ELECTROMYOGRAPHICAL COMPARISON OF CONCENTRIC AND ECCENTRIC PHASE DURING SELECTED ABDOMINAL EXERCISES

The purpose of this study was to compare the electromyographical (EMG) activity / amplitude (force) variation of contractions (Concentric and Eccentric) during sit-up exercises on rectus abdominis. The amplitudes of contraction of all the quadrants during three different sit up were recorded. Ten male subjects selected for the experiment were of All India Intervarsity level players from Aligarh Muslim University, Aligarh. Their mean age, height and weight was 20.6 years, 167.4 cm and 62.6kg respectively. The Student Physiograph (Biodevices, Ambala) for the group experimentation and research was used for EMG recording. All procedures were standardized. Three sets of observations were made on each subject. The electrodes were located over the belly of the muscles and oriented along its longitudinal axis. The concentric and eccentric phase of the sit-up exercises were undertaken and were analyzed by paired t-test, that revealed no significant difference (0.05 level). Our findings support the concept that abdominal strengthening exercises can differentially activate various abdominal muscle groups, but contradict some traditionally held assumptions regarding the effects of specific phase exercises.