Range of Motion is defined as the ability of a joint to pass through normal range in flexion and extension. It is common for range of motion to become inhibited after injury, surgery, or secondary to pain. Range of motion can be restored in two ways: passive or active. Passive range of motion is done while the muscles are completely relaxed and the therapist performs the range of motion to the joint without assistance by the patient. This is especially important in patients that are unable or too painful to move on their own. Active range of motion is performed by the dog independently with no assistance by the therapist. Performing range of motion is essential to preventing stiffness and compensation while keeping joints lubricated and mobile.