Physical Examination of the Throwing Athlete’s Elbow
A combination of valgus force and a rapidly decelerating arm at the follow-through phase of pitching causes a shear force between the medial aspect of the olecranon tip and the olecranon fossa. This shear force can result in chondrolysis, osteophyte formation, and loose bodies, particularly in the posteromedial elbow. This valgus extension overload (VEO) syndrome often results in loss of full extension and symptoms, which may be attributed to osteophytes or fractured and nonunited fragments in the olecranon fossa or the olecranon tip. Frank crepitus may also be present with extension testing caused by loose bodies or synovial reaction over osteophytes. Assessing for VEO using the extension impingement test, the examiner places continuous valgus stress on the elbow while quickly extending from 20° to 30° of flexion (Figure 4A) to terminal extension (Figure 4B) repeatedly. The examiner repeats this without valgus load while palpating the posteromedial olecranon for tenderness to differentiate impingement caused by instability from pain over the medial olecranon without instability (Figure 4C). Particular attention should be focused posteriorly in athletes with medial instability, as MCL injuries and VEO syndrome often occur in conjunction in the throwing athlete.
Repetitive acceleration and deceleration of the arm can also cause stress fractures. With stress fractures, pain is often noted more distal and lateral on the olecranon, but tenderness may be palpable medially from posteromedial impaction that occurs from the valgus load during the overhead throwing motion. In immature athletes, the repetitive sudden snap of full extension in the deceleration phase of throwing can cause olecranon apophysitis. Frank avulsions can occur as well but are usually preceded by chronic posterior elbow pain with possible loss of full extension.
The late cocking phase of the throwing motion (just before throwing) hyperextends the elbow and places significant strain on the elbow. Repetitive strain can cause painful posterior impingement. The arm bar test is extremely sensitive (Figure 5).13 With the patient’s elbow extended, shoulder internally rotated, and hand on the examiner’s shoulder, the examiner pulls down on the olecranon to simulate forced extension and reproduces the pain associated with posteromedial impingement.
Last, though triceps tendon injuries are rare, ruptures most often occur at the origin of the lateral head of the triceps. As the initial swelling and ecchymosis subside, a palpable gap is pathognomonic for rupture. Extensor weakness can often be observed, but extension may still be possible from anconeus triceps expansion with the aid of gravity. With the elbow overhead, the athlete must extend the elbow against gravity and will exhibit weakness against resistance.
5. Examine the anterior aspect of the elbow
Anteriorly, the bulk of the flexor-pronator group restricts the extent of joint palpation, and the soft tissues are usually injured. The antecubital fossa is a triangular area on the anterior aspect of the elbow that is bounded superiorly by a horizontal line connecting the medial epicondyle to the lateral epicondyle of the humerus, medially by the lateral border of the pronator teres muscle and laterally by the medial border of the brachioradialis muscle. From lateral to medial, the antecubital fossa contains the radial nerve, the biceps brachii tendon, the brachial artery, and the median nerve. Evaluating this area is important because a visible defect, change in muscle contour, or proximal retraction of a muscle belly can indicate a muscular rupture. In particular, a distal biceps rupture (rare) may be accompanied by weakness and pain in supination and, to a lesser degree, in flexion. It is important to note that, in the case of a partial biceps rupture, ecchymosis may not appear, as the hematoma is confined by the intact lacertus fibrosis.24 The hook test can be used to evaluate for the presence of an intact distal biceps tendon (Figure 6).25 The patient abducts the shoulder, flexes the elbow to 90°, and actively supinates the forearm while the examiner attempts to hook an index finger laterally under the tendon. The test is negative if the finger can be inserted 1 cm under the tendon and positive if no cordlike structure can be hooked. Partial biceps tendon ruptures or tendinitis may exhibit tenderness of the distal biceps tendon and pain on resisted supination with a negative hook test. Often, resisted elbow flexion with the elbow at maximal extension elicits pain at the biceps insertion. Clicking with forearm rotation near the insertion of the tendon, which may be caused by an inflamed radial bursa between the distal biceps tendon and the radial tuberosity, may be associated with impending rupture.
