Analysis of muscle activations in lower extremities muscles at various angles of ankle flexion using wedges during static squat exercise

[Purpose] This study aimed to investigate changes in activation of the rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius muscles during one-legged squats performed at various angles of ankle flexion. With the use of wedges, the muscles were activated at different angles of ankle flexion angles to establish the appropriate posture necessary for muscle strengthening and rehabilitation. [Subjects and Methods] Healthy adults aged 20–40 years were recruited from Good Morning Hospital in Ulsan City. Of the 22 participants, two dropped out during the tests, leaving a final sample of 20 participants. The wedges were 100 mm wide and 200 mm long and had inclinations of 10°, 30°, and 50°. EMG Analyzer software was used to measure muscle activation. [Results] A significant difference in the activation of the rectus femoris muscle at various angles of ankle flexion was seen. The gastrocnemius muscle exhibited significant differences in activation among the 0°–30°, 0°–50°, and 10°–50° inclinations. [Conclusion] Wedge-assisted muscle activation under different ankle flexion angles can be introduced as an effective exercise option under clinical conditions.