By Abby Sims

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Yankees setup man Joba Chamberlain joined his colleague, Rafael Soriano, on the DL yesterday.  It was reported on that a strained flexor tendon will keep Chamberlain out at least 10-14 days before he can begin a throwing program — one that will require an additional three to four weeks before he can work his way back into the lineup.

Manager Joe Girardi said that Chamberlain had been pitching with the issue for several weeks until finally feeling badly enough to report it.  Results of an MRI confirmed the diagnosis. With a very effective 2.83 ERA in 28.2 innings so far this season, Chamberlain will be missed.  He hasn’t allowed a run in his last eight appearances, while striking out 24 in the process.

Where is the flexor tendon?

A tendon is the extension of a muscle, attaching it to the bone.  In looking at many reports of Joba’s injury, I could find no mention of the specific tendon involved.  However, a NY Times report stated that Chamberlain’s soreness is in the forearm, near the inside of the elbow.  This is commonly referred to as medial epicondylitis, or golfer’s elbow.  Most involved in this diagnosis are the wrist flexors and the pronator teres muscle.

There are a number of flexors in the forearm; two that control wrist flexion (bending the wrist palmward) and several other deeper muscles that are responsible for flexing/bending, the fingers. This diagram depicts the primary wrist flexors, as well as palmaris longus, which is not present in all people and, when available, is often used to surgically reconstruct torn elbow ligaments (Diagram).

The Pronator Teres also attaches to the inner elbow.  This muscle acts to turn the palm downward, and along with the wrist flexors, is often an issue with golf elbow (Diagram).

What causes Medial Epicondylitis and what are the symptoms?

Medial epicondylitis may begin as a microtear between the pronator teres and the Flexor Carpi Radialis  (FCR) and is fairly common in pitchers due to the stress placed on the inner elbow during the acceleration phase of the pitching motion.

This same repetitive stress can also cause tears of the ulnar (medial) collateral ligament of the elbow, leading to Tommy John Surgery.  The diagnosis is sometimes unclear initially, because in either case there may also be inflammation of the adjacent anterior (front) joint capsule, the flexor pronator mass, the ulnar (medial) collateral ligament, and the ulnar nerve.

Symptoms include tenderness at the inner elbow and at the flexor/pronator muscles and tendons.  Pain, present with contraction of the muscles (into wrist flexion and/or pronation), is heightened when working against resistance. Grip strength is often affected.  If the ulnar nerve is involved, it too is tender, and may result in weakness and atrophy of muscles of the hand.

Tightness and/or weakness of the wrist flexors may be factors that predispose to medial epicondylitis, whether the sufferer is a professional pitcher, a weekend hacker, or an office worker who is keyboarding for prolonged periods day after day.

What is the course of treatment?

Medial epicondylitis generally responds well to conservative management with physical therapy, sometimes accompanied by cortisone injection in the early phase of care. Those not responding to treatment may require surgery. Hopefully, Joba Chamberlain will be on the right side of that equation.


Abby Sims has a Masters degree in Physical Therapy from Duke University and a Bachelors in Physical Education from Rutgers University. She has owned and operated orthopedic and sports physical therapy practices in New York City for the past 30 years. During that time Abby has had the pleasure of working with many professional athletes and celebrities.

In addition to her clinical work and speaking at medical conferences, Abby and her husband, sportscaster Dave Sims, provide media coaching for athletes via their AthletiSense communications program. You can follow Abby’s daily fitness/wellness tips on Twitter @abcsims


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