Nerve impingement-brachial plexus, sacral plexus

Written by Roger Fontaine
June 2000
Active Healing Therapeutic Massage Clinic

Legal liability disclaimer:The author does not intend this article to be a self-diagnosis tool
for disk herniation or neural stenosis or any other neurological dysfunction. This article is only intended to provide some information related to sources of pain with neurological origins.

Any individual suffering from neural pain may wish to consult with their physician or specialist before seeking massage therapy.

I am a graduate in Winnipeg in advanced massage therapies.

I have studied neurology for three years within the context of massage therapy studies and would like to share in as simple as possible language what might be causing nerve impingement in the brachial plexus (shoulder/arm complex) and lumbar/sacral complex.

The nerves which serve the arm come out of the gap between the vertebrae below C5,6,7 and T1. This is called the ‘brachial plexus’.

One branch goes to the left arm and the other to the right arm, via the armpit and contains five main nerves, the axillary, radial, musculocutaneous, median, and ulnar.

There is an annular disk between the vertebrae made of a fibrous outer disk and an inner gelatinous pulposa.

When this disk dries out, one of them being aging; for many reasons, it narrows the gap between the vertebrae and can impinge, entrap, or irritate the nerve by rubbing it the wrong way, excuse the humour. Another cause of nerve impingement related to disks is the anterior or posterior herniated disk. This happens when due to an over-flexed or over-extended spine or due to anterior/posterior or lateral shearing when there is excessive pressure placed upon the disk and the inner portion, the gelatinosa, protrudes posteriorly and impinges the posterior nerve root. This can happen during an activity of sports or over-exertion during gardening or other occasional nature. Sometimes this type of injury can happen because of an imbalance in musculature between left and right, flexors and extensors, causing the strain and subsequent herniation of the disc.

The other main cause for vertebral nerve impingement is vertebral subluxation, caused by hypertonic (tight) muscles which because of overuse or trauma have twisted or rotated the vertebrae left or right, anterior or posterior, and impinged the nerve.

I’ve heard of neurosurgeons performing laminectomies where they remove the laminaes between the anterior part of the vertebrae and the posterior processes and then fuse the vertebrae together. This limits motion but also limits the friction. While they remove the laminaes, they also enlarge the gap where the nerve exits by digging out the bone between the vertebrae.

This procedure is also often performed in the lumbar area where many posterior herniations occur, esp. between L4-L5, L5-S1.

The scenario which includes pain being severe upon ‘arising’, during hip extension, makes sense. Any nerve impingement at the sacrum or lumbar area will pull the ‘erector spinae’ all the way up the back to the neck and irritate any nerve impingement in the cervicals “neck” area. This will cause the pain possibly to be referred into the shoulders, arms, neck, and face.

The muscles which support the back are the extensor group, which are along each side of the spine, which attach to the sacrum between the hips, the iliac crest of the hips, and climb to the neck, attach to the transverse and spinous processes of all the vertebrae. They are responsible for back extension, side-bending, and rotation.

Any ‘stenosis’ or narrowing of the gaps between the vertebrae may cause nerve impingement.

Which brings me to the other aspect of why I wrote this article. That has to do with the benefits of massage. Sometimes there are muscles which are’hypertonic’: tight.

These muscles may have become that way because of chronic overuse, guarding: which occurs when there is surrounding trauma and the muscles contract to protect the surrounding area by limiting movement. Unfortunately sometimes these muscles don’t know when to turn off and elongate after the guarding is no longer needed or useful. And so they stay shortened and tight. Massage therapy can help relax and elongate these muscles and in many instances relieve nerve impingement. The nerves sometimes go through these muscles or between two fascicles “bundles” of muscles and can impinge nerves.

The resulting pain will be similar to vertebral stenosis(narrowing) and the patient may present themselves with similar pain to the upper brachial plexus, or to the lower sciatic like pain, caused by the tight piriformis muscle in the gluteal ‘buttocks’ region. Because the sciatic nerve which innervates the posterior leg, runs between the piriformis muscle and the obturator foramen which is the opening where the sciatic nerve passes through to go from the anterior of the sacrum to beneath the gluteus maximus and then down the leg,

A tight piriformis will impinge the sciatic nerve upon arising or hip extension, or when externally rotating the leg. This pain is usually felt when driving for a long time, or when going from sitting to standing, crossing the leg over the knee would be impossible because of the increase in pain. View article: http://149.56.20.213/~healingm/backpain.html

This treatment , piriformis release, can be performed by any remedial massage therapist who has been trained to recognize the difference between a herniated disk, an impinged disk due to stenosis, and a hypertonic muscle situation. The straight’well’ leg test or the slump test will test for a herniated disk. A negative test would lead one to suspect the piriformis, esp. is there is pain upon lateral rotation of the leg ,esp. with hip flexed. Herniated disks usually herniate to one side appearing unilaterally,

There is not much which massage therapies can do to assist a herniated disk condition, except to release some of the muscles which may be guarding the dysfunctional vertebrae allowing for more movement. This may not be the best thing to do because the guarding muscles are preventing more pain and motion in the region to minimize future injury. The advantage gained by more mobility may be offset by the disadvantage of increased risk of further injury with excessive motion.

The best solution would be to apply ice, for ten minute sessions every hour, in the acute stage; contrast hot(three minutes) and cold(one minute) applications in the sub-acute stage on injury. This usually is one week to three weeks after the initial injury.

Besides the rest and reduced stress on the area for the period of acute recovery, the hernia usually will heal or rectify itself without surgery. It is only in rare cases where spinal fusion of the vertebrae is required because the pain is too intense with motion.

In the neck and shoulder, the brachial plexus can be impinged beneath the trapezius, or , between the neck muscles and the sterno-cleido-mastoid “scm”.

Or it can be impinged between the clavicle “collarbone’ and the ribs by a tight pectoralis minor and major. Shoulders which are rotated forward, usually accompanied by a hunchback are symptoms of a possible tight pectoralis.

There is a ‘pec minor’test which can be performed. Raise your arms up above your head. If you get tingling, numbness in the arms and fingers , usually unilaterally, to one side, that would confirm a tight pectoralis. It is possible to have the neurological deficit bilaterally, on both sides, but this would be less common.

Treatment for a tight pectoralis can be performed by any qualfied massage therapist with assessment capabilities.