Heel Wedges and Carbon Fiber Custom Dynamic Orthoses to Control Knee Biomechanics

The proposed study evaluates the effect of medial and lateral wedges and carbon fiber custom dynamic orthoses (CDOs) on lower limb forces and motion during walking. Previous work has used foam wedges of different stiffness and height placed under the heel to alter CDO alignment and alter lower limb mechanics. Medial or lateral wedges have been used by individuals with unilateral knee osteoarthritis in effort to reduce knee loading. In this study, medial and lateral wedges will be placed in participants shoes, with the tall side of the wedge placed on the medial or lateral aspect of the shoes, and participants will walk at controlled and self-selected speeds and complete physical performance measures. Participants will also walk without a CDO. The proposed study will provide evidence that can be used by physicians when treating knee osteoarthritis.

The primary purpose of this line of research is to investigate the effects of combined carbon fiber custom dynamic orthosis (CDO) and medial or lateral wedge use on biomechanics during gait in effort to reduce unilateral knee compartment loading. The medial or lateral wedges are composed of foam, run the length of the foot, and will be placed so the tall side of the wedge is on the medial (Medial Wedge) or lateral (Lateral Wedge) aspect of the shoe to preferentially load the medial and lateral edges of the foot respectively. The use of medial and lateral wedges to treat unilateral knee osteoarthritis (OA) has been studied previously, generally without combined use of a foot and ankle brace such as a CDO. Previous work has demonstrated that foam wedges, of different height and stiffness, placed under the heel of a CDO affects sagittal plane gait biomechanics, including ankle plantarflexion and knee extension moments. The additional support and restriction of motion at the ankle associated with CDO use may emphasize results seen at the knee with medial or lateral wedging. Therefore, the proposed effort is designed to evaluate how different medial or lateral wedges placed under a CDO influence frontal plane knee biomechanics during level over-ground gait and physical performance during tests of agility, speed, and lower limb power. The proposed study will provide evidence that can be used by physicians when treating knee osteoarthritis.

In this research study, data will be collected from a cohort of healthy adult participants with no history of lower limb injuries or functional deficits. Participants will be evaluated using a series of study measures under each of the four conditions; without a brace (NoCDO), with a brace and no wedge (CDO), with a brace and a medial wedge placed in the shoe (Medial), and with a brace and a lateral wedge placed in the shoe (Lateral). The wedge will be placed in a medial and lateral position to determine effectiveness of combined wedging and CDO use in treating both medial and lateral knee OA. Testing will be randomized for each participant. Participants will walk on a level-ground walkway at self-selected and controlled speeds. Physical performance measures will incorporate tests of agility, speed, and lower limb power to ensure that the CDO and wedge do not negatively affect physical function. Questionnaires will be used to evaluate participants' pain and perception of comfort and smoothness for each testing condition.

Eligibility Criteria:
Inclusion Criteria:

* Between the ages of 18 and 45
* Healthy without current complaint of lower extremity pain, spine pain, open wounds or active infections, or medical or neuromusculoskeletal disorders that have limited their participation in work or exercise in the last 6 months
* Able to hop without pain
* Able to perform a full squat without pain
* Ability to speak and understand English

Exclusion Criteria:

* Medical or neuromusculoskeletal disorders that have limited their participation in work or exercise in the last 6 months
* Diagnosed with a moderate or severe brain injury
* Lower extremity injury resulting in surgery or limiting function for greater than 6 weeks
* Injuries that would limit performance in this study
* Diagnosed with a physical or psychological condition that would preclude functional testing (e.g. cardiac condition, clotting disorder, pulmonary condition)
* Uncorrected visual or hearing impairment(s)
* Require use of an assistive device
* Unhealed wounds (cuts/abrasions) that would prevent CDO use
* BMI \> 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