You may be describing two things. The first is a problem called cervical myelopathy. Myelopathy is a condition of impaired spinal cord, which can be caused by disc protrusion in the neck (cervical spine). The second is proprioception. Proprioception is a term used to describe a joint's sense of where it is in space, how fast it is moving, and in what direction.
Pressure on the spinal cord can impair knee proprioception. It's not likely that exercise for the legs will change the sense of proprioception until the underlying cause (disc protrusion) is taken care of first.
See your doctor before attempting any exercise program. A change or worsening of symptoms with disc protrusion requires medical attention.