Effects of the Width in the Base of Support on Trunk and Lower Extremity Muscle Activation During Upper Extremity Exercise

상지운동 동안 기저면의 넓이 변화가 체간과 하지의 근 활성도에 미치는 영향

  • 윤혜선 (대한병원 물리치료실) ;
  • 최흥식 (한서대학교 물리치료학과) ;
  • 김택훈 (한서대학교 물리치료학과) ;
  • 신헌석 (한서대학교 물리치료학과) ;
  • 이강성 (한서대학교 의료보장구학과)
  • Published : 2004.09.17


This study was designed to determine the effects of different widths in the base of support (BOS) on trunk and lower extremity muscle activation during upper extremity exercise. Twenty-seven healthy male subjects volunteered for this study. Exercises were performed for a total of 10 trials with a load of 10 repetitions maximum (10 RM) for each of the various widths of BOS (10 cm, 32 cm, 45 cm). The width of a BOS is the distance between each medial malleoli when a subject was in a comfortable standing position. Electromyography was used to determine muscle activation. Surface bipolar electrodes were applied over the tibialis anterior, medial gastrocnemius, biceps femoris, rectus femoris, gluteus maximus, upper rectus abdominis, and elector spinae muscle. Electromyographic (EMG) root mean square (RMS) signal intensity was normalized to 5 seconds of EMG obtained with a maximal voluntary isometric contraction (MVIC). The data were analyzed by atwo-factor analysis of variance (ANOVA) with repeated-measures ($3{\times}7$) and Bonferroni post hoc test. The results were as follows: (1) There were significant differences in the width of the BOS (p=.006). (2) The post hoc test showed significant differences with the BOS between 10 cm and 32 cm, between 10 cm and 45 cm and between 32 cm and 35 cm (p=.008, p=.003, p=.011). (3) There was no interaction with the BOS and muscle. (p=.438) There were no significant differences in the muscle activation (p=.215).