Traumatic Lower Limb Injury
Conditions
Keywords
Plantar Force, Ankle Foot Orthosis, Carbon Fiber Orthosis, Biomechanics
Brief summary
Carbon fiber custom dynamic orthoses (CDOs) and unloading ankle foot orthoses (AFOs) have shown varying levels of success in reducing forces acting on different regions of the bottom of the foot during gait. CDOs and unloading AFOs have shown differing offloading capabilities across different regions of the foots (hindfoot, midfoot, forefoot) which may be related to a distinct difference between CDOs and unloading AFOs: CDOs do not suspend, or distract, the foot away from the footplate. The purpose of this study is to determine the effects of CDOs and heel distraction height (the distance between the heel and the footplate) on limb loading and motion during gait as well as patient reported pain, and comfort.
Detailed description
Carbon fiber custom dynamic orthoses (CDOs) have been used to improve function, reduce pain, and offload the foot and ankle for individuals with a number of conditions affecting the lower extremity. CDOs consist of a proximal cuff that wraps around the leg just below the knee, a posterior carbon fiber strut that bends to store and return energy during mid to late stance, a semi-rigid carbon fiber footplate, and, in some cases, a foam heel wedge placed in the shoe. Unloading ankle foot orthoses (AFOs) have also been used for a number of lower extremity conditions, including traumatic injuries, in effort to reduce forces and pressure acting under the foot. Unloading AFOs have been created using many different designs, which include a proximal cuff just below the knee, a rigid strut (made of metal, plastic, etc.), and some sort of foot component (footplate, shoe, etc.). Both CDOs and unloading AFOs have shown varying levels of success in reducing forces acting on different regions of the bottom of the foot during gait. The differences in loading may be related to a distinct difference between CDOs and unloading AFOs: CDOs do not suspend, or distract, the foot away from the footplate. The purpose of this study is to determine the effects of CDOs and heel distraction height (the distance between the heel and the footplate) on limb loading and motion as well as patient reported pain and comfort. In this study, forces acting under the foot will be measured using wireless Loadsol insoles (Novel GMBH, St. Paul, MN) as participants walk without an orthosis (NoCDO) and with a CDO with three different posterior strut lengths resulting in three different levels of heel distraction (0cm, 1cm, 2cm) at self-selected and controlled speeds. Additionally, gait kinematic and kinetics will be measured using infrared motion capture cameras (Vicon Motion Systems Ltd., Denver, CO) and force plates (AMTI, Watertown, MA). Participants will be provided a lift for the contralateral limb to reduce the effects of leg length discrepancies during walking. Loadpad force measuring sensors (Novel GMBH, St. Paul, MN) will be used to measure forces within the CDO proximal cuff. After walking in each condition, participants will complete questionnaires concerning pain and orthosis comfort.
Interventions
The carbon fiber custom dynamic orthoses (CDOs) used in this study will consist of a semi-rigid carbon fiber footplate, a carbon fiber posterior strut, and a proximal cuff that wraps around the leg below the knee. The CDO will be modular in design which will allow three carbon fiber struts of the same stiffness and differing lengths to be used to implement 0cm, 1cm, and 2cm levels of heel distraction height. A longer posterior strut will move the carbon fiber footplate away from the participants foot to create the heel distraction height.
Sponsors
Fabtech Systems
University of Iowa
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
SINGLE (Subject)
Masking description
Participants will be blinded, to the greatest extent possible, to the different CDO heel distraction heights.
Intervention model description
In this study, forces acting under the foot (hindfoot, midfoot, forefoot, and total foot) will be measured using wireless Loadsol insoles (Novel GMBH, St. Paul, MN) as participants walk without an orthosis (NoCDO) and with a CDO with three different posterior strut lengths resulting in three different levels of heel distraction (0cm, 1cm, 2cm) at self-selected and controlled speeds. Gait kinematics and kinetics will be measured using infra-red motion capture cameras (Vicon Motion Systems Ltd., Denver, CO) and force plates (AMTI, Watertown, MA). Testing order of the CDO conditions will be randomized to prevent influence of testing order.
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
1. Ages 18-65 years 2. Traumatic hindfoot injury (soft tissue injury or fracture affecting the hindfoot or ankle) 3. Mechanical pain with limb loading (\>=4/10 on Numerical Pain Rating Scale) 4. Ability to walk 50 feet at a slow to moderate pace 5. Ability to walk without a cane or crutch 6. 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, etc. 3. Ankle weakness resulting from spinal cord injury or central 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. Uncorrected visual or hearing impairments 9. Require use of a knee stabilizing device to perform daily activities (i.e., Knee ankle foot orthosis, knee orthosis, etc.) 10. Pregnancy 11. Body mass index greater than 40 kg/m2
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Modified Socket Comfort Score | Baseline | Comfort scores range from 0 = most uncomfortable to 10 = most comfortable, and from 0 = least smooth to 10 = most smooth |
| Force Impulse (forefoot) | Baseline | Plantar force impulse (Ns) across the forefoot (distal 40% of sensor) will be calculated using the integral of the force over the stance phase as participants walk without a CDO and with each CDO. |
| Peak Force (hindfoot) | Baseline | Plantar forces (N) will be measured across the hindfoot (proximal 30% sensor) as participants walk without a CDO and with each CDO. |
| Peak Force (forefoot) | Baseline | Plantar forces (N) will be measured across the forefoot (distal 40% of sensor) as participants walk without a CDO and with each CDO. |
| Force Impulse (hindfoot) | Baseline | Plantar force impulse (Ns) across the hindfoot (proximal 30% sensor) will be calculated using the integral of the force over the stance phase as participants walk without a CDO and with each CDO. |
| Numerical Pain Rating Scale | Baseline | Pain will be assessed using a standard 11-point numerical pain rating scale, in which 0 = no pain and 10 = worst pain imaginable |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Peak Ankle Moment | Baseline | Peak ankle plantarflexion moment (Nm/kg) during gait. |
| Peak Ankle Power | Baseline | Peak ankle push-off power (W/kg) during gait. |
| Peak Force (total foot) | Baseline | Plantar forces (N) will be measured across the total foot (100% of sensors) as participants walk without a CDO and with each CDO. |
| Force Impulse (total foot) | Baseline | Plantar force impulse (Ns) across the total foot (100% of sensors) will be calculated using the integral of the force over the stance phase as participants walk without a CDO and with each CDO. |
| Peak Force (midfoot) | Baseline | Plantar forces (N) will be measured across the midfoot (middle 30% of sensor) as participants walk without a CDO and with each CDO. |
| Force Impulse (midfoot) | Baseline | Plantar force impulse (Ns) across the midfoot (middle 30% of sensor) will be calculated using the integral of the force over the stance phase as participants walk without a CDO and with each CDO. |
| Ankle Range of Motion | Baseline | Peak ankle dorsiflexion (degrees) during gait. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Semi-Structured Interview | Baseline | Participants will be asked a number of open ended questions to help determine what factors influenced their perception of each study condition. |
Countries
United States
Contacts
Primary ContactJason M Wilken, PT, PhD
Backup ContactKirsten M Anderson, PhD
Outcome results
None listed