Arm pain is a pretty broad topic, because it includes direct injuries to the arm as well as injuries to the neck, cervical nerves, and shoulder joint complex. I will focus on the neck and cervical nerve injuries in this article, and will do separate articles on the shoulder joint complex and the direct injuries/conditions of the arm like carpal tunnel and tennis elbow.
Normal Anatomy
The nerves that exit out between each set of cervical (neck) vertebrae innervate the shoulder, arm, and hand. (The spinal nerve is like a large cable with thousands of individual nerve fibers in it.) The spinal nerves exit and then some of them, reform to make the brachial plexus, which in turn then split apart and innervates different aspects of the shoulder, arm and hand. Part of what chiropractors and medical doctors do is to assess through physical findings and tests where the injury to the nerve is occurring (before, at, or after the brachial plexus).
Symptoms – Cervical radiculopathy
When a spinal nerve is impinged upon or compromised by a vertebral subluxation (a vertebrae that is misaligned, and stays misaligned) then the signals to arm/hand change. For some the symptoms that are felt include tingling, numbness, sharp pain, itching, no feeling, or there is no difference in the feeling of the arm. If the nerves that are compromised are to the muscles, then the muscles won’t know to contract and move your arm or hand. It is muscle weakness rather than pain that is the symptom. It can also be any combination of the above symptoms, again depending on which nerve fibers are being affected.
How do the nerves get impinged or compromised?
The spinal nerves come off of the spinal cord inside the vertebrae (see image) and then exit through the Intervertebral Foramina (IVF) to go out through the neck and down into the shoulder, arm, and hand. Think of the IVF as the mouth to a cave opening that the nerve exits from. The cervical vertebrae above and below do move. When the vertebrae move out of place and stay out of place they can impinge the spinal nerve. Think of the vertebrae as the soil around the opening of the cave, if there is a collapsing or a landslide of that soil, it is going partially close off the opening to the cave, and the nerves have less room to exit, but they still have to exit, so they are compressed or impinged.
How do the vertebrae get out of place to begin with?
There are lots of reasons for the cervical vertebrae to get misaligned. Injuries playing sports, car accidents (even minor ones), neck strains and sprains, falls, sleeping wrong over long periods of time, poor posture, improper computer work station ergonomics, and repetitive movements always to the same side. All or any of these can cause the vertebrae to get misaligned. However, it is not just a misalignment that causes the problem, it is that vertebrae has stayed out of place and there has been constant pressure on the nerve. Additionally, disc bulges, disc degeneration and osteoarthritic spurs can also compromise the spinal nerve – these are again indications that the condition has been there over a long period of time.
How do you fix or correct the problem?
Many times simple chiropractic adjustments (replacing the misaligned vertebrae) and specific exercises to strengthen the neck muscles and increase mobility will be sufficient to reduce the symptoms. However, the longer you wait, the more damage is being done, and the longer it will take to recover.