Thesis
Incorporating in vivo data into a computational modeling framework to assess the effects of carbon fiber bracing on ankle joint function and contact mechanics
University of Iowa
Master of Science (MS), University of Iowa
Summer 2021
DOI: 10.17077/etd.005932
Abstract
In the U.S. alone, tens of millions of people experience limb impairment and ambulatory disabilities, which are often associated with pain and decreased health-related quality of life due to suboptimal intervention techniques [1]. Post-traumatic osteoarthritis (PTOA) is one of the leading causes of mobility-related disability, with approximately 5.6 million cases in the U.S. [2]. PTOA is a form of osteoarthritis that develops following traumatic injury, such as intra-articular fracture (IAF). Long-term consequences are often associated with IAFs, including joint stiffness and development of PTOA [3], due to elevated contact stress exposures from residual incongruities on the articular surface [4]. Carbon fiber bracing is an attractive intervention technique following traumatic injury, as it has been shown to effectively address a number of other functional deficits [5-8], and it may reduce pain and prevent the development of PTOA by reducing contact stress production at the ankle. However, literature about the effects of carbon fiber custom dynamic orthosis (CDO) design on resulting function is limited, given the limitations of directly capturing certain biomechanical quantities and measures, such as in vivo dynamic muscle forces. Musculoskeletal modeling and movement simulation allow for a thorough investigation of parameters that are difficult to measure directly, such as muscle force, joint reaction force, and articular contact stress, which may have important implications for mobility outcomes and/or development of pain or PTOA. By following a computational modeling approach, the effects of carbon fiber bracing can be assessed in the context of PTOA and other mobility-related conditions.
By studying the effects of three different CDO designs—the MalleoLok, a PhatBrace with moderate stiffness, and a PhatBrace with firm stiffness—across a normative 6-subject study group, carbon fiber bracing was found to significantly reduce soleus muscle force, axial joint reaction force at the ankle, and tibiotalar contact stress-time exposure compared to a no brace baseline. Specifically, the two PhatBrace conditions were found to produce significant differences in resulting plantarflexor muscle forces, while all three bracing conditions produced significant reductions in ankle joint reaction force and mean cumulative contact stress-time exposure across the tibiotalar surface. In comparing results across bracing conditions, the PhatBrace devices reduced ankle pushoff power, forefoot forces, model-estimated soleus force, and model-estimated ankle joint reaction force significantly more than the MalleLok device, but no significant differences in these measures were observed across varying PhatBrace stiffnesses, indicating that device stiffness may not significantly affect results.
Taken together, results indicate that carbon fiber bracing may be a viable method for reducing tibiotalar contact stress, making it a potential mode of intervention for preventing PTOA development following traumatic lower limb injury.
Details
- Title: Subtitle
- Incorporating in vivo data into a computational modeling framework to assess the effects of carbon fiber bracing on ankle joint function and contact mechanics
- Creators
- Molly Corlett
- Contributors
- Don Anderson (Advisor)Jason Wilken (Advisor)Edward Sander (Committee Member)Seth Dillard (Committee Member)Anne Silverman (Committee Member)
- Resource Type
- Thesis
- Degree Awarded
- Master of Science (MS), University of Iowa
- Degree in
- Biomedical Engineering
- Date degree season
- Summer 2021
- DOI
- 10.17077/etd.005932
- Publisher
- University of Iowa
- Number of pages
- xii, 69 pages
- Copyright
- Copyright 2021 Molly Corlett
- Language
- English
- Description illustrations
- color illustrations
- Description bibliographic
- Includes bibliographical references (pages 59-62).
- Public Abstract (ETD)
Limb impairment and mobility-related disabilities are often associated with pain and decreased quality of life, due to unsatisfactory treatment options. Post-traumatic osteoarthritis (PTOA) is one of the leading causes of mobility-related disability, with approximately 5.6 million cases in the U.S. [2]. PTOA is a form of osteoarthritis that develops following traumatic injury and is associated with long-term consequences if allowed to progress.
Carbon fiber bracing is an attractive intervention method following traumatic injury, as it has been shown to effectively address a number of other mobility-related conditions [5-8]. However, literature about the effects of carbon fiber custom dynamic orthosis (CDO) design on resulting function is limited, as it is difficult to capture certain measures experimentally, such as muscle forces while walking. Musculoskeletal modeling and walking simulation produce estimations of measurements that are difficult to measure directly, such as muscle force and forces produced at the ankle joint. By following a computational modeling approach, the effects of carbon fiber bracing can be assessed in the context of PTOA and other mobility-related conditions.
By studying the effects of three different CDOs across a normative 6-subject study group, carbon fiber bracing was found to significantly reduce soleus muscle force, axial joint reaction force at the ankle, and tibiotalar contact stress-time exposure compared to a no brace baseline. These results indicate that carbon fiber bracing may be a viable method for reducing tibiotalar contact stress, making it a potential mode of intervention for preventing PTOA development following traumatic lower limb injury.
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering
- Record Identifier
- 9984124171602771
Metrics
256 File views/ downloads
100 Record Views