Helical AFO
orthosis, EVA foam, AFO
The helical ankle–foot orthosis (hAFO) from InnovPulse (Vernaison, France) [All the hAFOs were custom designed and fabricated from multiple layers of carbon. Layers of dry carbon fibre were superimposed between 2 closed end PVA bags over the plaster positive and epoxy resin was injected to bind the layers. The pieces were positioned over the tracing of the AFO on the plaster positive. The resin was then polymerised. The hAFO was cut along the trace using a diamond Dremel wheel. The edges were rounded on a rotary power tool before hand-finishing with fine-grain sandpaper. After cleaning with alcohol, EVA foam (1.5 mm) was fitted on the distal part of the hAFO, up to the lower edge of the lateral malleolus. The strap was then added on the proximal part of the orthosis.The same trim line was used for all hAFOs: a helical shaped band passed laterally under the metatarsal heads, medially over the dorsum of the foot, under the heel, anterior to the lateral malleolus, behind the calf and fixed with the strap just distal to the knee (Fig. 