The Effects of Heel Distraction Height on Foot Loading With Carbon Fiber Custom Dynamic Orthoses

Not Applicable

Recruiting

• Conditions: Traumatic Lower Limb Injury
• Interventions: Device: Carbon Fiber Custom Dynamic Orthosis (CDO)

• Registration Number: NCT06127316
• Lead Sponsor: University of Iowa

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.

Study Timeline

• Study First Submitted: 2023-11-06
• Study First Submitted QC: 2023-11-06
• Study First Posted: 2023-11-13
• Status Verified: 2024-08
• Study Start: 2024-08-16
• Last Update Submitted: 2024-08-26
• Last Update Posted: 2024-08-28
• Primary Completion: 2025-05-01
• Study Completion: 2025-09-01

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 20

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

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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

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
1cm Distraction	Carbon Fiber Custom Dynamic Orthosis (CDO)	Participants will complete study activities while wearing a CDO with 1cm of heel distraction height
0cm Distraction	Carbon Fiber Custom Dynamic Orthosis (CDO)	Participants will complete study activities while wearing a CDO with 0cm of heel distraction height
2cm Distraction	Carbon Fiber Custom Dynamic Orthosis (CDO)	Participants will complete study activities while wearing a CDO with 2cm of heel distraction height

Primary Outcome Measures

Name	Time	Method
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
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 (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.
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.
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

Secondary Outcome Measures

Name	Time	Method
Ankle Range of Motion	Baseline	Peak ankle dorsiflexion (degrees) during gait.
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 (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.
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.
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.

Trial Locations

Locations (1)

University of Iowa; 🇺🇸 Iowa City, Iowa, United States