Postural Stability Changes Following Static Loading in Athletes with and without Anterior Cruciate Ligament Reconstruction

Introduction: This study investigated the effect of change in postural stability after applying static load during internal perturbation among professional athletes with and without anterior cruciate ligament (ACL) surgery. Materials and Methods: The participants of the present study were 20 athletes with sixteen months post ACL reconstruction surgery and 20 healthy matched athletes. Each participant performed transitional tasks from double limb stance to single leg stance (SLS) and again to double limb stance on the force plate before and after the application of 10 minutes of constant loading. Area, fore-after range (the meaning of fore-after is anterior- posterior and in articles, this term has been used instead of anterior-posterior) range fore- after (Rfa), range sideway (Rsw), mean velocity (Mv) and confidence ellipse (Ce) of the center of pressure were measured. Results: Rsw (P=0.009) and area (P=0.009) in response to static loading in the healthy group showed a decrease and an increase of area (P=0.009) in response to static loading in the ACLR group was seen on the double limb stance phase. Mv (P<0.001) and area (P<0.001) were bigger in the ACLR group after static loaded on the integration phase. Conclusion: Decreased capacity of passive structures to maintain postural stability against perturbation was observed due to positional change among athletes with a history of ACL reconstruction surgery.