Stretch-Load Demands of Multiple Hops: Implications for Athletic Performance and Rehabilitation

Background: /Objectives: This study aimed to quantify the kinetic demands of multiple hops in series, movement tasks that are commonly used in strength and conditioning and physiotherapeutic practice. Focus was placed on comparing the demands of a quintuple-hop task to a triple-hop task, with particular focus on quantifying the eccentric braking stretch-load demands. Methods: Forty-four male university athletes (age 20.1 ± 1.4 years; body mass 71.2 ± 8.6 kg; stature 171.9 ± 5.1 cm) completed the hopping tasks across track-embedded force platforms, where braking and propulsion kinetics were measured across 54x track-embedded force platforms. Results: Significant (p < 0.001) averaged in-creases in maximal vertical (~32%) and horizontal braking impulses (~56%) for both TH and QH tasks were noted across hops. The last two hops of the QH task were found to have greater averaged vertical (~58%) and horizontal (~180%) stretch-load demands than the two initial hops (p < 0.001). Conclusions: This is the first study in which an extensive summary of kinetic measures for both triple and quintuple hops has been reported. The findings highlight the biomechanical, stretch-load aspects of these exercises, which can help practitioners better prescribe and program hops for injury prevention, rehabilitation, and performance enhancement.