Although people often refer to a disc herniation as a slipped disc, the disc doesn't actually slip out of place. Rather, the term herniation means that the material at the center of the disc has squeezed out of its normal space. This condition mainly affects people between 30 and 40 years old.
lntervertebral discs separate the vertebrae. The discs are made of connective tissue. Connective tissue is the material that bolds the living cells of the body together. Most connective tissue is made of fibers of a material called collagen. These fibers help the disc withstand tension and pressure.
A disc is made of two parts. The center, called the nucleus, is spongy. It provides most of the disc's ability to absorb shock. The nucleus is held in place by the annulus, a series of strong ligament rings surrounding it. Ligaments are connective tissues that attach bones to other bones.
Healthy discs work like shock absorbers to cushion the spine. They protect the spine against the daily pull of gravity. They also protect it during strenuous activities that put strong force on the spine, such as jumping, running, and lifting.
Herniation occurs when the nucleus in the center of the disc pushes out of its normal space.
The nucleus presses against the annulus, causing the disc to bulge outward. Sometimes the nucleus herniates completely through the annulus and squeezes out of the disc. Although daily activities may cause the nucleu s to press against the annu lus, the body is normally able to withstand this pressure. However, as the annulus ages, it tends to crack and tear. It is repaired with scar tissue. This process is known as degeneration . Over time, the annulus weakens, and the nucleus may begin to herniate (squeeze) through the damaged annulus. At first, the pressure bulges the annulus outward. Eventually, the nucleus may herniate completely through the outer ring of the disc.
Lumber Disc Herniation
Causes of Herniation
Vigorous, repetitive bending, twisting, and lifting can place abnormal pressure on the shock absorbing nucleu s of the disc. If great enough, this increased pressure can injure the annulus, leading to herniation. A lumbar disc can also become herniated during an acute (sudden) injury. Lifting with the trunk bent forward and twisted can cause a disc herniation. A disc can also herniate from a heavy impact on the spine, such as falling from a ladder and landing in a sitting position.
Herniation causes pain from a variety of sources. It can cause mechanical pain that comes from the parts of the spin e that move during activity, such as the discs and ligaments. Pain from inflammation occurs when the nucleus squeezes through the annulus. A disc herniation may also put pressure against a spinal nerve. Pressure on an irritated or damaged nerve can produce pain that radiates along the nerve. This is called neurogenic pain. This pressure on the nerve can also cause sensations of pins, needle s, and numbness where the nerve travels down the lower limbs. The muscles controlled by the nerves also weaken, and sensation in the skin where the nerve goes is impaired .
Cauda Equina Syndrome
Rarely, symptoms involve changes in bowel and bladder function. A large disc herniation that pushes straight back into the spinal canal can put pressure on the nerves that go to the bowels and bladder. The pressure may cause low back pain, pain running down the back of both legs, and numbness or tingling between the legs in the area you would contact if you were seated on a saddle. The pressure on the nerves can cause a loss of control in the bowels or bladder. This is an emergency. If the pressure isn't relieved, it can lead to permanent paralysis of the bowels and bladder. This condition is called cauda equina syndrome. Doctors recommend immediate surgery to remove pressure from the nerves.
Physical Therapy Care
- Aerobic exercise
- Manual therapy
- Traction if appropriate