The Test-Retest Reliability of Force Plate-Derived Parameters of the Countermovement Push-Up as a Power Assessment Tool

Abstract

CONTEXT: Muscular power output of the upper limb is a key aspect of athletic and sporting performance. Maximal power describes the ability to immediately produce power with maximal velocity at the point of release, impact, or takeoff, with research highlighting that the greater an athlete's ability to produce maximal power, the greater the improvement in athletic performance. Despite the importance of upper-limb power for athletic performance, there is presently no gold-standard test for upper-limb force development performance. OBJECTIVE: The aim of this study was to investigate the test-retest reliability of force plate-derived measures of the countermovement push-up in active males. DESIGN: Test-retest design. SETTING: Controlled laboratory. PARTICIPANTS: Physically active college athletes (age 24 [3] y, height 1.79 [0.08] m, body mass 81.7 [9.9] kg). INTERVENTION: Subjects performed 3 repetitions of maximal effort countermovement push-up trials on Kistler force plates on 2 separate test occasions 7 days apart. MAIN OUTCOME MEASURES: Peak force, mean force, flight time, rate of force development, and impulse were analyzed from the force-time curve. RESULTS: No significant differences between the 2 trial occasions were observed for any of the derived performance measures. Intraclass correlation coefficient and within-subject coefficient of variation calculations indicated performance measures to have moderate to very high reliability (intraclass correlation coefficient = .88-.98), coefficient of variation = 5.5%-14.1%). Smallest detectable difference for peak force (7.5%), mean force (8.6%), and rate of force development (11.2%) were small to moderate. CONCLUSION: Force platform-derived kinetic parameters of countermovement push-up are reliable measurements of power in college-level athletes.