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Ármannsdóttir AL, Lecomte C, Lemaire E, Brynjólfsson S, Briem K. Perceptions and biomechanical effects of varying prosthetic ankle stiffness during uphill walking: A case series. Gait Posture 2024; 108:354-360. [PMID: 38227995 DOI: 10.1016/j.gaitpost.2024.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 12/28/2023] [Accepted: 01/02/2024] [Indexed: 01/18/2024]
Abstract
BACKGROUND Prosthetic foot stiffness, which is typically invariable for commercially available prosthetic feet, needs to be considered when prescribing a prosthetic foot. While a biological foot adapts its function according to the movement task, an individual with lower limb amputation may be limited during more functionally demanding gait tasks by their conventional energy storing and return prosthetic foot. RESEARCH QUESTION How do changes in prosthetic foot stiffness during incline walking affect biomechanical measures as well as perception of participants. METHODS Kinetic and kinematic data were collected during incline walking, for five participants with trans-tibial amputation. A mixed model analysis of variance was used to analyse the effects of changing the stiffness during incline walking, using a novel variable-stiffness unit built on a commercially available prosthetic foot. Biomechanical results were also analysed on an individual level alongside the participant feedback, for a better understanding of the various strategies and perceptions exhibited during incline walking. RESULTS Statistically significant effects were only observed on the biomechanical parameters directly related to prosthetic ankle kinematics and kinetics (i.e., peak prosthetic ankle dorsiflexion, peak prosthetic ankle power, dynamic joint stiffness during controlled dorsiflexion). Participant perception during walking was affected by changes in stiffness. Individual analyses revealed varied perceptions and varied biomechanical responses among participants. SIGNIFICANCE While changes in prosthesis mechanical properties influenced the amputee's experience, minimal immediate effects were found with the overall gait pattern. The reported inter-participant variability may be due to the person's physical characteristics or habitual gait pattern, which may influence prosthesis function. The ability to vary prosthetic foot stiffness during the assessment phase of setting up a prosthesis could provide useful information to guide selection of the appropriate prosthetic device for acceptable performance across a range of activities.
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Affiliation(s)
- Anna Lára Ármannsdóttir
- Research Centre of Movement Science, University of Iceland, Reykjavík, Iceland; Össur hf., Grjótháls 5, 110 Reykjavik, Iceland.
| | - Christophe Lecomte
- Faculty of Industrial Engineering, Mechanical Engineering and Computer Science, School of Engineering and Natural Sciences, University of Iceland, Reykjavík, Iceland; Össur hf., Grjótháls 5, 110 Reykjavik, Iceland
| | - Edward Lemaire
- Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Sigurður Brynjólfsson
- Faculty of Industrial Engineering, Mechanical Engineering and Computer Science, School of Engineering and Natural Sciences, University of Iceland, Reykjavík, Iceland
| | - Kristín Briem
- Research Centre of Movement Science, University of Iceland, Reykjavík, Iceland
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Pitkin M. The Moment Criterion of Anthropomorphicity of Prosthetic Feet as a Potential Predictor of Their Functionality for Transtibial Amputees. Biomimetics (Basel) 2023; 8:572. [PMID: 38132511 PMCID: PMC10741750 DOI: 10.3390/biomimetics8080572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 11/19/2023] [Accepted: 11/21/2023] [Indexed: 12/23/2023] Open
Abstract
The purpose of this paper is to discuss a new quantitative mechanical parameter of prosthetic feet called the Index of Anthropomorphicity (IA), which has the potential to be adopted as an objective predictor of their functionality. The objectives are to present the research findings supporting the introduction of IA and unify previous results into a coherent theory. The IA is founded on the moment criterion of the anthropomorphicity of prosthetic feet. The term "anthropomorphicity" is defined for this application. Studies with a small number of human subjects and prostheses have shown that the value of the parameter is positively correlated with patient comfort and with the restoration of certain normal gait characteristics. Confirmatory studies with controlled human trials and mechanical tests with a wider selection of prosthesis types can give prosthesis manufacturers a new criterion to follow in the design process, and prosthetists may use the IA for selecting more suitable prostheses for a patient's comfort and health.
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Affiliation(s)
- Mark Pitkin
- Poly-Orth International, Sharon, MA 02067, USA;
- Department of Orthopaedics and Physical Medicine and Rehabilitation, Tufts University School of Medicine, Boston, MA 02111, USA
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Vaca M, Stine R, Hammond P, Cavanaugh M, Major MJ, Gard SA. The Effect of Prosthetic Ankle Dorsiflexion Stiffness on Standing Balance and Gait Biomechanics in Individuals with Unilateral Transtibial Amputation. JOURNAL OF PROSTHETICS AND ORTHOTICS : JPO 2022; 34:10.1097/JPO.0000000000000451. [PMID: 36407034 PMCID: PMC9670249 DOI: 10.1097/jpo.0000000000000451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Affiliation(s)
- Miguel Vaca
- Department of Biomedical Engineering - Northwestern University, Evanston, IL
- Jesse Brown VA Medical Center, Chicago, IL
- Northwestern University Prosthetics-Orthotics Center, Dept. of Physical Medicine & Rehabilitation, Feinberg School of Medicine, Chicago, IL
| | | | | | - Michael Cavanaugh
- Jesse Brown VA Medical Center, Chicago, IL
- Northwestern University Prosthetics-Orthotics Center, Dept. of Physical Medicine & Rehabilitation, Feinberg School of Medicine, Chicago, IL
| | - Matthew J. Major
- Department of Biomedical Engineering - Northwestern University, Evanston, IL
- Jesse Brown VA Medical Center, Chicago, IL
- Northwestern University Prosthetics-Orthotics Center, Dept. of Physical Medicine & Rehabilitation, Feinberg School of Medicine, Chicago, IL
| | - Steven A. Gard
- Department of Biomedical Engineering - Northwestern University, Evanston, IL
- Jesse Brown VA Medical Center, Chicago, IL
- Northwestern University Prosthetics-Orthotics Center, Dept. of Physical Medicine & Rehabilitation, Feinberg School of Medicine, Chicago, IL
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Ruxin TR, Halsne EG, Turner AT, Curran CS, Caputo JM, Hansen AH, Hafner BJ, Morgenroth DC. Comparing forefoot and heel stiffnesses across commercial prosthetic feet manufactured for individuals with varying body weights and foot sizes. Prosthet Orthot Int 2022; 46:425-431. [PMID: 35426860 DOI: 10.1097/pxr.0000000000000131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 02/15/2022] [Indexed: 02/03/2023]
Abstract
BACKGROUND Despite the effects of prosthetic foot mechanical properties on gait of people with lower limb amputation, scant forefoot and heel stiffness data exist to help guide prosthetic foot prescription. OBJECTIVE To measure forefoot and heel linear stiffness properties across commonly prescribed commercial prosthetic foot models and to describe variations in stiffness across feet targeted for users with different body weights and foot sizes. STUDY DESIGN Mechanical testing of five types of commercial prosthetic feet across nine user body weight and foot size combinations. METHODS Linear forefoot and heel stiffness (force vs. displacement) data were collected for 41 prosthetic feet. Quasistatic testing was conducted at -15 and +20 degrees to isolate loading of the heel and forefoot, respectively. RESULTS Overall, there was a significant relationship between user body weight and both forefoot and heel stiffness, when adjusted for foot size and type ( P < 0.001). However, there were a substantial number of inconsistencies across foot type within example user body weight and foot sizes combination. Furthermore, the relative order of forefoot stiffness across foot type differed from the relative order of heel stiffness across foot type. CONCLUSIONS The inconsistencies and differences in relative order of forefoot and heel stiffness across commercial foot type suggest the importance of publishing objective stiffness and other mechanical properties of prosthetic feet. These data can aid clinicians in better matching mechanical properties of prosthetic feet with the functional goals and abilities of prosthesis users.
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Affiliation(s)
- Talia R Ruxin
- VA RR&D Center for Limb Loss and Mobility (CLiMB), VA Puget Sound Health Care System, Seattle, WA, USA
| | - Elizabeth G Halsne
- VA RR&D Center for Limb Loss and Mobility (CLiMB), VA Puget Sound Health Care System, Seattle, WA, USA
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA
| | - Anne T Turner
- VA RR&D Center for Limb Loss and Mobility (CLiMB), VA Puget Sound Health Care System, Seattle, WA, USA
| | - Carl S Curran
- Human Motion Technologies LLC d/b/a Humotech, Pittsburgh, PA, USA
| | - Joshua M Caputo
- Human Motion Technologies LLC d/b/a Humotech, Pittsburgh, PA, USA
| | - Andrew H Hansen
- Minneapolis VA Health Care System, Minneapolis, MN, USA
- Departments of Rehabilitation Medicine & Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Brian J Hafner
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA
| | - David C Morgenroth
- VA RR&D Center for Limb Loss and Mobility (CLiMB), VA Puget Sound Health Care System, Seattle, WA, USA
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA
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Raschke S. Editorial Opinion: Value Within the Prosthetic and Orthotic Provision Process. CANADIAN PROSTHETICS & ORTHOTICS JOURNAL 2022; 5:38442. [PMID: 37614475 PMCID: PMC10443494 DOI: 10.33137/cpoj.v5i1.38442] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
This Editorial presents an overview of the uptake of clinical outcome measures in the prosthetics and orthotics sector and considers how the use of objective measures contribute to demonstrating value provided. A decade ago, payors began to demand objective data to document costs vs. benefits from prosthetic and orthotic providers. The speed with which the sector responded to help develop measures and to begin to integrate them into practice is remarkable. This suggests an encouraging resilience and ability to adapt on the part of the sector as other trends such as Values-Based Health Care emerge to challenge the sector.
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Affiliation(s)
- S.U. Raschke
- British Columbia Institute of Technology (BCIT), 3700 Willingdon Avenue, Burnaby, British Columbia, Canada
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Halsne EG, Curran C, Caputo JM, Hansen A, Hafner BJ, Morgenroth D. Emulating the Effective Ankle Stiffness of Commercial Prosthetic Feet Using a Robotic Prosthetic Foot Emulator. J Biomech Eng 2022; 144:1141731. [PMID: 35722979 DOI: 10.1115/1.4054834] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Indexed: 11/08/2022]
Abstract
Prosthetic foot selection for individuals with lower limb amputation relies primarily on clinician judgment. The prosthesis user rarely has an opportunity to provide experiential input into the decision by trying different feet. A prosthetic foot emulator (PFE) is a robotic prosthetic foot that could facilitate prosthesis users' ability to trial feet with different mechanical characteristics. Here, we introduce a procedure by which a robotic PFE is configured to emulate the sagittal plane effective ankle stiffness of a range of commercial prosthetic forefeet. Mechanical testing was used to collect data on five types of commercial prosthetic feet across a range of foot sizes and intended user body weights. Emulated forefoot profiles were parameterized using Bezier curve fitting on ankle torque-angle data. Mechanical testing was repeated with the PFE, across a subset of emulated foot conditions, to assess the accuracy of the emulation. Linear mixed-effects regression and Bland-Altman Limits of Agreement analyses were used to compare emulated and commercial ankle torque-angle data. Effective ankle stiffness of the emulated feet was significantly associated with the corresponding commercial prosthetic feet (p<.001). On average, the emulated forefeet reproduced the effective ankle stiffness of corresponding commercial feet within 1%. Furthermore, differences were independent of prosthetic foot type, foot size, or user body weight. These findings suggest a PFE could be an effective tool for emulating commercial prosthetic feet, enabling prosthesis users to quickly trial different feet and provide experiential input as part of a prosthetic foot prescription.
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Affiliation(s)
- Elizabeth G Halsne
- Center for Limb Loss and Mobility, VA Puget Sound Health Care System, 1660 S Columbian Way (MS 151), Seattle, WA 98108; Department of Rehabilitation Medicine, University of Washington, 1959 NE Pacific Street, Box 356490, Seattle, WA 98195
| | - Carl Curran
- Human Motion Technologies LLC d/b/a Humotech, 630 William Pitt Way, U-PARC, Building A2, Pittsburgh, PA 15238
| | - Joshua M Caputo
- Human Motion Technologies LLC d/b/a Humotech, 630 William Pitt Way, U-PARC, Building A2, Pittsburgh, PA 15238
| | - Andrew Hansen
- Minneapolis Adaptive Design & Engineering (MADE) Program, Minneapolis VA Health Care System, 1 Veterans Dr (MS 151), Minneapolis, MN 55417; Departments of Rehabilitation Medicine & Biomedical Engineering, University of Minnesota, Rehabilitation Science Program, MMC 388, 420 Delaware St. SE, Minneapolis, MN 55455
| | - Brian J Hafner
- Department of Rehabilitation Medicine, University of Washington, 1959 NE Pacific Street, Box 356490, Seattle, WA 98195
| | - David Morgenroth
- Center for Limb Loss and Mobility, VA Puget Sound Health Care System, 1660 S Columbian Way (MS 151), Seattle, WA 98108; Department of Rehabilitation Medicine, University of Washington, 1959 NE Pacific Street, Box 356490, Seattle, WA 98195
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Turner AT, Halsne EG, Caputo JM, Curran CS, Hansen AH, Hafner BJ, Morgenroth DC. Prosthetic forefoot and heel stiffness across consecutive foot stiffness categories and sizes. PLoS One 2022; 17:e0268136. [PMID: 35536854 PMCID: PMC9089881 DOI: 10.1371/journal.pone.0268136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 03/24/2022] [Indexed: 11/18/2022] Open
Abstract
Prosthetic foot stiffness plays a key role in the functional mobility of lower limb prosthesis users. However, limited objective data exists to guide selection of the optimal prosthetic foot stiffness category for a given individual. Clinicians often must rely solely on manufacturer recommendations, which are typically based on the intended user’s weight and general activity level. Availability of comparable forefoot and heel stiffness data would allow for a better understanding of differences between different commercial prosthetic feet, and also between feet of different stiffness categories and foot sizes. Therefore, this study compared forefoot and heel linear stiffness properties across manufacturer-designated stiffness categories and foot sizes. Mechanical testing was completed for five types of commercial prosthetic feet across a range of stiffness categories and three foot-sizes. Data were collected for 56 prosthetic feet, in total. Testing at two discrete angles was conducted to isolate loading of the heel and forefoot components, respectively. Each prosthetic foot was loaded for six cycles while force and displacement data were collected. Forefoot and heel measured stiffness were both significantly associated with stiffness category (p = .001). There was no evidence that the relationships between stiffness category and measured stiffness differed by foot size (stiffness category by size interaction p = .80). However, there were inconsistencies between the expected and measured stiffness changes across stiffness categories (i.e., magnitude of stiffness changes varied substantially between consecutive stiffness categories of the same feet). While statistical results support that, on average, measured stiffness is positively correlated with stiffness category, force-displacement data suggest substantial variation in measured stiffness across consecutive categories. Published objective mechanical property data for commercial prosthetic feet would likely therefore be helpful to clinicians during prescription.
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Affiliation(s)
- Anne T. Turner
- VA RR&D Center for Limb Loss and Mobility (CLiMB), VA Puget Sound Health Care System, Seattle, Washington, United States of America
- Elson S. Floyd College of Medicine, Washington State University, Spokane, Washington, United States of America
| | - Elizabeth G. Halsne
- VA RR&D Center for Limb Loss and Mobility (CLiMB), VA Puget Sound Health Care System, Seattle, Washington, United States of America
- Department of Rehabilitation Medicine, University of Washington, Seattle, Washington, United States of America
| | - Joshua M. Caputo
- Human Motion Technologies LLC d/b/a Humotech, Pittsburgh, Pennsylvania, United States of America
| | - Carl S. Curran
- Human Motion Technologies LLC d/b/a Humotech, Pittsburgh, Pennsylvania, United States of America
| | - Andrew H. Hansen
- Minneapolis VA Health Care System, Minneapolis, Minnesota, United States of America
- University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Brian J. Hafner
- Department of Rehabilitation Medicine, University of Washington, Seattle, Washington, United States of America
| | - David C. Morgenroth
- VA RR&D Center for Limb Loss and Mobility (CLiMB), VA Puget Sound Health Care System, Seattle, Washington, United States of America
- Department of Rehabilitation Medicine, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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Effects of shear force reduction during mechanical testing and day-to-day variation on stiffness of commercial prosthetic feet: a technical note. Prosthet Orthot Int 2022; 46:206-211. [PMID: 35412527 DOI: 10.1097/pxr.0000000000000088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 11/01/2021] [Indexed: 02/03/2023]
Abstract
BACKGROUND Mechanical testing is the principal method used to quantify properties of commercial prosthetic feet in a controlled and standardized manner. To test feet in a mechanical testing machine without overconstraining the system, tangential shear forces must be minimized. However, there is scant published information comparing techniques for reducing shear forces during mechanical testing. Furthermore, there are no data on variability in linear stiffness across testing sessions. OBJECTIVES To compare techniques for reducing shear forces during mechanical testing of prosthetic feet and to evaluate variation in linear stiffness across testing sessions. STUDY DESIGN Repeated measures. TECHNIQUE Force-displacement data were collected at two pylon progression angles, one for the forefoot and one for the heel, and compared across three conditions: roller plate (RoPl), low-friction interface on the shoe (SB), and no method for reducing shear forces (NoSB). Data were collected for a range of commercial prosthetic foot models and sizes. Select data were collected over multiple days to assess variation over test sessions. RESULTS Differences in stiffness between RoPl and SB test conditions ranged from -0.9% to +2.6% across foot models. By contrast, differences between RoPl and no method for reducing shear conditions ranged from -2.9% to +14.6%. Differences in linear stiffness between test sessions ranged from -2.2% to +3.6%. CONCLUSIONS Methods for reducing shear force in this study demonstrated roughly equivalent effects. Thus, a low-friction interface may be used as a less expensive and less complex method for reducing shear force in prosthetic foot testing. In addition, mechanical testing results were relatively consistent across multiple test sessions, lending confidence to test consistency.
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Ármannsdóttir AL, Lecomte C, Brynjólfsson S, Briem K. Task dependent changes in mechanical and biomechanical measures result from manipulating stiffness settings in a prosthetic foot. Clin Biomech (Bristol, Avon) 2021; 89:105476. [PMID: 34517194 DOI: 10.1016/j.clinbiomech.2021.105476] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 08/28/2021] [Accepted: 09/03/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND Adaptation of lower limb function to different gait tasks is inherently not as effective among individuals with lower limb amputation as compared to able-bodied individuals. Varying stiffness of a prosthetic foot may be a way of facilitating gait tasks that require larger ankle joint range of motion. METHODS Three stiffness settings of a novel prosthetic foot design were tested for level walking at three speeds as well as for 7,5° incline and decline walking. Outcome measures, describing ankle range of motion and ankle dynamic joint stiffness were contrasted across the three stiffness settings. Standardized mechanical tests were done for the hindfoot and forefoot. FINDINGS Dorsiflexion angle was incrementally increased with a softer foot and a faster walking speed / higher degree of slope. The concurrent dynamic joint stiffness exhibited a less systematic change, especially during INCLINE and DECLINE walking. The small difference seen between the stiffness settings for hindfoot loading limits analysis for the effects of stiffness during weight acceptance, however, a stiffer foot significantly restricted plantarflexion during DECLINE. INTERPRETATIONS Varying stiffness settings within a prosthetic foot does have an effect on prosthetic foot dynamics, and differences are task dependent, specifically in parameters involving kinetic attributes. When considering the need for increased ankle range of motion while performing more demanding gait tasks, a foot that allows the users themselves to adjust stiffness according to the task at hand may be of benefit for active individuals, possibly enhancing the user's satisfaction and comfort during various daily activities.
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Affiliation(s)
- Anna L Ármannsdóttir
- Research Centre of Movement Science, University of Iceland, Sæmundargata 2, 102 Reykjavík, Iceland.
| | - Christophe Lecomte
- Faculty of Industrial Engineering, Mechanical Engineering and Computer Science, School of Engineering and Natural Sciences, University of Iceland, Sæmundargata 2, 102 Reykjavík, Iceland; Össur hf., Grjótháls 5, 110 Reykjavik, Iceland
| | | | - Kristín Briem
- Research Centre of Movement Science, University of Iceland, Sæmundargata 2, 102 Reykjavík, Iceland
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Tryggvason H, Starker F, Armannsdottir AL, Lecomte C, Jonsdottir F. Speed Adaptable Prosthetic Foot: Concept Description, Prototyping and Initial User Testing. IEEE Trans Neural Syst Rehabil Eng 2020; 28:2978-2986. [PMID: 33151884 DOI: 10.1109/tnsre.2020.3036329] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This article presents a novel design of a prosthetic foot that features adaptable stiffness that changes according to the speed of ankle motion. The motivation is the natural graduation in stiffness of a biological ankle over a range of ambulation tasks. The device stiffness depends on rate of movement, ranging from a dissipating support at very slow walking speed, to efficient energy storage and return at normal walking speed. The objective here is to design a prosthetic foot that provides a compliant support for slow ambulation, without sacrificing the spring-like energy return beneficial in normal walking. The design is a modification of a commercially available foot and employs material properties to provide a change in stiffness. The velocity dependent properties of a non-Newtonian working fluid provide the rate adaptability. Material properties of components allow for a geometry shift that results in a coupling action, affecting the stiffness of the overall system. The function of an adaptive coupling was tested in linear motion. A prototype prosthetic foot was built, and the speed dependent stiffness measured mechanically. Furthermore, the prototype was tested by a user and body kinematics measured in gait analysis for varying walking speed, comparing the prototype to the original foot model (non-modified). Mechanical evaluation of stiffness shows increase in stiffness of about 60% over the test range and 10% increase between slow and normal walking speed in user testing.
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Schnall BL, Dearth CL, Elrod JM, Golyski PR, Koehler-McNicholas SR, Ray SF, Hansen AH, Hendershot BD. A more compliant prosthetic foot better accommodates added load while walking among Servicemembers with transtibial limb loss. J Biomech 2020; 98:109395. [PMID: 31668413 DOI: 10.1016/j.jbiomech.2019.109395] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 10/03/2019] [Accepted: 10/06/2019] [Indexed: 11/16/2022]
Abstract
Selecting an optimal prosthetic foot is particularly challenging for highly active individuals with limb loss, such as military personnel, who need to seamlessly perform a variety of demanding activities/tasks (often with and without external loads) while minimizing risk of musculoskeletal injuries over the longer term. Here, we expand on prior work by comparing biomechanical and functional outcomes in two prosthetic feet with the largest differences in mechanical response to added load (i.e., consistently "Compliant" and "Stiff" forefoot properties). In each foot, fourteen male Servicemembers with unilateral transtibial limb loss (from trauma) completed instrumented gait analyses in all combinations of two loading conditions (with and without 22 kg weighted vest) and two walking speeds (1.34 and 1.52 m/s), as well as the Prosthesis Evaluation Questionnaire. With the Stiff foot, sound limb peak loading was 2% smaller (p = 0.043) in the loaded versus unloaded condition, but similar between loading conditions in the Compliant foot (note, the Stiff foot was associated with larger loads, overall). Independent of load or walking speed, the Compliant (versus Stiff) foot provided 67.9% larger (p < 0.001) prosthetic push-off, 17.7% larger (p = 0.01) roll-over shape radii, and was subjectively favored by 10 participants. A more Compliant versus Stiff prosthetic foot therefore appears to better accommodate walking with and without added load, and reinforce the notion that mechanical properties of prosthetic feet should be considered for near-term performance and longer-term (joint) health.
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Affiliation(s)
- Barri L Schnall
- Research & Development Section, Department of Rehabilitation, Walter Reed National Military Medical Center, Bethesda, MD, USA
| | - Christopher L Dearth
- Research & Development Section, Department of Rehabilitation, Walter Reed National Military Medical Center, Bethesda, MD, USA; DoD-VA Extremity Trauma and Amputation Center of Excellence, Bethesda, MD, USA; Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Jonathan M Elrod
- Research & Development Section, Department of Rehabilitation, Walter Reed National Military Medical Center, Bethesda, MD, USA
| | - Pawel R Golyski
- Research & Development Section, Department of Rehabilitation, Walter Reed National Military Medical Center, Bethesda, MD, USA
| | - Sara R Koehler-McNicholas
- Minneapolis Department of Veterans Affairs Health Care System, Minneapolis, MN, USA; Division of Rehabilitation Science, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Samuel F Ray
- Research & Development Section, Department of Rehabilitation, Walter Reed National Military Medical Center, Bethesda, MD, USA
| | - Andrew H Hansen
- Minneapolis Department of Veterans Affairs Health Care System, Minneapolis, MN, USA; Division of Rehabilitation Science, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Brad D Hendershot
- Research & Development Section, Department of Rehabilitation, Walter Reed National Military Medical Center, Bethesda, MD, USA; DoD-VA Extremity Trauma and Amputation Center of Excellence, Bethesda, MD, USA; Department of Rehabilitation Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA.
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