By Emily Delzell
People who use an ankle foot orthosis (AFO) after a stroke retain significant deficits in neuromuscular function and blood flow many years later, according to research from the University of Oklahoma in Oklahoma City.
In nine people who were, on average, 14 years poststroke and had used an AFO for seven years, investigators measured quadriceps strength, calf endurance, lower limb soft tissue composition and muscle cross-sectional area, calf resting blood flow, and plantar flexor central neural drive. They defined the sound limb as the control.
Quadriceps strength, triceps surae endurance, and calf cross-sectional area were greater in the sound limb (relative differences: 76.3% ± 16.6%, 146.4% ± 24.6%, and 25.6% ± 5.7%, respectively). The unaffected limbs had greater resting blood flow, peak torque, and plantar flexor central neural drive (relative differences: 38.7% ± 5.9%, 94.4% ± 17.9%, and 43.6% ± 12%, respectively).
Functional abilities varied widely within the cohort. Investigators noted that, because few studies have evaluated the physiological effect of AFOs in stroke patients, it’s not clear whether the devices improve or worsen deficits.
The Journal of Geriatric Physical Therapy epublished the results in July.
Sherk KA, Sherk VD, Anderson MA, et al. Lower limb neuromuscular function and blood flow characteristics in AFO-using survivors of stroke. J Geriatr Phys Ther 2014 Jul 15. [Epub ahead of print]