Radial tunnel syndrome occurs when the radial nerve in your arm is compressed. The radial nerve travels through the radial tunnel located on the top (dorsum) of the forearm. The radial nerve can be compressed or irritated in the radial tunnel due to repetitive movements, forceful forearm movements or injury. Radial tunnel syndrome causes hand weakness and pain in the forearm near the elbow. Most cases are treated with rest, rehabilitation and splinting.