Lower back pain is one of the most common health complaints in Australia, affecting around four million people at any given time. For most, it’s something that comes and goes — a few days of stiffness after a long week, or a sharp episode triggered by an awkward movement. For others, it becomes a persistent presence that affects work, sleep, and quality of life. Understanding what actually causes lower back pain is the foundation for managing it effectively.
The Anatomy Behind the Pain
The lumbar spine — the five vertebrae that make up the lower back — is a remarkable structure. It bears the majority of the body’s weight, provides the flexibility needed for bending and twisting, and protects the spinal cord and the nerve roots that supply the legs. Supporting all of this are the intervertebral discs, which act as shock absorbers between the vertebrae, a complex arrangement of ligaments, and the muscles of the lower back, abdomen, and hips that collectively hold everything together.
When any of these structures is under excessive stress, injured, or not functioning well, pain is the result. The challenge is that lower back pain can arise from multiple different sources — which is why two people with “bad backs” may have completely different underlying causes and respond to very different treatments.
Muscular and Soft Tissue Causes
The most common cause of acute lower back pain is muscular strain — overstretching or tearing muscle fibres or the ligaments and tendons that support the lumbar spine. This typically happens during sudden or awkward movements: lifting something heavy with a bent back, twisting while carrying a load, or simply bending forward at an unlucky angle.
Muscular strains can range from mild — a few days of stiffness that resolves with rest — to significant tears that cause severe, limiting pain. Even when the initial injury resolves, the surrounding muscles often remain in protective spasm, which can prolong pain and lead to altered movement patterns that set the stage for future problems.
Disc Problems
The intervertebral discs are one of the most frequently implicated structures in lower back pain. Discs can bulge, herniate, or degenerate — each presenting somewhat differently but all capable of producing significant pain. A bulging or herniated disc occurs when the soft inner material of the disc pushes outward, potentially pressing on nearby nerve roots. When the nerve root that forms part of the sciatic nerve is compressed, the result is the characteristic leg pain and neurological symptoms of sciatica.
Disc degeneration is a natural process of ageing, but it doesn’t inevitably cause pain. Many people have significant disc changes on imaging with no symptoms at all. When degeneration is symptomatic, it typically presents as a deep, aching lower back pain that is worse with prolonged sitting or standing and relieved by movement.
Joint and Facet Problems
The facet joints connect adjacent vertebrae and play a critical role in guiding spinal movement. Like any joint in the body, they can become inflamed, restricted, or arthritic. Facet joint pain typically presents as a localised ache in the lower back that worsens with extension and rotation. The sacroiliac joints — where the spine meets the pelvis — are another common source of lower back and buttock pain that is frequently missed or misattributed.
Postural and Lifestyle Factors
Many cases of lower back pain don’t have a single traumatic cause — they develop gradually through accumulated postural stress, sedentary behaviour, and the demands of daily work. People who spend long hours sitting at desks, driving, or working in sustained bent postures are placing chronic load on the structures of the lumbar spine in ways that eventually become symptomatic.
Deconditioning — the loss of the strength and flexibility needed to support healthy spinal function — is an underappreciated contributor. A lifestyle that involves limited physical activity gradually reduces the capacity of the muscles, ligaments, and joints to handle everyday loads, making the spine more vulnerable to injury and strain.
When to Be Concerned
Most lower back pain is mechanical and not dangerous. However, certain features warrant prompt medical assessment: lower back pain accompanied by bowel or bladder dysfunction, pain that is constant and unrelenting regardless of position, significant weakness in the legs, or pain that wakes you from sleep. Pain following significant trauma, or back pain in someone with a history of cancer or osteoporosis, also requires urgent attention.
For pain that persists beyond a few weeks, is recurring, or is significantly limiting your function, a proper assessment by a qualified practitioner is important. Identifying the specific cause of your pain allows treatment to be targeted and appropriate — and significantly improves outcomes compared to a generic approach.
Getting the Right Assessment and Treatment
Chiropractic care is one of the most evidence-supported approaches to lower back pain management. A thorough chiropractic assessment takes into account not just the physical findings but your history, lifestyle, and goals — providing a clear picture of what’s driving your symptoms and a tailored plan to address them.
Our clinics in Moorebank, Revesby, and Seven Hills provide comprehensive assessment and treatment for lower back pain. If back pain is affecting your daily life, our team is ready to help. Find your nearest clinic and book online today.
