Radial Tunnel Syndrome (Forearm)

Introduction

Radial tunnel syndrome occurs when the radial nerve in the 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. Surgery is recommended when all other treatments have failed.

Anatomy

Your radial nerve originates from nerve roots in the neck which then combine about the base of the neck and shoulder, and travels down your arm. The radial tunnel is made of muscles and bones. From the radial tunnel, the radial nerve runs underneath the supinator muscle. It then branches out into your forearm and hand. Near the supinator, the radial nerve branches into a sensory nerve and the motor branch called the posterior interosseous nerve. The radial nerve controls movements in the muscles on the back of your arm and forearm, which are mainly extensors. The posterior interosseous nerve controls extension movements in your wrist, fingers, and thumb.

Causes

Radial tunnel syndrome occurs when the radial nerve is compressed. This can happen if the radial tunnel is too small. Repetitive movements, such as twisting movements of the forearm, forceful wrist movements, gripping, and pinching can irritate, stretch, or compress the nerve. This type of injury can occur on the job, for instance in construction or manufacturing work. A direct blow to the forearm or elbow can also injure the radial nerve.

Symptoms

Radial tunnel syndrome causes an aching pain in the forearm. The pain is centered a few inches below your elbow joint where the radial nerve travels beneath the supinator. The pain may become worse when you extend your wrist, turn your palm upward (supinate), or hold something while your arm is straight out. Your forearm, wrist, and hand may feel weak. You may have difficulty extending your wrist, which is termed wrist drop.

Diagnosis

Your doctor can diagnose radial tunnel syndrome by reviewing your medical history and examining your arm. You should tell your doctor about your activities, injuries, and symptoms. X-rays will be performed to check for abnormalities that may be affecting the nerve. Pinpointing the location of the pain source is necessary to distinguish radial tunnel syndrome from other conditions, such as tennis elbow.

Treatment

The most important way you can relieve your symptoms is to avoid the repetitive movements that caused the problem. If repetitive movements are part of your job, you should take frequent breaks and modify your work duties. An occupational therapist can evaluate your workstation and may be able to help you prevent injuries.

Your doctor can refer you to a hand therapist or occupational therapist for splinting and rehabilitation. A splint will position your arm to allow the radial nerve to heal. At rehabilitation, you will learn proper ways to do your activities to reduce irritating the radial nerve. Your therapist will use modalities, such as icing and heat to ease your pain. You will also learn exercises to keep your forearm and hand muscles healthy

Surgery

Surgery for radial tunnel syndrome is used only when all other treatment options have failed. The goal of surgery is to relieve the pressure on the radial nerve to eliminate your symptoms. Radial nerve surgery is usually an outpatient procedure.

There are generally two approaches to the radial nerve. There is a muscle splitting approach, which limits exposure to the region of the supinator muscle, or an extended approach that addresses all possible sites of radial nerve compression in the forearm. Your surgeon will decide which approach is most appropriate for your case. Tissues that are compressing your radial nerve are incised, easing pressure on the nerve. At the end of the procedure, your skin is stitched and bandaged. You will wear a splint on your arm and participate in rehabilitation therapy for several weeks.

Recovery

Recovery from radial tunnel syndrome is different for everyone. Your recovery will depend on the extent of your condition, the type of treatment you received, and your compliance with therapy and splinting. Recovery following surgical treatment can take months. You should experience improvements in about four to six weeks with nonsurgical treatments. Your doctor will let you know what to expect

Prevention

You may prevent radial tunnel syndrome by avoiding repetitive movements including twisting the forearm, extending the wrist, and gripping. It is important to take frequent breaks if you must perform these motions. It is helpful to have an occupational therapist examine your work site to make modifications to possibly prevent injuries.

If you experience radial tunnel syndrome, you may enhance your recovery by complying with your splint wearing schedule and attending all of your rehabilitation therapy appointments. Practice your home therapy exercise program. Integrate activity modifications to protect your radial nerve.

This information is intended for educational and informational purposes only. It should not be used in place of an individual consultation or examination or replace the advice of your health care professional and should not be relied upon to determine diagnosis or course of treatment.

The iHealthSpot patient education library was written collaboratively by the iHealthSpot editorial team which includes Senior Medical Authors Dr. Mary Car-Blanchard, OTD/OTR/L and Valerie K. Clark, and the following editorial advisors: Steve Meadows, MD, Ernie F. Soto, DDS, Ronald J. Glatzer, MD, Jonathan Rosenberg, MD, Christopher M. Nolte, MD, David Applebaum, MD, Jonathan M. Tarrash, MD, and Paula Soto, RN/BSN. This content complies with the HONcode standard for trustworthy health information. The library commenced development on September 1, 2005 with the latest update/addition on February 16, 2022. For information on iHealthSpot’s other services including medical website design, visit www.iHealthSpot.com.