Health Information > The Spine > The Intervertebral Discs and Spinal Joints
The Intervertebral Discs and Spinal Joints
The intervertebral discs are a prevalent source of lower back pain as they are one of the most frequently injured spinal structures. The discs connect adjacent spinal vertebrae together and provide a degree of shock absorption in the torso.
Disc Structure
 The structure of the spinal disc resembles a jelly filled doughnut. The inner aspect of the disc contains a gel-like substance called the nucleus pulposus. Surrounding the nucleus are tough fibrocartilagenous fibers called the annulus fibrosis. These annular fibers contain the inner nuclear material similar to a basketball skin containing the air within.
Back to top
Causes of Disc Injury
Disc injury occurs when the annular fibers of the disc are torn. Because the inner regions of the annulus lack "pain" innervation, injuries contained to the inner annulus occur without one's knowledge.
Common causes of annular disc tears include:
- uncorrected spinal misalignments
- prolonged sitting
- poor postural habits
- poor lifting habits
- improper workstation setup and ergonomics
- improper lifting techniques
- extended periods of vibratory forces (truck and auto drivers, jack hammer operators, etc.)
- Other factors have been shown to increase the susceptibility of disc injury:
- inadequate diet and nutrition
- smoking
- obesity
- lack of physical activity
Types of Disc Injury
 There are 3 main types of disc injuries. The first disc injury consists of annular fiber tears which do not extend to the outer aspects of the disc. Thus, the inner nuclear material is prevented from completely escaping the disc.
The second type of disc injury, commonly referred to as a disc herniation, consists of annular tears which run from the innermost aspects of the annulus (where the nucleus is) to the outermost aspects of the annulus. In this type of injury, the pressurized nuclear material can squeeze through the tears in the annulus and escape to the outside of the disc. When this occurs, the nuclear material may come in contact with nearby spinal nerves and even the spinal cord.
In the third type of disc injury, referred to as a disc bulge, the inner nucleus loses hydration; common in those with prolonged spinal stress and the elderly. This results in "bulging" of the disc much like a tire "bulges" when it contains inadequate amounts of air. Similar to the previous injury, the nearby spinal nerves and spinal cord may become impinged from the bulging disc.
Back to top
Symptoms of Disc Injury
The symptoms of disc injury depend upon the location of the disc tears and whether or not the spinal nerves or spinal cord are affected.
When tearing of the annulus occurs within it's inner portion only, generally pain is not experienced. As previously stated, this is because the inner regions of the annulus lack pain receptors. When tearing of the annulus occurs in the outer annular fibers, mild to excruciating pain is felt in a generalized manner. If a lumbar disc is affected, for instance, diffuse low back pain with associated paraspinal muscle spasm is typical.
When numerous partial tears coalesce to form tears which run clear through the thickness of the annulus, the gel-like nucleus is able to escape the disc. If a spinal nerve or the spinal cord is contacted the individual may experience symptoms of pain, numbness, tingling and/or weakness within either or both lower extremities. In rare cases patients may lose the ability to control bowel and bladder functions. If this occurs, immediate medical intervention is required as the condition can become permanent.
Back to top
Treatment of Disc Injuries
Disc injuries respond favorably to chiropractic care. This is because chiropractic treatments focus on the dysfunctional spinal segments and not just the symptoms of the disc injury. Pain killers, anti-inflammatory and muscle relaxants do nothing to treat the cause of disc injuries and have been shown to induce further injury.
Chiropractic treatments provide fast, effective, safe and long lasting relief from disc injuries. This is because the chiropractor's approach focuses on restoring spinal alignment, spinal function and overall spinal health, which are the primary factors responsible for the development of disc injuries.
Chiropractic doctors are experts in maintaining proper spinal alignment and function, both of which play a critical role in minimizing spinal stresses - the stresses that are responsible for injury and accelerated degenerative processes in spinal discs.
Back to top
The Facet Joints
Many spinal experts actually consider the facet joints to be the most common source of spinal pain and discomfort.
Each vertebrae possesses 2 sets of facet joints - one set for articulating to the vertebrae above and one set for the articulation to the vertebrae below. In association with the spinal discs, the facet joints allow for movement between the individual vertebrae of the spine.
The facet joints are under a constant load from the weight of the body and are involved in guiding general motion and preventing extreme motions in the trunk. Repetitive or excessive trunkal motions, especially in rotation or extension, can irritate and injury facet joints or their encasing fibers. Also, abnormal spinal biomechanics - similar to a wheel out of alignment - and bad postural habits can significantly increase spinal stresses and thus greatly accelerate the wear and tear on the facet joints.
Chiropractic doctors identify and treat facet joint abnormalities and stresses along with other spinal abnormalities to keep backs and bodies healthy and free from pain.
Back to top
The Spinal Muscles and Ligaments
Spinal muscles and ligaments attach to the vertebrae, ribs, and pelvis to permit and manage various trunkal motions including - forward and backward bending, side to side bending, and rotation or twisting. When a spinal motion occurs in excess or a muscle is worked beyond its capacity whether suddenly or gradually over time, injury occurs.
Sprains and strains of the muscles or ligaments upset the normal balance of the spine. Spinal structural alignment and biomechanics can be significantly altered. These alterations make the spinal components (discs, facets, vertebrae, nerves, etc.) increasingly prone to injury and degenerative processes.
Doctors of chiropractic rehabilitate spinal muscles and ligaments to prevent spinal imbalances. Proper spinal alignment and spinal biomechanics can only occur with healthy muscles and ligaments.
Back to top
The Sacroiliac Joint
The sacroiliac joint is another spinal component which undergoes very large spinal stresses. Either the ligaments supporting the joints or the actual joint surfaces can be a source of low back pain and even refer pain into the lower extremities.
There are 2 sacroiliac joints formed by the articulation between the sacrum and 2 ilium bones of the pelvis. Like the other spinal structures, the sacroiliac joints can be injured through acute trauma, repetitive movements, and poor posture, to name a few.
Symptoms include lower back pain with the pain occasionally extending down the back of the leg. Additionally, hip pain, knee pain as well as foot and ankle pain may be present due to increased stress in those joints as a result of an alteration of pelvic biomechanics.
Sacroiliac problems are extremely common in pregnancy. During this time, the pelvis experiences many physical stresses due to weight and hormonal factors. Chiropractic care throughout pregnancy is essential in minimizing pelvic and spinal stresses. A study published in the journal Obstetrics and Gynecology found 7 out of 10 women obtained sacroiliac pain relief from chiropractic spinal manipulation.
A simple but surprisingly effective way to identify pelvic misalignments is to check for uneven leg lengths. Lay on a flat surface then have friend or family member compare the bottom of both heels for symmetrical length. If there is any discrepancy between leg lengths you may have a pelvic or lower back misalignment.
Chiropractic adjustments are frequently applied to the ilium and sacrum to successfully normalize and restore sacroiliac joint position and biomechanics.
Back to top
The Nervous System
The nervous system is the master controller of all cells, tissues and organs. Nerves control the heart, lungs, immune system, endocrine system, as well as our thoughts and other cognitive processes. Effectively, the nervous system is in charge of directing and overlooking all bodily functions - keeping us alive and healthy, fighting off diseases and infections, and healing us after we have sustained injury.
Many people are surprised to learn that the spine plays a key role in protecting the nervous system. In fact, the main function of the spinal column (in addition to providing movement for the torso) is to encase and protect the spinal cord and nerve roots. Without this protection it's unlikely that we would survive a relatively small slip and fall injury.
As the spinal cord descends from the brain, spinal nerve roots peel away from the spinal cord at each vertebral level and exit through openings made by adjacent vertebrae. These small protective pathways are called intervertebral foramen or IVF's and permit safe exit of the delicate nerve roots to the rest of the body. Because of the location of the IVF, herniated or bulging spinal discs, subluxated vertebrae, arthritic bony growths, and inflammatory biochemicals from nearby injured tissues commonly irritate or impinge upon the spinal nerve roots.
When there is irritation and interference to a nerve, messages or impulses traveling along that nerve can get scrambled. Some signals become only slightly altered while others may completely fail to reach their destination. As this process continues, those cells, tissues and organs which depend on the affected nerves for communication become less effective in performing their many important tasks and become less able to maintain their optimal health. Ultimately, the affected tissues can deteriorate, degenerate and become nonfunctional and diseased.
This model of disease helps explain why so many patients under chiropractic care have noted dramatic improvements with many seemingly "non-spinal" conditions such as dizziness, ulcers, ear infections, asthma, menstrual pains and low energy levels, to name a few. While its not prudent to claim chiropractic treatments may eliminate or treat such conditions, many patients have experienced phenomenal relief.
Chiropractors are the only doctors trained to detect and treat vertebral misalignments and fixations as well as many other common spinal abnormalities which cause nerve irritation and interference. Correcting nerve irritation and interference allows the body to function the way it was meant to. Back to top |
