PHYSICAL EXAMINATION OF THE UPPER ARM AND ELBOW
Physical examination of the upper arm and elbow should progress in a systematic manner from inspection to palpation to assessment of range of motion and should include a thorough neurovascular examination. Specific tests can also be included, when appropriate, for detecting certain pathologic processes. Findings should be compared with those from the contralateral side, and a global limb assessment should be performed to rule out overlapping or contributing disorders.
Inspection can note swelling, ecchymosis, abrasions, or lacerations from acute traumatic injuries or muscle atrophy and scars from chronic conditions or prior surgeries. The carrying angle of the elbow should be assessed to determine the presence of malalignment from prior trauma or skeletal growth disturbance. This angle is formed by the humerus and ulna with the hand and forearm fully supinated and the elbow fully extended and measures 10 to 20 degrees of valgus, with slightly more valgus on average in females than males. Valgus (cubitus valgus) or varus (cubitus varus) malalignment is diagnosed when the carrying angle is greater than or less than these normal values, respectively.
Palpation should be performed to detect sites of tenderness, deformity, and swelling or effusion that further indicate the presence of an acute or chronic injury or pathologic process. The subcutaneous nature of much of the elbow allows several important structures to be easily palpable (see Plate 2-1). Anteriorly, this includes contents of the antecubital fossa, such as the distal biceps tendon, brachial artery, and median nerve. The medial epicondyle and ulnar nerve are noted medially. Laterally, this includes the lateral epicondyle, the radial head, and the “soft spot.” A joint effusion is best detected in the “soft spot,” a normal depression in the posterolateral aspect of the elbow that is defined by the lateral epicondyle, the tip of the olecranon, and the radial head. Finally, the tip of the olecranon and the distal triceps tendon are prominent landmarks posteriorly.
Elbow range of motion is assessed in flexion and extension, as well as with forearm pronation and supination, and includes evaluation of both active and passive motion. The normal flexion-extension arc of the elbow ranges from 0 degrees to 140 to 150 degrees, plus or minus 10 degrees. The normal pronationsupination arc ranges from 75 to 80 degrees of pronation to 80 to 85 degrees of supination. Pronation and supination should be assessed with the elbow in 90 degrees of flexion, with the thumb-up position consid- ered neutral rotation. The functional range of elbow motion needed to complete most activities of daily living has been shown to range from 30 to 130 degrees (flexion-extension) and from 50 to 50 degrees (pronation-supination). Therefore, considerable motion loss at the elbow may be tolerated. Typically, extension is the first motion lost with most pathologic conditions around the elbow.
A thorough neurovascular examination of the upper extremity should include motor and sensory testing of all relevant peripheral nerves (axillary, musculocutaneous, median, radial, ulnar), palpation of distal pulses (radial, ulnar), and the assessment of capillary refill.