The role of anticipatory postural adjustments in a vertical jump after a one-step motion

Preparatory actions prior to the intended movements significantly contribute to better performance. Preceding posture control, which is known as anticipatory postural adjustments (APAs), is crucial for utilizing energy without loss in the main movements. Therefore, the present study attempted to clarify the role of APAs in vertical jumps with preparatory actions such as one-step motion. We defined APAs as the onset of activation or deactivation of postural muscles preceding the main movement (thrust) in a vertical jump. Our results revealed that preceding muscle activities of the erector spinae (ES) and gastrocnemius medialis (GAM) were associated with increasesin the center of mass (COM) velocity, range of COM anterior‒posteriorsway (COM y range) and ankle joint angle. These COM and joint angles can be effective factors in determining the jump height. The results indicate that APAs contribute to stabilizing posture and generating a reaction force for main movements, which could play a role in high performance. It is suggested that APAs are essential in converting the horizontal energy of one-step preparatory motion into vertical energy during the thrust phase for higher jumps.