The electric shock that appears with walking

Few symptoms are as precisely localized and as intense as the pain of Morton's neuroma. The patient describes a sensation of electric shock or sharp burning between the 3rd and 4th toes that appears with walking — especially in tight shoes — and forces them to stop, remove the shoe, and massage the foot for relief. Some report the sensation of "walking on a pebble" or "a fold in the sock that isn't there". The pain can be intense enough to limit daily activities such as short walks.

Morton's neuroma is not a true tumor but rather fibrosis and thickening of the plantar interdigital nerve — usually between the 3rd and 4th metatarsals. Repetitive compression of the nerve by the deep transverse metatarsal ligament, aggravated by narrow shoes and high heels, generates segmental demyelination and perineural inflammation. Electroacupuncture with needling in the intermetatarsal space provides direct neuromodulation of the affected nerve, reducing neural hypersensitization without the risks of repeated corticosteroid injections.

How the interdigital nerve generates neuropathic pain

  1. Mechanical compression of the interdigital nerve

    The plantar interdigital nerve passes between the metatarsal heads, beneath the deep transverse metatarsal ligament. Narrow shoes compress the metatarsal heads against one another, repeatedly crushing the nerve. The space between the 3rd and 4th metatarsals is the most affected because it receives branches from two plantar nerves — medial and lateral.

  2. Perineural fibrosis and demyelination

    Repetitive compression causes chronic inflammation around the nerve (perineural fibrosis), followed by segmental demyelination. The nerve thickens — potentially reaching 5–8 mm in diameter — and becomes hypersensitive. This thickening is the "neuroma" visible on ultrasound and MRI.

  3. Peripheral sensitization and neural ectopia

    The damaged nerve generates ectopic impulses (spontaneous electrical discharges) that the patient perceives as shocks or burning. Voltage-gated sodium channels accumulate at the demyelination zone, making the nerve hyperexcitable. Any mechanical pressure — even simple body-weight bearing — fires these impulses.

  4. Electroacupuncture and neural desensitization

    Electroacupuncture applied in the intermetatarsal space modulates nociceptive transmission via activation of inhibitory interneurons in the spinal cord (gate control) and release of endogenous opioids. The 2 Hz frequency is particularly effective for neuropathic pain, promoting progressive desensitization of the hyperexcitable nerve.

Clinical data on Morton's neuroma

3rd–4th
INTERMETATARSAL SPACE
is the most affected in about 65% of cases — followed by the 2nd–3rd space in 30% of cases
4:1
WOMEN TO MEN
female prevalence reflects the habitual use of narrow shoes and high heels, which compress the forefoot
30%
OF NEUROMAS
are bilateral — always examine the contralateral foot when the diagnosis is made on one side
70–80%
RESPONSE RATE
to adequate conservative treatment (wide shoes + insoles + medical acupuncture) — reserving surgery for refractory cases

Identifying Morton's neuroma

Critérios clínicos
06 itens

Interdigital neuropathic pain — typical pattern

  1. 01

    Electric-shock or burning pain between the 3rd and 4th toes

  2. 02

    Worsens with walking, especially in tight shoes or high heels

  3. 03

    Relief upon removing the shoe and massaging the space between the toes

  4. 04

    Sensation of a "pebble" or "lump" under the sole when stepping

  5. 05

    Tingling or numbness radiating to the adjacent toes

  6. 06

    Positive Mulder test — lateral compression reproduces the shock

Myths and facts about neuropathic foot pain

Myth vs. Fact

MYTH

Morton's neuroma can only be resolved with surgery

FACT

Neurectomy (surgical removal of the neuroma) is reserved for cases refractory to conservative treatment. Most patients improve with shoe modification (wide toe box, no heel), metatarsal pad, and medical acupuncture. Surgery, although effective, can cause permanent numbness in the adjacent toes and, in some cases, stump neuroma — a painful complication.

MYTH

If the pain is in the foot, the problem is always plantar fasciitis

FACT

Plantar fasciitis causes pain on the sole of the foot, under the heel, that worsens upon getting up in the morning. Morton's neuroma causes electric-shock pain between the toes that worsens with walking. They are completely different conditions in location, mechanism, and treatment. Diagnostic confusion is frequent and leads to ineffective treatments.

MYTH

Corticosteroid injection cures the neuroma

FACT

Corticosteroid injections may temporarily relieve perineural inflammation (4–12 weeks) but do not reverse nerve fibrosis. Repeated injections can cause atrophy of the plantar fat pad — worsening metatarsalgia in the long term. Medical acupuncture with electroacupuncture offers neuromodulation without the local side effects of corticosteroids.

The importance of footwear in treatment

Treatment protocol

Diagnosis and footwear modification
1st visit

Mulder test for clinical confirmation. Forefoot ultrasound for neuroma measurement (if available). Immediate footwear guidance: wide toe box, no heel, metatarsal pad. Assessment of differential diagnoses (diabetic neuropathy, mechanical metatarsalgia).

Intermetatarsal electroacupuncture
Sessions 1–4

Needling of the affected intermetatarsal space (dorsal approach, between the metatarsal heads). 2 Hz electroacupuncture with needles positioned in the interdigital spaces for direct neuromodulation of the interdigital nerve. Dry needling of the plantar interossei when they show trigger points.

Treatment of proximal chains
Sessions 3–6

Assessment and treatment of trigger points in the intrinsic foot muscles (abductor hallucis, flexor digitorum brevis) and gastrocnemius-soleus. Mobilization of the metatarsophalangeal joints. Strengthening exercises for the intrinsic foot muscles (towel exercise, active toe spreading).

Consolidation and prevention
Sessions 7–10

Spacing of sessions according to improvement. Reinforcement of footwear and insole guidance. Biomechanical gait assessment to correct perpetuating factors. Gradual return to impact activities (running, long walks) with appropriate footwear.

Clinical pearl: the lateral compression test

Frequently asked questions

FREQUENTLY ASKED QUESTIONS · 04

Frequently Asked Questions

Running intensifies compression of the interdigital nerve and may worsen symptoms. In the acute treatment phase, replacing running with lower-impact activities (cycling, swimming) is recommended. After clinical improvement, running can be reintroduced gradually with wide-toe-box footwear and a metatarsal pad. Running shoes with an ample toe box are essential.

High heels do not directly cause the neuroma but are one of the main aggravating and perpetuating factors. The heel shifts body weight to the forefoot, increasing compression on the metatarsal heads and the interdigital nerve. Combined with a pointed toe, the effect is multiplied. Reducing high-heel use is one of the most impactful measures in treatment.

Medical acupuncture with electroacupuncture is part of conservative treatment, which resolves most cases. Surgery (neurectomy) is indicated when complete conservative treatment fails after 3–6 months. The advantage of conservative treatment is preserving toe sensation — surgery inevitably causes permanent numbness in the area innervated by the removed nerve.

Diabetic neuropathy causes bilateral, diffuse, symmetric burning in both feet (a "stocking" pattern), with progressive sensory loss. Morton's neuroma causes localized shock in a specific interdigital space, usually unilateral, that worsens with mechanical compression and relieves upon removing the shoe. The physician differentiates these conditions by clinical examination and, when necessary, by electroneuromyography.