요부 안정화 운동에 따른 몸통 근육들의 근활성도 비교

The Comparison of Trunk Muscle Activities During Sling and Mat Exercise

The purpose of this study was to verify the most effective spinal stabilization exercises program by comparing the activities of muscles contributing to spinal stabilization during four types of exercises using a sling and a mat. Twenty healthy males were recruited and each subjects performed four types of exercises. Exercise I was performed in a quadruped position with the subjects lifting the left arm and the opposite leg on the mat. Exercise 2 was performed in a prone position while holding a sling with the right hand and the left knee was fully extended while lifting the left arm and right leg. Exercise 3 was performed in quadruped position while holding a sling with one the right hand and lifting the opposite arm and leg. In exercise 4, subjects were instructed to maintain a balance push-up position while holding slings with both hands in 10 ㎝ forward reaching with extended elbows. Electromyographic (EMG) activities were recorded from the multifidus, external oblique, internal oblique, abdominal rectus, and erector spinalis muscles during the exercises. The EMG amplitude of each muscle was normalized to the amplitude in the maximal voluntary isometric contraction (MVIC) of each muscle. Repeated ANOVA and Bonferroni’s tests were used to compare the differences in the muscle activity according to the types of exercise. The EMG amplitudes of all the muscles were significantly different according to the types of exercises (p＜.05). The highest EMG activities of each muscle was as follow; multifidus was 73.38%MVIC in exercise 3, the erector spinalis was 40.03%MVIC in exercise 3, the external oblique was 135.88%MVIC in exercise 4, the internal oblique was 128.60%MVIC in exercise 4, and the rectus abdominalis was 95.24%MVIC in Exercise 4. The types of exercises showed a significant difference in composition rate of EMG amplitudes of each muscle (p＜.05). EMG composition rate of the multifidus was high in exercise 1 and 3. However, EMG composition rates of the external oblique, internal oblique, and the rectus abdominals were high in exercise 2 and 4. These results showed differences in EMG activities of muscles contributing to trunk stabilization during different therapeutic exercises. Therefore, the type of exercise should be carefully selected to effectively strengthen a specific trunk stabilizer.