Purpose: This study was designed to evaluate the effects of the different condition of leg support surface on the upper extremity and core muscle activity during the push-up exercise. Methods: Fifteen healthy subjects that were practicable push-ups were recruited in this study. Subjects were instructed the push-up exercise in the different condition of the leg support surface. Each condition of support surface was set to the high and lower, and the unstable and stable condition. Muscle activation was measured by using the surface electromyography (EMG), and recorded from the triceps brachii, serratus anterior, latissimus dorsi, rectus abdominis, abdominal external oblique, and erector spinea muscle. Results: In the results of experiments, there was no significant difference of muscle activation in upper extremity between the high unstable and high stable support surface. By contrast, muscle activation of the rectus abdominis and abdominal external oblique was significantly higher in the low unstable support surface, compared with those of the low stable support surface. It is well known that the core muscle was important to stabilization of trunk stability. Conclusion: This result demonstrates that the low and unstable support surface for the lower extremity was suited for training of core muscle for trunk stabilization during the push-up exercise.

This study was designed to compare the effects of a 12-weeks adjustment therapy & mat exercise program with a 12-weeks Gym-ball & mat exercise program on sEMG(surface electromyograph) and Cobb's angle of spinal in low back pain patients. [METHOD] Thirty-seven patients as a subject were volunteered to participate in this study and were randomly assigned to one of three groups, i.e., adjustment therapy & mat exercise complex treatment group(AG: n=15), Gym-ball & mat exercise complex treatment group(BG: n=12) and mat exercise group(CG: n=10), respectively. The pretest-midtest-posttest randomized-groups design was utilized in this study. In pre test, the sEMG(surface electromyograph) and the Cobb's angle were measured. The sEMG test included both sides back muscle activity difference during isometric back extension. The subjects in the AG group progressed adjustment therapy and mat exercise treatment, performed for 50 minutes per session, 3 times per week for 12 weeks, whereas the subjects in the BG group went through the Gym-ball and mat exercise training, performed for 60 minutes per session, 3 times per week for 12 weeks. The subjects in the CG group went through mat exercise treatment, performed for 30 minutes per session, 3 times per week for 12 weeks. In mid-post test, all variables were measured again as same manner as the pre test. The data collected in the pre, mid and post tests at the AG, BG and CG group was analyzed by utilizing RMD two-way ANOVA. [RESULT] 1) There was statistically significant(p<.001) decrease in latissimus dorsi and erector spinae muscle in the AG group and the BG group but the CG group were no significant decrease in the both sides muscle activity difference. The result of Post-hoc test was CG> AG, BG. 2) The Cobb's angle was statistically significant(p<.001) decrease in the AG group and the BG group but the CG group were no significant decrease. The result of Post-hoc test was CG> AG, BG.[CONCLUSION] The result of Post-hoc test was CG> AG, BG. In short term care, the adjustment therapy & mat exercise complex treatment better than the Gym-ball & mat exercise complex treatment for reduce the low-back pain.