Low Back Conditions
Back pain is a common ailment that affects 80-85% of people at some time in their lives. The severity can range from mere nuisance to major disability. There are a number of potential causes of back pain including poor lifting technique, overuse, and trauma.
In most cases, back pain can be dealt with effectively, if the right approach is taken. However, there are a wide variety of factors that can contribute to back pain. To successfully treat back pain, these factors must be identified and treated as they affect each individual.
What Are the Factors That Contribute to Most Back Pain?
What is currently known is that there are a number of anatomical structures that can cause low back pain:
Current evidence has found that the intervertebral disc is responsible for approximately 40% of low back pain. This can be due to a frank herniation or more commonly to small tears in the disc. These small tears can allow the gel that is held in the middle of the disc to seep out into these tears and irritate the nerve endings in the outer portion of the disc. This is known as disc derangement/disruption. If the gel leaks all the way out and press on one of the nerve roots that exit the spinal cord in front of the disc (herniation), pain in the leg can develop, along with neurological symptoms such as numbness, tingling and muscle weakness. This is commonly referred to as sciatica. Click here for visual tutorial.
The sacro-iliac is the cause of low back pain in approximately 15-25% of cases. The sacro-iliac joint is located at the base of the spine and is important for normal gait and the transferring of forces from the lower extremity to the upper extremity. It is commonly injured when in a flexed and rotated position (as in shovelling) and in women who are pregnant or who have just given birth. Pain emanating from this joint can be quite severe and can refer down the leg and into the groin region.
Facet (aka Spinal Joint)
The facet joints account for approximately 15-20% of low back pain. These joints can be injured with repetitve motions, especially lifting and rotating. This limits the facet’s resiliency and shock absorption capacity, thereby decreasing normal range of movement and thus becoming painful. In addition, because the joint contains receptors, the dysfunction can cause abnormal signals to be sent to the central nervous system that can cause the muscles related to that joint to either become tense or, conversely, to become limp.
Lumbar Spine Stenosis
Stenosis is greek for "to choke". Essentially, the spinal canal becomes narrowed which irritates the nerves and spinal cord. Narrowing can occur secondary to arthritis and bone spurs, a herniated disc or thickening of the ligaments in the spine. Most patients presenting with lumbar spine stenosis develop the symptoms later in life, however, some individuals are born with a narrowed canal. This is known as "congenital stenosis". Symptoms experienced with stenosis are termed "neurogenic claudication" and are low back, buttock and leg pain, numbness or discomfort which occurs with walking, standing and bending backwards. The symptoms typically resolve when bending forward or sitting down.
The hip has been implicated as a cause of low back pain. Several research studies have found that following a total hip replacement patients have complete resolution of their low back pain. The hip can cause referral of pain to the buttocks or down the leg often mimicking other forms of low back pain. Additionally, it can alter gait and stance leading to increased strain on the lumbar spine.
Muscle strain or overactivity can lead to focal areas of irritation. The involved muscle will react by either becoming shortened and tight or limp and inhibited. In either case, one thing that can happen in these muscles is the development of trigger points, areas of congestion within the muscle where there is increased irritation to the surrounding nerve endings. These trigger points can cause pain to refer to other areas and have been implicated in the development of low back pain and leg pain.
Stability of the lumbar spine is gained through the intimate relationship between the muscles, ligaments and spinal cord/brain. When we suffer one episode of low back pain, the signaling between these structures is inhibited and the muscles stop working. Patients often complain of low back pain towards the end of the day or after movement/exercise. This is due to the increased "sloppiness" of the joint as it is not held tight by the stabilizing structures. The anatomical structures that typically become injured in this scenario are the disc, facet joint/capsule, and ligaments.