This condition isn’t as common as Tennis elbow. It’s described as the inflammation of the tendons emerging from the Medial Epiicondyle of the elbow (inner surface of the elbow). It affects the Common Flexor Origin from which the tendons responsible of Flexing the wrist emerge.
It arises from overuse activities of the wrist and hand either in sports ( Tennis, Golf, archery …. Etc) or in hobbies such as knitting and needle work.
This group of muscles is responsible for flexing the wrist and it also plays a major role in elbow stability.
When the elbow joint is extended the last degrees of extension (10-15 degrees) the forearm deviates laterally (outward) from the line of the Humerus forming what is called CARRYING ANGLE. This angle is vital to allow the elbow to fully extend and it is important to clear the forearms from the hips when arms swing during walking . In throwing this angle is under great stress and the elbow is stabilized by the action of the flexor group originating from the medial epicondyle of the elbow which subjects them to a great deal of tension.