Understanding Lumbago and Sciatica
Lumbago is simply another term for low back pain, while sciatica is pain radiating down the leg below the knee in the distribution of the sciatic nerve, suggesting nerve root compromise. These are distinct clinical entities that require different diagnostic and therapeutic approaches 1.
Lumbago (Low Back Pain)
Lumbago refers to pain occurring primarily in the lower back region, which may extend to the buttocks and thighs but does not follow a specific nerve root distribution 2. The term has historical origins from medieval times, when it was believed that diseases were transmitted by evil spirits using bows and arrows—hence the German term "Hexenschuss" (witch's shot) 3.
Key Characteristics:
- Pain localized to the lumbar spine, buttock, and thigh regions
- Often has sudden onset triggered by everyday movements or strain
- May spread to the sacroiliac joint region and outer buttock
- Does not radiate below the knee in a nerve root pattern
Pathophysiology:
The underlying mechanisms can include:
- Muscular strains and spasm
- Discogenic pain from annular tears in the disc
- Facet joint dysfunction (possibly from meniscoid entrapment stretching the joint capsule)
- Ligamentous strain 3, 2
Most cases represent "nonspecific low back pain"—pain without signs of serious underlying conditions like cancer, infection, cauda equina syndrome, spinal stenosis, or radiculopathy 1.
Sciatica
Sciatica is pain radiating down the leg below the knee in the distribution of the sciatic nerve, suggesting nerve root compromise due to mechanical pressure or inflammation 1. This is the most common symptom of lumbar radiculopathy.
Key Characteristics:
- Pain follows a specific nerve root distribution down the leg
- Must extend below the knee to be considered true sciatica
- More than 90% of symptomatic lumbar disc herniations occur at L4/L5 and L5/S1 levels 1
- May be accompanied by sensory impairment, weakness, or diminished reflexes in the affected nerve root distribution
Clinical Distinction:
The critical difference is anatomical distribution: lumbago stays in the back/buttock/thigh region, while sciatica extends below the knee in a dermatomal pattern 1. A typical history for sciatica (back and leg pain in a typical lumbar nerve root distribution) has fairly high sensitivity but uncertain specificity for herniated disc 1.
Associated Findings:
When evaluating sciatica, assess specific nerve root levels:
- L4 nerve root: knee strength and reflexes
- L5 nerve root: great toe and foot dorsiflexion strength
- S1 nerve root: foot plantarflexion and ankle reflexes 1
Clinical Pitfalls
Do not confuse leg pain that doesn't extend below the knee with true sciatica—this is referred pain from the back, not radiculopathy 1. The distinction matters because sciatica may warrant different imaging and treatment considerations, including potential candidacy for epidural steroid injections or surgery if symptoms persist despite conservative management 1.
The natural history of lumbar disc herniation with radiculopathy shows improvement within the first 4 weeks with noninvasive management in most patients 1, making the distinction between lumbago and sciatica important for setting appropriate patient expectations and treatment plans.