Although the backhand swing in tennis is the main contributor of lateral epicondylitis, many other repetitive motions (painting with a paintbrush, running a chain saw, typing on a keyboard improperly) can cause trauma and injury to the outer forearm muscles. This is the wrist extensor group that attaches to a tendon that then attaches to the bump (lateral epicondyle) on the outside of the forearm. (Fig. 1) Through repetitive extension (wrist up) motions; hammering nails, picking up heavy buckets, pruning shrubs, this tendon becomes inflamed. This may cause pain and tenderness at the outside elbow and may go all the way down to the middle and ring finger. (Fig. 2) Pain may also be felt when the wrist is bent backward when picking something up with a straight elbow, or holding something with a stiff wrist. Chiropractic has been shown to help.
This also may be caused by Tendonosis.