Intense Rigidity of the Arms Due to Isolation of Motoneurones by a Spinal Tumour

In man, persisting muscular rigidity* is usually associated with severe brain damage, as in the decerebrate state and various extrapyramidal disorders.It may also be seen following tetanus.More rarely, cervical cord damage may cause rigidity of the muscles of the arms and shoulder girdle instead of the more usual spasticity.Rigidity of spinal origin is poorly recognized, but recently Penry, 132 *Muscular rigidity is said to be present in a limb when muscles actively resist passive movement of a joint no matter what the direction of displacement.The posture imposed on the limb by rigid muscles partly depends on the size of the opposing muscle groups, and partly on the distribution and reflex accessibility of the motoneurone discharge causing the rigidity.