Pathophysiology of impairment in patients with spasticity and use of stretch as a treatment of spastic hypertonia.

Paralysis, muscle shortening, and muscle overactivity are the three main disabling factors in patients with spasticity. Occurring after most central lesions, muscle overactivity and shortening are not equally spread throughout all muscles of the body. In an agonist-antagonist couple, there is invariably "greater" overactivity and shortening of one versus the other. This is the rationale for the use of targeted local treatments that train the weaker agonist and stretch and partially block the more overactive and shorter antagonist. Central paralysis, muscle shortening, and muscle overactivity are intertwined, and the three corresponding therapies, motor training, stretch, and local partial blocks, should be implemented in combination. This triple treatment is the main condition for any functional recovery. Muscle shortening occurs acutely after a central nervous system lesion; therefore its treatment should be implemented as rapidly as possible.