pronator syndrome
Last reviewed 01/2018
Pronator syndrome (pronator teres syndrome) is a compression neuropathy of the proximal median nerve as it passes between the two heads of the pronator muscle in the proximal forearm
- condition is rare compared with more distal compression of the median nerve (carpal tunnel syndrome)
Repetitive use of the pronator muscle as seen in people on factory assembly lines (especially hammering) and in some musicians is a key predisposing factor
- presents with pain over the proximal median nerve and sensory disturbance
in the lateral three and a half fingers of the palmar aspect of the hand (median
nerve distribution)
- may be weakness of the flexor pollicis longus, the flexor digitorum profundus of the index finger and the pronator quadratus
Investigation
- condition can be made diagnosed clinically
- key finding is tenderness over the proximal forearm, aggravated by resisted pronation of the forearm (opposite movement to Yergason's test)
- weak flexor muscles of the thumb and index finger may lead to a weak
pincer movement and there may be sensory loss in the median nerve distribution
of the hand
- Tinel's test at the wrist should be negative but positive over the
proximal forearm
- Phalan's test should be negative
- a nerve conduction study is useful in excluding the more common carpal tunnel syndrome
Management
- mainstay of treatment is physiotherapy. Referral for guided corticosteroid injections or surgical decompression should be considered in resistant cases or where there is significant weakness
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