Effects of stance foot centre of pressure and timing of heel lift on ground reaction force and stride mechanics in Amateur baseball pitchers.

The movement and positioning of the body during the early phases of the pitching motion can have cascading effects on downstream mechanics. While stride mechanics have been the focus of recent research, the role of stance foot mechanics in generating ground reaction force (GRF) and influencing stride kinematics remains unclear. This study aimed to determine whether stance foot centre of pressure (COP) location and heel lift timing are related to stride-phase GRF and stride kinematics in baseball pitchers. Biomechanical data were collected from 60 high school and 15 collegiate pitchers using a motion capture system and force platforms. Within the high school pitchers, COP location at the time of peak forward GRF and heel lift timing were analysed in relation to GRF and stride mechanics. Most high school and collegiate pitchers generated peak forward force through the forefoot and maintained heel contact with the ground throughout most (~85%) of the stride phase of pitching. The timing of heel lift and COP location at the time of peak forward GRF were not associated with forward propulsive force, stride mechanics, or ball speed, but were associated with pelvis orientation at lead foot contact in high-school pitchers.