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For further information, see CMDT Part 41-03: Spine Problems

Key Features

Essentials of Diagnosis

  • Nerve root impingement is suspected when pain is leg-dominant rather than back-dominant

  • Alarming symptoms include unexplained weight loss, failure to improve with treatment, severe pain for > 6 weeks, and night or rest pain

  • Cauda equina syndrome is an emergency; often presents with bowel or bladder symptoms (or both)

General Considerations

  • Low back pain is the condition associated with the highest years lived with disability

  • Cause is often multifactorial, making the exact cause difficult to diagnose

  • There are usually degenerative changes in the lumbar spine involving the disks, facet joints, and vertebral endplates (Modic changes)

  • Aggravating factors of flexion and prolonged sitting suggests anterior spine disk problems

  • Aggravating factors of extension suggests facet joint, stenosis, or sacroiliac joint problems

  • Alarming symptoms for back pain caused by cancer include

    • Unexplained weight loss

    • Failure to improve with treatment

    • Pain for > 6 weeks

    • Pain at night or rest

    • History of cancer and age > 50 years

  • Alarming symptoms for infection include

    • Fever

    • Rest pain

    • Recent infection (urinary tract infection, cellulitis, pneumonia)

    • History of immunocompromise or injection drug use

  • Cauda equina syndrome is suggested by

    • Urinary retention or incontinence

    • Saddle anesthesia

    • Decreased anal sphincter tone or fecal incontinence

    • Bilateral lower extremity weakness

    • Progressive neurologic deficits

  • Risk factors for back pain due to vertebral fracture include

    • Use of corticosteroids

    • Age > 70 years

    • History of osteoporosis, severe trauma, and presence of a contusion or abrasion


  • Remains the number one cause of disability globally

  • Is the second most common cause for primary care visits

  • Annual prevalence is 15–45%

  • Annual health care spending for low back and neck pain is estimated to be $87.6 billion

Clinical Findings

  • The majority of patients with persistent low back pain have co-occurring areas of pain, especially

    • Axial pain (18–58%)

    • Extremity pain (6–50%)

    • Multi-site musculoskeletal pain (10–89%)

  • With the patient sitting,

    • Motor strength, reflexes, and sensation can be tested (Table 41–2)

    • Major muscles in the lower extremities are assessed for weakness by eliciting a resisted isometric contraction for about 5 seconds

    • Comparing the strength bilaterally to detect subtle muscle weakness is important

    • Similarly, sensory testing to light touch can be checked in specific dermatomes for corresponding nerve root function

    • Knee, ankle, and Babinski reflexes can be checked

  • In the supine position,

    • The hip should be evaluated for range of motion, particularly internal rotation

    • The straight leg raise test puts traction and compression forces on the lower lumbar nerve roots (eTable 41–1)

  • In the prone position,

    • The clinician can carefully palpate each vertebral level of the spine and sacroiliac joints for tenderness

    • A rectal examination is required if the cauda equina syndrome is suspected

Table 41–2.Neurologic testing of lumbosacral nerve ...

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