Influence of jump-landing direction on dynamic postural stability and hamstring-to-quadriceps co-activation ratio

ABSTRACT

This study investigated the effect of jump landing direction and leg dominance on the Dynamic Postural Stability Index (DPSI) and the importance of the hamstring-to-quadriceps (H/Q) co-activation ratio. Fifteen female sports players performed unilateral jump landing, for the dominant (DL) and the non-dominant (NDL) legs in anterior (AJL), lateral (LJL), and vertical directions (DJL). The results indicated that the DPSI was higher in DJL compared to LJL and AJL. Besides, the DPSI score during DJL was higher in NDL indicating lower stabilization capacity associated with a lower H/Q co-activation ratio. A significant correlation was found between H/Q co-activation ratio and DPSI in the DL during AJL (r = −0.57). Current results suggest that DJL was more appropriate to evaluate dynamic postural stability since it highlights limb asymmetry. In addition, H/Q co-activation appears to play an essential role in the effectiveness of ground reaction force stabilization during jump landing.

KEYWORDS:

• Jump landing
• ground reaction forces
• postural dynamic stabilization
• co-activation
• asymmetry

Acknowledgments

The authors would like to acknowledge all the participants for their participation. The present study was funded by the China Scholarship Council [grant number 201708070091].

Disclosure statement

No potential conflict of interest was reported by the author(s).