• 한국전문물리치료학회지
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• 제21권3호
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• pp.1-10
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• 2014

The aim of this study was to investigate the effect of hip external rotation angle on pelvis and lower limb muscle activity during prone hip extension. Sixteen healthy men were recruited for this study. Each subject performed an abdominal drawing-in maneuver (ADIM) in a prone position, and extended the dominant hip at three different hip external rotation angles ($0^{\circ}$, $20^{\circ}$, $40^{\circ}$) with a $30^{\circ}$ hip joint abduction. Activity of the gluteus maximus (G Max), gluteus medius (G Med), and hamstring (HAM) and the G Max/HAM and G Med/HAM ratios were determined with surface electromyography (EMG). The EMG signal was normalized to 100% maximum voluntary isometric contractions (MVICs) and expressed as %MVIC. Data were analyzed by one-way repeated analysis of variance (alpha level=.05) and the Bonferroni post hoc test. Significant differences in G Max and G Med muscle activity were noted among the three different hip external rotation angles. G Max muscle activity increased significantly at both $40^{\circ}$ (p=.006) and $20^{\circ}$ (p=.010) compared to a $0^{\circ}$ hip external rotation angle. G Med muscle activity increased significantly at $20^{\circ}$ (p=.013) compared to a $40^{\circ}$ hip external rotation angle. The G Max/HAM activity ratio increased significantly at both $40^{\circ}$ (p=.004) and $20^{\circ}$ (p=.014) compared to a $0^{\circ}$ hip external rotation angle. The G Med/HAM activity ratio increased significantly at $20^{\circ}$ (p=.013) compared to a $40^{\circ}$ hip external rotation angle. In conclusion, $40^{\circ}$ and $20^{\circ}$ hip external rotation angles are recommended to increase G Max activity, and $20^{\circ}$ hip external rotation is advocated to enhance G Med muscle activity during prone hip extension with ADIM and $30^{\circ}$ hip abduction in healthy subjects.

• 대한정형도수물리치료학회지
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• 제16권1호
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• pp.26-36
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• 2010

Purpose: The study compared the muscle activity and ratio of upper trapezius (UT) to lower trapezius (LT) activity between acute and chronic whiplash-associated disorder (WAD) patients. Methods: Twelve healthy (male: 7), 14 acute WAD (male: 7), and 11 chronic WAD (male: 3) volunteers participated in this study. Electromyography using a surface EMG recorded the activity of the upper trapezius and lower trapezius of both shoulders (dominant and non-dominant) during $120^{\circ}$ elevation when standing and shoulder depression when sitting. The testing order was selected randomly. Subjects were asked to maintain each experimental position for 5 seconds at end range. EMG activity was normalized using the maximal voluntary isometric contraction (MVIC) elicited using a manual muscle-testing technique. One-way repeated measures analysis of variance (ANOVA) was used to compare the average root mean square (RMS) value of EMG activity for each condition. Results: The EMG activity of the dominant UT for chronic WAD subjects was significantly higher than for acute WAD subjects during $120^{\circ}$ elevation (p<.05). The EMG activity of the dominant LT for acute WAD subjects was significantly lower than for the control group (p<.05) during $120^{\circ}$ elevation. The EMG activity of the dominant LT for WAD patients was significantly lower than for the control group during shoulder depression (p<.05), and the chronic WAD patients scored significantly the lowest (p<.01). The dominant UT/LT for chronic WAD patients was significantly higher than the ratio for acute WAD subjects during shoulder depression (p<.05); this result was higher than for the control group (p<.01). The non-dominant UT/LT (ratio) for chronic WAD patients was significantly higher than the ratio for acute WAD subjects during shoulder depression (p<.05). Conclusion: The UT for chronic WAD subjects was hyperactive when compared to the acute WAD subjects, and the was hypoactive for both acute and chronic patients, therefore intra-trapezius imbalance was more prevalent during shoulder depression.

• 대한임상전기생리학회지
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• 제8권1호
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• pp.23-29
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• 2010

Purpose : This study is to offer clinical primary data that examines the change of imaging structure and the quantitative evaluation of muscle activity on myofascial trigger points. This study examines neuromuscular physiological characteristic by comparing the differences in physical findings, pressure pain threshold, imaging, and electrophysiological characteristics in latent and active myofascial trigger points muscle and normal muscle through the following experimental procedures. Methods : The participants for the study were thirty-three adults in their twenties. We divided three groups into normal, latent and active myofascial trigger points groups by physical findings. We analyzed the results of measured pressure pain, threshold for pain, ultrasound imaging perform for structure characteristic of muscle, surface EMG according to type of muscle contraction for function of muscle contraction. Results : Significant differences were indicated in pressure pain threshold (p<0.05). Significant differences were discovered in the ultrasound imaging analysis. There were increases in muscle Echogenicity white area index (p<0.001). There were significant differences that decrease in %MVIC (p<0.05), increase in MDF (p<0.05). Conclusion : From these results, active rnyotascial trigger points muscle showed quality deterioration on ultrasound imaging and decreased function of muscle contraction, increased motor unit action potential of II type fiber, and electrophysiologically. Imaging structure and neuromuscular physiological characteristic can be diagnostic and quantitative analytical techniques for myofascial pain syndrome and a primary factor that reflected in physical therapy intervention.

• The Journal of Korean Physical Therapy
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• 제28권2호
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• pp.106-111
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• 2016

Purpose: The aim of this study is to determine the effect of glenohumeral (GH) rotation position in modified knee push-up plus exercise (MKPUP) by examining the surface electromyography (EMG) amplitude in serratus anterior (SA), pectoralis major (PM), and upper trapezius (UTz) and the activity ratio of each muscle. Methods: A total of 22 healthy subjects volunteered for the study. Each subject performed the MKPUP at $0^{\circ}$, $45^{\circ}$, and $90^{\circ}$ of GH joint internal rotation. EMG of the SA and PM, UTz was compared between GH rotation positions and each muscle activity ratio. EMG was used to measure the muscle activity in terms of ratios to maximal voluntary isometric contraction (MVIC). Results: The difference in EMG activity during the exercise in three GH joint internal rotation positions was observed with the SA and the PM. The greater the GH joint internal rotation angle was, the lower the activity of the PM. In contrast, the SA showed higher activity. However, the activity of UT was similar under all conditions. The ratio of the SA and the PM was considerably greater at $90^{\circ}$ GH joint internal rotation than at $0^{\circ}$ and $45^{\circ}$. Conclusion: When excessive activation of the PM or imbalanced activation between the PM and the SA occurs, the MKPUP exercise is most effective at $90^{\circ}$ of GH joint internal rotation. Use of this position would be a beneficial strategy for selective strengthening of the SA and minimizing PM activation.

• 한국운동역학회지
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• 제13권1호
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• pp.95-108
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• 2003

The purposes of this study were to analyze the muscle activities and the characteristics of muscle recruiting patterns of upper trunk for Ssirum dutguri technique using three top-ranked elite Ssirum players. The EMG technique was used to record muscle activities of both right and left sides of latissimus dorsi, biceps brachii, and erector spinae. Six surface electrodes were placed on the surface of the selected muscles and one ground electrode was also attached on the back of neck(C7). One video camera was also used to record the Ssirum motion to define 4 events and 3 phases for further analysis. The raw EMG data were filtered with band pass filter (50-400 Hz) to remove artifacts and then low pass filtered (4 Hz) to find the linear envelope which resemble muscle tension curve. This filtered EMG data were normalized to MVIC for the purpose of comparion between the subjects. The results were indicated that each subject with different physical characteristics showed very different muscle activity patterns. Although Ssirum dutguri is considered as foot technique the player grasped opponent's satba(belt) with both hands when they play. Because of this reason, activities of upper trunk muscles were relatively high. However, direct comparison between upper and lower body muscles was not possible due to the lack of the data in present study. Interestingly, all threes subjects showed that erector spinae muscle activity was comparatively higher than those of latissimus dorsi and biceps brachii. This implies to reinforce back muscle as a routine of training to improve performance or to prevent back injury.

• 문화기술의 융합
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• 제5권2호
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• pp.337-344
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• 2019

본 연구는 경남소재 H대학에 재학 중인 20~30대를 대상으로 연구목적, 연구내용, 측정방법을 설명한 후 본 실험에 참여하기로 동의한 남녀 16명을 대상으로 실시하였다. 스쿼트 운동시 세 가지 조건, 즉 선자세, 60도 굴곡자세, 90도 굴곡자세 저항에 따른 넙다리곧은근, 가쪽넓은근, 안쪽넓은근, 앞정강근, 장딴지근 활성도의 전후차를 비교하기 위하여 대응표본 T-검정을 실시하였고, 저항에 따른 각 근육을 비교하기 위하여 반복측정에 의한 분산분석(repeated measured ANOVA)을 실시하였다. 60도 무릎관절 굴곡, 90도 무릎관절 굴곡시 앞정강근을 제외한 넙다리곧은근, 안쪽넓은근, 가쪽넓은근, 장딴지근에서 통계학적으로 근활성도가 증가하는 것으로 나타났고, 90도 무릎관절 굴곡시에는 안쪽넓은근에 비해 가쪽넓은근의 근활성도의 값이 큰 것으로 나타나 슬개대퇴동통증후군에도 좋지 않은 영향을 미치는 것으로 나타났다. 이 연구를 바탕으로 키높이 깔창을 착용한 상태에서의 운동의 슬개대퇴동통증후군을 악화시킬 수 있으므로 키높이 깔창을 착용하지 않는 것이 좋을 것으로 사료된다.

• The Journal of Korean Physical Therapy
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• 제24권3호
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• pp.216-222
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• 2012

Purpose: Weight-bearing exercise is a type of physical exercise that is widely performed for rehabilitation after acquiring nervous-system diseases or sports-related injuries. It is one of the most commonly prescribed rehabilitation programs for strengthing of the lower extremities. Weight-bearing exercise is important for the conduct of such activity of daily living (ADLs) as walking, and up and down the stairs. The purpose of this study was to investigate the muscle activities during one-leg standing and one-leg squatting, the two most representative weight-bearing exercises. Methods: A total of 43 elderly (60~70 years old) males who could perform weight-bearing exercises were included in the study. During the one-leg standing and one-leg squatting, the electromyographic (EMG) signals were quantified as maximum voluntary isometric contraction (%MVIC) using surface EMG, and then the muscle activities of the lower extremities during the two exercises were compared. For statistical analysis, an independent sample t-test and one-way ANOVA were performed. Results: The results of the study are as follows: (1) in the one-leg standing, the activity of the gluteus medius was the greatest among the vastus medialis, vastus lateralis, bicep femoris, (2) in the one-leg squatting, the activity of the vastus medialis was the greatest; and (3) the activity was greater in the one-leg squatting than in the single-leg standing exercise. Conclusion: The one-leg standing and squatting exercises are suitable for strengthening the muscles for the prevention of and recovery from lower-extremity injury, and for functional ADL in elderly people. In addition, dynamic exercise was shown to be more effective than static exercise for strengthening the muscles.

• 대한통합의학회지
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• 제9권4호
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• pp.283-289
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• 2021

Purpose : The purpose of this study is to investigate the effect of mid frequency electrical stimulation during squat exercise on the muscle activity and muscle activity ratio of vastus medialis oblique and vastus lateralis, and to prepare scientific basic data for exercise intervention using mid frequency electrical stimulation. Methods : This study was conducted with students from University C located in Busan, and among a total of 123 subjects, 12 subjects who complained of knee joint dysfunction between 80 and 90 points using the Kujala patellofemoral score (KPS) were used. All subjects participated in the experiment for 3 days, and MVIC values were measured for normalization of muscle activity values on the first day. For the two days, participants participated in the experiment and performed squat exercise or squat exercise receiving mid-frequency electrical stimulation in random order. Measurements were taken in the squat position immediately after the squat exercise, and muscle activities of vastus medialis oblique and vastus lateralis were measured. The measured data were compared through the dependent t test, and the statistical significance level was set to .05. Results : According to the results of this study, in the case of applying mid-frequency electrical stimulation together in the ratio of vastus medialis oblique and vastus lateralis muscle activity during squat exercise, higher values were observed compared to the case of not applying mid-frequency electrical stimulation together, and statistically significant. Also, when mid-frequency electrical stimulation was applied to both vastus medialis oblique and vastus lateralis activities during the squat exercise, higher values were shown compared to the case where the mid-frequency electrical stimulation was not applied together, but there was no statistically significant difference. Conclusion : The results of this study reported that mid-frequency electrical stimulation provided to vastus medialis oblique increased the muscle activity ratio of vastus medialis oblique and vastus lateralis. Therefore, the improvement of coordination due to the enhancement of the activity of vastus medialis oblique through mid-frequency electrical stimulation will be more helpful in the treatment of patellofemoral pain syndrome patient. In addition, it is hoped that the electrical stimulation method applied to exercise will be widely used.

• 국제물리치료학회지
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• 제1권2호
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• pp.185-191
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• 2010

Background: This study investigated effective posture for gluteus medius rehabilitation training and effects of isometric muscle activity by electrophysiology through EMG while performing dynamic isotonic behavior of weight placed differently on upper limbs. Method: 16 healthy male subjects 20 to 29 years of age volunteered for the study. Lateral stabilizer right gluteus medius activity was assessed using EMG while the right lower extremity maintains single limb support, and the left upper extremity elevation movement maintains 5 seconds without load, 1RM to 1 repetition, 5RM to 5 times, 10RM to 10 times, 5RM and 10RM maintain 5sec. Results: Comparison of the mean value of EMG data showed a statistically more significant difference in upper extremity elevation movement on opposite upper extremity added weight than one that was not added on a single limb weight bearing posture(p>.05). Weight supported side gluteus medius activity for 1RM, 5RM, 10RM weight difference and movement repetition did not differ(p>.05). Comparison in maximum value showed statistically significant differences in not adding weight on upper limb elevation exercise and 1RM, 5RM, 10RM repeated behavior. Elevation behavior and repetition appeared over 70% of MVIC. Conclusion: Unilateral weight bearing stance added weight in the opposite upper limb elevation movement was an indirect exercise to effectively stimulate gluteus medius activity. Applying various added weight will have effective exercise on the early stages of rehabilitation because activity gluteus medius did not differ through added weight.

• The Journal of Korean Physical Therapy
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• 제25권5호
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• pp.337-342
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• 2013

Purpose: This study was conducted in order to determine the effect of visual and tactile feedback on muscle activity of the gluteus maximus (Gmax) and abdominal muscles and the motion of pelvic rotation during performance of clam exercise (CE). Methods: Thirteen subjects without low back pain were recruited for this study. Each subject was instructed to perform the CE without and with feedback. The subjects were instructed to keep pelvic from rotating backwards by palpating the ASIS and monitoring the pelvic movement by themselves during performance of CE with feedback. The electromyographic (EMG) activities of Gmax and abdominal muscles were collected using surface EMG. Angles of pelvic rotation were measured using a 3-dimensional motion-analysis system. Paired t-tests were used for comparison of EMG activities in each muscle and the angle of pelvic rotation. Results: The EMG activities of all abdominal muscles were not significant between CM without and CM with feedback (p>0.05). The EMG activity of Gmax was significantly greater in CM with feedback compared with CM without feedback (without vs. with feedback; 14.2% vs. 20.7%MVIC) (p<0.05). The angle of pelvic rotation was significantly less in CM with feedback compared with CM without feedback (without vs. with feedback; $15.3^{\circ}$ vs. $10.8^{\circ}$ ) (p<0.05). Conclusion: Therefore, these findings suggest that CM with the visual and tactile feedback is effective in activation of the Gmax and correcting of the uncontrolled lumbopelvic rotation during CE.