From the Guidelines
The nerves emerging from the C6-C7 spinal segments primarily include the C7 spinal nerve roots, which are crucial components of the brachial plexus, affecting the triceps muscle, wrist extensors, and finger extensors 1. These nerves are responsible for motor functions such as elbow extension, wrist straightening, and finger extension. The sensory distribution from C7 includes the middle finger, parts of the index and ring fingers, and the posterior aspect of the forearm and hand.
Key Areas Affected by C6-C7 Nerves
- Triceps muscle: responsible for elbow extension
- Wrist extensors: enable wrist straightening
- Finger extensors: control finger extension
- Sensory distribution: middle finger, index and ring fingers, and posterior forearm and hand
Clinical Presentation of C6-C7 Nerve Damage
- Weakness in elbow extension, wrist extension, and finger extension
- Sensory changes in the middle finger and corresponding areas
- Commonly affected in cervical radiculopathy due to disc herniation or foraminal stenosis at the C6-C7 level The brachial plexus, formed from the C5 to T1 ventral rami, is a complex network of nerves that can be affected by various conditions, including plexopathy and radiculopathy 1. Understanding the nerve distribution and clinical presentation of C6-C7 nerve damage is essential for accurate diagnosis and treatment of conditions affecting this spinal segment.
From the Research
Nerves Emerging from C6-C7 Spinal Segments
The nerves emerging from the C6-C7 spinal segments are associated with the radial nerve and its branches.
- The radial nerve is responsible for innervating the muscles of the forearm and hand, including the extensor carpi radialis longus, extensor carpi radialis brevis, and supinator muscles 2.
- The C7 nerve root contributes to the innervation of the lateral pectoral, thoracodorsal, and radial nerves, with a minor contribution to the long thoracic nerve 3.
Parts of the Body Affected
The nerves emerging from the C6-C7 spinal segments affect the following parts of the body:
- The radial nerve and its branches innervate the muscles of the forearm and hand, including the thumb and fingers 2, 4.
- The C7 nerve root contributes to the innervation of the muscles of the shoulder, elbow, and wrist, including the latissimus dorsi, triceps, and wrist extensors 3.
- The lateral cutaneous antebrachial nerve, which is related to the C6 spinal segment, innervates the skin of the lateral forearm and thumb 5.
Myotomes Associated with C6-C7 Spinal Segments
The myotomes associated with the C6-C7 spinal segments are:
- C6: deltoid, infraspinatus, biceps brachii, and brachioradialis muscles 6.
- C7: triceps brachii, flexor carpi radialis, and extensor digitorum muscles 6.
- The C6 and C7 spinal segments also contribute to the innervation of the extensor carpi radialis longus and brevis muscles, and the pronator teres muscle 6.