Overview

The radial nerve is located in the arm, extending from the shoulder down the back of the upper arm. It carries essential sensory information from the back of the hand, guiding the perception of touch, temperature, and pain. When the radial nerve gets injured, it can result in a range of worsening conditions.

In cases where the nerve is completely severed or severely damaged, paralysis can occur. It can lead to a loss of wrist and finger extension, making it difficult to perform simple tasks such as lifting objects or grasping items. Understanding the anatomy and function of the radial nerve is essential for healthcare professionals and individuals interested in maximising their physical capabilities.

[caption id="attachment_23637" align="alignnone" width="666"] Radial Nerve anatomy[/caption]

What is Radial Nerve?

The radial nerve is a major nerve in the upper extremity that originates from the brachial plexus, a network of nerves in the neck and shoulder regions. It travels downward along the arm, branching out to innervate various muscles and provide sensory information. As the name suggests, it runs along the radial bone (forearm bone on the thumb side) and plays a crucial role in the movement and sensation of the arm and hand.

Anatomy of the Radial Nerve

The radial nerve is one of the primary nerves in the upper limb, originating from the brachial plexus. It is the largest branch of the plexus's posterior cord and is a crucial component of the peripheral nervous system. The nerve travels down the arm and extends into the hand, allowing for motor and sensory functions.

The radial nerve originates from the posterior cord of the brachial plexus, which stems from the roots of the spinal nerves C5 to T1. It passes through the axilla and runs along the posterior aspect of the arm.

It then bifurcates into two branches: the deep radial nerve and the superficial radial nerve.

- Deep radial nerve: The deep radial nerve is responsible for providing innervation to the extensor muscles of the forearm, which enable us to extend the wrist, fingers, and thumb. These muscles are crucial in fine motor activities such as writing, typing, and gripping objects.
- Superficial radial nerve: On the other hand, the superficial radial nerve provides sensory innervation to the dorsum (back) of the hand. It contributes to touch sensation, temperature perception, and overall sensory feedback from the back of the hand.

Function of the Radial Nerve

Here are some common functions of the radial nerve:

- Motor Function: These muscles extend the wrist, fingers, and thumb. It performs crucial daily activities such as grasping, writing, and picking up objects.
- Sensory Function: The superficial radial nerve provides sensory innervation to the dorsum (back) of the hand. This sensory feedback is essential for daily activities that involve handling objects, ensuring our interaction with the environment remains intact.

Common Radial Nerve Injuries

Any injury or damage to the radial nerve can significantly impact the functionality of the upper limb. Some common radial nerve injuries include the following:

- Radial nerve palsy: When the radial nerve is compressed or damaged, radial nerve palsy can occur, leading to weakness or paralysis of the forearm and hand muscles. Symptoms may include difficulty extending the wrist, fingers, and thumb and a loss of sensation on the back of the hand.

[caption id="attachment_23634" align="alignnone" width="664"] Radial Nerve Palsy[/caption]

- Radial tunnel syndrome: Similar to carpal tunnel syndrome, radial tunnel syndrome occurs when the radial nerve is compressed as it passes through the radial tunnel in the forearm. It can cause pain, weakness, and a tingling sensation in the forearm and hand.

When to Consult a Doctor

You can also get in touch with the expert Endocrinologist doctors at Narayana Healthcare based in your city to get immediate attention and medical support during injuries, health disorders or any other health concern.

Conclusion

The radial nerve is vital to the upper limb's intricate neural network. From its origin in the brachial plexus to its branches extending into the hand, this nerve enables the motor and sensory functions required for everyday activities.

References

- https://my.clevelandclinic.org/health/body/21617-radial-nerve
- https://www.ncbi.nlm.nih.gov/books/NBK534840/