An initial evaluation of eight abdominal exercises for their ability to provide stabilisation for the lumbar spine.

Eight abdominal strengthening exercises were investigated in order to evaluate their ability to promote stabilisation of the lumbar spine. Twenty-three healthy volunteers aged between 18 and 32 participated in the study. During each of the selected exercises, surface electromyography was used to measure the level of motor unit activity in the right upper rectus abdominis, the right lower rectus abdominis, the right oblique abdominis and right lumbar para-vertebral muscles. A formula, based on the relative importance of each muscle in the proposed stability pattern was devised and used to give a single 'stability' score in order to compare each of the eight exercises tested. Results indicated that the exercises which involved applied rotatory resistance to the trunk appeared to activate a more appropriate stability pattern for the lumbar spine.