Lower Back Pain

Causes, conditions, and how physical therapy helps

What causes lower back pain?

Your lower back (the lumbar spine) stacks five vertebrae, cushioned by discs and supported by muscles, ligaments, and joints. Pain usually appears when the demand placed on these tissues outpaces what they can comfortably handle. Causes generally sort into a few groups.

The most common type is non-specific mechanical back pain — a strain of the muscles or ligaments after lifting, twisting, a sudden movement, or simply too much sitting. It can be intense but is rarely dangerous, and it typically settles with time and gentle activity.

Disc, joint, and nerve causes

Sometimes a disc bulges or herniates and irritates a nearby nerve, producing pain that travels into the buttock or leg (sciatica). The small facet joints at the back of the spine or the SI joint in the pelvis can also become painful, as can age-related changes like degenerative disc disease or narrowing of the spinal canal (spinal stenosis).

Long hours sitting, repetitive bending, deconditioning, and a sudden spike in activity all raise the odds of a flare. Importantly, "wear and tear" seen on scans is common in pain-free people too — so imaging findings don't always explain symptoms.

Common lower back conditions

Lumbar strain, herniated disc, sciatica, spinal stenosis, degenerative disc disease, facet joint syndrome, SI joint dysfunction, and spondylolisthesis are the conditions we see most. Each has its own detailed guide.

Common lower back symptoms

Pain when standing up, pain that radiates down the leg, morning stiffness, being unable to straighten up after lifting, and one-sided pain are some of the most common patterns. How your back behaves often hints at the cause — which is why a focused exam usually beats rushing to an MRI.

How physical therapy treats lower back pain

A physical therapist looks at how your spine, hips, and core move together, identifies which positions and tissues drive your pain, and builds a graded plan. Treatment commonly blends targeted exercise, movement and posture retraining, hands-on techniques, and education to reduce fear of movement. For most back pain, active exercise-based PT is a first-line, guideline-recommended treatment.

Red flags — when to seek urgent care

Get emergency care for loss of bladder or bowel control, numbness around the groin or inner thighs, or sudden severe weakness in both legs (possible cauda equina syndrome). Also seek prompt evaluation for back pain with unexplained weight loss, fever, a history of cancer, significant trauma, or a throbbing sensation in the abdomen.

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