Spasticity or muscular hypertonicity is a isorder of the body motor system, and especially the central nervous system (CNS), in which certain muscles are continuously contracted. This contraction causes stiffness or tightness of the muscles and may interfere with gait, movement, and speech. Depending on severity, the person with the spastic muscles may or may not feel it. However, it can often be severely disabling . The human motor system is not always linked with the sensory systems, nor the voluntary-muscle systems.