Table 4.

Common Diagnostic Testing for Patients with Chronic Low Back Pain

DIAGNOSTIC TEST	INTERPRETATION	LIMITATIONS
History
Quality and severity of pain	burning/tingling/electric shock like paresthesias = neuropathic pain Dull, aching = nociceptive pain	Poor specificity Coexistence of more than one pain state Different mechanisms can produce same symptoms No gold standard
Physical Exam
Straight leg raise (SLR) test	Lumbar radiculopathy/ sciatic nerve irritation	Low specificity (e.g. many patients have hamstring and gluteal tightness eliciting pain upon SLR). Unable to distinguish between L4, L5, S1 root or sciatic nerve.
Dermatomal sensory loss/Myotomal deficit	root compression/ damage	Inconsistent finding Significant dermatomal/myotomal overlap
Musculoskeletal maneuvers, e.g. facet loading, sacroiliac joint and hip maneuvers, low back palpation	Anatomic localization of pain driver	Poor specificity multiple structures are simultaneously stimulated
Investigations
NCS/ EMG	Presence/ absence of neuropathy or radiculopathy	Only evaluates large-diameter fibers (not A-δ and C fibers) Lesions proximal to DRG are not routinely captured
Quantitative Sensory Testing	“sensory fingerprint” indicative of pain mechanism	Time consuming and resource heavy No gold standard Same disease with multiple sensory clusters
MRI imaging	Degenerative changes judged as causative of pain syndrome	Poor specificity. Degree of degenerative changes does not correlate with symptoms Only anatomical changes considered (but not functional e.g. inflammation, etc)

NOTE. Examples of commonly used diagnostic tools including patient's symptoms, exam findings and ancillary testing with clinical interpretations and shortcomings.