• Physical Therapy Korea
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• v.28 no.1
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• pp.27-35
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• 2021

A weak or dysfunctional gluteus medius (Gmed) is related to several pathologies, and individuals with hip abductor weakness have Gmed weakness. This study aimed to systematically review the literature associated with the anatomy and function of the Gmed, and the prevalence, pathology, and exercise of Gmed weakness. Papers published between 2010 and 2020 were retrieved from MEDLINE, Google Academic Search, and Research Information Sharing Service. The database search used the following terms: (glut* OR medius OR hip abduct*) AND weak*. The Gmed plays an important role in several functional activities as a primary hip abductor by providing pelvic stabilization and controlling hip adduction and internal rotation. Weakness of the Gmed is associated with many disorders including balance deficit, gait and running disorders, femoroacetabular impingement, snapping hip, gluteal tendinopathy, patellofemoral pain syndrome, osteoarthritis, iliotibial band syndrome, anterior cruciate ligament injury, ankle joint injuries, low back pain, stroke, and nocturia. Overuse of the tensor fasciae latae (TFL) as a hip abductor due to Gmed weakness can also cause several pathologies such as pain in the lower back and hip and degenerative hip joint pathology, which are associated with dominant TFL. Similarly, lateral instability and impaired movements such as lumbar spine lateral flexion or lateral tilt of the pelvis can occur due to compensatory activation of the quadratus lumborum for a weakened Gmed while exercising. Therefore, the related activation of synergistic muscles or compensatory movement should be considered when prescribing Gmed strengthening exercises.

• Physical Therapy Korea
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• v.23 no.3
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• pp.57-67
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• 2016

Background: Many previous studies recommended the side-lying hip abduction (SHA) exercise for targeting the gluteus medius (Gmed) and gluteus maximus (Gmax) muscle activity while the decreasing tensor fasciae latae (TFL) activation. Mischoice of hip position and angle in SHA may increase the risk of lower extremity injuries and undesirable muscle activation. However, information is limited on the effect of composite hip flexion angles and hip rotation on the gluteal muscle activity during SHA. Objects: This study aimed to compare muscle activity (Gmed, TFL, and Gmax) and activity ratios (Gmed/TFL, Gmax/TFL, and Gmed/Gmax) using surface electromyography (EMG) during SHA exercise at three different hip flexion angles either with or without internal rotation (IR) in subjects with Gmed weakness. We hypothesized that applying hip flexion and IR during SHA would increase gluteal muscle activity and decrease TFL activity. Methods: Muscle activity and activity ratios in 20 volunteers with Gmed weakness during 6 different SHA were investigated with surface EMG. One-way repeated-measures analysis of variance was used to determine the statistical significance. Results: Significant differences were found among the six different exercises for Gmed ($F_{2,41}=11.817$, p<.001) and Gmax ($F_{3,52}=5.513$, p=.003) muscle activity, and Gmed/TFL ($F_{3,54}=8.735$, p<.001) and Gmax/TFL ($F_{2,37}=4.019$, p=.028) activity ratios. Conclusion: Applying hip flexion is an effective method for increasing gluteal activity, and it elicits great Gmed/TFL and Gmax/TFL activity ratios during SHA in subjects with Gmed weakness.

• PNF and Movement
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• v.20 no.2
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• pp.285-293
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• 2022

Purpose: The purpose of this study was to confirm that the activation of the contralateral muscles changes according to posture after applying the proprioceptive neuromuscular facilitation leg pattern. Methods: Ten healthy adults (four males and six females) with no history of current musculoskeletal/neurological injuries were recruited for this study. Abdominal muscle (transverse abdominis) and hip joint muscle (gluteus maximus and gluteus medius) activation was assessed using surface electromyography (Ultium EMG, Noraxon Inc., USA). We evaluated muscle activation during the application of the PNF leg pattern. The data were analyzed using the SPSS version 21.0 program. Results: The results were found to be statistically significantly different in the 90/90 supine posture and sitting posture for the gluteus maximus (p < 0.05). The results were found to be not statistically significantly different for the transverse abdominis according to posture (p > 0.05). The results were found to be not statistically significantly different for the gluteus medius according to posture (p > 0.05). Conclusion: Application of the PNF leg pattern resulted in a significant change in the muscle activation of the contralateral segment according to posture, and the 90/90 supine posture induced high muscle activation of the gluteus maximus. In addition, the activation of the transverse abdominis was high in all three postures.

• Journal of Korean Physical Therapy Science
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• v.21 no.1
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• pp.13-20
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• 2014

Purpose : The purpose of this study was to analyze and compare the surface electromyography(EMG) activity of trunk region muscle between normal subjects and chronic low back pain(CLBP) patients during one leg stance. Methods : The subjects were 27 people, were consisted of 12 subjects who don't have low back pain and 15 subjects who have low back pain from 19 to 28 year of age(mean age 22.22). We used surface EMG to evaluate the activity of the Rectus abdominis, External abdominal oblique, Quadratus lumborum, Gluteus medius muscle. We used independent two samples t-test for statistical data. Results : The result of this study showed that the maximal voluntary isometric contraction(%MVIC) ratio of the trunk muscles was higher in patients with CLBP than in normal subject. But there were no statistically significant differences. There were statistically significant differences of the activity of the Quadratus lumborum, Gluteus medius muscle(p<0.05).

• Physical Therapy Rehabilitation Science
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• v.10 no.2
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• pp.90-97
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• 2021

Objective: The purpose of this study was to find out how the back instability during clam exercise (CE) causes changes in pelvic rotation and hip joint abductor muscle activity, and to find out the effects with different methods of application of pressure biofeedback. Design: Comparative study using repeated measures. Methods: Each subjects performed the clam exercise (CE) without pressure biofeedback, the clam exercise with pressure biofeedback applied to the back (CE-PBU to back), and the clam exercise with pressure biofeedback applied to the side (CE-PBU to side). The amount of pelvic rotation was measured using myomotion. And the muscle activity of the muscle gluteus medius and the tensor fasciae latae was measured using EMG device. One-way repeated measures ANOVA followed by the Bonferroni post test were used to compare the EMG activity in each muscle and pelvic rotation angle during the CE, CE-PBU to back, CE-PBU to side. Results: The amounts of pelvic rotation was the lowest in CE-PBU to back (p< 0.05) and the ratio of muscle activity of the muscle gluteus / tensor fasciae latae was the highest in CE-PBU to back (p< 0.05). Conclusions: It is thought that, in order to stabilize the waist-pelvis and increase hip joint muscle strength in subjects with back instability, applying clam exercise with pressure biofeedback applied to the lower back is effective in improving waist-pelvic movements and selectively strengthening the muscle gluteus medius.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.415-422
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• 2020

This study investigates the relationship between muscular strengths and gait characteristics of the elderly. Totally, 107 subjects, aged 65 to 85 years, participated in this study. Researchers measured muscle strengths (grip force, toe grip force, gluteus medius, and gluteus maximus forces) and walking characteristics (walking speed, cadence, step length, single leg support, and double legs support). Dynamometers and inertial measurement unit-based shoe systems were used for measuring muscular strength and gait characteristics, respectively. No significant difference was observed in strengths and walking characteristics between the young elders (YE, 65-74 years) and the old elders (OE, 75-85 years). For each age, muscular strength significantly correlated with some gait parameters. Forces of gluteus medius and gluteus maximus muscles showed better significant correlations between some gait parameters for all age groups, as compared to grip force and toe grip force. Regression coefficients between walking speed and grip force did not vary with age. We conclude that muscular strengths in OE better explained the gait characteristics than in YE subjects. Even though grip strength is an easily measured variable for senior fitness test, forces of gluteus medius and gluteus maximus muscles are more meaningful for understanding the walking characteristics of elderly people.

• The Journal of Korean Physical Therapy
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• v.22 no.5
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• pp.57-61
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• 2010

Purpose: The purpose of this study was to identify the effect of active foot arch support on the muscles of lower extremity electromyographic activity during squat exercise in persons with pronated foot. Methods: The study subjects were 16 persons with pronated foot. They have no history of surgery in lower extremity and trunk and limitation of range of motion or pain when performing squat exercise. Each subject was measured the navicular drop (ND) to determine the pronated foot. And then the subjects were asked to perform three repetitions of a $90^{\circ}$ knee flexion squat in both conditions which are 1) preferred squat and 2) squat with active foot arch support. Results: Paired t-test revealed that squat with active foot arch support produced significantly greater EMG activities in abductor hallucis (p=0.00), proneus longus (p=0.03) and gluteus medius (p=0.04) than preferred squat. But the EMG activities of tibialis anterior, vastus medialis oblique and vastus lateralis were not showed significantly different between the both squat conditions. Conclusion: The findings of this study suggest that active foot arch support during squat increase the activities of lower extremity muscles which are the abductor hallucis, proneus longus and gluteus medius. Also, the abductor hallucis which is one of the planter intrinsic muscle and peroneus longus play a role in support of the foot arch and active foot arch support induced the increase of the activity of gluteus medius. Therefore active foot arch support can change the lower extremity biomechanics as well as passive foot support such as foot orthotics and taping.

• Korean Journal of Applied Biomechanics
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• v.22 no.3
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• pp.365-371
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• 2012

We aimed to analyze the muscle activity of adolescent patients with idiopathic scoliosis during gait and develop the wearing of musculo-skeletal functional garment by applying the principle of sports taping based on the result of the analysis. We selected 20 male students between the ages of 13 and 18 and divided them into 2 groups: one group consisted of 10 patients with idiopathic scoliosis <20 degrees of Cobb's Angle: the other group had 10 normal students. Using, we measured and analyzed the muscle activity of 8 different regions: left and right latissimus dorsi, left and right thoracolumbar fascia, left and right gluteus medius, and left and right biceps femoris during gait. Our results can be summarized as follows: Firstly, in patients with idiopathic scoliosis, the gait showed a significantly low activity of the right latissimus dorsi muscle when the left foot was supported on the ground(p<.05). Secondly, in the overall gait cycle, the patients showed a higher activity of the right thoracolumbar fascia and right gluteus medius than that seen in the normal students: however, this difference was not statistically significant. Thirdly, by applying sports taping on the bisis of the results, this study developed the wearing of musculo-skeletal functional garment that could maximize the stimuli of the right latissimus dorsi and alleviate muscle contraction of the right thoracolumbar fascia and right gluteus medius, while expanding the spinal line upward and downward, by focusing on the difference between left and right muscular strength of the muscle activity of the bright latissimus dorsi. Overall, we expect that by wearing of musculo-skeletal functional garment, the muscular functions in adolescents with idiopathic scoliosis.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.5 no.2
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• pp.94-98
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• 2012

Calcific tendinitis is characterized by inflammation around calcium hydroxyapatite crystal deposits. Minimally invasive extracorporeal shock wave therapy (ESWT) has been postulated to be an effective treatment option for treating calcific tendinitis. In clinical practice, shock waves usually are aimed at the painful area after palpation and not focused. It has been known that exact fluoroscopic focusing of ESWT at the calcific deposit for treatment of calcifying tendinopathy is highly effective. Ultrasound is a simple, inexpensive and radiation-free diagnostic tool that has been used to demonstrate tendinopathy including calcific tendinitis. However, focusing of shock wave under ultrasound is less well established. We present a patient in whom large calcific tendinitis of gluteus medius was completely resolved by exact focusing of ESWT by ultrasound with literature review.

• Physical Therapy Korea
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• v.22 no.3
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• pp.71-80
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• 2015

Hip muscle activation and strengthening exercise programs are often used to prevent and treat various lower extremity injuries. Common exercise programs include squat exercises. The purposes of this study were to investigate gluteus medius (GMED) and tensor fasciae latae (TFL) muscle activity, and to assess the GMED/TFL ratio during squat exercises involving different isometric hip contraction conditions. Different types of isometric hip contraction were standard squat without hip contraction, squats with isometric hip adduction, and squats with isometric hip abduction. Twenty (10 males and 10 females) healthy subjects ($23.7{\pm}2.8$ years old) were recruited. Subjects performed the squat exercises with the back supported by a wall and knees flexed to $60^{\circ}$. Surface electromyography (EMG) was used to measure GMED and TFL activity. One-way repeated analysis of variance was used to compare GMED and TFL muscle activity and the GMED/TFL ratio. GMED and TFL EMG activity was significantly higher during squats with isometric hip adduction and abduction compared with the standard squat without hip contraction (p<.05). Between the isometric hip adduction and abduction contraction conditions, only the TFL EMG activity was significantly higher during squats with isometric hip adduction than isometric hip abduction (p<.05). The GMED/TFL ratio was significantly higher during squats with isometric hip adduction than isometric hip abduction (p<.05). Squats with isometric hip adduction and abduction improved GMED and TFL muscle activity. Furthermore, the GMED/TFL ratio was higher during isometric hip adduction than isometric hip abduction. Our data indicate that squat exercises involving isometric hip adduction enhance GMED muscle activity.