Abnormal posturing that occurs with little stimulation is a sign of serious central nervous system damage. Problems with or damage to the nervous system may appear as posturing when a person does certain tasks, such as walking on the sides of the feet, toes, or heels.
Normally when a muscle contracts, the muscles on the opposite side of the joint offer resistance to the contraction. Abnormal posturing occurs when damage to the central nervous system (brain or spinal cord) reduces or prevents opposition to muscle contraction in certain muscle groups.
See the following types of abnormal postures:
Decerebrate posture -- the arms and legs are out straight and rigid, the toes point downward, and the head arches backward
Decorticate posture -- the body is rigid, the arms are stiff and bent, the fists are tight, and the legs are straight out
Opisthotonos -- the back is rigid and arching and the head is thrown backwards
An affected person may alternate between different postures as the condition changes.
Injury or swelling of a part of the brain, spinal cord, or nervous system is the most common cause of abnormal posturing. The type of posturing depends on the type and area of the nervous system involved.