PNF and Movement 2023; 21(2): 255-263
Immediate Effect of Biofeedback Training of Gluteus Medius on Dynamic Balance during Single Leg Squat
Kyung-Hye Yang, P.T., M.S.1⋅Jong-Chul Jung, M.S.2⋅Du-Jin Park, P.T., Ph.D.3
1Department of Physical Therapy, Graduate School, Catholic University of Pusan
2Department of Physical Therapy, Pusan National University Yangsan Hospital
3Department of Physical Therapy, College of Health Sciences, Catholic University of Pusan
Correspondence to: Du-Jin Park (
Received: July 14, 2023; Revised: July 31, 2023; Accepted: August 4, 2023; Published online: August 31, 2023.
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Purpose: This study aims to investigate the immediate effects of electromyography (EMG) biofeedback training of the gluteus medius on dynamic balance during single leg squats in healthy individuals.
Methods: The sample size in this study was estimated using the G-power program at an effect size of 0.4, a significance level (α) of 0.05, and a testing power of 0.90. In addition, as a result of considering the 10% dropout rate, this study recruited 21 healthy individuals (8 males and 13 females). All subjects measured the Y-balance test-lower quarter (YBT-LQ) and limits of stability (LOS) before and after a single leg squat (SLS) and SLS with EMG biofeedback training of the gluteus medius (SLSEB). They were trained for 10 minutes for each exercise, and two dynamic balance tests were performed three times.
Results: There was a significant difference in the YBT-LQ score between the two exercises (p < 0.05). In the YBT-LQ score, there was a significant difference before and after SLS and SLSEB (p < 0.05). SLSEB showed a significantly higher YBT-LQ score than SLS (p < 0.05). There was a significant difference in LOM between the two exercises (p < 0.05). However, there was no significant difference between the two exercises.
Conclusion: A single-leg squat with EMG biofeedback exercises is an effective method to improve dynamic balance, such as the YBT-LQ.
Keywords: Gluteus medius, Biofeedback, Single leg squat, Balance

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