On the relationship between lower extremity muscles activation and peak vertical and posterior ground reaction forces during single leg drop landing

Aim. Anterior cruciate ligament (ACL) injury continues to be an important medical issue for athletes participating in sports. Vertical and posterior ground reaction forces have received considerable attention for their potential inluence on ACL injuries. The purpose of this study was to examine the relationship between electromyographic activity of lower extremity muscles and the peak vertical and posterior ground reaction forces during single leg drop landing. Methods. Thirteen physical education male students participated in this correlation study. Electromyographic activities of gluteus medius, biceps femoris, medial gastrocnemius, soleus as well as anterior tibialis muscles along with ground reaction forces were measured. Participants performed single- leg landing from a 0.3m height on to a force platform. Landing was divided into two phases: 100 ms preceding ground contact and 100 ms proceeding ground contact. Pearson correlation test was used to determine the relationships between these muscles activity and peak vertical and posterior ground reaction forces. Results. The results of the study indicated that the activity of soleus and tibialis anterior in pre -landing phase were positively correlated with peak vertical ground reaction force ([P≤0.04], [P≤0.008], respectively). However, no signiicant correlation was found between the activities of other muscles in pre-landing phase and peak vertical as well as peak posterior ground reaction forces. Also, no signiicant correlation was found between the activities of muscles in post-landing phase and peak vertical as well as peak posterior ground reaction forces. Conclusion. Soleus loading shifts the proximal tibia posterior at the knee joint and tibialis anterior prevent hyperporonation of the ankle, a mechanisms of ACL injury. Hence, neuromuscular training promoting preparatory muscle activity in these muscles may reduce the incidence of ACL injuries.