PubMed | University of Tunis, University Claude Bernard Lyon 1, Qatar Orthopaedic and Sports Medicine Hospital, Edith Cowan University and 1 Tunisian Research Laboratory Sport Performance Optimisation
Type: | Journal: International journal of sports physiology and performance | Year: 2016
This study examined differences between ground reaction force (GRF)-based parameters collected from five types of plyometric push-ups. Between-trial reliability and the relationships between parameters were also assessed.Thirty-seven highly active commando soldiers performed three trials of five variations of the plyometric push-up in a counterbalanced order: Standard-Countermovement-Push-up (SCPu), Standard-Squat-Push-up (SSPu), Kneeling-Countermovement-Push-up (KCPu), Kneeling-Squat-Push-up (KSPu) and Drop-Fall-Push-up (DFPu). Vertical GRF was measured during these exercises using a portable Kistler force-plate. The GRF applied by the hands in the starting position (Initial-Force-Supported), Peak-GRF and Rate-of-Force-Development-During-Takeoff, Flight-Time, Impact-Force and Rate-of-Force-Development-Impact upon landing were determined.During standard position exercises (SCPu and SSPu) the Initial-Force-Supported and Impact-Force were higher (p<0.001) when compared to kneeling position exercises (KCPu, KSPu and DFPu). The Peak-GRF and Rate-of-Force-Development-During-Takeoff were higher (p<0.001) in the countermovement-push-up exercises (CMP - SCPu, KCPu and DFPu) than squat-push-up exercises (SP - SSPu and KSPu). Further, the Flight-Time was greater (p<0.001) during kneeling position exercises compared with standard position exercises. A significant relationship (p<0.01) between Impact-Force and the Rate-of-Force-Development-Impact was observed for CMP and SP exercises (r=0.83 and r=0.62, respectively). The Initial-Force-Supported was also negatively related (p<0.01) to the Flight-Time for both CMP and SP (r=-0.74 and r=-0.80, respectively). It was revealed that the Initial-Force-Supported and the Peak-GRF-During-Takeoff had excellent reliability; however other parameters had poor absolute reliability.It is possible to adjust the intensity of plyometric push-up exercises and train athletes muscle power by correctly interpreting GRF-based parameters. However, caution is required as some parameters had marginal absolute reliability.