Relative incidence of needle EMG abnormalities in the anterior tibial and gastrocnemius muscles.

Foot drop resulting from weakness of the anterior tibial muscle is commonly encountered in clinical practice. We analyzed the incidence of needle electromyographic (EMG) abnormalities in the anterior tibial and gastrocnemius muscles from traumatic injuries to the sciatic nerve and also from different non-traumatic lower motor neuron conditions. In both traumatic and non-traumatic cases, the anterior tibial muscle showed relatively more EMG abnormalities compared to the gastrocnemius. It appears that the anterior tibial muscle is more susceptible to injury from a variety of pathologic conditions, as opposed to the gastrocnemius muscle.