Trim Line
The shaped cut edge of a thermoplastic orthosis that determines the device's flexibility, rigidity, and the anatomical coverage it provides.
Full Definition
In orthotic fabrication, the trim line is the deliberately shaped border of a thermoplastic shell after excess material has been removed. The position of the trim line directly governs the mechanical stiffness of the device: trim lines placed anterior to the malleoli on an AFO, for example, result in greater rigidity than lines placed posterior. Editors working on clinical or laboratory documents should note that 'trim line' is two words (not 'trimline'), and should be hyphenated only in adjectival use (e.g., 'trim-line position'). The term is distinct from 'brim,' which describes the upper margin of a device such as a KAFO.
Usage
Usage note: Write as two words: 'trim line.' Hyphenate only in adjectival constructions. Trim-line position is a clinically significant variable and should not be paraphrased loosely.
In Context
- "The orthotist's notes specified a posterior trim line to produce a flexible, ground-reaction AFO effect." — Orthotic fabrication record
- "Ensure 'trim line' is consistently written as two words and not merged into 'trimline' in the laboratory order." — Editorial checklist