The Summerville Sun

Presented by Dr. Drew McPhail
Chiropractic Physician

Understanding Your Spine, Part I

Spinal Anatomy

An engineering marvel, your spinal column supports the weight of your head and body; serves as the main attachment for your neck and back muscles; and provides protection for nerves that carry messages from your brain to the rest of your body.

The spine is comprised of 24 spinal vertebrae, which lay two inches below the skin and are stacked one on top of the other from the top of your pelvis to the bottom of your skull.

The seven cervical (neck) vertebrae are the smallest because they support the least weight. The upper cervical vertebrae are shaped differently to allow for rotation of the head and neck. The remaining cervical vertebrae have "u" shaped joints, called Luschka joints, which limit sideways bending and rotation of the neck.

The twelve thoracic (chest) vertebrae are larger and have dish-shaped attachments for the ribs.

The five lumbar (lower back) vertebrae are the largest because they carry all the weight of the body above the waist.

These vertebrae are held in place by tough, fibrous bands of tissue called ligaments, which surround the spine.

Between the spinal vertebrae (except the top two), flat, semi hard ligaments called Intervertebral discs bind two vertebrae together. These discs are made of tough, fibrous material surrounding a jelly-like center. This jelly-like center is about 80% water. Bearing weight compresses the discs during the day, forcing out the water, which accounts for a daily height loss of one-half to one inch. As the spine rests at night, no longer bearing weight, the discs reabsorb the water and height is restored.

Your spinal cord is a pliable column of nerve tissue within the spinal canal, about 17 inches long and the width of your little finger. The spinal cord controls all communication messages between the brain and every cell, tissue, and organ in the body. It extends from the bottom of your brain to your second lumbar vertebrae, about at your waist.

Spinal nerves exit the spinal cord between both sides of each vertebra. The nerves that leave the spinal cord in the upper neck become the nerves of the neck and head. The nerves that leave the spinal cord in the lower neck become the nerves of the arms and hands. The nerves that leave the spinal cord in the lower back form the nerves going down the legs.

Your neck

The motion of your neck is quite different from that of the rest of your spine. Nearly half of your neck movement occurs at the upper two cervical vertebrae, immediately below your skull, where there are no Luschka joints to limit rotational movement. Because this area is highly movable, it is very vulnerable to injury.

When the spinal cord is injured, messages cannot get through from the body to the brain, and vise versa. Depending on where the cord is hurt, and how much damage is done, the injury can mean partial or complete paralysis, or even death.

Neck Pain is caused when the vertebra of the cervical spine becomes misaligned due to injury, muscle weakness, or excessive or repetitive stress. Understanding your Spine, Parts II & III will discuss the primary causes of Neck Pain.

Excerpt from "Neck Pain, You Don't Want It, You Don't Need it", a publication edited by Peter G. Fernandez, DC, to which Dr. McPhail is a contributing author. These books can be purchased at Dr. McPhail's Chiropractic Office at 215 East 5th North Street (Hwy 78). For more information about back and neck pain relief, please visit www.drmcphail.com or call Dr. McPhail at 873-2225

Understanding Your Spine, Part III (July 31, 2008)

"Understand Your Spine, Part I", discussed Spinal Anatomy. "Understanding Your Spine, Part II" discussed Spinal Misalignment, Muscle Weakness, and Structural Disorders of the Spine as "Primary Causes of Neck Pain."

"Primary Causes of Neck Pain" (continued)

Injuries A significant percentage of misalignments of the neck are caused by injury, which can severely damage fragile neck structures. Neck vertebrae can be broken, dented, or crushed. Whiplash injuries from automobile accidents are a primary reason people seek chiropractic care. Sports and falls also contribute greatly to neck injuries.

Strains and Sprains When a muscle or tendon is stretched or torn, it is called a strain. A sprain is when ligaments or discs are stretched, ripped, or ruptured. A muscle can be suddenly ripped (strain) and occurs quite often in athletes who overexert a muscle. Ligaments can also be ripped by a sudden effort (sprain).

Muscles can be strained to a lesser degree by repetitiously doing a one- sided activity over a long period of time.

Continuously pulling on the muscles on one side of your neck, such as when working or reading in a bent-over posture, stretches them little by little, and ultimately injures the muscles. The prolonged bending of your head and neck forward stretches your neck muscles, which weakens them and allows your vertebrae to shift out of alignment.

Continued stretching of these muscles can cause them to fray and possibly rip over time. The same pattern of overstretching, fraying, and then ripping can also occur with ligaments. A minor repetitious sprain may lead to a more serious sprain, and ultimately to a rupture of the ligaments.

Muscles are responsible for moving bones and supporting proper posture. When spinal muscles become strained, the spine sags in one direction, causing misaligning vertebrae that can then put pressure on the nerves that leave from the spine to all other parts of the body.

Pressure on nerves can hurt and even become incapacitating. Ligaments hold bones together. If a spinal ligament is stretched or ripped (a sprain), vertebrae will misalign, resulting in irritated nerves and spinal problems. Therefore, preventing strains and sprains of the neck and back muscles is paramount for avoiding more serious neck problems.

Whether caused by an injury, continuous poor posture, strains, sprains, or an infection, neck pain is something that should be taken seriously. Even minimal pain means that something is wrong and needs to be fixed. If it is not fixed, it will likely get worse.

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