Disc bulges result from the herniation of the intervertebral discs of the spine, causing them to protrude beyond their usual boundaries. Contrary to popular opinion, your disc has not ‘slipped’ or moved from its usual location. Discs are the ‘shock absorbers’ that sit between each vertebrae in your spine. When you bend your spine to move, they change shape to allow your spine to move. Also, when you carry something heavy, they compress to take the load. However, repetitive loading or compression can also weaken their structure and cause injury over time.
A bulging disc occurs from ongoing overloading to the disc, which causes it to protrude outside its usual margins. However, unlike a disc herniation which is more severe, the nucleus (inner portion) of the disc remains within the annulus fibrosus (outer portion).A bulging disc is a condition in which the nucleus (inner portion) of a spinal disc remains contained within the annulus fibrosus (outer portion), unlike a herniated disc in which the nucleus leaks out of the disc.
Despite bulges resulting from degenerative and age related processes, they are still prevalent in the younger and middle aged population (1). Below is a table (3) showing the amount of pressure placed upon the discs in your spine, as created by different postures and positions. As you can see, even sitting increases disc pressure, and sitting upright for prolonged periods places a lot more strain on your discs compared to lying down or sitting reclined.
A disc bulge does NOT have to become a permanent injury, or degenerate further over time. With the right treatment, Physiotherapy can be equally effective in the long term as surgery (2) in diminishing your symptoms, reduce the risk of future injury. You are likely to be able to return to the activities that you enjoy with confidence.
Your Physiotherapist will guide you through a series of exercises that help to strengthen key muscles that provide support to your pelvis and spine. For lower back disc injury, these include the Transversus Abdominis (often known as ‘your core’), and your gluteals (buttock muscles). These muscles help to provide the ‘framework’ to hold your pelvis and back stable when you are sitting, standing, running, or participating in any sport or activity. Think of them like the frame of a house, that provide rigidity, and reduce the likelihood of damage from external forces. This will assist in reducing the loading through your spinal discs, hence protecting them from further damage in the future.
The Movement Mill
(1) Schoenfeld, A. J., & Weiner, B. K. (2010). Treatment of lumbar disc herniation: evidence-based practice. International journal of general medicine, 3, 209.
(2) Wilke, H. J., Neef, P., Caimi, M., Hoogland, T., & Claes, L. E. (1999). New in vivo measurements of pressures in the intervertebral disc in daily life. Spine, 24(8), 755-762.
(3) Humphreys, S. C., & Eck, J. C. (1999). Clinical evaluation and treatment options for herniated lumbar disc. American family physician, 59(3), 575.