The purpose of this study is to analysis of muscle fatigue in the upper trapezius and splenius capitis muscles according to therapy table height variation. The subjects were consisted of 15 healthy adults(10 males, 5 females) who had no medical history of neurological and musculoskeletal problems. In experiment, wireless electrode EMG system was measured for each the upper trapezius and splenius capitis muscles during the treatment performed on table. the differences in the muscle fatigue was compared for 4 types of table height(-6cm, -3cm, 0, +3cm from elbow in 90° flexion position). Muscle fatigue according to therapy table height were significant difference except for left upper trapezius. And muscle fatigue of right upper trapezius and splenius capitis showed significant decrease in +3cm table height compared to -6cm table height(p<.05). Muscle fatigue of right upper trapezius and splenius capitis were the highest in -6cm table height, but those were the lowest in +3cm table height. This study propose to change therapy table height higher than +3cm from elbow in 90° flexion position, if you hope to reduce muscle fatigue.

This study investigated the effects of axillary crutch length on trunk muscle activity and lumbo-pelvic-hip complex movements during crutch gait. Eleven healthy men participated in this study. The participants performed a three-point gait with optimal, shorter, and longer crutch lengths. Weight-bearing (WB) side was determined as the dominant leg side. The electromyography (EMG) activity of the bilateral rectus abdominis (RA) and erector spinae (ES) muscles and lumbo-pelvic-hip complex movements were monitored using a three-dimensional motion system with wireless surface EMG. Differences in the EMG activity of RA and ES muscles and range of motion (ROM) of lumbar spine, pelvis, and hip among conditions were analyzed using one-way repeated-measures analysis of variance, and a Bonferroni correction was conducted. There was less RA muscle activity on the WB side under the optimal crutch length condition compared with shorter and longer crutch length conditions (p<.05). The EMG activity of the RA muscle on the non-WB side and ES muscle on the WB side were significantly decreased under the optimal crutch length condition compared with shorter crutch length condition (p<.05). No significant differences in the EMG activity of the ES muscle on the non-WB side and ROM of lumbo-pelvic-hip complex were found among conditions (p>.05). These findings indicate that the optimal crutch length improves the trunk muscle efficiency during crutch gait.

The purpose of this paper is to suggest the strategical lifting postures able to alleviate imbalanced EMG amplitude leading to an increase in low back muscle fatigue while lifting asymmetric load dynamically. Eleven male subjects are required to lift symm

목적 : 본 연구는 상위흉수손상군, 하위흉수손상군, 정상군을 대상으로 체간과 상지의 컴퓨터 사용과 관련된 여덟 가지 근육의 활성도를 측정하여 흉수손상자에게 적절한 키보드의 위치를 제시하고자 실시되었다. 연구방법 : 연구대상자는 미국 척수 손상 협회(American Spinal Injury Association; ASIA) A 또는 B의 흉수손상자 중 상위흉수손상자(T2-T8) 9명, 하위흉수손상자(T9-T12) 11명, 그리고 정상인 9명이었다. 적절한 키보드의 위치를 알아 보고자 두 가지 위치 즉, 팔꿈치 굽힘 100°위치와 팔꿈치 굽힘 70°위치에서 근활성도를 측정하였다. 모든 대상자는 2분간 메트로놈의 박자에 맞춰 키보드 중간열의 키를 1초에 4타의 속도로 타이핑하였으며 이때 표면근전도기를 이용하여 목과 어깨의 목세움근, 위등세모근, 앞어깨세모근, 뒤세모근, 중간등세모근과 손목폄근군, 그리고 척수손상자의 체간유지 보조근육인 넓은 등근과 큰가슴근의 근활성도(%RVC)를 측정하였다. 결과 : 상·하위흉수손상군의 측정치는 정상인과 동일하게 팔꿈치 굽힘 100°의 자세에 비해 팔꿈치 굽힘 70°인 위치에서 위등세모근, 손목폄근군, 앞어깨세모근의 활성도가 유의하게 낮게 나타났다. 또한 하위흉수손상군의 경우 정상인과 다르게 팔꿈치 굽힘 100°높이에서 목세움근과 넓은등근의 활성도가 유의하게 증가하였다. 결론 : 흉수손상자의 체간과 상지의 근긴장도를 감소시키기 위해 적절한 키보드 위치는 팔꿈치 굽힘 70°정도의 높이였다. 차후 연구에서는 보다 많은 척수손상자를 대상으로 장시간의 포괄적 컴퓨터 작업을 적용하여 장애특성에 적합한 VDT 환경을 파악하는 연구가 필요할 것으로 사료된다.

This study aimed to identify the asymmetry observed in the electromyography (EMG) activity patterns of selected trunk and thigh muscles between the affected and unaffected sides during the sit-to-stand movement in ambulatory patients with post-stroke hemiparesis. This study included 20 patients with post-stroke hemiparesis. The differences between stroke fast walkers (, 11 subjects) and stroke slow walkers (<8 m/s, 9 subjects) were compared. The activation magnitude and onset time of the multifidus, lumbar erector spinae, hamstrings, and quadriceps during the sit-to-stand movement were recorded through surface EMG. Moreover, the EMG activation magnitude and onset time ratios of each bilateral corresponding muscle from the trunk and leg were measured by dividing the relevant values of the unaffected side by those of the affected side. In all the subjects, the activation magnitudes of the multifidus, hamstring, and quadriceps on the affected side significantly decreased compared to those on the unaffected side (p<.05). The onset time of muscle activity in the affected side was markedly delayed for the multifidus and quadriceps during the task (p<.05). The activation magnitude ratios of the quadriceps were markedly decreased in the stroke slow walkers as compared to those in the stroke fast walkers. These findings indicate that the asymmetry in the multifidus, hamstring, and quadriceps muscle activation patterns in patients with post-stroke hemiparesis may be due to the excessive muscle activation in the unaffected side to compensate for the weakened muscle activity in the affected side. Our findings may provide researchers and clinicians with information that can be useful in rehabilitation therapy.

The purpose of this study is to identify which width of the base of support(BOS) is safer and more effective in lifting by comparing muscle activations and body sways when lifting objects under the width variation of the BOS. A total of fifteen healthy adults participated in this study. For the width variation of the BOS, the participants changed the width between their feet into three different types(10cm, 32cm, 45cm) and lifted a 10kg four times in each type after going up on a force plate. In order to measure body sways according to the width variation of the BOS, a motion analysis system was used. In addition, in order to measure the muscle activations of lower extremities, including the erector spinae, gluteus maximus, rectus femoris, and tibialis anterior, an electromyogram(EMG) analysis was employed. In addition, the Borg's scale was drawn by quantifying the subjective discomfort levels felt from each width of the BOS. In conclusion, no statistically significant differences according to the width variation of the BOS were observed(p=.295, .308)(p>.05). However, a statistically significant difference was exhibited between the Borg's scale, which indicates the discomfort levels from lifting performances, and the width variation of the BOS (p=.000*).

The purpose of this study was to assess the influence of patellar height on quadriceps muscles' electromyography (EMG) activity during a squat exercise in adults with patella baja. For the study, we recruited 15 volunteers who had patella baja on the right side. We measured the EMG activity of the right rectus femoris, vastus medialis oblique, and vastus lateralis muscles during squat exercises under two conditions, specifically with and without an infra-patellar strap. The infra-patellar strap was applied below the tested patella to elevate the patella to a normal height. A paired t-test was used to compare the effects of patella height on EMG activity of the quadriceps muscles. The EMG activity of the rectus femoris (RF), vastus medialis oblique (VMO), and vastus lateralis (VL) muscles were significantly decreased during the squat exercise with the infra-patellar strap compared to the same exercise without the infra-patellar strap (p<.05), while the VMO/VL ratio was not different significantly between two conditions (p>.05). The findings of this study suggest that an infra-patellar strap may benefit people with patellar baja, as changes in patellar height could improve the efficiency of the quadriceps muscles.

The purpose of this study was to compare electromyography (EMG) activity for the middle and lower trapezius muscle according to various shoulder abduction angles. Thirty healthy male subjects were recruited for this study. Each subject performed three repetitions of horizontal abduction at 75˚, 90˚, 125˚, 160˚, and 180˚ of shoulder abduction angle in a prone position. Surface EMG activity was recorded from the middle and lower trapezius while the subjects held for five seconds at a predetermined position. The EMG activity was normalized using the maximal voluntary isometric contraction (MVIC) elicited using a manual muscle testing technique. A repeatedly measured ANOVA was performed by Bonferroni's post hoc test. The EMG activity of the middle and lower trapezius was significantly different among shoulder abduction angles (p<.05). The greatest level of muscle activity for the middle and lower trapezius were demonstrated at and of shoulder abduction angle, respectively. These results suggest that middle and lower trapezius strengthening exercise and manual muscle testing should be performed at different shoulder abduction angles.

The aim of this study was to compare electromyography activity for long and lateral heads of triceps brachii muscle according to forearm positions during different triceps strengthening exercises. The muscle activities for long and lateral head of triceps brachii were measured by surface electromyography. Fifteen healthy volunteers participated for this study and performed elbow extension in three different elbow extension exercises (elbow extension in a supine position; EES, elbow extension with shoulder abduction at 90 degrees in a prone position; EESA, and elbow extension with one arm at the side of the trunk in a prone position; EESP) and forearm positions (supination, neutral, and pronation). A two-way repeated measures ANOVA was used to compare the effects of the exercise positions and forearm positions. The EMG activities of the long head of the triceps brachii increased significantly during EESP with forearm supination, whereas the activity of the lateral head of the triceps brachii increased significantly during EESA with the forearm in a neutral position (p<.05). The results of this study suggest that exercise positions and forearm positions should be considered for selectively strengthening the long and lateral heads of triceps brachii muscles.

The purpose of this study was to assess visual biofeedback's influence on trunk muscles' (EMG) activity and endurance holding time for correct position during whole-body tilt exercise. For the study, we recruited 14 volunteers who showed no symptom of lumbar disease during medical tests. We measured the EMG activity of their rectus abdominis, external abdominal oblique, internal abdominal oblique and erector spinae muscles, and their endurance holding time for correct position during anterior and posterior whole-body tilt under two conditions: whole-body tilt with and without visual biofeedback. Resistance with gravitational force on the trunk during whole-body tilt was applied by using a device that had a monitor on which the subjects could check their alignment and that sounded an alarm if a subject's alignment collapsed. The study showed an increase in the EMG activity of external abdominal oblique, internal abdominal oblique/rectus abdominis ratio and endurance holding time for correct position during both anterior and posterior whole-body tilt with visual biofeedback compared with without visual biofeedback (p<.05). We suggest that the whole-body tilt exercise with visual biofeedback could be a beneficial strategy for selectively strengthening the internal abdominal oblique muscle and minimizing the rectus abdominis muscle's activity while maintaining correct alignment during whole-body tilt exercise.

본 연구에서는 근전도 신호를 활용하여 정상인의 보행과 관련된 상지와 하지 근육의 신호를 확인하고 저항센서를 이용하여 정상적인 보행 패턴을 확인하였다. 대학생 15명을 대상으로 정지해 있을 때와 평지를 보행할 때, 상지의 4부위(대흉근과 승모근)와 하지의 10부위(대퇴직근, 대퇴이두근, 내측광근, 외측광근, 반막양근, 반건양근, 가자미근, 장비골근, 내비복근과 외비복근)에 전극을 부착하여 근전도를 측정하였다. 저항센서는 양측 발바닥의 8부위에 센서를 부착하여 보행시 발에 가해지는 압력을 측정하였다. 그 결과, 근전도 신호는 정지상태에 비하여 보행 시에 허벅지의 외측광근과 반건양근을 제외하고 모든 근육에서 유의하게 높은 진폭을 가졌다. 또한 보행주기의 두 단계인 입각기와 유각기와 관련된 근육을 확인하였다. 저항 센서의 신호 분석 결과, 평균 보폭 주기 동안 크게 입각기와 유각기의 두 주기와 세부적으로 여덟 단계 - 초기 접지기, 하중 반응기, 중간 입각기, 말기 입각기, 전 유각기, 초기 유각기, 중간 유각기, 말기 유각기 - 의 보행 주기를 확인할 수 있었다.

본 연구에서는 유머를 경험하는 동안 나타나는 아동의 안면근육반응을 확인하고 유머 정서에 의해 유발된 안면근육반응과 우울 수준과의 관계를 연구하였다. 실험에 앞서 또한 아동의 우울 수준을 측정하기 위하여 12~13세의 아동 43명(남 22명)에게 한국판 PIC 검사의 우울 척도를 평가하도록 하였다. 실험이 시작되면, 자극이 제시되기 전 60초 동안 안정 상태를 측정한 후, 유머를 유발하는 시청각 동영상 자극을 제시하는 동안 안면근육반응(양측 추미근, 구륜근)을 측정하였다. 자극 제시가 끝나면 자신이 경험한 정서를 정서평가척도 상에 평가하도록 하였다. 아동의 95.3%(41명)이 유머를 경험하였다고 보고하였고 그 강도는 3.81(5점 만점)로 나타났다. 안면근육반응은 안정 상태에 비하여 유머 자극이 제시되었을 때 유의하게 증가하였다. 안면근육반응과 우울 수준과의 상관을 확인한 결과, 우측 추미근에서 유의한 부적 상관이 나타났다. 이는 우울 점수가 높은 아동일수록 유머를 경험할 때 안면근육을 적게 움직임을 의미한다.

The purpose of this study was to compare EMG activity for pectoralis major muscle during shoulder movement with various abduction angle and rotation position in supine position. Fifteen healthy subjects were recruited for this study. All subjects performed shoulder horizontal adduction holding a 2 kg dumbbell in shoulder abduction 40˚, 70˚, 90˚, 130˚, 160˚ with shoulder neutral, internal rotation (IR), and external rotation (ER). Surface EMG activity was recorded from pectoralis major clavicle part and pectoralis major sternum part for 5 seconds and EMG activity was normalized to the value of maximal voluntary isometric contraction (%MVIC). Dependent variables were examined with 3 (Neutral, IR, ER) 5 (40˚, 70˚, 90˚, 130˚, 160˚) analysis of variance with repeated measures. The EMG activity of pectoralis major muscle was significantly different between shoulder abduction angles and between shoulder rotation positions (p<.05). The highest value of EMG activity of pectoralis major clavicle part among shoulder abduction angles was in 70˚ and, 90˚ in that order. The highest value of EMG activity of pectoralis major sternum part among shoulder abduction angles was in and 130˚, 90˚ in that order. According to the rotation degree, shoulder ER showed the highest value and IR showed the lowest value in both muscle parts. These results suggest that shoulder abduction 70˚, 90˚, 130˚ will be effective during manual muscle testing (MMT) and strengthening exercise for pectoralis major muscle. It is also supposed that shoulder ER is the efficient posture for strengthening of pectoralis major muscle.

목적 : 본 연구의 목적은 뇌졸중 환자의 손기능에 대한 근전도 바이오피드백 훈련의 효과를 조사하는 것이다. 연구 방법 : 발병 6개월 이상인 뇌졸중 환자 10명을 무작위로 실험군과 대조군으로 각각 5명씩 배정하였다. 실험군은 근전도 바이오피드백 훈련을 1일 1회, 주 5일, 6주 동안 수행하도록 하였다. 훈련의 1회기는 15초의 휴식기와 5초간의 추적과제를 수행하는 활동기로 구성되며 1회 훈련동안 추적과제를 총 40번 시행하였다. 반면, 대조군의 모든 치료 상황은 바이오피드백 훈련을 제외하고는 실험군과 같았다. 손기능을 검사하기 위하여 훈련 전·후에 개정된 Ashworth 척도, Fugl-Meyer 평가, 상자와 나무토막 검사, 뇌졸중 상지기능 검사를 실험군과 대조군 모두에게 실시하였다. 결과 : 실험군은 개정된 Ashworth 척도를 제외한 모든 검사에서 훈련 후의 결과가 훈련 전의 결과와 비교하여 통계적으로 유의한 차이를 보였다(p<.05). 대조군은 모든 검사에서 유의한 차이를 보이지 않았다(p>.05). 또한 집단간 비교에서 실험군의 훈련 후 손기능 향상이 모든 검사에서 대조군에 비하여 통계적으로 유의하게 높았다(p<.05). 결론 : 본 연구는 실시된 근전도 바이오피드백 훈련이 뇌졸중 환자의 손기능 향상에 효과적임을 지지한다.

The purpose of this study was to investigate the trunk and lower extremity muscle activity induced by three different intensity conditions (intensity 1, 3, 5) of whole body vibration (WBV) during bridging exercise. Surface electromyography (EMG) was used to measure trunk and lower extremity muscles activity. Eleven healthy young subjects (6 males, 5 females) were recruited from university students. The collected EMG data were normalized using reference contraction (no vibration during bridging) and expressed as a percentage of reference voluntary contraction. To analyze the differences in EMG data, the repeated one-way analysis of variance was used. A Bonferroni's correction was used for multiple comparisons. The study showed that EMG activity of the rectus abdominis, external oblique, internal oblique, erector spinae and rectus femoris muscles was not significantly different among three intensity conditions of WBV during bridging exercise (p>.05). However, there were significantly increased EMG activity of the medial hamstring muscle (p=.001) and medial gastrocnemius muscle (p=.027) in the intensity 3 condition compared with the intensity 1 condition. This result can be interpreted that vibration was absorbed through the distal muscles, plantar flexor and knee flexor.

This study examined the vastus medialis oblique (VMO) and the vastus lateralis (VL) onset time differences (OTD) during quadriceps contraction in different hip positions. Twelve healthy subjects were recruited (four men, eight women). Surface EMG activities of the VMO and VL were measured during a quadriceps strengthening exercise in a long sitting condition and in a sitting at a chair with feet hanging condition. For each condition, subjects were tested in two hip positions (neutral and adduction). The OTD between the two muscles was calculated for each condition, by subtracting the onset time of the VL from the VMO. Therefore, the negative value of OTD represent earlier EMG onset of the VMO compared to the VL. The OTD was not significantly different between the hip neutral and the hip adduction position in the long sitting condition (p=.064). However, the OTD was significantly different between the hip neutral position (15.83±109.51 ms) and hip adduction position (-5.58±121.08 ms) during the sitting at a chair with feet hanging condition (p=.047). The negative OTD value in the hip adduction condition during quadriceps strengthening exercises is the result of earlier onset of the VMO than VL. Therefore, quadriceps contraction in the hip adduction position can prevent the risk of patella lateral tracking. We expect that quadriceps strengthening exercise in the hip adduction position will be a safe way to prevent patellofemoral pain syndrome resulting from abnormal patella lateral tracking.

목적 : 본 연구의 목적은 손가락 폄근에 실시한 근전도 유발 전기자극 치료가 편마비 환자의 손기능 회복에 미치는 영향을 알아보고자 하였다. 연구 방법 : 20명의 뇌졸중 환자를 무작위로 EMG-stim군과 대조군에 각각 10 명씩 배정하였다. EMG-stim 군은 하루에 30분씩 2회, 주 5일, 10주 동안 (총 100회) 손가락 폄근에 EMG-stim 치료를 실시하였다. 반면, 대조군에게는 어떠한 치료도 실시하지 않았다. 손 기능을 검사하기 위하여 치료 전·후에 적분 EMG, 관절 운동 범위, 퍼듀 페그보드 검사를 EMG-stim군과 대조군 모두 실시하였다. 결과 : 치료 전·후 EMG-stim군은 적분 EMG, 관절 운동 범위, 퍼듀 페그보드 검사에서 유의하게 개선되었다(p<.05). 그러나 대조군은 유의한 차이가 나지 않았다(p>.05). 또한 집단 간 비교에서 EMG-stim 군은 대조군에 비하여 모든 종속 변수에서 유의하게 개선되었다(p<.05). 결론 : 본 연구에서 장기간 동안 집중적으로 실시한 EMG-stim 치료는 뇌졸중 환자의 손기능 회복에 효과적이라는 결론을 내릴 수 있다.

The purposes of this study were to compare core muscle activities with and without the use of Pilates resistive equipment during bridging exercises and to investigate the efficacy of a Pilates device. Fourteen healthy individuals (6 males, 8 females) between 20 to 26 years of age were examined. They were engaged in a bridging exercise with and without a magic circle. Three consecutive repetitions of each exercise were performed. Surface electromyography (sEMG) was used to measure the electrical activities of the right side internal oblique, the adductor longus, the multifidus, and the gluteus maximus muscles. Normalized EMG activities were compared using a paired t-test and the level of significance was set at =.05. The results showed that the EMG activities of the internal oblique (p=.0078), the adductor longus (p=.0007), and the gluteus maximus (p=.0001) muscles were significantly higher when using the magic circle during the Pilates bridging exercise. Also, statistically significant change existed in the multifidus muscle (p=.0106). The bridging exercise, combined with hip adduction using the magic circle, may enhance core stabilization. Therefore, using a magic circle during hip adduction combined with bridging exercise may be recommended usefully for individuals wanting to strength the core muscles. Further research is needed to access the nature of motor control of the Pilates mat exercises and to deliver exercise intervention for lower back pain patients.

Most Authors reported that mouth guard is a part of equipment for body-contact sports players. Mouth guards protect orofacial injuries but have some problems in breathing and speaking. Some authors reported that mouth guards have also improve the muscle strength and sport ability. This experiment was performed to study the change of masseter muscle EMG after wearing of mouth guard. 10 D university male base ball players were participated in this study. After impression taking, mouth guards were constructed and weared. Masseter muscle EMG and nasal ventilation after ten day's adaptation were checked. They were requested clenching with or without mouth guard. EMG and nasal ventilation were checked by iworx 104 instrument simultaneousley. The result showed that masseteric EMG were improved and nasal ventilation were stable after wearing mouth guard. It concluded that mouth guard had improved muscle activity and stabilized the nasal ventilation depend on experimental method.

본 연구는 젊은층과 고령층을 대상으로 계단 상하행시 하지근군의 근전도(EMG; Electromyogram)를 측정하여 발휘근육부위와 근피로 정도와의 관계를 파악하기 위해 근전도 amplitude 분석을 실시하여, 비교하였다. 피험자는 젊은층과 고령층 각각 20명이었으며, 하지근 8부위(전경골근, 내측광근, 외측광근, 대퇴직근, 반건양근, 대퇴이두근, 내비복근, 외비복근)에 전극을 부착하여 계단 상하행 전후의 근전도를 측정하였다. 그 결과 젊은층은 계단 상하 보행 후 모든 측정 부위의 근전도 amplitude가 커졌으며, 고령층도 전경골근과 대퇴직근을 제외한 근육 6부위에서 근전도 amplitude가 커졌다. 또한 젊은층과 고령층의 amplitude 분석 값을 비교해 보면, 대퇴이두근과 내비복근을 제외한 모든 근육부위에서, 젊은층의 amplitude 값이 고령층에 비해 계단 상하 보행 전후 변화가 더 크게 나타났으며 특히 전경골근은 통계적 유의차가 인정되었다(p<0.05). 이와 같이 젊은층에 비해 고령층은 근육량이 적으므로 amplitude의 변화가 작은데, 노인들을 위한 제품 또는 환경 설계시 노인 근전도의 특성을 고려하여 측정하고 분석해야 할 것이다.