Floor-Reaction Orthosis
Also written as: FRO — Floor-Reaction Orthosis
An AFO variant designed to harness ground reaction forces to assist knee extension during stance phase, typically indicated for patients with weak quadriceps.
Full Definition
A floor-reaction orthosis (FRO) is a rigid or semi-rigid ankle–foot orthosis with an anterior tibial shell or strap that positions the ankle in slight plantarflexion, allowing the ground reaction force vector to pass anterior to the knee joint. This creates an external knee-extension moment that compensates for quadriceps weakness, particularly in conditions such as crouch gait secondary to cerebral palsy or post-polio syndrome. Editors will encounter this term in paediatric orthotics literature, rehabilitation reports, and gait laboratory outputs. The abbreviation FRO should be expanded on first use. The term is sometimes incorrectly rendered as 'floor reaction AFO,' which is redundant; 'floor-reaction orthosis' or 'FRO' is preferred.
Usage
Usage note: Hyphenate 'floor-reaction' as a compound modifier. Expand FRO on first use. Avoid the redundant phrase 'floor-reaction AFO.'
In Context
- "A bilateral floor-reaction orthosis was prescribed to manage the child's crouch gait pattern." — Paediatric orthotics clinical report
- "The FRO was fabricated from 4 mm carbon fibre composite to minimise weight while maintaining the stiffness required for knee-extension assistance." — Gait laboratory case study