Extrinsic Posting
A wedge or addition applied to the outer (plantar) surface of an orthotic shell to alter foot and limb alignment, as opposed to material built into the shell itself.
Full Definition
Extrinsic posting refers to the addition of wedging material—typically ethylene vinyl acetate (EVA) or cork—bonded to the external plantar surface of an orthotic device. It is used to control subtalar and midtarsal motion by tilting the device relative to the shoe's insole. Because it is applied outside the shell, it can be easily modified or replaced without remaking the device. Editors must distinguish it from intrinsic posting, where the correction is ground into the shell material itself. The term is commonly found in laboratory work orders and clinical prescription forms.
Usage
Usage note: Always distinguish from 'intrinsic posting' in clinical documents; conflating the two misrepresents the construction method and may affect billing codes.
In Context
- "The work order specified 4° extrinsic rearfoot posting to control excessive subtalar eversion." — Orthotic laboratory work order
- "Extrinsic posting was preferred over intrinsic posting as it allowed the clinician to adjust the correction at subsequent follow-up visits." — Clinical case report