Reliability of a New Medicine Ball Throw Power Test

Abstract

The purpose of this study was to examine the reliability of a new upper body medicine ball push-press (MBP-P) test. Twenty-three strength trained volunteers performed a series of supine MBP-P throws using loads representing 5% and10% of their 5RM bench press (5 repetitions at each load). Throws were performed on a force platform (2000 Hz), with medicine ball kinematic data collected using a high-speed motion capture (500 Hz). Testing was repeated after 7–10 days to quantify intertest reliability. Maximal force (Fmax), impulse at Fmax, time to Fmax, and maximum rate of force development (RFDmax) were all calculated from the force platform outputs, with maximum ball velocity (Velmax) and maximum ball acceleration (Accelmax) developed from the kinematic data. Reliability was assessed using intraclass correlation (ICC), coefficient of variation (%CV), and typical error. Medicine ball kinematic variables were more reliable (CV% = 2.6–5.3, ICC = 0.87–0.95) than the various force platform derived power variables (CV% = 7.9–26.7, ICC = 0.51–0.90). The MBP-P test produces reliable data and can be used to quantify many standard power based measures, with the key findings have implications for athletic populations requiring high velocity, light load upper body pushing power.