Nerves originate from the spinal cord and have a variety of functions. They supply the muscles and conduct sensory impulses. If a nerve in a finger is injured, the patient may lose sensation to the digit. If the nerve is injured in the arm, the muscles may waste and the hand may become weak. The area of loss of sensation in the hand depends on which nerves are injured.
A strange and potentially devastating problem is a partial nerve injury causing pain, stiffness, swelling and skin changes know as chronic regional pain syndrome. This syndrome can occur without nerve injury and also after trivial trauma. Early identification and treatment can prevent permanent loss of function.