Tennis elbow? Maybe not.
ART Literature Review:
by Everett Johnson, DC, ART
Tennis elbow… Maybe not.
Tennis elbow (lateral epicondylitis) is the most common overuse injury of the elbow joint. Lateral epicondylitis is an overuse syndrome generally caused by repetitive use of the wrist extensors or sustained power gripping. It is described as gradual onset aching pain that is worse with activities. The pain may be present at night and it typically only affects one side. It occurs equally in men and women, usually between the ages of thirty to fifty. On occasion, someone will have these symptoms but they resist or delay most forms of treatment. This condition was first introduced back in 1883, and was termed radial tunnel syndrome, as a resistant form of lateral epicondylitis. The symptoms are so similar to each other that it makes it rather difficult to determine one from the other.
The elbow joint is composed of the distal end of the humerus or arm bone, and the radius and ulna bones of the forearm. The lateral epicondyle is on the outer end of the humerus and serves as the attachment for muscles that extend, or pull the wrist back. The main muscle involved in lateral epicondylitis is extensor carpi radialis brevis. Other muscles attaching at this site can be involved, but are far less commonly the problem.
At this same area of the outside elbow, but deeper is another set of anatomic structures that can mimic the pain of lateral epicondylitis. The supinator muscle also comes from the lateral epicondyle and has two heads. It travels away from the elbow and twists around the radius of the forearm to attach to it. This muscle is involved in supination, or turning the hand palm up. The radial nerve comes from the outer part of the arm and crosses the elbow joint. It splits into two branches at the upper margin of the supinator muscle. One of the nerves goes over the supinator and the other goes between the two heads of the muscle. The one going between the two heads of supinator muscle is called the deep branch of radial nerve, or posterior interosseus nerve (PIN), and is considered to be part of the culprit of resistant tennis elbow, or radial tunnel syndrome.
As the deep branch of the nerve crosses the upper border of the muscle to go between the two heads it has an opportunity to be trapped by the muscle. This area of entrapment is called the Arcade of Frohse. With repeated trauma or repetitive motion the upper border of this muscle can become fibrous and cause compression on the nerve. Symptoms of this compression or entrapment of the nerve are typically the same as described above for tennis elbow with the addition of:
-Pain on the back of the forearm or back of the hand
-Pain intensity increases with extension of the wrist and fingers
-There may be some weakness of the hand.
-Typically, these symptoms occur after significant repetitive use of the upper extremity.
Diagnostic tests can be performed to evaluate the function of the nerve and to get an understanding of the location of the problem, but sometimes are not very helpful, and are typically negative. A simple method to determine this condition, that has been used is called the “middle finger extension test”. The forearm and hand are held straight out in front with the fingers extended. The doctor then pushes down on the middle finger of the patient and notes the patients response. An increase in pain as the patient resists the doctors push is considered a positive response. The problem is, activation of these same muscles is also painful for people experiencing tennis elbow. One author differentiated the two conditions by stating that this test is positive if it is more painful than if the doctor flexes the patients fingers and wrist with the elbow straight.
Conservative treatment should be considered for this condition, with one author recommending waiting up to six months before considering a surgical procedure. A case study published in the Journal of the Canadian Chiropractic Association in 2009 looked at the conservative management of the posterior interosseus nerve in a baseball pitcher.9 This report describes a 21 year old pitcher with pain on the back of his forearm while pitching that was worse after approximately 35 pitches. Flexing his wrist while turning his hand palm down elicited pain, as did palpation over the area of the supinator muscle and the author noted a “snapping band” during palpation of the Arcade of Frohse.
The patient was treated conservatively over a 38 day period with resolution of symptomatology and return to pre-injury status. The author used Active Release Techniques®, augmented soft tissue techniques and neuromobilization techniques, designed to maximize the sliding motion of the nerve through the structures. A sport specific rehabilitation protocol was also used to keep the athlete conditioned for his sport.
Active Release Techniques® has been teaching providers how to work on this and similar conditions for over 20 years. Consult with your Certified ART® provider for more information on treatment protocols, or go to www.activerelease.com to find a provider in your area.