Foot Drop: EMG/NCS Localization and Differential Diagnosis

The Clinical & Business Connection Newsletter

Clinical Insight

Foot drop is a clinical finding, not a diagnosis — and its evaluation illustrates precisely why electrodiagnostic testing is indispensable in neuromuscular medicine. The differential for foot drop spans peroneal mononeuropathy, lumbosacral radiculopathy (L4–L5), sciatic neuropathy, lumbosacral plexopathy, and central causes, all of which can produce an identical clinical presentation. EMG and nerve conduction studies (NCS) are the most reliable means of localizing the lesion and characterizing its severity.

NCS Findings by Etiology

• Peroneal mononeuropathy at the fibular head: Reduced or absent peroneal motor amplitude with slowing or conduction block across the fibular head. Superficial peroneal sensory SNAP may be reduced or absent, distinguishing this from radiculopathy. Tibial NCS normal.

• L4–L5 radiculopathy: NCS typically normal (compression proximal to dorsal root ganglion). EMG reveals denervation in L4–L5 myotomes, including tibialis anterior, peronei, and — critically — the short head of the biceps femoris and paraspinals, distinguishing it from peroneal mononeuropathy.

• Sciatic neuropathy: Peroneal division is more commonly affected than tibial; tibial NCS may be normal while sural is abnormal. Denervation in sciatic-innervated muscles above the knee confirms the diagnosis.

• Lumbosacral plexopathy: Multi-level NCS abnormalities including sensory; denervation across multiple myotomes not explained by a single root or nerve trunk.

Musculoskeletal Ultrasound adds valuable structural information — detecting peroneal nerve thickening, mass lesions, ganglion cysts at the fibular head, and fibular fractures that may not be apparent on physical examination.

Refer for electrodiagnostic evaluation when foot drop is present, when the differential includes both peripheral and radicular etiologies, when surgical planning is under consideration, or when progression over time needs to be objectively documented.

References

1. Katirji B. Peroneal neuropathy. Neurol Clin. 1999.
2. Preston DC, Shapiro BE. Electromyography and Neuromuscular Disorders. 3rd ed. Elsevier. 2012.
3. AANEM. Recommended policy for electrodiagnostic medicine. Muscle Nerve. 1999.

Business Success Strategy

Increasing Patient Volume Through Relationship Marketing

In a referral-driven healthcare environment, the most durable source of new patient volume is not advertising — it is the trust of other clinicians. Relationship marketing is the practice of building, nurturing, and systematizing those clinical relationships so that referrals flow consistently, not just when your name happens to come to mind.

The distinction matters: traditional outreach gets you noticed. Relationship marketing gets you remembered and chosen when a patient with a complex presentation needs a trusted resource.

Five Practical Strategies

1. Make every touchpoint a value exchange.

Every interaction with a referring physician — a phone call, a report, a hallway conversation — is an opportunity to deliver clinical value, not just confirm a referral. Reports that answer clinical questions clearly, quickly, and completely are themselves a form of relationship marketing.

2. Follow up on referrals with a brief clinical summary.

A short, direct call or note after a referred patient’s evaluation closes the loop and signals that their referral mattered. Physicians who feel their patients are being well cared for refer more. This is the highest-leverage touchpoint in the referral cycle.

3. Segment your referral base and communicate accordingly.

Not all referring physicians need the same message. A neurologist values technical precision in your reports. A primary care physician values speed and clear next-step recommendations. Tailoring your communications by specialty increases the relevance — and the stickiness — of each interaction.

4. Create consistent, low-effort touch points.

Clinical newsletters (like this one), educational updates, and periodic check-in calls keep you present in the minds of referring providers without requiring significant time investment. Consistency over time outperforms any single high-effort campaign.

5. Involve your administrative team.

Relationship marketing does not begin and end with the clinician. When your front desk, referral coordinators, and billing team are responsive, warm, and reliable, the entire practice becomes easier to work with — and that matters enormously to the administrative staff of referring offices who manage the logistics.

Referrals follow relationships. Relationships follow value. Build the value first — and the volume follows!

Spotlight on Excellence

Bibi Razack

Scheduling and Communications Officer

Bibi has been in healthcare management for the past 10 years, where she was primarily responsible for the administration, coordination, and oversight of the facility.

Updates You Should Know

The Introduction to EMG, Nerve Conduction Studies, and Musculoskeletal Ultrasound Imaging course just wrapped — and it was a phenomenal success.

This quarter, Hands-On EMG Testing hosted the American Academy of Clinical Electrodiagnosis (AACE) and the American Academy of MSK Ultrasound (AAMU) for the Introduction to EMG, Nerve Conduction Studies, and Musculoskeletal Ultrasound Imaging with 40+ clinicians gathering for two days of intensive, hands-on training.

Attendees left with:

• Real-world skills in EMG, nerve conduction studies, and MSK ultrasound imaging
• The clinical context needed to make more confident, accurate referrals
• 20.5 CEUs (physical therapy professionals) or 20.5 CMEs (physicians and medical providers)
• A direct connection to the HODS Leadership Team, who works personally with your admin and marketing staff to tailor strategies for your practice and market

The energy in the room was electric — and the demand is only growing!

Want in on the next one? For all upcoming dates and locations please visit emgintro.com.

How We Can Help

Hands-On EMG Testing serves physicians and patients across several locations in Manhattan, Queens, the Bronx, Brooklyn, and Long Island.

To refer a patient, please use our online referral form. To learn more about our services, email in**@********mg.com, or call +1 (855) 248-4021.

If you are interested in incorporating our Medical Diagnostic Model into your practice to provide immediate testing results and create a strong business opportunity, please contact Dr. Dimitrios Kostopoulos at di**@********mg.com.