Over the last ten years the Spring Lite Foot plate, Toe-Off AFO and the Walk-On AFO initiated the application of an off the shelf, dynamic Pre-Preg Carbon foot plate. The complexity of fabrication, requiring One-Off engineering, delayed the development of this technology into the custom orthotic industry. Almost immediately, these prefabricated carbon foot plates showed us the functional application of "Dynamic Response."
Dynamic Response is defined as a structure that has a resistance to flexion which increases, as the flexion increases.
Plastics (Poly-P, Poly-E and Co-poly) have response characteristics to flexion that decrease as flexion increases.
Metal springs offer an increasing response characteristic but both metal and plastics present a size and thickness that is not practical to create enough force to be functional against the force vectors in gait. Pre-Impregnated Carbon offers an increasing gradient resistance to flexion while maintaining a low profile and ultra-light weight structure.
We have Pre-Engineered numerous designs which can be applied to the variety of patient shapes. These designs have enabled us to develop a variety resistance force categories to empower the practitioner with a spectrum of Dynamic response tools. With these tools, the functional levels the practitioner can reach with their patients are unlimited.
The "Dynamic Response AFO" design utilizes the long, flat, custom fabricated energy storing posterior spring to create a lever arm for M/L control of the molded foot plate. The wrap around foot shell is flexible to allow proper bio-mechanics of the calcaneous and the mid-foot throughout the gait cycle. The proximal calf shell is custom molded to the patient's model in order to maintain the direction of the action of the posterior strut to flex in the correct direction, creating a rotational control of the forefoot. The combination of the long lever arm and the rotational guidance of the forefoot create a substantial Valgus/Varus control with no rigid maintenance at the ankle.
The design has been modified to accommodate the partial foot amputee. The energy storing characteristics of the posterior spring is enhanced with the rigid toe-plate extending beyond the amputation. This also eliminates the distal pressure from the dorsiflexion of the toes, and directs the dorsi/plantar flexion of the foot to occur at the ankle. The amputation proximal to the metatarsal heads, which commonly result in a pronation of the fore-foot and valgus calcaneal alignment, can be maintained in a sub-talar neutral position. Partial foot amputations with toes remaining may require a more flexible toe plate to maintain range.