What is Pronator Syndrome?
Pronator syndrome is compression of the median nerve as it passes through the proximal forearm, near the elbow. Unlike carpal tunnel syndrome (which affects the same nerve at the wrist), pronator syndrome involves compression higher up in the arm.
The median nerve can be compressed at several points in this region, most commonly between the two heads of the pronator teres muscle. This condition is much less common than carpal tunnel syndrome but can cause significant symptoms.
Pronator syndrome typically affects people who perform repetitive gripping and forearm rotation activities - common in occupations like carpentry, mechanics, and assembly line work.
Compression Sites
A fibrous band above the elbow (present in 1% of people)
Bicipital aponeurosis - a fibrous extension of biceps tendon
Most common site - between two heads of the muscle
Fibrous arch at the FDS origin
Symptoms
Pronator Syndrome vs Carpal Tunnel
Key differences to distinguish these two median nerve compression syndromes
| Feature | Pronator Syndrome | Carpal Tunnel |
|---|---|---|
| Night symptoms | Rare | Common - often wakes from sleep |
| Location of numbness | Includes palm (palmar cutaneous branch) | Spares palm |
| Forearm pain | Present and prominent | Usually absent |
| Tinel's at wrist | Negative | Usually positive |
| Phalen's test | Negative | Usually positive |
Treatment Options
- Activity modification and rest
- NSAIDs for inflammation
- Elbow splinting to reduce pronation
- Physical therapy - nerve gliding exercises
- Ergonomic workplace modifications
- Indicated if conservative treatment fails
- Release all potential compression sites
- Usually outpatient procedure
- Success rate: 80-90%
- Recovery: 4-6 weeks for light activity