Innervation of Leg and Arm
1. Foot drop (weakness of the tibialis anterior muscle) can be caused by lesions to the common peroneal nerve or L5 nerve root.
2. Testing the dorsal scapular and long thoracic nerves is useful in trying to differentiate between root and plexus lesions. If there is a deficit in one of these nerves (clinically or electrically), the lesion is proximal to the plexus.
3. The median nerve is involved in carpal tunnel syndrome. There are typically no objective findings in the exam of a patient with this syndrome.
