Navicular Drop Test
Pronunciation: NAV-ik-yuh-ler
Also written as: NDT — Navicular Drop Test
A clinical measurement technique that quantifies medial longitudinal arch mobility by recording the vertical descent of the navicular tuberosity from subtalar joint neutral to relaxed bilateral standing.
Full Definition
The navicular drop test (NDT), described by Brody (1982), measures the vertical displacement in millimetres of the navicular tuberosity between a seated subtalar joint neutral position and relaxed bilateral standing. A navicular drop of 10 mm or more is generally considered clinically significant and is associated with excessive foot pronation and medial longitudinal arch collapse. The test is widely used in orthotic assessment to guide decision-making about arch support height and rearfoot posting. Editors should note that this is formally a test name and should be capitalised accordingly; 'navicular drop' (lowercase) refers to the measurement outcome.
Usage
Usage note: Capitalise as 'Navicular Drop Test' when referring to the clinical procedure; use lowercase 'navicular drop' when referring to the numeric measurement obtained. NDT abbreviation should be defined on first use.
In Context
- "A navicular drop of 12 mm on the right foot was recorded using the Navicular Drop Test, confirming significant hyperpronation." — Orthotic assessment documentation
- "The clinical report noted an asymmetric navicular drop (right 13 mm, left 7 mm), warranting unilateral orthotic intervention." — Podiatric biomechanics referral letter