Dr. Kevin Yip

Dr Kevin Yip
Orthopaedic Surgeon
MBBS(UK), FRCS(EDIN), FAM(SING), FHKCOS(ORTHO)

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Resisted extension of the wrist

Positioning.

The subject stands with the arm hanging, the elbow extended and the wrist in
neutral position (between pronation and supination,and between flexion and extension). The examiner stands level with the subject’s elbow.
The contralateral arm lifts and carries the elbow and keeps it extended. The hand stabilizes the forearm. The other hand is placed at the dorsum of the subject’s hand.

Procedure.

Resist the subject’s attempt to extend the wrist.

Common mistakes:

• The subject is allowed to lift the arm up.
• The elbow is allowed to flex. This can be prevented by the examiner’s arm keeping the subject’s elbow well raised.
• The wrist is not held in neutral position, which puts stress on non-contractile structures.

Anatomical structures tested:

Muscle function:

• Imporla1lt wrist extensors:

Extensor digitorum communis
Extensor carpi radialis longus
– Extensor carpi radialis brevis
– Extensor carpi ulnaris

• Less importmlt wrist extensors:
– Extensor indicis proprius
– Extensor pOllicis longus
– Extensor digiti minimi.

Common pathological situations:

• When elbow pain is elicited, tennis elbow – a lesion in the radial extensors of the wrist – is most probable. Other possibilities are a lesion of the extensor carpi ulnaris or of the extensor digitorum.
• Weakness may result from a radial nerve lesion or from either the C6 or C8 nerve root. Bilateral weakness suggests either lead poisoning, or bronchus carcinoma, or a more general neurolOgical disease.

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