Spinal reflexes take important part in our movement. After spinal cord injury (SCI), reflexes often change. For many years, researchers and doctors have assumed that abnormally acting spinal reflexes lead to movement problems, without clear scientific evidence. For example, in people who suffer spasticity, a common problem after SCI, walking is disturbed, presumably because stretch reflexes (e.g., knee jerk reflex) and some other reflexes are not working well. Yet, which reflex is causing a problem in what way has not been well understood. Such understanding is very important in developing and applying effective therapies for improving gait recovery after SCI. Therefore, in this project, we are studying spinal stretch reflexes and other reflexes during walking, to understand how these reflexes contribute to spastic gait problems in people with chronic incomplete SCI. Successful completion of this project will result in better understanding of spastic gait problems, which in turn, will help us develop more effective therapy application and improve the quality of life in people after SCI.