yoga book / pathology / werferellbogen

Definition

Overuse injury to the ulnar (medial) collateral ligament of the elbow joint caused by repeated, intense throwing movements. This is a typical sports injury; it primarily affects baseball pitchers, but the injury is also known to occur in American football, volleyball, tennis and javelin throwing. The acceleration of the arm during a throw consists of a wind-up, the actual throwing motion and the stop. Particular stress is placed on the lig. ulnar collateral ligament (MCL), as the truncohumeral and scapulohumeral muscles cause the upper arm to move from a backward motion to a forward motion and from exorotation into internal rotation, whilst the forearm, due to its inertia and the thrown object, only follows the upper arm’s movement with a delay. The ulnar collateral ligament is reported to have a load-bearing capacity corresponding to a valgus moment of only approximately 33 Nm; however, in sports, torques or impulses of over 60 Nm in some cases occur. Shear forces of up to 300 N are calculated for the medial elbow, whilst compressive forces of up to 500 N are calculated for the lateral elbow. Muscles such as the palmar flexors of the wrist, finger flexors and the pronator teres are unable to adequately absorb these forces, so that over time, ligamentous insufficiency of the MCL develops, accompanied by medial gapping, i.e. the joint giving way in the valgus direction. This, in turn, impairs force distribution within the joint and can lead to osteoarthritis with the formation of osteophytes. The ulnar nerve may also be affected by medial gapping. The development of golfer’s elbow due to compensatory actions by the forearm muscles originating at the medial epicondyle is also possible. Further complications may include the formation of loose bodies and, in some cases, radiocapitellar osteochondral lesions resulting from lateral compression. Furthermore, medial traction apophysitis at the medial epicondyle (94% in one study), as well as in cases of repeated forceful hyperextension of the elbow joint osteophyte formation at the olecranon and stress fractures of the olecranon. It appears that changes to throwing technique do not necessarily solve the problem, as they can only reduce the stress, whilst the factor of repetition remains an important contributing cause.

Cause

1. Repeated, vigorous throwing movements

Predisposing

1. existing valgus instability

Diagnosis

1. clinical: palpation, valgus stress

Symptoms

1. asymptomatic at the outset
2. Pain on the inside of the elbow when throwing
3. Instability with medial gapping, sometimes asymptomatic

Complications

1. Golfer’s elbow
2. lateral osteoarthritis of the elbow joint
3. Irritation of the ulnar nerves
4. free joint bodies
5. Traction apophysitis
6. radiocapitellar, osteochondral lesions
7. Osteophyte formation at the olecranon

Therapy

1. Stress reduction

DD