Radial tunnel syndrome is an uncommon painful condition of the elbow that mimics tennis elbow.  The pain is located on the outside of the arm near the elbow.  The pain is of a deep and aching character and is located in the muscle mass of the elbow.  It may radiate either up or down the arm.  Radial Tunnel Syndrome occurs when a branch of the radial nerve becomes entrapped as it makes its way down from the spinal chord through the shoulder and into the arm and hand.  Prolonged compression of this nerve may lead to muscle weakness and difficulty holding or gripping objects with the hand.   The compression may come from fibrous bands, blood vessels that compress the nerve or adjacent muscles that may compress it.  The pain may occur after injury or as a result of repetitive motions of the arm.  It may be difficult to distinguish Radial Tunnel Syndrome from Tennis Elbow.  Electromyography (EMG) and Nerve Conduction Studies (NCV) may help to distinguish Radial Tunnel Syndrome from other problems such as cervical radiculopathy.  X-rays are useful to exclude any bony problems such as fractures.  MRI of the elbow may also be useful to look for other problems such as cysts or elbow joint issues that may also be confused with Radial Tunnel Syndrome.   Treatment begins with conservative modalities such as heat, ice and physical therapy.  Non-steroidal anti-inflammatory medications are useful to decrease the pain.  Injection of the radial nerve may be useful.  Persistent pain that is not responsive to conservative treatment may require surgery to release the nerve.