The lower back is also called the lumbosacral area of the back. It is the part of the back between the bottom of the ribs and the top of the legs.
Most of the lower back is made up from muscles that attach to, and surround, the spine. The spine is made up of many bones called vertebrae. The vertebrae are roughly circular and between each vertebra is a disc. The discs between the vertebrae are a combination of a strong fibrous outer layer and a softer, gel like center. The discs act as shock absorbers and allow the spine to be flexible.
Strong ligaments also attach to adjacent vertebrae to give extra support and strength to the spine. The various muscles that are attached to the spine enable the spine to bend and move in various ways.
The spinal cord, which contains the nerve pathways to and from the brain, is protected by the spine. Nerves from the spinal cord come out from between the vertebrae to take and receive messages to various parts of the body.
About 8 in 10 people have one or more bouts of low back pain. In most cases, it is not due to a serious disease or serious back problem, and the exact cause of the pain is not clear. This is called non-specific lower back pain. The usual advice is to keep active, and do normal activities as much as possible. Pain medication may be necessary for a short time. In most cases, the pain clears within a week or so but may recur from time to time. Chronic (persistent) pain develops in some cases, and further treatment may then be needed.
Nerve root pain means that a nerve coming out from the spinal cord (the root of the nerve) is irritated or pressed on. (Many people call this a trapped nerve.) You feel pain along the course of the nerve. Therefore, you typically feel pain down a leg, sometimes as far as to the calf or foot. The pain in the leg or foot is often worse than the pain in the back. The irritation or pressure on the nerve may also cause pins and needles, numbness or weakness in part of a buttock, leg or foot.
Cauda Equina Syndrome – Rare, But An Emergency:
Cauda equina syndrome is a particularly serious type of nerve root problem. This is a rare disorder where the nerves at the very bottom of the spinal cord are pressed on. This syndrome can cause low back pain plus: problems with bowel and bladder function (usually unable to pass urine), numbness in the saddle area (around the anus), and weakness in one or both legs. This syndrome needs urgent treatment to preserve the nerves to the bladder and bowel from becoming permanently damaged. See your health care provider immediately if you suspect cauda equina syndrome.
While most of the time it is simply a muscular issue, what else could it be? Think about the location and what other organs are in that area:
You may only have low back pain when your kidneys are involved, but usually there are other symptoms. Kidney infections, stones, and traumatic bleeding of the kidney (hematoma) are frequently associated with low back pain. Diagnosis can involve urinalysis, ultrasound, or other imaging studies of the abdomen. You may exhibit low back pain with painful urination, blood in urine, inability to urinate or even frequency.
Pregnancy commonly leads to low back pain by mechanically stressing the lumbar spine (changing the normal lumbar curvature) and by the positioning of the baby inside of the abdomen. Additionally, the effects of the female hormone estrogen and the ligament-loosening hormone relaxin may contribute to loosening of the ligaments and structures of the back. Pelvic-tilt exercises and stretches are often recommended for relieving this pain. Women are also recommended to maintain physical conditioning during pregnancy according to their doctors’ advice.
Ovarian cysts, uterine fibroids, and endometriosis not infrequently cause low back pain. Precise diagnosis can require gynecologic examination and testing.
Most of us (about 8 in 10 people) will have a bout of non-specific low back pain at some point in our life. The severity can vary. However, it is difficult to quote exact figures as to outlook. This is partly because it is so common and many people with back pain do not consult a doctor. Roughly, it is thought that:
- Most non-specific back pains ease and go quickly, usually within a week or so.
- In about 7 in 10 cases, the pain has either gone or has greatly eased within four weeks.
- In about 9 in 10 cases the pain has gone or has greatly eased within six weeks.
However, once the pain has eased or gone it is common to have further bouts of pain (recurrences) from time to time in the future. Also, it is common to have minor pains on and off for quite some time after an initial bad bout of pain. In a small number of cases the pain persists for several months or longer. This is called chronic back pain.
Evidence suggests that the best way to prevent bouts of low back pain is simply to keep active, and to exercise regularly. This means general fitness exercise such as walking, running, swimming, etc. There is no firm evidence to say that any particular back strengthening exercises are more useful to prevent back pain than simply keeping fit and active. It is also sensible to be back aware. For example, do not lift objects when you are in an awkward twisting posture.