The purpose of this study is to determine the ability of carbon fiber off loading orthoses to reduce plantar pressure while providing an augmented plantarflexor power to improve walking and function. Results of this study could lead to increased use of carbon fiber off loading orthoses for patients with diabetes, peripheral neuropathy, and foot wounds as a way augmenting wound healing and preventing future recurrences of wounds.

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:

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

Exclusion Criteria:

1. Unable to ambulate and complete testing required for study participation.
2. 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.
3. Neurological diseases that affects walking

Baseline data collected in a brace provided as standard of care. A finite element model was constructed of the brace and provided input for changes in brace construction. This process took 9 months and the participant was tested in the model informed brace 11 months after initial testing

Risks to participants were the possibility of discomfort, blister, or sore while getting used to a new brace and falling during peak plantar pressure testing. Participants were told to contact the study team immediately if any of these they experienced discomfort, blisters, or sores when adapting to the new brace. During peak plantar pressure testing a study team member walked beside the participant holding a gait belt around the waist to make sure they did not fall.