Body Parts: Bringing it all together -- Ligaments

By: BRADLEY J. FIKES - Staff Writer | Saturday, October 7, 2006 4:53 PM PDT ∞

Yeah, bones get a lot of attention, but they'd be pretty useless by themselves. We'd flop around like a bony jellyfish. But connect those bones together and you've got a flexible, strong skeleton that supports the body.

What's doing all this connecting? Something that doesn't get mentioned in songs: Ligaments.

Ligaments are tough, fibrous bands of tissue that link one bone to a second, or one part of a bone to another. These bands are made up of fibers of collage (They're related to, but not the same as tendons, which link bone to muscle). These connections form flexible points of movement, called joints.

How tough is tough? Often, bones will break before ligaments do. There's two reasons for this, one anatomical and one functional. Ligaments are slightly elastic, and bones are usually rigid. So force that would break a bone will often leave the ligament intact.

The functional reason is that bones heal more quickly than ligaments. That's because ligaments have a poor blood supply, means they take a long time to heal. It is also why they are white, incidentally.

Ligaments are mostly made of collagen, yes the same substance injected into lips to make them fuller. But ligament collagen is formed in long, tough threads, tightly packed. The rest, or about one-fifth of ligament composition, comes from fibroblasts, cells that produce ligament tissue, and special proteins called proteoglycans.

While all ligaments by definition connect bones, not all ligaments form joints. For example, ligaments in the skull connect the various bones of the skull, which are normally immobile. But travel on down to the jaw, and ligaments play a major role in the hinge called the temporomandibular joint. Ligaments, tendons and muscles traverse this joint, holding it in place and moving it when desired.

Injury, excess pressure, arthritis or other conditions can disrupt the joint's functioning, causing TMJ disorder. (One wonders what kind of jaw disorders occur with certain snakes that can dislocate their jaws, which remain attached only by ligaments. That's how these snakes can swallow prey larger than themselves.)

A ligament in the skull connects to a little-known bone in the throat called the hyoid, that attaches to the base of the tongue. This is not a true joint, because the hyoid doesn't move in relation to any other bone.

Moving on down, the shoulder sockets, elbows, wrists, thigh, knee and ankle all form major points, lashed together with ligaments.

All these points are vulnerable to sprains, which are stretches or tears in ligaments. Turning your ankle the wrong way when running is an excellent way to get an ankle sprain. A sprained joint wobbles, making it unstable. It's usually often painful, the body's signal not to move it.

The knee is a complex joint, and especially vulnerable to sprains. It is connected by four ligaments, of which the anterior cruciate ligament is a star player in many athletic injuries. This ligament prevents the tibia, or shin bone, from sliding too far forward. The posterior cruciate ligament prevents the tibia from sliding too far backward. The two other ligaments, as you would expect, prevent the tibia from sliding too far left or right.

Immediately after the injury, you have a choice between R.I.C.E. or M.E.A.T. The first is an acronym for Rest, Ice, Compression and Elevation. It's intended to reduce swelling and relieve pain. The second is Movement, Exercise, Analgesics and Treatment. It's intended to hasten the healing process.

However, ligaments do better on the carnivorous diet, because of their poor blood circulation. Coldness and immobility reduce the already low blood supply to ligaments, so it's not a good long-term idea. Bottom line: R.I.C.E. is good for immediately after a ligament injury, when you don't know what kind of injury you have. Then, with your doctor's guidance, shift to a M.E.A.T. diet.

Contact staff writer Bradley J. Fikes at (760) 739-6641 or bfikes@nctimes.com.

"The head bone's connected to the neck bone.

The neck bone's connected to the shoulder bone.

The shoulder bone's connected to the back bone.

The back bone's connected to the hip bone ..."

---- Dry Bones

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