposed method during several consecutive trials to assess the inter-trial reliability. The low bias (<5%) and narrow limits of agreement between both methods for maximal horizontal force (638 ± 84 N), velocity (10.5 ± 0.74 m/s), and power output (1680 ± 280 W); for the slope of the force-velocity relationships; and for the mechanical effectiveness of force application showed high concurrent validity of the proposed method. The low standard errors of measurements between trials (<5%) highlighted the high reliability of the method. These findings support the validity of the proposed simple method, convenient for field use, to determine power, force, velocity properties, and mechanical effectiveness in sprint running.