Radial tunnel syndrome is a painful condition caused by irritation or compression of the radial nerve as it passes between the radius bone and the supinator muscle next to it, just below the outside of the elbow. It is characterised by pain on the outside of the elbow that extends into the upper forearm. In some cases, there can be pins and needles or numbness in the web space between the thumb and index finger on the back of the hand. There is typically no loss of strength.
--What causes radial tunnel syndrome?
Radial tunnel syndrome is caused when the radial nerve is compressed or rubbed when it passes through a canal in the upper forearm. This compression can be intermittent, such as lifting a bag with a straight arm next to your side, or in prolonged activities, such as data entry or mouse clicking. Other activities, such as mopping, vacuuming or driving, also result in pain. It can also be a structural compression, which is rarer, when anatomical structures next to the nerve push on it. As the nerve becomes more irritated, the nerve becomes sensitive and more easily aggravated by the same activity, which is often why it feels as though it gets worse over time. Neck and back posture can impact on radial tunnel syndrome by limiting the ability of the nerve to move freely through its canal, making it easier to compress.
--How do I know if I have radial tunnel syndrome?
There are good reasons to think that you may have radial tunnel syndrome if:
- you have a deep, aching pain that is just below the elbow in the forearm muscles
- you have lesser pain on the bony point on the outside of your elbow
- the pain is made worse by gripping (with twisting), pushing or data entry tasks
- you have altered or absent sensation between your thumb and index finger on the back of your hand
- you have had tennis elbow that does not respond to management.
When you have radial tunnel syndrome, you typically get pain with gripping activities, using a mouse and activities where you have to push down while gripping, such as cutting vegetables. The pain can often be reduced by pulling your shoulders back, as this can change the way the nerve behaves.
Unlike tennis elbow, which has similar symptoms and aggravating activities, radial tunnel syndrome does not give you tenderness on the outer tip of the elbow. Instead, there is usually a locally tender spot about three to four finger widths closer to the wrist.
--How can physiotherapy help with radial tunnel syndrome?
Accurate diagnosis is crucial in the selection of the best treatment for radial tunnel syndrome. Your physiotherapist will be able to accurately assess your elbow pain and differentiate the source of your pain. Through the process of a detailed history and examination, they will determine the source of your pain and the contribution of factors such as posture and workload.
In radial tunnel syndrome, early management is crucial to try and prevent damage to the nerve through either ongoing trauma or secondary inflammation and swelling. If there is loss of sensation, the outcome is generally not as good, so an early and accurate diagnosis is essential.
Part of your physiotherapy management may include stretches for your chest muscles, neck and upper back to reduce any role posture has on the nerve tissue. They may also use ultrasound, dry needling or ice.
You may be given strengthening exercises or have your back taped to assist your posture. This may involve a gym-based program or exercises that you can perform at home.
Another treatment that your physiotherapist may use is mobilisation of your neck, which can assist with the mobility of the nerve. They may also include specific stretches or gliding movements to assist the mobility of the radial nerve as it passes around the elbow.
Your physiotherapist will be able to talk to you about whether you need further medical assessment, whether you may need to discuss medication or injection with your GP, or referral to a specialist.
--How effective is physiotherapy for radial tunnel syndrome?
There are many factors that determine the effectiveness of physiotherapy in the treatment of radial tunnel syndrome. If there are no anatomical causes of the nerve compression and the pain can be changed with postural changes, the recovery from radial tunnel syndrome can be within a few weeks.
If there is loss of sensation or an anatomical (your body's structure) cause for the compression, physiotherapy can be less useful. In these cases, your physiotherapist will refer you to your doctor to discuss the possibility of investigations and other treatments such as injections or surgery.
--What can I do at home?
There are many things that you can do at home to help reduce the pain of radial tunnel syndrome.
- The first place to start is carefully working out which activities make your pain worse, and trying to modify or eliminate these activities as to not bring on your symptoms too frequently. This may not always be practical but every little bit counts.
- Stretching the muscles across your chest and neck can help reduce any impact that these may have on the function of the nerve. This can be especially effective if there is a postural link to you nerve pain. Make sure the stretches do not make your pain worse after you have finished doing them.
- It can be worth trialling some ibuprofen, which can help reduce the inflammation, or speaking to your pharmacist or GP about stronger anti-inflammatory medication.
- Ice can be helpful, but many people find ice to be too uncomfortable when applied over nerves.
As with all injuries, accurate diagnosis is a crucial part of best management.
--How long until I feel better?
In simple cases, radial tunnel syndrome can resolve within a number of weeks. This is especially the case if the pain can be relieved with stretching the chest muscles and postural changes. For people who have had their symptoms for more than a couple of months, management of the condition can take up to 3–6 months.
The presence of anatomical compression or loss of nerve function delays recovery and is associated with longer time to recovery.
