Leland A. Barker, John R. Harry, Janet S. Dufek, John A. Mercer

In soccer matches, jumps involving rotations occur when attempting to head the ball for a shot or pass from set pieces such as corner kicks, goal kicks, and lob passes. However, the 3-dimensional ground reaction forces used to perform rotational jumping tasks are currently unknown. Therefore, the purpose of this study was to compare bilateral, 3-dimensional, ground reaction forces of a standard countermovement jump (CMJ0) to a countermovement jump with a 180° rotation (CMJ180) among Division 1 soccer players. Twenty-four participants from the university's soccer team performed 3 trials of the CMJ0 and the CMJ180. Dependent variables included jump height, downward and upward phase times, vertical (Fz) peak force and net impulse relative to mass, and medial-lateral (ML) and anterior-posterior (AP) force couple values. Statistical significance was set a priori at α = 0.05. CMJ180 reduced jump height, increased the AP force couple in the downward and upward phases, and increased upward peak Fz (p<0.05). All other variables were not significantly different between groups (p>0.05). However, we did recognize downward peak Fz trended lower in the CMJ0 condition (p=0.059), and upward net impulse trended higher in the CMJ0 condition (p=0.071). It was concluded jump height was reduced during the rotational jumping task, and rotation occurred primarily via AP ground reaction forces through the entire countermovement jump. Coaches and athletes may consider additional rotational jumping in their training programs to mediate performance decrements during rotational jump tasks.