a commom characteristic of cp is spasticity, which refers to increased tone, or tension, in a muscle. normally, muscles must have enough tone to maintain posture or movement against the force of gravity while at the same time providing flexibility and speed of movement. the command to tense, or increase muscle tone, goes to the spinal cord through nerves from the muscle itself. the command to be flexible, or reduce muscle tone, comes to the spinal cord from nerves in the brain. these two commands must be well coordinated in the spinal cord for muscles to work smoothly and easily while maintaining strength. in a person with cp, damage to the brain has occurred. the damage tends to be in the area of the brain that controls muscle tone and movement of the arms and legs. the brain of the individual with cp is therefore unable to influence the amount of flexibility a muscle should have. the command from the muscle itself dominates the spinal cord and, as a result, the muscle is too tense, or spastic. the brain damage in cp cannot be reversed and produces life-long disabilities
approximately 80% of patients with cp have varying degrees of spasticity. once spasticity has developed with cp, it never resolves spontaneousy. spasticity adversely affects muscles and joints of the extremities, causing abnormal movements, and is especially harmful in growing children. the known adverse effects of spasticity are inhibition of movement, inhibition of longitudinal muscle growth, inhibition of protein synthesis in muscle cells, limited stretching of muscles in daily activities, and development of muscle and joint deformities. patients with cp do not have deformities of the extremities at birth but develop them over time. spasticity of muscles, along with the limitations on stretching and use of muscles in daily activities, is a major cause of deformities.
orthopaedic operations, including muscle release and tendon-lengthening procedures, are also used to treat deformities associated with spastic cp. orthopaedic surgery certainly improves range of motion of the joints and makes it easier for children to move the lower extremities. orthopaedic surgery does not reduce spasticity directly but treats only the consequences of spasticity. along with physical therapy and occupational therapy for stretching, strengthening, and facilitating good movement patterns, the goal is for children to develop maximal independence within the limits of their motor and associated deficits. with appropriate management, many children can lead near-normal lives.