Main Article
Spinal manipulation is a powerful method to remove the cause of pain, but it also can improve the function of the visceral organs such as the gastrointestinal tract, liver, kidneys, adrenals, and even the eyes.
Spinal manipulation is done by all Chiropractors, as well as some Naturopathic Medical Doctors (NMD) and some Doctors of Osteopathy (DO). Allopathic Medical Doctors (MD) are rarely trained to do spinal manipulation.
The spinal column consists of a number of bones (vertebrae), starting with the occiput skull bone, then 7 cervical vertebrae, 12 thoracic vertebrae, 5 lumbar vertebrae, the sacrum (which consists of 4 or 5 bones during fetal development, but which fuse into one bone by early childhood), and the coccyx (tailbone).
Each of these vertebrae have freely movable joints called facet joints that connect to the vertebrae above and below; the thoracic vertebrae also have freely movable joints that connect the vertebrae to the corresponding ribs. All of these joints can be damaged. When any of the bones that form a joint become partially dislocated from their normal position, we say that there is a subluxation (or in more severe cases, a luxation). Trauma often causes subluxations.
Joints can also become fibrotic due to prolonged inflammation and subluxations, and lose their normal ability to move (articulate). This can lead to a fixation. Localized swelling or muscle splinting can also interfere with free movement of the joint.
In addition, there is an intervertebral disc that is shaped like a "jelly donut" between each pair of vertebrae, which acts like a cushion or shock absorber. These intervertebral discs can become damaged by trauma, age, or drugs (especially tobacco or nicotine) that reduce blood flow to the discs. The discs can then shrivel up and lose their cushioning ability, bulge, or rupture.
Between each pair of adjacent vertebrae there is a pair of holes called intervertebral foramina, one on the left of the vertebrae and the other on the right. Through these holes pass segmental nerve roots, arteries that provide blood for the intervertebral discs and nerves, veins that drain the blood back out, and lymphatic vessels that drain out metabolic waste.
Subluxations, fixations, swelling, muscle splinting, and disc problems can constrict the flow of blood, lymph, and nerve signals coming from the affected segmental nerve roots. Lymphatic drainage and nerve function are most easily disrupted.
When this happens, the parts of the body that are controlled by each affected nerve root can develop dysfunction. Visceral organs can become diseased, muscles can become weak, and pain or numbness may afflict the part of the body that is affected.
Anything that causes subluxations, fixations, swelling, muscle splinting, or disc problems can cause pain and/or stiffness in the region of the affected joint, as well as visceral organ dysfunction, muscle weakness, pain, and numbness of the part of the body that gets its nerve supply from the affected nerve root.
Spinal manipulation can help permanently resolve these issues in many cases, and can usually eliminate the need for invasive "cutting" back surgery. (Ruptured discs may require surgery).
Segmental Nerve Root Functions
The nerve supply from each segmental nerve root can be traced to each visceral organ, muscle, and region of the skin, as presented below. Traditional Chinese Medicine (acupuncture) identifies similar points along the "urinary bladder" and "governing" channels or meridians.
Knowing which organ, muscle, or skin region is affected can help identify the location in the spine of the cause. Similarly, knowing the location of in the spine of a problem can help predict where the patient's complaints will be located.
In the list below, the vertebra are numbered from the top down as C1, C2, .... C7, T1, T2, ..., T12, L1, L2, ..., L5, and S1, S2, ..., S4. The segmental nerve roots exit the spine above the cervical vertebrae, and below the thoracic and lumbar vertebrae. The sacral nerve roots exit through holes in the body of the sacrum. There is also a nerve root named C8, which exits below the C7 vertebra. Nerve roots exiting on the left serve the left side of the body, and nerve roots exiting on the right serve the right side of the body.
Visceral Organs and their Nerve Roots
- C1
- Pituitary gland, brain, ear, eye
- C2
- Eye, tongue, ear, heart
- C3
- Diaphragm
- C4
- Diaphragm
- C5
- Vocal cords, diaphragm
- C6
- Tonsils
- C7
- Thyroid
- C8
- T1
- Heart, thyroid, esophagus, trachea
- T2
- Heart, lung
- T3
- Heart, lung
- T4
- Heart, lung, gall bladder
- T5
- Heart, liver, esophagus, blood circulation
- T6
- Esophagus, stomach, spleen, pancreas, duodenum
- T7
- Stomach, spleen, pancreas, duodenum, liver, gall bladder
- T8
- Stomach, spleen, pancreas, liver, gall bladder, adrenal glands
- T9
- Stomach, spleen, pancreas, liver, gall bladder, adrenal glands, reproductive organs, small intestine
- T10
- Stomach, spleen, pancreas, appendix, reproductive organs, small intestine, large intestine
- T11
- Kidney, reproductive organs, small intestine, large intestine, bladder, adrenal glands, ileocecal valve
- T12
- Kidney, reproductive organs, small intestine, large intestine, bladder, adrenal glands, ileocecal valve
- L1
- Reproductive organs, large intestine, bladder
- L2
- Reproductive organs, large intestine, bladder, appendix
- L3
- Reproductive organs, large intestine, bladder, prostate
- L4
- Prostate
- L5
- Prostate
- S1
- Prostate, bladder
- S2
- Prostate, bladder, reproductive organs
- S3
- Prostate, bladder, reproductive organs
- S4
- Reproductive organs
- Coccyx
Muscles and their Nerve Roots
- C1
- C2
- C3
- C4
- C5
- C6
- C7
- C8
- T1
- T2
- T3
- T4
- T5
- T6
- T7
- T8
- T9
- T10
- T11
- T12
- L1
- L2
- L3
- L4
- L5
- S1
- S2
- S3
- S4
- Coccyx
Skin regions and Associated Nerve Roots
Each spinal nerve root is associated with a different region of skin, which are called dermatomes. For example, see printable dermatome chart.
Cranial Nerves
In addition to spinal nerve roots, nerves can also start directly in the brain, and then pass out of the skull through small holes called foramina to travel to various parts of the body. Many of these foramina are in close proximity to the joint between the occipital bone and C1; subluxation, inflammation, irritation, or swelling of this joint can adversely affect the function of these cranial nerves.
Of particular note is the vagus nerve, which "wanders" throughout the body, to help provide the nerve supply to the brain, ears, tongue, larynx, pharynx, esophagus, lungs, stomach, heart, liver, spleen, gallbladder, adrenals, kidney, pancreas, intestines, reproductive organs, and ureter.
Parasympathetic and Sympathetic Nerves
The autonomic nervous system coordinates the activities of the various visceral organs as well as blood flow to the muscles. The autonomic nervous system is broken down into sympathetic and parasympathetic nerves. When the person is in "fight or flight" mode (running from danger), the sympathetic nerves are more activated than the parasympathetic nerves. When the person is in "chill out" mode (couch potato), the opposite is true. Parasympathetic nerves include the vagus nerves and the sacral nerves S2, S3, S4. All other spinal nerves are sympathetic.
Blood Supply to the Brain
Approximately one third of the blood supply to the brain flows up through the cervical vertebrae. Subluxation, swelling, or inflammation in the region of the occiput or cervical vertebrae can often reduce blood flow to the brain, thus causing symptoms including headaches and light-headedness.