In an adult patient (20‑70 years) presenting with low‑back pain, which orthopedic bedside examinations should be performed to assess nerve‑root irritation, facet‑joint pathology, sacroiliac involvement, and muscular or ligamentous strain?

Orthopedic Bedside Examinations for Lumbar Spine Assessment

For adult patients with low back pain, perform the straight-leg raise test for nerve root irritation, at least three sacroiliac provocation tests for SI joint involvement, and assess for centralization with repeated movements to identify discogenic pain. 1, 2, 3

Nerve Root Irritation Testing

Straight-Leg Raise (SLR) Test

• The straight-leg raise test is the primary examination for detecting lumbar disc herniation with radiculopathy, demonstrating 91% sensitivity but only 26% specificity. 1
• Perform by raising the affected leg while the patient is supine; reproduction of radicular pain suggests nerve root compression, typically from disc herniation at L4/L5 or L5/S1 (which account for >90% of symptomatic herniations). 1

Crossed Straight-Leg Raise Test

• The crossed straight-leg raise (raising the unaffected leg to reproduce pain in the affected leg) is more specific at 88% but less sensitive at 29%. 1
• A positive crossed SLR more strongly suggests true nerve root compression when present. 1

Neurological Examination

• Assess knee strength and reflexes (L4 nerve root), great toe and foot dorsiflexion strength (L5 nerve root), foot plantarflexion and ankle reflexes (S1 nerve root), and map the distribution of sensory symptoms. 1
• Document motor strength grading (e.g., 4/5 weakness in tibialis anterior suggests L4/L5 radiculopathy). 1

Discogenic Pain Assessment

Centralization Phenomenon

• Test for centralization by having the patient perform repeated lumbar extension movements; pain that moves from the leg toward the midline suggests discogenic origin with an informative positive likelihood ratio of 3.06. 3
• This test helps differentiate disc-related pain from other sources and can guide conservative management strategies. 3

Sacroiliac Joint Testing

Provocation Test Battery

• Perform at least three SI joint provocation tests; positive responses to three or more tests suggest SI joint dysfunction as the pain source. 2, 3
• The combination of multiple positive provocation tests yields an informative positive likelihood ratio of 2.41 and negative likelihood ratio of 0.35. 3

Clinical History Component

• Absence of midline low back pain (pain lateral to midline) increases the likelihood of SI joint involvement with a positive likelihood ratio of 2.44. 3
• SI joint pain typically presents as unilateral lower back or buttock pain that may radiate to the posterior thigh. 2

Facet Joint Assessment

Clinical Examination Limitations

• No single physical examination maneuver reliably identifies facet joint pain; diagnosis requires correlation of clinical presentation with imaging findings or diagnostic blocks. 4, 3
• Facet-mediated pain typically presents as axial low back pain without significant radicular symptoms. 5, 4

Spinal Stenosis Evaluation

Pseudoclaudication Assessment

• Distinguish spinal stenosis from disc herniation by assessing for pseudoclaudication: leg pain that worsens with walking or standing and improves with sitting or forward flexion. 1
• Spinal stenosis is more common in patients over 65 years and presents differently than acute radiculopathy from disc herniation. 1

Red Flag Assessment

Immediate Evaluation Required

• Assess for urinary retention, fecal incontinence, and saddle anesthesia to rule out cauda equina syndrome, which requires urgent MRI and surgical evaluation. 1, 6
• Check for progressive motor weakness at multiple levels, which warrants immediate imaging and specialist referral. 1

Cancer and Infection Screening

• Evaluate for history of cancer, unexplained weight loss, age over 50 years, fever, IV drug use, or recent infection. 1, 6
• These red flags necessitate urgent MRI rather than continued conservative management. 1, 6

Fracture Risk Assessment

• Assess for osteoporosis risk factors including postmenopausal status, steroid use, significant trauma, or advanced age. 1, 6

Common Pitfalls to Avoid

• Do not rely solely on the straight-leg raise test specificity; use it as a screening tool and confirm with neurological examination findings. 1
• Avoid assuming a single positive SI joint provocation test is diagnostic; require at least three positive tests for clinical significance. 2, 3
• Do not order imaging based on physical examination alone in the absence of red flags or failure of 6 weeks of conservative therapy. 7, 1, 8
• Remember that many imaging abnormalities appear in asymptomatic individuals, so clinical correlation is essential. 7