FOREARM, WRIST, AND HAND

CHAPTER 6


FOREARM, WRIST, AND HAND


image



Précis of the Forearm, Wrist, and Hand Assessment*




History (sitting)


Observation (sitting)


Examination (sitting)



Active movements



Passive movements (as in active movements)



Resisted isometric movements (as in active movements, in the neutral position)


Functional testing



Special tests (sitting)



Reflexes and cutaneous distribution (sitting)



Joint play movements (sitting)



Palpation (sitting)


Diagnostic imaging


DIP, Distal interphalangeal; MCP, metacarpophalangeal; PIP, proximal interphalangeal.


*After any examination, the patient should be warned of the possibility of exacerbation of symptoms as a result of the assessment.




SELECTED MOVEMENTS



ACTIVE MOVEMENTS image



image
Figure 6-1 During flexion of the wrist, the motion is more midcarpal and less radiocarpal. During extension of the wrist, the motion is more radiocarpal and less midcarpal. (Modified from Sarrafian SK, Melamed JL, Goshgarian GM: Study of wrist motion in flexion and extension, Clin Orthop 126:156, 1977.)








INDICATIONS OF A POSITIVE TEST




Pronation and supination. Active pronation and supination of the forearm and wrist are approximately 85° to 90°, although this varies from individual to individual. It is more important to compare the movement with that of the normal side. Approximately 75° of supination or pronation occurs in the forearm articulations. The remaining 15° is the result of wrist action.


Wrist flexion and extension. Wrist flexion is 80° to 90°; wrist extension is 70° to 90°. The end feel of each movement is tissue stretch.


Radial and ulnar deviation. Radial and ulnar deviations of the wrist are 15° and 30° to 45°, respectively. The normal end feel of these movements is bone to bone.


Finger flexion. Flexion of the fingers occurs at the metacarpophalangeal joints (85° to 90°), followed by the proximal interphalangeal joints (100° to 115°) and the distal interphalangeal joints (80° to 90°).


Finger extension. Extension occurs at the metacarpophalangeal joints (30° to 45°), the proximal interphalangeal joints (0°), and the distal interphalangeal joints (20°). The end feel of finger flexion and extension is tissue stretch.


Finger abduction and adduction. Finger abduction occurs at the metacarpophalangeal joints (20° to 30°); the end feel is tissue stretch. Finger adduction (0°) occurs at the same joint.


Thumb flexion. Thumb flexion occurs at the carpometacarpal joint (45° to 50°), the metacarpophalangeal joint (50° to 55°), and the interphalangeal joint (80° to 90°). It is associated with medial rotation of the thumb as a result of the saddle shape of the carpometacarpal joint.


Thumb extension. Extension of the thumb occurs at the interphalangeal joint (0° to 5°); it is associated with lateral rotation. Flexion and extension take place in a plane parallel to the palm of the hand.


Thumb abduction and adduction. Thumb abduction is 60° to 70°; thumb adduction is 30°. These movements occur in a plane at right angles to the flexion-extension plane.



CLINICAL NOTES/CAUTIONS




• Pathological conditions in structures other than the joint may restrict ROM (e.g., muscle spasm, tight ligaments/capsules). If the examiner suspects a problem with these structures, passive movement end feels will help differentiate the problem.


• Most functional activities of the hand require the fingers and thumb to open at least 5 cm (2 inches), and the fingers should be able to flex within 1 to 2 cm (0.4 to 0.8 inches) of the distal palmar crease.


• If the patient complains of pain on supination, the examiner can differentiate between the distal radioulnar joint and the radiocarpal joints by passively supinating the ulna on the radius with no stress on the radiocarpal joint. If this passive movement is painful, the problem is in the distal radioulnar joint, not the radiocarpal joints. The normal end feel of both movements is tissue stretch, although in thin patients, the end feel of pronation may be bone to bone.


• Wrist flexion decreases as the fingers are flexed, just as finger flexion decreases as the wrist flexes, and movements of flexion and extension are limited, usually by the antagonistic muscles and ligaments.


• The digits are medially deviated slightly in relation to the metacarpal bones. When the fingers are flexed, they should point toward the scaphoid tubercle. In addition, the metacarpals are at an angle to each other.



FANNING AND FOLDING OF THE HAND1 image



image
Figure 6-2 Fanning (A) and folding (B) of the hand.











SPECIAL TESTS FOR LIGAMENT, CAPSULE, AND JONT INSTABILITY2–5


Relevant Special Tests










Mechanism of Injury


The most common mechanism of injury is trauma, such as a fall onto the hand (FOOSH) or wrist. Injury also can occur whenever the ligaments are subjected to tensile forces that exceed their physiological capacities. Because the ligaments are damaged, passive stability is lost and active stability is needed. The muscles, tendons, and nerves of the wrist and forearm provide the active stability to the region. However, in the wrist and hand, most joints have no direct muscle or tendon attachment. Instead, the tendons of the muscle overlie the affected joint and have no direct control over the wrist motion or stability. As a result, instability is common after trauma and persists without the neuromuscular system contribution. Although the initial mechanism is different when ligament damage is the result of disease processes, the reason for the lack of stability in the joint is similar.



LIGAMENTOUS INSTABILITY TEST FOR THE FINGERS image



image
Figure 6-3 Position for testing ligamentous instability of the fingers.












THUMB ULNAR COLLATERAL LIGAMENT LAXITY OR INSTABILITY TEST6,7 image



image
Figure 6-4 A and B, Testing the stability of the ulnar collateral ligament in the thumb of a normal individual. In extension, the thumb was stable, but in flexion, it appeared to be unstable. This was caused by the laxity of the dorsal capsule at the metacarpophalangeal joint. (From Nicholas JA, Hershman EB (eds): Upper extremity in sports medicine, p 580, St. Louis, 1989, Mosby.)












LUNOTRIQUETRAL BALLOTTEMENT (REAGAN’S) TEST8–10 image



image
Figure 6-5 Lunotriquetral ballottement test for lunatotriquetral interosseous membrane dissociations.












LUNOTRIQUETRAL SHEAR TEST8,11 image



image
Figure 6-6 Lunotriquetral shear test.


Tags:
Jun 7, 2016 | Posted by in ORTHOPEDIC | Comments Off on FOREARM, WRIST, AND HAND

Full access? Get Clinical Tree
Get Clinical Tree app for offline access