Individual stiffness optimization of dorsal leaf spring ankle-foot orthoses in people with calf muscle weakness is superior to standard bodyweight-based recommendations.

The study only evaluated walking on level ground. It is unknown if the more flexible optimized AFO performs as well during other daily activities like stair climbing or walking uphill, where stiffer AFOs might be beneficial. The optimization procedure was primarily based on walking energy cost, which may bias the results toward stiffness levels that favor this specific metric. The study used a specific brand of AFO (Carbon Ankle7), so the exact stiffness values may not directly translate to other dorsal leaf spring devices. Three participants were excluded from the analysis because their left and right legs were optimized separately, which might introduce selection bias.

The study was funded by the Prinses Beatrix Spierfonds. No other conflicts of interest were declared in the provided text.

Do not assume that a more flexible AFO is universally superior. The study found that the supplier's recommendation was often too stiff for level-ground energy efficiency, but the authors explicitly warn that this flexibility might worsen performance in conditions requiring more support, such as loaded walking or stairs.