Abstract
This study determined the concurrent validity and reliability of force, velocity and
power measurements provided by accelerometry, linear position transducer and Samozino’s
methods, during loaded squat jumps. 17 subjects performed squat jumps on 2 separate
occasions in 7 loading conditions (0–60% of the maximal concentric load). Force, velocity
and power patterns were averaged over the push-off phase using accelerometry, linear
position transducer and a method based on key positions measurements during squat
jump, and compared to force plate measurements. Concurrent validity analyses indicated
very good agreement with the reference method (CV=6.4–14.5%). Force, velocity and
power patterns comparison confirmed the agreement with slight differences for high-velocity
movements. The validity of measurements was equivalent for all tested methods (r=0.87–0.98).
Bland-Altman plots showed a lower agreement for velocity and power compared to force.
Mean force, velocity and power were reliable for all methods (ICC=0.84–0.99), especially
for Samozino’s method (CV=2.7–8.6%). Our findings showed that present methods are
valid and reliable in different loading conditions and permit between-session comparisons
and characterization of training-induced effects. While linear position transducer
and accelerometer allow for examining the whole time-course of kinetic patterns, Samozino’s
method benefits from a better reliability and ease of processing.
Key words
muscle power - linear transducer - accelerometry - force plate - ballistic movements
