The purpose of this study was to analyze and compare series of muscle activity during plank exercises with use of togu-jumper. Ten male students (age 26.9±1.7 yrs, height 172.2±5.7 cm, weight 66.5±7.5 kg) who have no musculoskeletal disorder related with one''s upper or lower limb were selected for subjects. To analyze and compare series of muscle activity, five of surface EMG electrodes were attached to the upper rectus abdominis (URA), lower rectus abdominis (LRA), external oblique abdominis (EO), erector spinae (ES) and gluteus maximus (GM). Each subject did plank exercise on stable support surfaces (Normal) and on unstable support surfaces with the togu-jumper. For each dependent variable, a one-way ANOVA with repeated measures was performed with significance level p<.05. Contrasts were performed to execute post tests for results with statistical significance.
The results of the study showed that the average nEMG values of URA and LRA increased in Upper (Togu-jumper used upper limb) compared to Normal. This is perhaps because the effects of rectus abdominis more than any other muscles for body stability. Aloso, the maximum nEMG values of LRA increased in Upper and Lower (Togu-jumper used lower limb) compared to Normal. Additionally, Maximum nEMG values of EO increased in Upper compared to Normal. This may have resulted due to correct body posture and balance; momentary strong muscle activity in LRA and EO. Therefore, Using togu-jumper on upper limb maximizes the performance of core training in plank exercise.
The results of the study may be further applied to method for effective training. It is considered that analysis research on modified plank exercise is required for further research. Additionally, It is necessary to analyze not only global muscle but also local muscle, as a comprehensive research, to suggest ideal method for plank exercise.