The purpose of this study was to propose a co-contraction profile(CCP)to assess co-con-traction of agonist and antagonist muscles about the knee in spastic hemiplegic gait.Surface EMG wasrecorded from quadriceps and hamstrings of 9 ablet-bodied subjects and 6 spastic hemiplegic subjects follow-ing stroke.Results showed that CCPs were high during weight bearing both in able-bodied subject walkingand in subjects with spastic hemiplegia. However, they were higher in most part of stance phase and lateswing phase in spastic hemiplegics compared to able-bodied subjects (P<0.05).The study concluded thatco-contraction profiles provide descriptive information on the sources of variation in co-contraction,particu-larly in co-contraction in assessment of spastic hemiparetic subjects following stroke.