EMG Muscle Sampling for Lumbosacral Radiculopathy

Essential Clinical Correlations

• The patellar reflex (L4 mediated) provides important clinical correlation 1
• The ankle jerk reflex (S1 mediated) provides essential clinical correlation 2

Diagnostic Sensitivity and Specificity

• Needle EMG sensitivity reaches 90% for lumbosacral radiculopathy, while NCS alone has low diagnostic value 3, 4

Recommended Examination Techniques

• Electrodiagnostic studies should confirm clinical diagnosis and differentiate radiculopathy from plexopathy 5, 2

Muscle Innervation Patterns

• The extensor hallucis longus is primarily L5 innervated for great toe extension 2