|MEDICAL ANIMATION TRANSCRIPT: |
Your spine is composed of individual bones called vertebrae. Your vertebrae form a protective tunnel called the spinal canal, which surrounds the spinal cord as it travels down the length of your spine. On each side of the spinal cord, spinal nerves exit the spinal canal through small bony channels called neural foramina. Your lumbar spine is the lower third of your spinal column. Between each vertebra, a flexible pad called an intervertebral disc acts as a shock absorber for your spine. Lumbar disc pressure can increase by more than 50% when you change from a standing position to bending over, or by more than 80% between a standing position and sitting with no back support. The intervertebral disc's tough, outer ring is known as the annulus fibrosis. The soft gel-like center is called the nucleus pulposus. During a traumatic injury, your spine may lurch forward forcefully, causing your vertebrae to compress the front of one or more of your lumbar discs beyond normal limits. As a result the back of your disc protrudes backward, causing small tears and thinning of your annulus fibrosis. Over time, your damaged annulus fibrosis may weaken and change shape, and your nucleus pulposus may dry out, and lose flexibility. As your intervertebral disc deteriorates, your nucleus pulposus may push your annulus outward, resulting in a disc bulge. Depending on its location, the bulge may push on, or impinge, one of your spinal nerves, your spinal cord, or your cuada equina, which is a collection of spinal nerve roots at the end of your spinal cord. Central disc bulges protrude backward into your spinal canal. Lateral disc bulges extend into your neural foramen. Severe lumbar disc injuries can tear your annulus fibrosis. Pressure from your vertebrae may push your nucleus pulposus out of your torn annulus, causing a disc herniation. A herniated lumbar disc can and impinge upon your cuada equina, or spinal nerves, and cause symptoms such as pain, numbness, or weakness in one or both of your legs. Treatments for lumbar disc injuries may include rest, anti-inflammatory medication, muscle relaxants, ice or heat applied to the injured area, physical therapy, an epidural steroid injection given directly into the area of nerve irritation, and in more severe cases, surgery.