Myotomes & Dermatomes Pain Help

By Simon Roulstone

 This page is offered by Simon who became a quadriplegic after a car crash. He has a phenomenal site that helps people understand the complexity of spinal damage and shows how you can choose to do what you want to do in life anyway. Some people let life happen others make things happen. Simon makes things happen! Please visit his site by clicking on the banner on the bottom of this page

This page describes the role of dermatome and myotome locations and how you can have pain at one area when the damage is really somewhere else. We urge people to take a dermatome map into your doctor  and show them the pain patterns

 Spinal nerves have motor fibers and sensory fibers. The motor fibers innervate certain muscles, while the sensory fibers innervate certain areas of skin. A skin area innervated by the sensory fibers of a single nerve root is known as a dermatome. A group of muscles primarily innervated by the motor fibers of a single nerve root is known as a myotome. Although slight variations do exist, dermatome and myotome patterns of distribution are relatively consistent from person to person.

myotomes-dermatomes by permission Apparelyzed.com

myotomes-dermatomes by permission Apparelyzed.com

Myotomes

Myotomes - Relationship between the spinal nerve & muscle
Dermatomes – Relationship between the spinal nerve & skin.

Each muscle in the body is supplied by a particular level or segment of the spinal cord and by its corresponding spinal nerve. The muscle, and its nerve make up a myotome. This is approximately the same for every person and are as follows:

C3,4 and 5 supply the diaphragm (the large muscle between the chest and the belly that we use to breath).

C5 also supplies the shoulder muscles and the muscle that we use to bend our elbow .

C6 is for bending the wrist back.

C7 is for straightening the elbow.

C8 bends the fingers.

T1 spreads the fingers.

T1 –T12 supplies the chest wall & abdominal muscles.

L2 bends the hip.

L3 straightens the knee.

L4 pulls the foot up.

L5 wiggles the toes.

S1 pulls the foot down.

S3,4 and 5 supply the bladder. bowel and sex organs and the anal and other pelvic muscles.

Dermatomes

 

Dermatome cortesy of Apparalysed.com (2009)

Dermatome Apparelyzed.com used by permission Click to enlarge (2009)

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Dermatome is a Greek word which literally means “skin cutting”. A dermatome is an area of the skin supplied by nerve fibers originating from a single dorsal nerve root.  The dermatomes are named according to the spinal nerve which supplies them. The dermatomes form into bands around the trunk but in the limbs their organisation is more complex as a result of the dermatomes being “pulled out” as the limb buds form and develop into the limbs during embryological development.

In diagrams or maps, the boundaries of dermatomes are usually sharply defined. However, in life there is considerable overlap of innervation between adjacent dermatomes. Thus, if there is a loss of afferent nerve function by one spinal nerve sensation from the region of skin which it supplies is not usually completely lost as overlap from adjacent spinal nerves occurs: however, there will be a reduction in sensitivity.

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4 Responses to “Myotomes & Dermatomes Pain Help”

  1. [...] down what you consider to be the most important things you want covered in your visit. You may want to refer to a dermatome map The reason you may want to do this is because chronic pain and injury can cause us to be sidetracked [...]

  2. [...]  There is no muscle that goes  all the way from your neck to the hand.   Since bending your head away from the hand tightens the nerves that go from your neck to your hand, you feel pulling. If you feel pain, numbness and tingling, this is a problem you should tell your doctor about. Nerve glides can be used in multiple body areas not just the hand and neck. Nerve pain is referred to other body areas and you can get an idea of the patterns  by looking at a dermatome map [...]

  3. Liz says:

    Brilliant website. I’m training to be a Bowen Therapist and am studying Anatomy & Physiology and Bioenergetics as I work as an energy hands on healer. I was struggling to get my head around the nerves of the body and dermatomes until I read your website – everything read easily and made complete sense. Many thanks for being such a great teacher.

  4. [...] on the conjoint origin of the piriformis muscle and tearing of the capsule at S3. See pain patterns here. The anterior rotation will loosen the iliolumbar ligaments, destabilize L4,5-S1 and increase shear [...]

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