Trokos

Test library › Foot, ankle & calf

Unable to perform single-leg hop

For: Syndesmosis (high ankle) sprain

An injury to the ligaments that hold the lower ends of the two lower-leg bones (tibia and fibula) together just above the ankle. Often from the foot being twisted outwards or forced upwards.

A weak test on its own
Sensitivity89%
Specificity29%
LR+ (positive)1.25
LR− (negative)0.37

What the numbers mean

  • Positive result: barely informative: a positive result changes little.
  • Negative result: a small shift: a negative result nudges the diagnosis down, but does not exclude it.

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

Other tests in the library for syndesmosis (high ankle) sprain

Source

Sman AD, Hiller CE, Rae K, et al. Diagnostic accuracy of clinical tests for ankle syndesmosis injury. Br J Sports Med. 2015;49(5):323–329. PubMed · single study

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.