Effects of lifting the non-paretic foot on muscle activity during the semi-squat exercise in hemiplegic patients

[Purpose] This study compared the electromyographic activity of the quadriceps in hemiplegic patients during the downward, maintenance, and upward phases of squat exercises performed with the feet parallel and with the non-paretic foot lifted. [Subjects] A total of 17 hemiplegic patients (9 males and 8 females) volunteered for this study. [Methods] All subjects performed squat exercises with the knees flexed to 30° and with the feet parallel (shoulder-width apart) or with lifting of the non-paretic foot (normalized to 25% of the knee height). [Results] The activity of the rectus femoris, vastus medialis oblique, and vastus lateralis muscles was significantly higher during squat exercises performed with the non-paretic foot lifted than with the feet parallel to each other. The activity of all muscles during the maintenance phase of the exercises was greater than that during the downward and upward phases. [Conclusion] Lifting the non-paretic foot during squats may represent an effective exercise for motor function rehabilitation in hemiplegic patients.