The Science of Low Back Pain
Mechanical low back pain typically involves dysfunction of the intervertebral discs, facet joints, sacroiliac joints, or surrounding musculature. The disc starts to lose its hydration and load distribution capabilities, which leads to increased stress on surrounding structures. The deep stabilizing muscles like multifidus and transverse abdominis often show delayed activation patterns, compromising segmental stability. Over time, this can lead to movement pattern changes that perpetuate the problem. When pain persists beyond 3 months, changes in the nervous system can amplify pain perception, making previously non-painful movements uncomfortable. When disc dysfunction progresses significantly, it may lead to disc herniation with potential nerve root compression (sciatica). Similarly, when facet joints become primary pain generators, this can develop into facet joint syndrome, while sacroiliac joint dysfunction may become a distinct condition requiring specific treatment approaches.
Contributing Factors
Poor posture and prolonged sitting create significant loads on your spine, particularly when you slouch or crane your head forward. Your core muscles - the deep abdominals and back extensors that act like an internal corset - often become weakened from inactivity, reducing the support they provide to your spine.
Heavy lifting with poor technique multiplies the forces through your discs. When you bend at the waist rather than squatting, you can increase disc pressure by up to 300%. Repetitive bending and twisting movements, especially under load, create the perfect storm for tissue overload.
Modern lifestyle factors play a huge role: prolonged sitting increases disc pressure by 40% compared to standing, and forward head posture from screen time changes how forces distribute through your entire spine. Even factors like tight hip flexors from sitting can alter your lumbar curve, forcing your back muscles to work overtime to maintain upright posture.