Cost of low back pain (LBP) in the United States is estimated at $177 billion annually. Back symptoms are the most common cause of disability in those <45 years; LBP is the second most common cause of visiting a physician in the United States; >80% of people will have LBP at some point in their lives.
Local pain: caused by injury to pain-sensitive structures that compress or irritate sensory nerve endings; pain located near the affected part of the back.
Pain referred to the back: abdominal or pelvic origin; back pain unaffected by posture.
Pain of spine origin: restricted to the back or referred to lower limbs or buttock. Diseases of upper lumbar spine refer pain to upper lumbar region, groin, or anterior thighs. Diseases of lower lumbar spine refer pain to buttocks, posterior thighs, calves, or feet.
Radicular back pain: radiates from spine to leg in specific nerve root territory. Coughing, sneezing, lifting heavy objects, or straining may elicit pain.
Pain associated with muscle spasm: diverse causes; accompanied by tense paraspinal muscles, dull or aching pain in the paraspinal region, and abnormal posture.
Include abdomen and rectum to search for visceral sources of pain. Inspection may reveal scoliosis or muscle spasm. Palpation may elicit pain over a diseased spine segment. Pain from hip may be confused with spine pain; manual internal/external rotation of leg at hip (with knee and hip in flexion) reproduces the hip pain.
Straight leg raising (SLR) sign—elicited by passive flexion of leg at the hip with pt in supine position; maneuver stretches L5/S1 nerve roots and sciatic nerve passing posterior to the hip; SLR sign is positive if maneuver reproduces the pain. Crossed SLR sign—positive when SLR on one leg reproduces symptoms in opposite leg or buttocks; nerve/nerve root lesion is on the painful side. Reverse SLR sign—passive extension of leg backward with pt standing; maneuver stretches L2–L4 nerve roots, lumbosacral plexus, and femoral nerve passing anterior to the hip.
Neurologic examination—search for focal atrophy, weakness, reflex loss, diminished sensation in a dermatomal distribution. Findings with radiculopathy are summarized in Table 50-1.
TABLE 50-1Lumbosacral Radiculopathy: Neurologic Features ||Download (.pdf) TABLE 50-1Lumbosacral Radiculopathy: Neurologic Features
|LUMBOSACRAL NERVE ROOTS ||EXAMINATION FINDINGS ||PAIN DISTRIBUTION |
|REFLEX ||SENSORY ||MOTOR |
|L2a ||— ||Upper anterior thigh ||Psoas (hip flexors) ||Anterior thigh |
|L3a ||— ||Lower anterior thigh ||Psoas (hip flexors) ||Anterior thigh, knee |
|Anterior knee ||Quadriceps (knee extensors) |
|Thigh adductors |
|L4a ||Quadriceps (knee) ||Medial calf ||Quadriceps (knee extensors)b ||Knee, medial calf |
|Thigh adductors ||Anterolateral thigh |
|L5c ||— ||Dorsal surface—foot ||Peronei (foot evertors)b ||Lateral calf, dorsal foot, posterolateral thigh, buttocks |
|Lateral calf ||Tibialis anterior (foot dorsiflexors) |
|Gluteus medius (hip abductors) |
|Toe dorsiflexors |
|S1c ||Gastrocnemius/soleus (ankle)...|