The Effects of AFO Heel Height and Stiffness on Gait

GROUP 1 Patient Inclusion criteria * Ages: 18-70 * Daily AFO use to address unilateral, below knee functional deficits that result from limb injury or musculoskeletal disease (e.g. fracture, muscle and/or nerve injury, ankle arthritis) * Greater than 2 weeks using their current AFO * Ability to walk 50 feet without use of an assistive device (Cane, crutch, etc.) * Ability to walk at a slow to moderate pace * AFO fits into traditional footwear * Able to read and write in English and provide written informed consent GROUP 1 Patient Exclusion criteria * Pain \> 6/10 while walking during testing or an increase in pain during testing of \> 2/10. * Central Nervous System disorder or disease (e.g. Stroke, Cerebral Palsy, Spinal Cord Injury, or other conditions that result in lower limb spasticity). * Disorder or disease that affects peripheral nerve function (e.g. diabetes, Charcot Marie Tooth). * Limited contralateral lower limb function due to injury or neurological/musculoskeletal disorder. * Use of a hinged/articulating AFO (e.g. Plantar flexion stop, Dorsiflexion assist/stop, free motion), Charcot Restraint Orthotic Walker (CROW) boot, AFOs that restrict all motion in the ankle and foot. * Use of an AFO that crosses the knee (Knee brace) * Insufficient space in shoe to accommodate the tallest heel wedge and their AFO * Visual or hearing impairments that limit walking ability or could limit the ability to comply with instructions given during testing * Pregnancy - Per participant self-report. Due 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of pregnant individuals, and resulting inability to account for its effect on resulting outcomes participants will be withdrawn from the study. * Body Mass index \> 40. GROUP 2 Patient Inclusion Criteria * Ages: 18-70 * Daily AFO use to address below knee functional deficits that result from disease involving the peripheral nervous system (e.g. Charcot Marie Tooth, Multiple Sclerosis, diabetes) * Greater than 2 weeks using their current AFO (unilateral or bilateral) * Ability to walk 50 feet without use of an assistive device (Cane, crutch, etc.) * AFO fits into traditional footwear * Ability to walk at a slow to moderate pace * Able to read and write in English and provide written informed consent GROUP 2 Patient Exclusion Criteria * Pain \> 6/10 while walking or an increase in pain during testing of \> 2/10 * Central Nervous System disorder or disease (e.g. Stroke, Cerebral Palsy, Spinal Cord Injury, or other conditions that result in lower limb spasticity) * Limited function due to limb injury (e.g. fracture, muscle and/or nerve injury) * Use of a hinged/articulating AFO (e.g. Plantar flexion stop, Dorsiflexion assist/stop, free motion), Charcot Restraint Orthotic Walker (CROW) boot, AFOs that restrict all motion in the ankle and foot. * Use of an AFO that crosses the knee (Knee brace) * Insufficient space in shoe to accommodate the tallest heel wedge and their AFO * Visual or hearing impairment that limit walking ability or limit the ability to comply with instructions given during testing * Pregnancy - Per participant self-report. Due 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 * Body Mass index \> 40.