Patting the knee with a little hammer causes the lower leg to make a outsize swinging motion.
Even if this procedure is carried out 4 inches above the knee the lower leg will swing out.

Stroking the foot soles is a touchy experience and the contraction of the toes shows a different reaction.
There is also an increase of the forearm reflex when tapping the elbow gently with a small hammer.

Disturbed reflex regulation is often the cause of movement disorders that can be caused by a neurological disorder.