Ground Reaction, Maximum Action: Reimagining Force Production in Elite Athletic Movement

Abstract

The article summarizes existing biomechanical data to introduce a paradigm shift in the conceptualization of force production in sprinting and associated events by coaches and practitioners. On the one hand, it can be stated that the generation of horizontal ground reaction force (GRF) is a key determinant of acceleration performance in elite athletic movement. Historical methods have focused on the overall development of lower body strength, but recent studies show that the ability to produce horizontal impulse, or more precisely propulsive impulse in the later parts of the contact with the ground, more significantly differentiates faster and slower athletes than vertical force production or braking force dissipation (Morin et al., 2015; Weyand et al., 2014). This review reviews the kinetic requirements of acceleration at three different stages: early acceleration (steps 1-4), mid-acceleration (steps 5-12), and transition to maximum velocity (steps 13+). Based on the research using instrumented force plate systems and statistical parametric mapping analysis, we show that performance determinants change to a concentration on concentric propulsion during early acceleration and braking force attenuation in athletes during the approach to maximal velocity (Colyer et al., 2018; Nagahara et al., 2018). It reports two synthesized data tables of elite versus sub-elite force- time properties at these phases and summarizes important training applications. We conclude that effective training programming should not be based on the notion that the same force production requirements are needed across all acceleration situations, but should focus on these phase-specific kinetic needs with specific interventions.

Keywords: Ground reaction force, sprint acceleration, elite athletes, force–time characteristics, biomechanics.