Nerve entrapment, particularly Carpal Tunnel Syndrome (CTS), is a familiar term for many, but it's just the tip of the iceberg when it comes to conditions affecting the Median Nerve. In this post we will chat about nerve entrapment syndromes of the 3 main nerves of the arm, shedding light on lesser-known culprits and emphasizing the importance of a whole-body approach.

A nerve entrapment refers to a condition where a peripheral nerve is compressed or irritated, leading to variable symptoms including pain, numbness, tingling, or weakness. Most commonly these entrapments will manifest in the arm or leg and typically won’t have associated spinal pain. Nerve compression can occur at various points along the nerve's pathway, and the specific symptoms depend on the location and extent of the entrapment. 

There are 3 main peripheral nerves that supply the arm and forearm being the median, radial and ulnar nerves. Common examples of entrapment of these nerves include Carpal Tunnel Syndrome, where the median nerve is compressed at the wrist, and Cubital Tunnel Syndrome, involving compression of the ulnar nerve at the elbow. These conditions often result from factors such as repetitive movements, anatomical abnormalities, or prolonged pressure on the nerves.

Beyond the Carpal Tunnel there are other common sites of Nerve entrapment and associated syndromes such as: 

Median Nerve Entrapment Sites:

• Pronator Teres Syndrome (PTS): The median nerve can be compressed as it passes through the pronator teres muscle in the forearm. Symptoms may include pain and numbness in the palm and thumb.

• Anterior Interosseous Nerve Syndrome (AINS): AINS involves compression of the anterior interosseous branch of the median nerve. This can lead to weakness in the pinch grip, although sensory symptoms are minimal.

• Superficial Palmar Branch Entrapment: Compression of the superficial palmar branch of the median nerve can cause symptoms such as numbness and tingling in the palm or fingers, especially during gripping.

• Thoracic Outlet Syndrome (TOS): The median nerve can be compressed as it passes through the thoracic outlet (shoulder and neck), leading to symptoms in the arm and hand. Thoracic Outlet Syndrome is a broader condition that can involve compression of multiple structures, including nerves.

Radial Nerve Entrapment Sites:

• Axilla (Axillary Nerve Compression): The radial nerve can be compressed in the axilla (armpit) region, leading to symptoms such as weakness and pain along the back of the arm.

• Spiral Groove (Spiral Radial Nerve Compression): As the radial nerve travels down the arm, it courses through the spiral groove of the humerus. Compression at this site can result in radial nerve entrapment, causing symptoms such as pain and weakness.

• Supinator Canal (Arcade of Frohse Compression): The supinator muscle forms a canal known as the supinator canal. Compression of the radial nerve within this canal, also known as the Arcade of Frohse, can lead to radial nerve entrapment, resulting in symptoms in the forearm.

• Wrist (Posterior Interosseous Nerve Compression): The radial nerve divides into the posterior interosseous nerve at the forearm. Compression of this branch at the wrist or proximal forearm can cause weakness and pain in the forearm and hand.

Ulnar Nerve Entrapment Sites:

• Cubital Tunnel (Ulnar Nerve Compression at the Elbow): The cubital tunnel is located on the inner side of the elbow. Compression of the ulnar nerve at this site can lead to Cubital Tunnel Syndrome, causing symptoms such as tingling and weakness in the ring and little fingers.

• Guyon's Canal (Ulnar Nerve Compression at the Wrist): Guyon's Canal is situated at the wrist on the palm side. Ulnar nerve compression at this site can result in symptoms like numbness and tingling in the ring and little fingers.

• Flexor Carpi Ulnaris (FCU) Arcade: The ulnar nerve may be compressed by the FCU muscle in the forearm, leading to symptoms such as numbness and weakness.

Why you might be feeling pain or experiencing symptoms in more than one area

Entrapment syndromes sometimes can develop into more radiating type pain or there may be concurrent pain in the same affected limb more distal or proximal to the initial site of entrapment.  This is known as the Double crush phenomenon which occurs when a nerve, already compressed at one site (like the wrist in carpal tunnel syndrome), becomes more vulnerable to symptoms if there's additional compression elsewhere (e.g., neck, shoulder, forearm). This concept suggests that multiple, even if subclinical or mild compressions collectively contribute the overall health of the nerve. It emphasizes the interconnected nature of nerve pathways and why it is important that treatment considers the whole nerve pathway rather than looking at the one area in isolation. 

Home Exercises and Stretches

Now you know a bit about nerve entrapment, here are some exercises and stretches you can try at home.

In the next videos we are demonstrating techniques that mobilise or move each of the nerves we have looked at in this post. It is important to note that nerve mobilisation should be gradual, and care should be taken to not “over stretch” these nerves.

Median Nerve Slider

Radial Nerve Slider

Ulnar Nerve Slider

In some instances, it may be too painful to perform the nerve sliding technique on the effected side, if that sounds like you it might be more beneficial to start by mobilising the nerve on the opposite side.

There are several different levels of nerve mobilisations, so if you are struggling with these nerve sliders it is important to have this technique tailored to your specific injury by a healthcare professional. It might be that you require additional targeted treatment to the soft tissue structures surrounding your nerve entrapment. First line treatment would typically involve soft tissue release, dry needling, other manual techniques that deload and reduce tension & pressure on the nerve directly or indirectly.

Why Professional Assessment Matters?

Nerve entrapment falls under the umbrella of peripheral neuropathy, which includes conditions that effect the nerves outside the brain and spinal cord. Causes of peripheral neuropathy range from the more common entrapment syndromes to complex causes including systemic diseases and metabolic conditions. Conditions like rheumatoid arthritis, diabetes, and endocrine disorders can contribute to nerve issues. Even pregnancy can play a role due to hormonal and physiological changes.

Duration and nature of symptoms, existing health conditions, and medical history all play a crucial role in the assessment of nerve entrapment syndromes. Chronic or episodic nerve symptoms, especially if bilateral or affecting multiple sites are good indicators that there is a deeper underlying cause that needs to be addressed.

It's important to note that nerve entrapment symptoms can vary, and a thorough evaluation by a healthcare professional is necessary for accurate diagnosis and appropriate management. If you suspect nerve entrapment or are experiencing symptoms, seeking medical advice is crucial for proper assessment and treatment.