In recent years, gait rehabilitation for patients with spinal cord injury has been progressed by introducing advanced robotics. As an equipment for such advanced rehabilitation, robot-driven gait orthosis "Lokomat[○!R]" (Hocoma AG) is available. In order to promote patient's voluntary muscle activity, Lokomat[○!R] has a function of adjusting the driving torque for knee and hip joints required for gait. Parameter regarding this torque adjustment is named the guidance force (GF). This study analyzed the relationship between the GF value and electromyography and motion of the lower extremity under nearly the same kinematic condition, in an attempt to clarify the effects of the GF value on patient's gait. Experiments employing 5 healthy volunteers demonstrated that the decrease of the GF value affected primarily to the local activity in electromyography of the lower extremity without modifying overall activity pattern as well as the ratio of 4 gait phases in kinematics.