Effects of various methods for ankle dorsiflexion during squats on lower extremity muscle activity and lower extremity alignment

The purpose of this study is to compare the effectiveness of different strategies to improve dorsiflexion during squats in people with limited dorsiflexion to determine which method is most effective for lower extremity muscle activity. Twenty people with limited dorsiflexion were selected. For squats, With-out, Heel lift, Stretching & Resistance Exercise (SRE) conditions were applied in random order. Lower extremity muscle activity and sagittal plane hip joint flexion angle and foot dorsiflexion angle were analyzed. As a result of the study, the muscle activity of the vastus lateralis and vastus medialis was found to be high in the Heel-lift condition in the three squat strategies during the eccentric contraction phase. Muscle activity of the tibialis anterior muscle was highest in the With-out condition in both the eccentric and concentric contraction phases. The hip joint flexion angle and foot dorsiflexion angle were the largest in the Stretching & Exercise strategy.This suggests that for those with limited dorsiflexion, a Heel-lift strategy is effective in increasing lower extremity muscle activity of the external and medial rectus during the squat motion, but that Stretching & Exercise strategies are more likely to prevent injury and address underlying issues with ankle range of motion.