Various exercise protocols have been introduced into clinical practice for improving trunk stability. Trunk and lumbar stability exercises on unstable surfaces have been recommended for improving lumbar stability, and unilateral leg-raising exercise o...
Various exercise protocols have been introduced into clinical practice for improving trunk stability. Trunk and lumbar stability exercises on unstable surfaces have been recommended for improving lumbar stability, and unilateral leg-raising exercise on the floor and a foam roll is often prescribed for improving trunk stability in clinic settings.This study compared abdominal muscle activity during unilateral leg raising in a hooked lying position among three types of surface condition: floor (FL), half-round foam roll (HR), and round foam roll (RR). Nineteen able-bodied volunteers who had no medical history of lower extremity or lumbar spine disease were recruited for this study. Muscle activity was recorded using surface electromyography (EMG) from both sides of the rectus abdominis (RA), obliquus externus abdominis (OE), and obliquus internus abdominis (OI) during unilateral leg raising. The normalized EMG activities were compared using a one-way repeated ANOVA.The study showed that the EMG activities of the left RA, right OE, and left OI during right-leg raising were significantly higher in the RR condition than in the FL condition. During left-leg-raising exercise, the EMG activities of all abdominal muscles except for the right OE were significantly higher in the RR condition than in the FL condition. When subjects unilaterally raised a leg, the EMG activity of the contralateral OI muscle was markedly higher in the RR condition than in the FL condition.These observations suggest that performing leg-raising exercise on a foam roll is a useful method for improving lumbar stability.