In saw a neurologist & he used a very small needle to see a nerve response in my foot. i have had pain ever since. could this have damaged a tendon?

Could it? : Anything is possible, but usually any discomfort goes away. Either ice air hot wet compresses should be applied to the site of pain.

Electromyogram (EMG): The electromyogram (EMG) is a study of the muscles and the neuromuscular junction. As you described, a small needle is used, and is usually placed in the belly of the muscle, not the tendon. If the pain doesn't resolve within a couple of days, let the neurologist or your primary care physician know. http://www.nlm.nih.gov/medlineplus/ency/article/003929.htm