Peak Plantar Pressures While Wearing a Carbon Fiber Off Loading Orthoses

The long term goal of this research is the successful incorporation of carbon fiber into an off loading device will provide protection to the insensate foot of people with diabetes by reducing localized peak pressures, and thus the risk of recurrence neuropathic foot wounds and fractures, while improving ankle power at push off that will allow individuals with loss of ankle muscle function to walk faster and return to dynamic activities required in their jobs and for full function in the community. The overall goal of this proposal is to determine effects of carbon fiber off loading orthoses (CFO) design characteristics (lay up and geometry of strut) on brace strength, weight, power return capacity, plantar off-loading and participant comfort using FE models, ex-vivo testing and human testing.

First, a CFO will be fabricated using geometry consistent with the current clinical standard. This representative CFO will serve as a baseline from which a finite element (FE) model will be built. The model will be altered as desired to determine the effects of variable design characteristics. The FE model will estimate brace deflection and stress when the CFO is designed with various lay up designs and brace thicknesses. We will use results from the FE model to fabricate a new CFO for study participants.

We will then measure peak plantar pressures during walking while the participants are barefoot, wearing the CFO consistent with current clinical standards, and wearing the new CFO fabricated based on the results of the FE model. We will also measure plantarflexor power during walking while the participants are wearing the CFO consistent with current clinical standards and while wearing the CFO designed based on the results of the FE model. It is believed that the FE model driven CFO design will lead to improved brace strength while reducing plantar pressure compared to barefoot and will have similar plantarflexor power as the CFO based on current clinical standards.

Inclusion criteria

• Daily life includes a minimum of moderate activity level (variable cadence walking)
• Have a Gillette or carbon off loading orthosis as a result of diabetes related foot impairments
• Diagnosis of diabetes mellitus and peripheral neuropathy
• Ability to ambulate in the community (K-level ≥ 2)
• Age > 21 years

Exclusion criteria

• Unable to ambulate and complete testing required for study participation.
• Severe foot deformity of the hindfoot or any deformity of the foot with a dislocation resulting in a bony prominence on the plantar/weightbearing surface of the foot.
• Neurological diseases that affects walking