Logan Steele
The radial nerve is a peripheral nerve that supplies movement and sensory function to parts of the arm, forearm, wrist, and hand. It is one of five nerve branches that extend from the brachial plexus. The radial nerve wraps around the humerus, the upper arm bone that runs from the shoulder to the elbow, and provides several smaller branches that supply motor (movement) function to muscles or sensory functions to the skin in the upper arm. The radial nerve divides into two major branches: a superficial branch that provides sensory information, and a deep branch that runs between muscles in the forearm, helping to rotate it and extend the wrist and fingers.
| Characteristics | Values |
|---|---|
| Definition | Radial nerve is a nerve in the human body that supplies the posterior portion of the upper limb. |
| Origin | The radial nerve originates from the brachial plexus, carrying fibres from the posterior roots of spinal nerves C5, C6, C7, C8 and T1. |
| Function | The radial nerve has both motor and sensory functions. |
| Motor function | The motor branches stimulate the triceps muscles on the back of the upper arm to straighten the elbow. It also stimulates the muscles in the outer part of the forearm that rotate the forearm and straighten the wrist and fingers. |
| Sensory function | The sensory branches supply the skin on the inner upper arm, the anterolateral arm, distal posterior arm, posterior forearm, and posterolateral wrist and hand areas. |
| Course | The radial nerve wraps around the humerus, the upper arm bone that runs from the shoulder to the elbow. It then passes through the radial tunnel, a narrow opening between bone and muscle at the outside of the elbow. |
| Branches | The radial nerve divides into two major branches: a deep branch and a superficial branch. The deep branch runs between muscles in the forearm and helps with rotation, while the superficial branch provides sensory information. |
| Clinical considerations | Radial nerve entrapment can occur when the nerve becomes injured or compressed, leading to pain and sensory or movement issues. Radial tunnel syndrome is a similar condition where the nerve is compressed specifically in the radial tunnel. |
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What You'll Learn
The radial nerve is a peripheral nerve
The radial nerve is one of five nerve branches that extend from the brachial plexus, which starts from nerves extending from the spinal cord in the lower neck and upper chest. The radial nerve exits the axilla posterior to the brachial artery and then enters the posterior arm compartment through the triangular interval. It then wraps around the humerus, the long upper arm bone that runs from the shoulder to the elbow, and provides branches to the long and lateral heads of the muscle.
The radial nerve has both motor and sensory functions. The motor branch stimulates the triceps muscles on the back of the upper arm, allowing the elbow to straighten. It also stimulates the muscles in the outer part of the forearm, allowing the forearm to rotate and the wrist and fingers to straighten. The sensory branch provides touch, pain, and temperature sensations for the skin on the inner upper arm, the back of the hand, and the web of skin between the thumb and index finger.
The radial nerve divides into two major branches: a deep branch and a superficial branch. The deep branch runs between the muscles in the forearm, helping with rotation, while the superficial branch provides sensory information. The deep branch of the radial nerve is also known as the posterior interosseous nerve, which pierces the supinator muscle and continues to the extensors of the forearm.
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It supplies movement and sensory information to the upper limb
The radial nerve is a peripheral nerve that supplies movement and sensory information to the upper limb. It takes a winding path from the lower armpit to the fingers, wrapping around the humerus (the upper arm bone) and supplying several smaller branches that provide either motor (movement) or sensory functions to the skin and muscles in the upper arm.
The radial nerve is one of five nerve branches that extend from the brachial plexus, which starts from nerves extending from the spinal cord in the lower neck and upper chest. The radial nerve exits the axilla (or armpit) posterior to the brachial artery and then enters the posterior arm compartment through the triangular interval. It then passes around the humerus' radial groove with the profunda brachii (deep brachial) artery.
The nerve supplies movement (motor) function to the triceps muscles on the back of the upper arm, allowing the elbow to straighten. It also stimulates muscles in the forearm that rotate the forearm and straighten the wrist and fingers. The motor branches stimulate the posterior arm muscles, posterior forearm muscles, and extrinsic wrist and hand extensors. The deep branch of the radial nerve provides motor innervation to the muscles in the posterior compartment of the arm and forearm, which are mostly extensors.
The radial nerve also supplies sensory information to the upper limb. The sensory branch provides touch, pain, and temperature sensations to the skin on the inner upper arm, the back of the hand, and the web of skin between the thumb and index finger. The sensory branches supply the skin on the anterolateral arm, distal posterior arm, posterior forearm, and posterolateral wrist and hand areas. The radial nerve's distribution diminishes from the thumb to the ring finger.
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The nerve branches stimulate the triceps brachii muscles
The radial nerve is a peripheral nerve that supplies movement and sensory function to parts of the arm, forearm, wrist, and hand. It takes a winding path from the lower armpit to the fingers. The nerve branches stimulate the triceps brachii muscles. The triceps brachii muscle has three heads: the lateral, medial, and long heads. Each head receives its own motor branch, which is thought to originate from the radial nerve. The triceps brachii is the largest muscle occupying the posterior compartment of the upper arm. It often appears as a horseshoe shape on the posterior aspect of the arm. Its main function is the extension of the elbow joint.
The radial nerve is one of five nerve branches that extend from the brachial plexus. The brachial plexus nerves start from nerves that extend from the spinal cord (nerve roots) in the lower neck and upper chest. The radial nerve wraps around the humerus, the upper arm bone that runs from the shoulder to the elbow. It provides several smaller branches that supply motor (movement) function to muscles or sensory functions to the skin in the upper arm.
The radial nerve splits into two major branches at the elbow: a superficial branch and a deep branch. The superficial branch only provides sensory information. The deep branch stimulates several muscles to make the wrist, hand, and fingers extend. Certain conditions can cause radial nerve injury, such as radial nerve entrapment or radial tunnel syndrome.
The motor branch of the long head of the triceps brachii arises from the axillary nerve, the posterior cord, or the radial nerve. Several studies have reported that the motor branch of the long head arises from the axillary nerve or posterior cord, while other studies and textbooks describe a sole radial innervation. The axillary nerve is often involved during shoulder injuries, so the precise identification of axillary versus radial innervation is clinically relevant for surgery and therapy.
The triceps brachii muscle is supplied with oxygen and nutrients from the branches of the deep brachial artery. The medial head was found to be predominantly formed by small type I muscle fibres and motor units, while the lateral head comprised a great quantity of large type IIb fibres and motor units. The long head consisted of a more balanced mixture of fibre types and motor units.
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Radial nerve injuries can cause pain and movement issues
The radial nerve is a peripheral nerve that supplies movement and sensory functions to parts of the arm, forearm, wrist, and hand. It allows you to move muscles and feel skin sensations in certain parts of your upper arm, forearm, wrist, and hand. The radial nerve is one of five nerve branches that extend from the brachial plexus. It starts in the lower armpit and wraps around the humerus, the upper arm bone that runs from the shoulder to the elbow.
Radial nerve entrapment occurs when the nerve is injured or compressed anywhere along its path. This can result in pain and sensory and/or movement issues depending on the location of the compression. Radial tunnel syndrome is a specific type of radial nerve entrapment that occurs when the nerve is compressed in the radial tunnel, a natural tunnel formed by muscles and ligaments in the elbow and forearm area.
Treatment for radial nerve injury aims to relieve symptoms while maintaining movement of the wrist and hand. In some cases, symptoms may resolve on their own without intervention. Doctors may prescribe medication or recommend physical therapy to build and maintain muscle strength. In more severe cases, surgery may be required to repair the nerve or remove any masses, such as benign tumors, that are compressing the nerve.
To diagnose a radial nerve injury, a doctor will perform a physical assessment, moving each joint in the upper arm and asking the patient to report any sensations of stretching, tingling, or pain. They may also use medical imaging techniques such as X-rays, ultrasounds, or MRIs to locate and assess the severity of nerve damage.
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The nerve wraps around the humerus and passes through the radial tunnel
The radial nerve is a peripheral nerve that supplies movement and sensory function to parts of the arm, forearm, wrist, and hand. It is one of five nerve branches that extend from the brachial plexus, which is a group of nerves that branch from the cervical spine (neck). The radial nerve takes a winding path from the lower armpit to the fingers.
The nerve wraps around the humerus, the long upper arm bone that runs from the shoulder to the elbow. It provides several smaller branches that supply motor (movement) function to muscles or sensory functions to the skin in the upper arm. The radial nerve gives function to the triceps muscles on the back of the arm, allowing the elbow to straighten.
The nerve then passes through the radial tunnel, a narrow opening between bone and muscle at the outside of the elbow. This is a natural tunnel formed by muscles and ligaments in the elbow and forearm area. At the elbow, the radial nerve splits into two major branches: a superficial branch and a deep branch. The superficial branch only provides sensory information, while the deep branch runs between muscles in the forearm, helping to rotate it and extend the wrist and fingers.
Radial tunnel syndrome occurs when the radial nerve is compressed in the radial tunnel. This can cause pain around the elbow, as well as weakness in the forearm and wrist.
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Frequently asked questions
The radial nerve is a peripheral nerve that supplies movement and sensory function to parts of the arm, forearm, wrist and hand.
The radial nerve has both motor and sensory functions. The motor branches stimulate the triceps brachii and the extensor muscles in the forearm. The sensory branches supply the skin on the anterolateral arm, distal posterior arm, posterior forearm, and posterolateral wrist and hand areas.
The superficial branch of the radial nerve provides sensory innervation to much of the back of the hand, including the web of skin between the thumb and index finger.
The deep branch of the radial nerve provides motor innervation to the muscles in the posterior compartment of the arm and forearm, which are mostly extensors.
