Effects of carbon versus plastic ankle foot orthoses on gait outcomes and energy cost in patients with chronic stroke

Abstract

Objective: To compare the walking performances of hemiplegic subjects with chronic stroke under 3 conditions: with a new standard carbon fibre ankle foot orthosis (C-AFO), with a personal custom-made plastic AFO (P-AFO), and without any orthosis (No-AFO). Design: Randomized, controlled crossover design. Patients: Fifteen chronic patients with stroke (3 women and 12 men, 59 [10] years, 13 [15] years since injury). Methods: Patients performed 3 randomized sessions (with C-AFO, P-AFO, no-AFO), consisting of a 6-min walk test (6MWT) with VO2 measurement and a clinical gait analysis. Energy cost (Cw), walking speed, spatio-temporal, kinetic, and kinematic variables were measured. Results: No significant differences were found between the C-AFO and P-AFO conditions. Distance and walking speed in the 6MWT increased by 12% and 10% (p < 0.001) and stride width decreased by -8.7% and -13% (p < 0.0001) with P-AFO and C-AFO compared with the No-AFO condition. Cw decreased by 15% (p < 0.002), stride length increased by 10% (p < 0.01), step length on affected leg increased by 8% (p < 0.01), step length on contralateral leg by 13% (p < 0.01), and swing time on the contralateral leg increased by 6% (p < 0.01) with both AFO compared with the No-AFO condition. Conclusion: The use of an off-the-shelf composite AFO (after a short habituation period) in patients with chronic stroke immediately improved energy cost and gait outcomes to the same extent as their usual custom-made AFO.

Keywords

• gait analysis
• foot drop
• ankle foot orthoses design
• energy expenditure
• hemiplegic patients