The Influence of Heel Wedge Properties on Roll-over of the Intrepid Dynamic Exoskeletal Orthosis (IDEO)

The Intrepid Dynamic Exoskeletal Orthosis (IDEO) is a type of ankle foot orthosis designed to reduce pain and improve function for individuals with foot/ankle pain and/or weakness. Because the IDEO restricts ankle movement, the geometry and mechanics of the device must be designed to allow for a smooth roll-over as the patient walks with the IDEO. The heel wedge, while not physically part of the IDEO, is an integral part of the IDEO-heel wedge-shoe "system". The goal of this research is to determine how heel wedge properties may contribute to the smoothness of roll-over during gait. Insight into the effects of heel wedge properties on roll-over will help optimize the design of the IDEO-heel wedge-shoe "system" and may produce guidelines for the customization of these features.

The proposed study includes a between groups comparison (for Aim 1) and a fully repeated crossover design (for Aim 2). It will be conducted in the Military Performance Lab (MPL) at the Center for the Intrepid (CFI), Brooke Army Medical Center, Joint Base San Antonio (JBSA)Fort Sam Houston, Texas. Subjects who use IDEOs will come to the Military Performance Lab for one test session during which they will walk in standardized shoes with six different heel wedges in random order. Control data will also be collected on able-bodied individuals. Control subjects will also come to the MPL for one test session in which they will walk using the same standardized shoes. For all subjects, biomechanical gait data will be collected as the subjects walk along a walkway in the MPL. This data will be used to calculate roll-over shape, instantaneous radius of curvature, Center of Pressure (COP) velocity, and ankle moment.

Eligibility Criteria:
IDEO Group

Inclusion Criteria:

* DEERS (Defense Enrollment Eligibility Reporting System) eligible patients at the CFI
* 18 - 55 years old
* Have a unilateral lower extremity injury resulting in foot/ankle weakness and/or pain
* Currently using an IDEO
* Use of the IDEO for greater than two weeks
* Able to ambulate without an assistive device
* Able to comply with gait analysis
* Able to provide written informed consent

Exclusion Criteria:

* Neurologic, musculoskeletal or other disease state affecting the contralateral limb that limits normal locomotion
* Spinal cord injury or central nervous system pathology
* Medical or psychological disease that would preclude safe gait analysis (ex. severe traumatic brain injury, stroke, renal failure, heart disease, severe anemia, etc.)
* Pain level of 4 or greater on a 0-10 scale
* Any open wound or infection on the foot
* Pregnancy

Control Group

Inclusion Criteria:

* DEERS eligible
* 18 - 55 years old
* Have no lower extremity injury which affects normal locomotion
* Able to comply with gait analysis
* Able to provide written informed consent

Control Group Exclusion Criteria:

* Neurologic, musculoskeletal or other disease state that limits normal locomotion
* Previous lower extremity injury requiring surgery (e.g. anterior cruciate ligament tear, femur fracture, etc) or currently affecting normal locomotion
* Any pain that affects normal locomotion
* Any open wound or infection on the foot
* Spinal cord injury or central nervous system pathology
* Medical or psychological disease that would preclude safe gait analysis (ex. severe traumatic brain injury, stroke, renal failure, heart disease, severe anemia, etc.)
* Pregnancy