Comparative Effect of Carbon Fiber Orthosis Cuff Design on Preference, Comfort, and Mechanics

University of Iowa35 enrolled

Overview

Carbon fiber custom dynamic orthoses (CDOs) consist of a proximal cuff that wraps around the leg just below the knee, a posterior carbon fiber strut that stores and returns energy during gait, and a carbon fiber foot plate that supports the foot and allows bending of the posterior strut. The proximal cuff is a primary interface between the patient and the CDO and may influence comfort, preference, limb mechanics and loading, and effective stiffness of the CDO. The important role of the proximal cuff has not been examined. The purpose of this study is to determine the effects of CDO proximal cuff design on patient reported outcomes, limb mechanics and loading, and CDO mechanical characteristics.

Traumatic lower limb injuries often result in poor functional outcomes with long-term negative effects. Carbon fiber custom dynamic orthoses (CDOs) can improve outcomes by reducing pain, supporting the limb, and transferring forces around the limb through the CDO. CDOs consist of a proximal cuff that wraps around the leg just below the knee, a posterior carbon fiber strut that stores and returns energy during gait, and a carbon fiber foot plate that supports the foot and allows bending of the posterior strut. The proximal cuff is a primary interface between the patient and the CDO and may influence comfort, preference, limb mechanics and loading, and effective stiffness of the CDO. Although CDOs are becoming more commonly prescribed following injury the evidence available to guide clinical practice remains limited. The important role of the proximal cuff has not been systematically examined. The purpose of this study is to determine the effects of CDO proximal cuff design on patient reported outcomes, limb mechanics and loading, and CDO mechanical characteristics. Two groups of individuals will participate: individuals with post-traumatic osteoarthritis in the ankle and healthy individuals. Testing will occur without an orthosis and while wearing orthoses with four proximal cuff designs representative of currently available devices: 1) a rigid patellar tendon bearing (PTB) clamshell cuff secured using a mechanical ratcheting system, 2) a PTB shell with a fixed pivot point secured with Velcro, 3) a rigid clamshell cuff secured with Velcro, and 4) a semi-rigid cuff with a flexible outer layer secured with Velcro.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Eligibility

Sex: ALLMin age: 18 YearsMax age: 65 YearsHealthy volunteers:

Medical Language ↔ Plain English

PARTICIPANTS WITH PTOA: Inclusion Criteria: 1. Ages 18-65. 2. Diagnosis of ankle PTOA. 3. Ability to walk 50 feet at a slow to moderate pace. 4. Ability to walk without a cane or crutch. 5. Ability to read and write in English and provide written informed consent. Exclusion Criteria: 1. Diagnosis with a moderate or severe brain injury. 2. Diagnosis with a physical or psychological condition that would preclude functional testing (e.g. cardiac condition, clotting disorder, pulmonary condition…). 3. Ankle weakness as a result of spinal cord injury or nervous system pathology. 4. Nerve, muscle, bone, or other condition limiting function in the contralateral extremity. 5. Rheumatoid or inflammatory arthritis. 6. Necrosis of any bones in the foot or ankle. 7. Pain of 8/10 or greater during walking. 8. Surgery on study limb anticipated in the next 6 months. 9. Uncorrected visual or hearing impairments. 10. Require use of a stabilizing device (i.e. Ankle Foot Orthosis or Knee Orthosis…) to perform daily activities. 11. Pregnancy 12. Body mass index greater than 40. HEALTHY ABLE-BODIED PARTICIPANTS: Inclusion Criteria: 1. Ages 18-65. 2. Without current complaint of lower extremity pain, spine pain, open wounds or active infection. 3. Ability to hop without pain. 4. Ability to perform a full squat without pain. 5. Ability to read and write in English and provide written informed consent. Exclusion Criteria: 1. Diagnosis with a moderate or severe brain injury. 2. Diagnosis with a physical or psychological condition that would preclude functional testing (e.g. cardiac condition, clotting disorder, pulmonary condition). 3. Medical conditions or injuries that have limited participation in work or exercise in the last 6 months. 4. Medical conditions of injuries limiting function for greater than 6 weeks. 5. Uncorrected visual or hearing impairments. 6. Use of an assistive device. 7. Pregnancy 8. Body mass index greater than 35.

Outcomes

Primary Outcomes

Peak Plantar Force (total foot)

Force data (N) collected from the total foot (100% of sensor), measured between the foot and orthosis during gait.

Time frame: Baseline

Plantar Force Impulse (total foot)

Plantar force impulse (Ns) across the total foot (100% of sensor) will be calculated using the integral of the force over the stance phase as participants walk in each study condition.

Time frame: Baseline

Peak Plantar Force (forefoot)

Force data (N) collected from the total foot (distal 40% of sensor), measured between the foot and orthosis during gait.

Time frame: Baseline

Plantar Force Impulse (forefoot)

Plantar force impulse (Ns) across the total foot (distal 40% of sensor) will be calculated using the integral of the force over the stance phase as participants walk in each study condition.

Time frame: Baseline

Peak Plantar Force (midfoot)

Force data (N) collected from the total foot (middle 30% of sensor), measured between the foot and orthosis during gait.

Time frame: Baseline

Plantar Force Impulse (midfoot)

Plantar force impulse (Ns) across the total foot (middle 30% of sensor) will be calculated using the integral of the force over the stance phase as participants walk in each study condition.

Time frame: Baseline

Peak Plantar Force (hindfoot)

Force data (N) collected from the total foot (proximal 30% of sensor), measured between the foot and orthosis during gait.

Time frame: Baseline

Plantar Force Impulse (hindfoot)

Plantar force impulse (Ns) across the total foot (proximal 30% of sensor) will be calculated using the integral of the force over the stance phase as participants walk in each study condition.

Time frame: Baseline

Numerical Pain Rating Scale

Pain will be assessed using a standard 11-point numerical pain rating scale, in which 0 = no pain and 10 = worst pain imaginable.

Time frame: Baseline

PROMIS Patient Reported Outcomes for Physical Function

The Patient Reported Outcome Information System (PROMIS) physical function Computer Adaptive Test (CAT) is a computerized assessment measuring physical function. It is scored using a T-score in which 50 is the mean of a relevant reference population and 10 is the standard deviation (SD) of that population. In a given PROMIS domain, a T-score above 50 represents more of the measured variable than the population average.

Time frame: Baseline

PROMIS Patient Reported Outcomes for Pain Interference

The Patient Reported Outcome Information System (PROMIS) pain interference Computer Adaptive Test (CAT) is a computerized assessment measuring pain interference. It is scored using a T-score in which 50 is the mean of a relevant reference population and 10 is the standard deviation (SD) of that population. In a given PROMIS domain, a T-score above 50 represents more of the measured variable than the population average.

Time frame: Baseline

Participant Device Preference

The participant will rank order their preference for their standard of care device (if applicable), NoCDO, CUFF-A, CUFF-B, CUFF-C, CUFF-D on a questionnaire.

Time frame: Baseline

Secondary Outcomes

Ankle Range of Motion

Peak ankle dorsiflexion (degrees) during gait.

Time frame: Baseline

Peak Ankle Moment

Peak ankle moment (Nm/kg) during gait.

Time frame: Baseline

Peak Ankle Power

Peak ankle power (W/kg) during gait.

Time frame: Baseline

Modified Socket Comfort Score (Comfort)

Comfort scores range from 0 = most uncomfortable to 10 = most comfortable.

Time frame: Baseline

Modified Socket Comfort Score (Smoothness)

Comfort scores range from 0 = least smooth to 10 = most smooth.

Time frame: Baseline

Comparative Effect of Carbon Fiber Orthosis Cuff Design on Preference, Comfort, and Mechanics

Overview

Conditions

Interventions

Eligibility

Locations (1)

Outcomes

Primary Outcomes

Secondary Outcomes