For surgical Treatment of spastic deformities of the foot, selective peripheral neurotomies were introduced. These neurotomies utilize microsurgical techniques and intraoperative electrical stimulation for better identification of the function of the fascicles constituting the nerve. Selectivity is required to supress the excess of spasticity without excessive weakening of motor strength and without producing exaggerated amyotrophy. To achieve this goal, minimum one fourth of the motor fibers must be preserved. Neurotomies may be indicated when spasticity is localized to muscle or muscle groups supplied by a single or a few peripheral nerves that are easily accessible. To help the surgeon decide if neurotomy is appropriate, temporary local anesthetic block of the nerve with bupivacaine can be useful. Such a test can determine if articular limitations result from spasticity, musculotendinous contractures, or articular ankyloses because only spasticity is decreased by the test. In additon, these tests give the patient a chance to appreciate what to expect from the operation.