• 한국전문물리치료학회지
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• 제29권3호
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• pp.215-224
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• 2022

Background: The presence of the lumbopelvic-hip neuromuscular chain is essential for dynamic spinal stabilization; its therapeutic effects on dynamic movements of the distal extremity segment and underpinning motor mechanism remain unknown and warrant further study on participants with low back pain (LBP). Objects: We aim to compare the effects of the broken chain exercise (BCE) and connected chain exercise (CCE) on electromyography (EMG) amplitude and onset time in participants with and without LBP. Methods: Randomized controlled clinical trial. A convenience sample of 40 nonathletic participants (mean age: 24.78 ± 1.70) with and without LBP participated in this study. All participants underwent CCE for 30 minutes, 30-minute daily. We measured EMG amplitude and onset times on bilateral erector spinae (ES), gluteus maximus (GM), hamstring (HAM), transverse abdominis (TrA), internal oblique (IO), and external oblique (EO) during the prone hip extension (PHE) test before and after the BCE and CCE. We used multivariate analysis of variance (MANOVA) to analyze the amplitude and onset time difference between exercises (BCE and CCE) and Pearson's correlations to determine any synergistic relationship among the HAM, GM, bilateral TrA/IO, and ES muscles. The statistical analyses were used at p < 0.05. Results: MANOVA showed that CCE was more decreased on EMG amplitude in HAM and bilateral ES, while increased GM and contralateral TrA/IO than BCE (p < 0.05). MANOVA EMG onset time data analyses revealed that the main effect of the conditions was significant for all HAM, GM, and bilateral ES muscles, whereas the main effect for the group was significant only for GM and contralateral ES in healthy and LBP groups. Pearson's correlation coefficient was computed to assess the relationship between BCE and CCE on dependent variables. In most of the muscles, there was a strong, positive correlation between the two variables, and there was a significant relationship (p < 0.001). Conclusion: CCE produced more effective and coordinated core stabilization and motor control mechanism in the lumbopelvic-hip muscles in participants with and without LBP during PHE than BCE.

• The Journal of Korean Physical Therapy
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• 제27권6호
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• pp.386-391
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• 2015

Purpose: This study investigated whether the strength imbalance between two muscles can affect the score of EMG based biofeedback game, and whether the EMG based biofeedback game score can be used as predictable indicator of the degree of muscle balance alternating the conventional strength measuring equipment. Methods: 40 participated in this study. Biodex was used to measure the peak torque/weight in order to calculate the muscle strength balance index between plantar flexor and dorsiflexor of ankle joint. And muscle balance index (MBI) was calculated. The EMG biofeedback game scores of dorsiflexor and plantar flexor were acquired, so that the EMG electrodes were attached at tibialis anterior and gastrocnemius. The relationship between the game score and the muscle balance index were analyzed. Results: There was negative correlation between the muscle balance index between plantar flexor and dorsiflexor and the peak torque/weight of plantar flexor (r=-0.70). And there was negative correlation between the muscle balance index between plantar flexor and dorsiflexor and the game score of plantar flexor (r=-0.83). Conclusion: The EMG biofeedback game score had significant relationship with muscle imbalance at ankle joint, so it seems that the game score can be used for predicting the degree of muscle imbalance as a parameter.

• 한국운동역학회지
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• 제22권3호
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• pp.333-339
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• 2012

Freezing of gait is a severely problem in people with Parkinson's disease. The purpose of this study was to investigate the muscle activities of adductor longus, gluteus medius, gluteus maximus, biceps femoris, rectus femoris, gastrocnemius, and tibialis anterior using Noraxon 8 channels EMG system during stop task in patients with Parkinson's disease. Seven parkinson's patients and age matched normal participants were recruited in the study. Filtered EMG signals were rectified, smoothed and integrated. To control for the altered timing and magnitude of activity, iEMG was normalized for time and peak value. The results indicated that the patients with Parkinson showed decreased gait cycle, stance phase, swing phase time, swing phase time ratio and increased stance phase time ratio than normal participants. The patients with Parkinson showed decreased gastrocnemius muscle activity time ratio, while increased tibialis anterior muscle activity time ratio than normal participants. During stance phase before stop, the patients with Parkinson showed relatively lower average and peak iEMG in anterior tibialis and gastrocnemius muscle than normal participants. During swing phase before stop, the patients with Parkinson showed relatively higher average iEMG in gastrocnemius muscle than normal participants. During stop phase, the patients with Parkinson showed relatively lower average and peak iEMG in anterior tibialis and gastrocnemius muscle than normal participants.

• 대한물리치료과학회지
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• 제19권1호
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• pp.55-62
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• 2012

Objectives : The purpose of this study was to determine the effects of high heeled shoes on the static & dynamic balance performance and electromyography(EMG) of back and lower extremity muscles. Materials & Methods : Sixteen women participated in this study. Subjects were composed two groups with LL shoes group and higher heel shoes group. We carried out Romberg's test and muscle activity of left and right Paraspinalis, Quadriceps femoris, Tibialis anterior, Gastrocnemius muscles by EMG in order to determine static balance performance according heel height. Using by Biorescue(Incenierie company), we trained subject to transfer of COG each direction(Anterior, posterior, Right, Left), we carried out this test for distance, surface, distance/surface in order to determine dynamic balance performance according heel height. The data were analyzed by independent t-test between lower and high heel height using SPSS(ver. 17.0)/PC program. Results : There was significant difference of distance(p<.05) of weight perturbation between lower and high group in dynamic balance performance and EMG value of left Gastrocnemius(p<.05), both Tibialis anterior(p<.05) muscle in static balance performance. Conclusions : Height of heel has effect on dynamic balance performance in distance of the Anterior, posterior direction. EMG of Gastrocnemius and Tibialis anterior muscles were affected by Romberg's test.

• 한국직업건강간호학회지
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• 제8권2호
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• pp.156-161
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• 1999

The EMG(Electromyography) analysis was used to identify the fact the degree of inclined step was selected as dependent variable and feet muscle fatigue was selected as a independent variable. In a final result from EMG test. the shift in median frequency (MF) with 20, 25, 30, 35 degree of inclined steps indicated that 30 degree step was identified as most effective for a decrease in feet muscle fatigue. In a department store, 80% of the workers are female standing sales workers. They work at standing on average 10 hours per day. They performed heavy duty jobs such as lifting, lowering. packing and carrying heavy materials. Furthermore, even though they have work shoes, they usually use various kind of high heels. Eventually, this situation develops low-back-pain (LBP) problems for female workers. In conclusion, it is recommended that a particular branch in a department store claimed this step can effectively to circulate blood and significantly decrease feet muscle fatigue in lower extremity.

• Biomedical Engineering Letters
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• 제8권4호
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• pp.345-353
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• 2018

This study suggested a new EMG-signal-based evaluation method for knee rehabilitation that provides not only fragmentary information like muscle power but also in-depth information like muscle fatigue in the field of rehabilitation which it has not been applied to. In our experiment, nine healthy subjects performed straight leg raise exercises which are widely performed for knee rehabilitation. During the exercises, we recorded the joint angle of the leg and EMG signals from four prime movers of the leg: rectus femoris (RFM), vastus lateralis, vastus medialis, and biceps femoris (BFLH). We extracted two parameters to estimate muscle fatigue from the EMG signals, the zero-crossing rate (ZCR) and amplitude of muscle tension (AMT) that can quantitatively assess muscle fatigue from EMG signals. We found a decrease in the ZCR for the RFM and the BFLH in the muscle fatigue condition for most of the subjects. Also, we found increases in the AMT for the RFM and the BFLH. Based on the results, we quantitatively confirmed that in the state of muscle fatigue, the ZCR shows a decreasing trend whereas the AMT shows an increasing trend. Our results show that both the ZCR and AMT are useful parameters for characterizing the EMG signals in the muscle fatigue condition. In addition, our proposed methods are expected to be useful for developing a navigation system for knee rehabilitation exercises by evaluating the two parameters in two-dimensional parameter space.

• 대한정형도수물리치료학회지
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• 제27권3호
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• pp.89-98
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• 2021

Purpose: The purpose of this study was to determine the effects of electromyography (EMG)-biofeedback based closed kinetic chain exercise (CKCE) on quadriceps muscle activity and dynamic balance ability in patellofemoral pain syndrome (PFPS). Methods: Thirty subjects with PFPS were included and they were divided into EMG-biofeedback using CKCE (Group I) and squat exercise using CKCE (Group II), each group consisted of 15 patients. Group I and Group II was performed by the patients for three times a week, for six weeks. sEMG was used to measure quadriceps muscle activity and star excursion balance test (SEBT) was used to measure dynamic balance ability. Results: According to the results of the comparisons between the groups, after intervention, quadriceps muscle activity and dynamic balance ability were significantly higher in Group I than in the Group II. Conclusion: Findings of this study suggest that EMG-biofeedback using CKCE that provides real-time biofeedback information on muscle contraction may have a beneficial effect on selective muscle strength of vastus medialis oblique muscle and dynamic balance ability in PFPS.

• 한국산학기술학회논문지
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• 제19권8호
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• pp.260-267
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• 2018

표면근전도(sEMG) 신호의 응용은 초기에는 단순히 근육 활성도의 유무를 판별하여 On/Off 의 스위치 기능으로 많이 사용되어 왔으나, 표면근전도 신호처리와 알고리즘의 발달로 휠체어의 방향 제어는 물론 수화를 인식하는 분야까지 확대되었다. 청각 장애인들의 언어 소통을 위한 중요한 수단인 수화나 지화는 미학습자와는 소통의 어려움이 존재해왔으며, 이러한 어려움을 해결하기 위해 수화나 지화를 인식하는 기술에 대한 연구가 지속적으로 수행되어 왔다. 최근에는, 수화나 지화 시연시에 활성화되는 근육의 신호를 활용하여 수화나 지화를 인식하는 방법이 중국 숫자지화 중심으로 적용되고 있는 추세이다. 하지만, 수화나 지화는 일반 음성언어와 마찬가지로 중국 숫자지화와 한국 숫자지화가 다르므로, 중국 숫자지화 시연시에 관여하는 근육이 한국 숫자지화 시연시에는 관여하지 않을 수가 있어, 인식률이 현저히 떨어질 수 있다. 그러므로 한국 숫자지화 시연시에 활성화되는 근육의 선정은 표면근전도 신호에 기반한 한국 숫자지화 인식률에 매우 중요하다. 하지만, 표면근전도 신호에 기반한 한국 숫자지화 인식에 대한 연구는 문헌에서 드물다. 본 연구에서는 표면근전도 신호를 활용한 한국수화 또는 한국지화의 인식에 관한 초기 연구로서, 한국 숫자지화를 시연시에 관여하는 아래팔근육을 제안하고 실험을 통하여 검증하기 위해 숫자 영(0)부터 다섯(5)의 여섯 가지 한국 숫자지화를 대상으로 인식하는 연구를 수행하였다. 이를 위해, 표면근전도 신호를 활용한 CNN 기반 지화인식 방법에 적용하여 여섯 가지 한국 숫자지화에 대하여 100%의 인식률을 확인함으로써, 여섯 가지 한국 숫자지화 인식을 위해 제안된 아래팔근육과 전극위치의 타당성을 검증하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 추계학술대회 논문집
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• pp.195-196
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• 2008

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.237-238
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• 2008