• 한국전문물리치료학회지
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• 제12권3호
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• pp.22-30
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• 2005

This study was designed to identify the effect of various decline boards and postures of lower extremities on surface electromyographic (EMG) activity of knee muscles during isometric single-leg decline squat exercises. The subjects were twenty young male adults who had not experienced any knee injury and their Q-angles were within a normal range. They were asked to perform single-leg decline squat exercises in five various conditions. The EMG activities of the gluteus maximus (GM), vastus lateralis (VL), vastus medialis (VMO), tibialis anterior (TA), and gastrocnemius (GCM) muscles were recorded in five various single-leg decline squat exercises by surface electrodes and normalized by maximal voluntary isometric contraction (MVIC) values. The normalized EMG activity levels were compared using one-way ANOVA with repeated measures. The results of this study were as follows: 1) Exercises 2 and 4 produced significantly greater EMG activity of VMO than did exercise 1 ($p_{adj}$<.05/10), 2) The VMO/VL ratio of EMG activity of exercise 4 was the highest, producing a significantly greater ratio than exercise 1 ($p_{adj}$<.05/10). These results show that single-leg lateral oblique decline squat exercise is the best exercise for selective strengthening of VMO, and the posture of the contralateral leg does also affect strengthening of VMO, but we'll need to research patellofemoral joint compression for clinical application of single-leg lateral oblique decline squat exercises.

• 대한정형도수물리치료학회지
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• 제26권1호
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• pp.47-54
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• 2020

Background: This study examined the changes in the leg muscle activities of 30 healthy subjects according to different pressures caused by isometric hip adduction during squat exercise. Methods: With their knee flexed at 60°, the subjects performed isometric hip adduction with a pressure of 0, 20, 40, and 60mmHg. Surface electromyography was used to measure their muscle activities. Changes in the activities of the muscles, such as the gluteus maximus (GMAX), Gluteus medius (GM), vastus medialis oblique (VMO), vastus lateralis oblique (VLO), biceps femoris (BF), and Tensor fasciae latae (TFL) muscles, were analyzed. Results: The activities of the VMO, VLO, GM, BF, and GMAX muscles were significantly different after exercise compared to that before exercise (p<.05). The activities of all the leg muscles measured were highest at a pressure of 60mmHg during isometric hip joint adduction. Conclusion: The pressure produced by isometric hip joint adduction during squat exercise increased the leg muscle activities of the subjects. These results will provide basic data on effective squat exercise to alleviate knee joint diseases.

• 한국운동역학회지
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• 제21권3호
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• pp.361-368
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• 2011

The purpose of this study was to investigate the effect of isometric hip adduction and abduction on the muscle activities of vastus medialis oblique(VMO) and vastus lateralis(VL) during leg squat exercises. This study consisted of 21 healthy subjects who had no medical history of anterior knee pain or lower extremity disorders. The ball and belt were used to isometrically adduct and abduct the hip joint during the leg squat exercise, respectively. The surface electromyograms of VMO and VL were analyzed, and the findings were used to calculate the VMO:VL ratio during 3 different quadriceps-strengthening exercises(leg squat, LS leg squat with isometric hip adduction, LSHD leg squat with isometric hip abduction, LSHB). The muscle activities of VMO and VL and the VMO:VL ratios were compared using the paired t-test with Bonferroni adjustment. The results showed that the muscle activities of VMO and VL during LSHD were greater than those during LSHB. The VMO:VL ratio was the highest during LSHD. This finding suggests that LSHD using a ball is more effective than LS and LSHB in selectively increasing the muscle activities of VMO. Therefore, we suggest that leg squat exercise with isometric hip adduction using a ball would be useful for maintaining correct patella tracking and for selectively strengthening VMO.

• 대한통합의학회지
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• 제9권4호
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• pp.299-309
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• 2021

Purpose : The purpose of this study was to compare the ankle pronation squat with the general squat and investigate the effect on the geun varum and the muscles around the knee. Methods : Subjects were chosen as the target for squat exercise with the distance between the knees more than 5 cm. The selected 30 students were randomly divided into 15 pronation squat group and 15 general squat group, and performed five sets movements 20 times. Global postural system (GPS) and digital goniometer were used to check the distance between the knees and the Q angle, and muscle activity was measured with EMG during squat exercise. Results: The result is as follows. First, as a result of analyzing the change in the distance between the knees, the distance between the knees decreased and the Q angle increased in the pronation squat group after exercise. Second, as a result of analyzing the change in muscle activity of the peroneus longus, the muscle activity increased in the pronation squat group after exercise, and it was more effective than the general squat group. Third, as a result of analyzing the change in the VMO (vastus medialis oblique) and VL (vastus lateralis) muscle activity ratio, the activity ratio of the pronation squat group increased after exercise, and the imbalance in the VMO/VL muscle activity was decreased. Conclusion: The pronation squat exercise applied to the ankle will greatly affect what is made into a balanced leg as decreased of the distance between knees, increased of Q angle, increased of the muscle activity of the peroneus longus and the ratio of VMO/VL.

• 대한물리치료과학회지
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• 제31권2호
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• pp.52-62
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• 2024

Background: This study was to investigate effects of narrow squat exercise according to ankle angle of Toe in 10° and Toe out 10° on women with genu varum. Design: Randomized Controlled Trial or Cross-sectional Study. Methods: 30 adult women with genu varum participated in this study. All subjects were randomly assigned to 15 people of narrow squat exercise in ankle angle of Toe in 10° group (TI) and 15 people of narrow squat exercise in ankle angle of Toe out 10° group (TO). The narrow squat exercise program was conducted three times a week for six weeks. The distance between the knees was measured by using Digital Vernier Caliper. The quadriceps angle (Q-angle) was measured by using Goniometer. The stride length and propulsion were measured through G-Walk Results: Both TI and TO groups showed effective significant differences in distance between the knees, Q-angle, and propulsion (p<.05). There was no significant difference in stride length (p>.05). Left leg propulsion was found to be significantly more effective in TI group than in TO group (p<.05). Conclusion: These results suggested that narrow squat exercise according to ankle angle of toe in 10° and toe out 10° was effective for genu varum. However, compared to TO group, TI group was more effective in gait propulsion. It is considered that narrow squat exercise in ankle angle of Toe in 10° can be suggested as an effective intervention method for women with genu varum.

• 대한물리의학회지
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• 제16권1호
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• pp.41-48
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• 2021

PURPOSE: The purpose of this study was to provide fundamental clinical data to be used in therapeutic approach to patients with patellofemoral pain syndrome by administrating the squat exercise combined with whole body vibration exercise to them and investigating the effect of such exercise to leg muscle activity and muscle fatigue. METHODS: The patients with patellofemoral pain syndrome were randomly assigned to experimental group I (n = 9) where only squat exercise was administered and experimental group II (n = 9) where the squat exercise combined with whole body vibration exercise was provided. The intervention program was administered for two weeks, four days a week, one session a day, three set a session, and 20 reps a set. The pre- and post-test were performed to measure muscle activity and muscle fatigue of vastus medialis and vastus lateralis. RESULTS: The muscle activity significantly changed in both group (p < .05, p < .01, respectively) and the muscle fatigue showed significant change only in group I (p < .05). In addition, there was significant difference between groups in change of muscle fatigue of both muscles (p < .05) but not in change of muscle activity. CONCLUSION: The results showed that both exercise are effective in improving muscle activity, however, that the squat exercise combined with whole body vibration exercise is more effective in preventing muscle fatigue.

• PNF and Movement
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• 제15권1호
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• pp.67-75
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• 2017

Purpose: The purpose of this study was to determine the effects of a functional movement correction exercise on the functional movement screen scores of badminton players. Methods: The participants consisted of 25 badminton players who were randomly assigned to an experimental group (n = 13) or a control group (n = 12); they engaged in exercise three times per week for eight weeks. The experimental group engaged in the functional movement correction exercise, while the control group engaged in general exercise. An FMS kit (USA) was used to measure the following: FMS score, deep squat, hurdle step, in-line lunge, shoulder mobility, active straight leg raise, trunk stability push up, and rotary stability. Results: The FMS score, deep squat, hurdle step, in-line lunge, shoulder mobility, active straight leg raise, and trunk stability push up, and rotary stability showed significant improvement in the experimental group (p < 0.05). Conclusion: The experiment confirmed that the functional movement screen scores of badminton players improve with effective exercise interventions.

• 대한물리의학회지
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• 제13권3호
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• pp.1-9
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• 2018

PURPOSE: The purpose of this study was to determine the effect of exercise therapy on low back pain (LBP), the function of paraspinal and abdominis muscles, and the sacrohorizontal angle as seen on the radiographs of the lumbar spine in a young female golf player with LBP. METHODS: This case report describes an 11-year-old female golfer who presented with LBP. The exercise therapy program comprised lumbar joint mobilization, lumbar spine flexion distraction, abdominal bridge, plank, side plank, and single-leg extensions from a 4-point kneeling position for 40 min/day; this was done twice a week for 8-weeks. LBP [visual analog scale (VAS) and Oswestry disability index (ODI)] and function of paraspinal and abdominis muscles [Ito test, curl-up test, $90^{\circ}$ stop test, squat test, opened eye one leg stance test (OEOL), and closed eye one leg stance test (CEOL)] were measured before and after 4 and 8 weeks of exercise therapy. The radiographs were analyzed for the lumbar Cobb's angle and sacrohorizontal angle before and after 8 weeks of exercise therapy. RESULTS: After 4 and/or 8 weeks of exercise therapy, VAS and ODI scores decreased; results for the Ito test, curl-up test, $90^{\circ}$ stop test, squat test, and OEOL and CEOL of muscle function improved; and the lumbar Cobb's angle and sacrohorizontal angle improved. CONCLUSION: These results suggest that exercise therapy improves LBP, muscle function, and radiographic parameters associated with LBP in young golf players. These findings have clinical implications for exercise therapy in young female golf players who have LBP.

• PNF and Movement
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• 제21권2호
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• pp.255-263
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• 2023

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.

• Physical Therapy Rehabilitation Science
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• 제2권1호
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• pp.57-61
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• 2013

Objective: To determine the correlation among three functional tests: single leg vertical jump (SLVJ), single leg hop for distance (SLHD), and single leg squat (SLSQ). Design: Cross sectional study. Methods: Twenty healthy men (n=10) and women (n=10) with no history of lower extremity dysfucntion participated in this study and performed in university research laboratory. The procedures consisted of a general warm-up, a task-specific warm-up, actual testing, and a cool down. All participants performed the three tests in random order. Each test was performed three times for the dominant and non-dominant lower extremity (LE). SLVJ, SLHD, SLSQ were measured using a standard tape measure. Results: Statistically significant difference was presented between dominant LE and non-dominant LE in each function test (p<0.05). The strongest correlation was between SLVJ and SLSQ, 0.939 and 0.883 for dominant and non-dominant LE, respectively (p<0.05). The weakest correlation was between SLVJ and SLHD, 0.713 for dominant (p<0.05) and between SLSQ and SLHD, 0.739 for non-dominant (p<0.05). Conclusions: There is a strong correlation between SLVJ and SLSQ, suggesting that each test measures similar constructs of function and can be substitutive, while weak correlation between SLSQ and SLHD suggest these two tests do not measure the same functional components and could be paired as outcome measures for the clinical assessment of LE function. It will provide physical therapist with scientific evidence for effective test combination of LE function assessment in clinical practice.