Iterative Design of Custom Dynamic Orthoses

The purpose of this study is to refine a pre-existing musculoskeletal model and finalize the procedures for inputting multiple data sources into the model to evaluate ankle articular contact stresses.

Healthy adult participants will complete testing using three generic sized carbon fiber custom dynamic orthoses (CDOs) and with no CDO. Participants will be blinded to the design variation of each device and will only know them as CDO-A, CDO-B, or CDO-C. Testing will be completed under 4 conditions: No-CDO, CDO-A, CDO-B, CDO-C, with each bracing condition (A/B/C) representing a CDO design variant. Physical performance measures will incorporate tests of agility, speed, and lower limb power to ensure that changes to device design do not negatively affect physical function. Questionnaires will be used to evaluate participants' current and desired activity level, pain with and without CDO use, satisfaction with the devices, perception of comfort and smoothness between devices, and preference between CDOs. Semi-structured interviews will be completed to fully capture the participant's perspective. Lower limb forces and motion will be assessed using a computerized motion capture system and force plates in the floor. Forces between the foot and CDO will be measured using force sensing insoles, and muscle activity data will be collected using surface electromyography. Devices will be mechanically tested, and participant demographic and anthropometric data will be recorded.

The information obtained from this study will help refine the musculoskeletal model data input methods to be used in future studies. The knowledge that will be gained from this investigation has the potential to substantially improve the long-term efficacy and efficiency of the musculoskeletal model and help improve ankle foot orthosis

Inclusion criteria

• Between the ages of 18 and 50
• Shoe size between women's 8 and 13.5 or men's 6.5 and 12
• Healthy individuals without a current complaint of lower extremity pain, spine pain, or medical or neuromusculoskeletal disorders that have limited participation in work or exercise in the last 6 months
• Full active range of motion of the bilateral lower extremities and spine
• Ability to hop without pain
• Ability to perform a full squat without pain
• Ability to read and write in English and provide written informed consent

Exclusion criteria

• Diagnosed moderate or severe brain injury
• Prior lower extremity injury resulting in surgery or limiting function for greater than 6 weeks
• Diagnosis of a physical or psychological condition that would preclude testing (e.g. cardiac condition, clotting disorder, pulmonary condition)
• Visual or hearing impairment that would interfere with instructions given during testing
• Require an assistive device
• Wounds to the foot or calf that would prevent CDO use
• BMI greater than 35
• Pregnancy - Per participant self-report. Due to the expected small number of pregnant individuals and resulting inability to account for its effect on resulting outcomes, participants will be withdrawn from the study