Trokos

Test library › Foot, ankle & calf

Modified web-space tenderness test (thumb-pad palpation)

For: Morton's neuroma

Thickening of a nerve between the long bones of the forefoot, most often between the third and fourth toes. Causes burning pain or tingling in the ball of the foot and into those toes.

Treat with caution (see below)
Sensitivity96%
Specificity100%
LR+ (positive)not calculable (specificity 100%)
LR− (negative)0.04

Its negative likelihood ratio reaches the usual rule-out threshold, but the book does not count it as a reliable rule-out test.

Caution: The 100% specificity rests on a single foot without the condition.

What the numbers mean

  • Positive result: no false positives were seen in the study, so no likelihood ratio can be calculated. How far to trust that depends on how many people without the condition were studied; see the caution above.
  • Negative result: see the caution above before relying on this result.

Work out what a result means for your patient: probability calculator

Source

Pitcher M, Moulson A, Pitcher D, Herbland A, Cairns MC. Diagnostic accuracy of subjective features and physical examination tests for Morton neuroma: a systematic review. Foot Ankle Orthop. 2024;9(4):24730114241291055. Full text (PubMed Central) · Single study (2015), in a 2024 review

Figures as they will appear in Rule It In, Rule It Out (Trokos, forthcoming). If a newer or better study changes them, this page changes with the book. Figures last updated from the book on 6 October 2026.

Get the book for spotting a high ankle sprain, and knowing when the Achilles is torn

This page gives the published figures. Rule It In, Rule It Out adds how to do this test, what counts as positive, how to read the result, and, where studied, whether combining it with other tests helps.

Coming in late 2026 as a PDF and a paperback. Join the list to hear when it's out

One study, one test, once a month

Rule It In is a free evidence letter for musculoskeletal clinicians: one recent study explained, one examination test with its real numbers. From Trokos, publisher of Rule It In, Rule It Out.