So what is a Bulging Disc or Herniated Disc?
Except in the cases of paraplegia or quadriplegia, it is impossible for a person to 'put their back out' as the vertebral bodies of the spine are held together by an inter- vertebral disc. This disc acts as a cushion and by deforming in all directions allows the spine to bend in all directions.
In the middle of this disc is a paste/gel like substance called the nucleus pulposus. This substance acts as a fulcrum for movement and as the disc deforms, it evenly distributes the forces throughout the disc. Enveloping this nucleus is a fibrous casing called the annulus fibrosis.
Research has shown that there are only two degrees of motion at each level between the 1st and 5th lumbar vertebrae and five degrees between the 5th lumbar and 1st sacral vertebrae. (Sahrmann 1997). Movement beyond this has been shown to result in tearing of the disc. Consequently, repeated minor trauma such as with bent, rotated postures may cause circumferential fissures in the annulus. As only the outer layers of the annulus receive a nerve supply, for a disc to become painful, a lesion must involve the outer third of the annulus. These defects then provide a potential pathway for the nucleus to seep into, causing the disc to bulge, split, tear and seep out.
By a person's 30's, the nucleus pulposus tends to dry out and consequently true herniations tend to occur in people in their 20's (Bogduk and Twomey 1991). However, disc bulging in the older person can occur due to degeneration of the nucleus and failure of the annulus. Again this pathology is usually associated with repeated poor postures and movement patterns and can lead to spinal canal stenosis, an important source of low back pain.
The most common age for disc prolapses to occur is in the 25 to 45 year old age group. It more common in males at a ratio of 3:2 with the most common site for prolapse being between L5/S1 (46.4%) and the L4/5 disc being the most common transitional area (40.4%).
Other influencing factors leading to disc prolapse include;
1. Poor posture and movement patterns, leading to increased joint strain, wear and tear and eventually fatigue.
2. Poor equipment and work station setup.
3. Congenital ill development - e.g. excessive spinal curvature
5. Joint malalignment
Signs and Symptoms
The size, severity and direction of the disc injury as well as the associated structures affected, will determine the presenting signs and symptoms. Herniated discs may occur suddenly or gradually, as a result of a single major traumatic event or as the result of some minor event. Stories such as "I bent over" or "I reached forward" are not uncommon and are often associated with a dull ache or knife like pain either in the midline or off to one side.
The lower back pain may initially be intermittent, but is worsened by sitting, bending and coughing/sneezing and often disturbs sleep. Generally, it is confined to the lower back region, but later may radiate into both or more often one leg.
The distance of radiation is more indicative of the severity of injury rather than the structures involved and whilst irritation of the sciatic nerve cause pain, direct pressure on the sciatica nerve results in numbness, tingling, weakness and loss of reflexes.
Whilst x-rays do not show soft tissue damage, they may indirectly show the effects of a prolapsed disc, by the presence of deformity, joint mal-alignment and flattening of the disc. Myelography, CT or MRI scans may also reveal a disc bulge or herniation.
Whilst pain associated with facet joint strains tends to be specific and isolated, disc prolapses pain tends to be more vague and diffuse. Bending which tends to aggravate disc prolapses tends to relieve pain associated with a spinal canal stenosis or spondylolythesis. In contrast, arthritic movements tend to be limited in all directions.
Treatment of acute disc injuries will vary with the severity and extent of the person's symptoms. A bulging disc with or without sciatic nerve involvement, treatment may include short term bed rest, electrotherapy, traction, graduated mobilization as well as a prescription of extension exercises and sometimes the use of taping or a back brace. These may be used in conjunction with anti-inflammatory medication to provide further relief.
It is important to avoid any movements or positions which aggravate your pain. McKenzie exercises may also be given along with 'hands on' and dry needling techniques to assist with pain reduction or to restore the mobility and promote an environment of healing.
Tissue healing may be further promoted through the use of electrotherapy, massage, joint and sciatic nerve mobilisation as well as back pain exercises to give sciatica pain relief. Spinal mobilisation and manipulation be combined with precise stretching and trunk stabilisation exercises to normalise spinal mobility and core control.
As improvement continues, stabilisation is progressed from slow, controlled contractions to faster and more automated activities to more approximate lifestyle conditions. Both strengthening and aerobic conditioning may then be built on top of this stabilisation base to give maximum protection against re-injury as well as to facilitate a higher level of physical performance.
Finally, lifestyle components such as work / home environments, equipment, as well as habitual movements and postures must also be addressed if optimal function is to be achieved and injury recurrence is to be minimised.
I hope that this helps.
- Rebates are available through your private insurance extras cover;
- For complex or chronic conditions, you may qualify for the EPC (Enhanced Primary Care Program) allowing you to receive 5 allied health services each calendar year with a referral from your doctor. For more information, please call Bodywise Health on 1 300 BODYWISE (263 994).