What is radial tunnel syndrome?
Radial tunnel syndrome (RTS) is a compressive neuropathy affecting the radial nerve as it courses through the proximal forearm. This condition occurs when the deep branch of the radial nerve, also known as the posterior interosseous nerve (PIN), experiences compression or irritation within the radial tunnel (Moradi et al., 2015).
The radial tunnel extends from the radiocapitellar joint to the distal edge of the supinator muscle. Common radial nerve compression sites include fibrous bands anterior to the radial head, the radial recurrent artery, and the proximal edge of the extensor carpi radialis brevis muscle.
Patients typically present with proximal forearm pain, which may radiate to the dorsal forearm or lateral elbow. This is why it might also be misdiagnosed with concerns in the lateral epicondyle. Radial tunnel syndrome can be confused with tennis elbow due to similar symptoms, such as pain in the forearm and weakness, emphasizing the importance of accurate diagnosis. However, unlike lateral epicondylitis, RTS pain is often more diffuse and can worsen with activities involving repetitive forearm pronation and wrist flexion (Naam & Nemani, 2012).
Carpal tunnel syndrome, the most common neuropathy, can be compared with radial tunnel syndrome. However, while carpal tunnel syndrome primarily causes numbness and tingling in the hand, radial tunnel syndrome is rare and presents with more diffuse forearm pain.
Key symptoms include:
- Localized tenderness over the radial tunnel
- Pain exacerbated by resisted middle finger extension
- Potential muscle weakness in severe cases
Recognizing these symptoms is crucial for accurate diagnosis and effective treatment planning of superficial radial nerve compression.










