Date of this Version
The primary purpose of this study was to evaluate test-retest reliability of the static (SP) and counter-movement (CMP) power push-up (PPU) test in young male athletes. The secondary purpose was to compare the reliability of vertical ground reactions forces versus torque measurements during the PPU tests. Twenty males (age = 11.60 ± 1.15 y) performed SPs and CMPs on force plates with the knees as the fulcrum on two laboratory visits separated by 2-7 days. Performance measurements included peak force (PF), rate of force development (RFD), peak torque (PT), rate of torque development (RTD), peak power (PP), average power (AP), eccentric impulse (ECC), and concentric impulse (CON) for both PPU techniques. Age, maturity offset, height, body mass, fat-free mass (FFM), and estimated arm cross sectional area (eCSA) were obtained as measurements of growth. Intraclass correlation coefficients (ICC), standard errors of measurement (SEM), coefficients of variation (CV), and minimum detectable changes (MDC) were reported. Only PF (ICC = 0.87-0.88, SEM = 59-84 N) and PT (ICC = 0.89-0.90, SEM = 60-88 N·m) showed acceptable reliability. Neither RFD, RTD, PP, AP, ECC, or CON were reliable outcomes. There were no meaningful differences between force-time and torque-time curve measurements. The SP showed slightly lower CVs (33-34%) than the CMP (CVs = 39-40%). Coaches and practitioners would need to see 58-71% increases in upper-body strength measurements evaluated via PPU on force plates to be 95% confident that the improvements exceeded the measurement variability.