Spastic cerebral palsy refers to a condition in which the muscle tone is increased, causing a rigid posture in one or more extremities [arm(s) or leg(s)]. This rigidity can be overcome with some force, ultimately giving way completely and suddenly the spasticity leads to a limitation of use of the involved extremity, largely due to the inability to coordinate movements. The spasticity occurs on one side of the body (hemiparesis), but it can also affect the four limbs (quadriparesis) or be limited to both legs (spastic diplegia). Spasticity is the result of damage to the white matter of the brain, but it can also be due to damage of gray matter. The degree of spasticity can vary, ranging from mild to severe. Children who are mildly affected may experience few limitations of their function while severely affected children may have little to no meaningful use of the affected limb(s). Spasticity, if not properly treated, can result in contractures, which are permanent limitations in the ability of joint movement. Contractures can be greatly limiting in the care of children with cerebral palsy. Spasdcity can also be quite painful, requiring medication to relax the muscle tone.