Nerve roots C6 and C7 are usually affected when there is a cervical disc herniation that affects the nerves. It is normal to have no neurological complications with a hernia in the neck. When it occurs, the root C6 and C7 are almost always affected. We will see in this post what happens when there is a lesion of the C6 root and we will understand its function.
The root C6 exits the column between the vertebrae C5 and C6. We have seven vertebrae in the cervical part of the spine that are called from C1 to C7 from top to bottom. The C5-C6 segment is the most worn level of the neck with time and effort. This suffering also involves injuries at the level of the intervertebral disc. If the disc ruptures and a hernia occurs, the C6 root coming out at this level can be damaged.
Nerve roots have one part that carries sensitive information and another that carries the motor signal to the muscles.
What sensitivity does the C6 root carry?
Each zone of the skin is innervated by more than one nerve root. This means that if someone touches an arm area for example, the signal will travel through more than one root. For this reason, when a single root is injured in the neck, the sensitivity can be partially lost, but not all in a certain area.
The C6 root carries the sensitivity approximately in the lateral zone of arm and forearm and in the thumb and index. This causes that when we have pinched the nerve by the hernia, the pain usually begins in the neck and descends by the arm by this zone. Sometimes the pain is more diffuse and we can not locate it so well.
What muscles move the C6 root?
At muscle level, the same thing happens with sensitivity on the skin. Almost all muscles receive signals from various nerve roots. This causes injury to a root cause weakness is those muscles but not a complete paralysis. That said, in each muscle arm usually dominates a root and if it is injured, the loss of strength can become important. It is said that the root is not usually completely damaged. That is why it is usual to see moderate force losses.
I am going to briefly analyze the most important muscles and then resume it so that we understand it. The root C6 is very protagonist in two muscles that are called radial. These two muscles (1st radial and 2nd radial, also called long radial and short radial) are responsible for moving the wrist backwards. There is another muscle that is responsible for doing this (the ulnar posterior) so this function will not be abolished, in addition to everything discussed before. When we talked about the root C7 we saw how the triceps was affected. In that case, the triceps is the only muscle competent to stretch the elbow so the affectation may be more striking.
The C6 root is the secondary actor in the muscles that flex the shoulder and the elbow. These muscles like the deltoid and the biceps are over C5 but also participate in C6.
In summary, in an important lesion of C6 weakness can be seen especially in elbow flexion and dorsiflexion of wrist. This is what we see when exploring. What the sufferer perceives is usually a weakness in lifting objects. On the one hand you notice that they escape from the hand (if they do not work well the muscles that carry the wrist back we have less gripping force) and on the other hand weakness to lift it (due to weak flexion of the elbow and shoulder) .
You may also like this blog.