Winged scapular (WS) causes muscle imbalance with abnormal patterns when moving the arm. In particular, the over-activation of the upper trapezius (UT) and decrease in activity of the lower trapezius (LT) and serratus anterior (SA) produce abnormal scapulohumeral rhythm. Therefore, the SA requires special attention in all shoulder rehabilitation programs. In fact, many previous studies have been devoted to the SA muscle strength training needed for WS correction. Objects: The purpose of this study was to investigate the effect of shoulder girdle muscle and ratio according to the angle of shoulder abduction and external weight in supine position. Methods: Twenty three WS patients participated in this experiment. They performed scapular protraction exercise in supine position with the weights of 0 ㎏, 1 ㎏, 1.5 ㎏, and 2 ㎏ at shoulder abduction angles of 0˚, 30˚, 60˚, and 90˚. The angle and weight applications were randomized. Surface electromyography (EMG) was used to collect the EMG data of the SA, pectoralis major (PM), and UT during the exercise. The ratio of PM/SA and UT/SA was confirmed. Two-way repeated analyses of variance were used to determine the statistical significance of SA, PM, and UT and the ratios of PM/SA and UT/SA. Results: There was a significant difference in SA according to angle (p<.05). Significant differences were also identified depending on the angle and weight (p<.05). The angle of abduction at 0˚, 30˚ and weight of 2 ㎏ showed the highest SA activity. However, there was no significant difference between PM and UT (p>.05). There was a significant difference between PM/SA and UT/SA in ratio of muscle activity according to angle (p<.05). Significant differences were found at PM/SA angles of 30˚, 60˚ and 90˚ (p<.05). For UT/SA, significant difference was only observed at 90˚ (p<.05). Conclusion: Based on the results of this study, in order to strengthen the SA, it was found to be most effective to use 1 and 1.5 ㎏ weights with abduction angles of 0˚ and 30˚ at shoulder protraction in supine position.

본 연구의 목적은 플랫 벤치 프레스에서 하지를 지면에 지지한 자세와 하지를 벤치에 지지한 자세에서의 동작 수행 시 대흉근 및 척추기립근의 근 활성 분석을 통해 벤치 프레스 응용동작에 뒷받침 할 만 한 근거자료를 찾고, 운동수행에 관한 효율적인 기초자료를 제시하는데 있다. 대상자는 아마추어 보디빌더 4명, 헬스 트레이너 2명으로 선정하였다. 측정을 위해 연구대상들의 대흉근과 척추기립근에 표면전극을 부착하였다. 벤치 프레스에 대한 동작구간을 설정하고 하지를 지면에 지지한 동작과 하지를 벤치에 지지한 동작으로 나눠 피험자별 10RM으로 각각 1세트씩 실시하는 방식으로 진행하였다. 데이터는 SPSS 20.0을 통하여 분석하였으며 다음과 같은 결과를 얻었다. 플랫 벤치 프레스 동작 시 하지의 지지 유형이 대흉근에는 영향을 미치지 않았지만, 척추기립근에서는 차이가 나타났다.

Purpose of this study is to describe the treatment, surgery, rehabilitation and return to daily life subject pectoralis major muscle rupture. The in patient with was a 26 years old, injured in training due to hyperextension and external rotation. Physical examination, manual test, and MRI were used to diagnose pectoral muscle rupture and operation took for the pectoralis major muscle rupture with allograft. The subject was referred for rehabilitation from 3 weeks. Range of motion (ROM) exercise was mainly performed until 3 months, strength was performed with tubing band, body weight, machine training and proprioceptive exercise. Shoulder range of motion (external rotation, flexion) were measured with goniometer and muscle strength (flexion, adduction, internal rotation) were measured with dynamometer. At 6momths, external rotation ROM was 50° (unaffected side 60°), and flexion almost recovered at 3 months. Muscle strength was gradually increased to 6.2kg, 15.7kg, and 27.0kg in flexion, while internal rotation The pain remained slightly after 9 months. The present results suggest that ROM exercise and strengthening exercise increase the muscle power and ROM, and decrease the pain.

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.