Although only gross estimates of strength are attainable in the clinical setting, the clinician must examine the strength of the elbow, wrist, and hand motors, particularly when assessing for a neurologic problem or a ten-donapathy. Biceps brachii muscle strength testing is best conducted against resistance with the forearm supinated and the shoulder flexed from 45° to 50° 1 (Fig. 3.10). Triceps strength testing, however, is best conducted with the shoulder flexed to 90° and the elbow flexed from 45° to 90° 1 (Fig. 3.11). Elbow extension strength is normally 70% of flexion strength.17 Pronation, supination, and grip strength then are studied with the elbow in 90° of flex-
ion and the forearm in neutral rotation. Supination strength is approximately 15% greater than pronation strength, and the dominant extremity is from 5% to 10% stronger than the nondominant extremity.17
Finally, the examiner tests the forearm musculature and hand intrinsic strength. The extensor carpi radialis longus musculotendinous unit is best studied with the elbow flexed to 30° and resistance applied to wrist extension.1 However, the extensor carpi radialis brevis musculotendinous unit is best isolated by providing resistance to wrist extension with the elbow in full flexion. The examiner studies the extensor carpi ulnaris muscle by resisted ulnar deviation of the wrist. Weakness in the wrist, finger, and thumb extensor might indicate a posterior in-terosseous nerve palsy. Similarly, the examiner should test the wrist, finger, and thumb flexors. Weakness of the flexor pollicis longus and flexor digitorum profundus muscles of the index finger is present in an entrapment palsy of the anterior interosseous nerve, which branches from the median nerve approximately 5 cm distal to the medial epicondyle.20 Finally, weakness in the hand in-trinsics can indicate ulnar nerve entrapment at the cubital tunnel.
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Everything you wanted to know about. How To Cure Tennis Elbow. Are you an athlete who suffers from tennis elbow? Contrary to popular opinion, most people who suffer from tennis elbow do not even play tennis. They get this condition, which is a torn tendon in the elbow, from the strain of using the same motions with the arm, repeatedly. If you have tennis elbow, you understand how the pain can disrupt your day.