Anatomic motor point localization for the treatment of gastrocnemius muscle spasticity.

The location of the motor point of the gastrocnemius muscle was accurately defined relative to surrounding bony landmarks to facilitate the approach to the nerve of the gastrocnemius muscle during treatment for gastrocnemius muscle spasticity. Anatomic dissection of 40 cadaver knees was undertaken for morphometric measurement. The distances from the epicondyle of the femur to the motor branch, and from the motor branch to the motor point of the nerve to the medial head of the gastrocnemius muscle were 3.68 +/- 11.44 mm, and 37.79 +/- 7.80 mm, respectively; while those of the nerve to lateral head of the gastrocnemius muscle were 4.45 +/- 11.96 mm, and 32.16 +/- 4.64 mm, respectively. The tibial nerve lay 44.57 +/- 5.45% and 56.30 +/- 4.73% from the lateral margins of the epicondyle and the fibular head, respectively. Careful consideration of the morphometry of the motor point of the gastrocnemius muscle may provide accurate anatomical guidance, and hence reduce complications during the chemical blockage of these nerves.