2026 Workshop Handout Bundle-W45J - Advanced US of the Lower Limb Nerves

W45J - Advanced US of the Lower Limb Nerves - Shook

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Neuromuscular ultrasound (NMUS) is an adjunct to clinical examination and electrodiagnostic testing—not a replacement. Its main value is answering anatomical questions: locating a lesion, identifying nerve enlargement or structural damage, and revealing causes such as compression, scar, cyst, hematoma, vascular abnormality, or tumor.<br /><br />Evidence is strongest for common fibular neuropathy at the fibular head, meralgia paresthetica, and tarsal tunnel syndrome. Ultrasound is also useful in suspected femoral or sciatic nerve injury, particularly after trauma or surgery, although evidence for these conditions is more limited. Findings may include focal enlargement, flattening, altered fascicular structure, discontinuity, or neuroma.<br /><br />Scanning should use appropriate probe frequency, short- and long-axis views, and comparisons with the opposite side and nearby nerve segments. In focal neuropathy, examine systematically and extend at least 5–10 cm beyond the suspected lesion. Document abnormal and normal comparison sites and any structural cause.<br /><br />Muscle ultrasound can help identify patterns of myopathy, atrophy, fatty replacement, or fibrosis and guide further testing. It can also screen for fasciculations in motor neuron disease; it complements, but does not replace, EMG and clinical assessment.<br /><br />Nerve and muscle measurements depend on equipment, technique, anatomy, and patient characteristics. Laboratories should standardize scanning and measurement procedures and establish local reference values rather than relying on universal cutoffs. Side-to-side comparisons can be particularly useful.<br /><br />Overall, NMUS adds rapid, noninvasive structural and dynamic information when interpreted in clinical context.

Keywords

neuromuscular ultrasound

NMUS

ultrasound

nerve enlargement

focal neuropathy

common fibular neuropathy

meralgia paresthetica

tarsal tunnel syndrome

nerve compression

muscle ultrasound

electrodiagnostic testing