Key kinematic differences between fast and slow athletes during initial acceleration

Initial acceleration is an essential component in many sports. This specific element of sprinting can be viewed as a separate and unique phase of speed. Important kinematic features of acceleration with field and court sport athletes are under debate within the scientific literature. The purpose of this study was to determine the major kinematic factors differentiating between fast and slow acceleration in field and court sport athletes. Twenty-six men performed 10-meter sprint testing in order to examine 2D analysis of the third step. Subjects were split into a fast group (FG) and slow group (SG) based on 10-meter sprint times. Independent samples t-tests determined variables that significantly (p ≤ 0.05) distinguished between fast and slow acceleration. Results showed 10-meter time, torso angle at touchdown, touchdown hip angle, hip-to-knee ratio, and eccentric ankle range of motion to be significantly different between groups. FG athletes contacted the ground with a more forward leaning torso and smaller hip angle, displayed a smaller change in ankle dorsiflexion during early stance, and had a larger change in hip ROM during stance relative to knee ROM. Field and court sport athletes appear to adopt similar kinematic strategies as sprint athletes, such as torso lean and ankle stiffness. Training programs focused on improving torso lean, ankle stiffness, and intermuscular coordination for horizontal propulsion could improve the effectiveness of key kinematic factors subsequently impacting initial acceleration performance.