Etiology — what causes it

Compression or inflammation of a lumbar nerve root. Causes include disc herniation (most common), foraminal narrowing from facet hypertrophy or osteophytes, spondylolisthesis, and less commonly synovial cysts or other space-occupying lesions. The pain is driven by mechanical compression combined with a chemical inflammatory cascade from disc nuclear material contacting the nerve.

Epidemiology — who gets it

Annual prevalence of clinically meaningful lumbar radiculopathy is roughly 3–5% of adults (Konstantinou & Dunn, Spine 2008). Highest incidence is between 45–64 years. L5 and S1 roots are involved in over 90% of cases.

Clinical signs

Dermatomal sensory disturbance, myotomal weakness, reflex changes (patellar for L4, hamstring/Achilles for S1), positive neural tension tests (SLR, slump test), and centralization with directional preference movement testing. Crossed SLR is highly specific for herniation-related root involvement.

Symptoms

Leg-dominant pain following a dermatomal pattern — sharp, shooting, electric, or burning. Pain often radiates below the knee. Numbness, tingling, or weakness in the involved distribution. Aggravation by sitting, forward bending, sneezing, and coughing.

Best evidence for chiropractic treatment

JOSPT clinical practice guidelines and the Cochrane reviews on radicular pain (Lewis et al., 2015) support conservative care as first-line for the majority of cases without progressive deficit. Graded exposure, neural mobilization, manual therapy in selected cases, and directional preference exercises have supporting evidence. The SPORT and Maine Lumbar Spine Study cohorts demonstrate that surgical and non-surgical outcomes converge by 1–2 years for most patients. Epidural steroid injection can provide short-term relief in select cases.

Subtypes

  • L4 radiculopathy. Anterior thigh and medial shin pain, quadriceps weakness, patellar reflex diminished.
  • L5 radiculopathy. Lateral leg and dorsum of foot pain, weak dorsiflexion and great toe extension, no reliable reflex change.
  • S1 radiculopathy. Posterior leg and lateral foot pain, weak plantarflexion, diminished Achilles reflex.

When to seek emergency care

Some symptoms need urgent medical attention — not a chiropractic visit. Call 911 or go to the nearest emergency department for: progressive limb weakness, loss of bowel or bladder control, saddle anesthesia (numbness in the groin/inner thighs), severe unrelenting pain unrelieved by position, signs of fracture after significant trauma, chest pain, stroke-like symptoms (face drooping, arm weakness, speech changes), or any rapidly worsening or unusual symptom.

Bottom line

Lumbar radiculopathy is usually treatable without surgery. Graded loading, neural mobilization, and time work for the majority — surgery is reserved for progressive deficit or persistent disabling pain.