Pressure distributions on the buttocks and thighs by the functional electrical stimulation on the gluteus maximus, sartorius and hamstring in the seating posture were analyzed for ten healthy young volunteers in order to determine which muscle can be stimulated for pressure ulcer prevention. Muscles were stimulated every 5 seconds over 30 seconds by the MP150 stimulator. Pressure distribution and ground reaction forces on the stimulated buttocks and thighs increased when the gluteus maximus was stimulated. Pressure on the stimulated thigh slightly decreased when stimulating sartorius and hamstring individually. With a simultaneous stimulation of the gluteus maximus and sartorius, pressures on the stimulated buttocks and thighs increased significantly, but pressure on the opposite buttock decreased significantly. With a simultaneous stimulation of the sartorius and hamstring, both pressure on the stimulated thigh and the ground reaction force significantly decreased.