Leg-Length Discrepancy
Also written as: LLD — Leg-Length Discrepancy
A difference in the measured length of the lower limbs, either structural (true) or functional, commonly addressed through heel raises or orthotic modifications.
Full Definition
Leg-length discrepancy (LLD) describes a measurable difference between the lengths of the two lower extremities. A structural LLD arises from actual skeletal asymmetry, while a functional LLD results from soft-tissue or biomechanical factors such as pelvic obliquity or hip contracture without underlying bony difference. In orthotic documentation, the distinction is clinically critical and must be preserved in editing, as the two types have different management pathways. Editors will encounter LLD in referral letters, prescription forms, and outcome reports. The term is frequently abbreviated, and editors should confirm the abbreviation is introduced before use.
Usage
Usage note: Always distinguish between structural and functional LLD in clinical documents; the type should be specified explicitly.
In Context
- "A structural leg-length discrepancy of 18 mm was confirmed on standing radiograph and a full-length shoe raise was issued." — Orthotics clinic letter
- "The document used 'LLD' without prior expansion; the editor introduced the full form 'leg-length discrepancy' at first mention in accordance with house style." — Copy-editing revision note