Selective Laser Sintered Versus Carbon Fiber Passive-Dynamic Ankle-Foot Orthoses: A Comparison of Patient Walking Performance

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Nicole G. Harper ◽  
Elizabeth M. Russell ◽  
Jason M. Wilken ◽  
Richard R. Neptune
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Lower Limb ◽  
Selective Laser Sintering ◽  
Foot Orthoses ◽  
Gait Performance ◽  
Ankle Foot Orthoses ◽  
Subject Specific ◽  
Walking Performance ◽  
Design Characteristics

Selective laser sintering (SLS) is a well-suited additive manufacturing technique for generating subject-specific passive-dynamic ankle-foot orthoses (PD-AFOs). However, the mechanical properties of SLS PD-AFOs may differ from those of commonly prescribed carbon fiber (CF) PD-AFOs. Therefore, the goal of this study was to determine if biomechanical measures during gait differ between CF and stiffness-matched SLS PD-AFOs. Subject-specific SLS PD-AFOs were manufactured for ten subjects with unilateral lower-limb impairments. Minimal differences in gait performance occurred when subjects used the SLS versus CF PD-AFOs. These results support the use of SLS PD-AFOs to study the effects of altering design characteristics on gait performance.

scholarly journals Manufacturing and analysis of carbon fiber knee ankle foot orthosis

2018 ◽  
Vol 7 (4) ◽  
pp. 2236 ◽  
Author(s):  
Ayad M. Takhakh ◽  
Saif M. Abbas
Keyword(s):  
Mechanical Properties ◽  
Spinal Cord ◽  
Carbon Fiber ◽  
Tensile Tests ◽  
Foot Orthoses ◽  
Well Control ◽  
Ankle Foot Orthosis ◽  
Cord Injury ◽  
Ankle Foot Orthoses ◽  
Foot Orthosis

Knee ankle foot orthoses (KAFOs) are used by paraplegia patients with low level spinal cord injury and having well control of the stem muscles. Four layers of carbon fiber with C- orthocryl lamination resin are used for manufacturing the knee ankle foot orthoses in this work. The mechanical properties of most of the components materials were estimated with the aid of fatigue and tensile test machines. Results of the tensile tests showed that the mechanical properties: yield stress, ultimate strength and modulus of elasticity were 92MPa, 105.7MPa and 2GPa respectively. The value of amidst pressure between the patient limb and the manufactured KAFO was measured using (F-socket) Mat scan sensor and these values of pressure were (663kPa) and (316kPa) for the thigh and calf regions respectively. 

Effect of Shoes on Stiffness and Energy Efficiency of Ankle-Foot Orthosis: Bench Testing Analysis

2017 ◽  
Vol 33 (6) ◽  
pp. 460-463 ◽  
Author(s):  
Toshiki Kobayashi ◽  
Fan Gao ◽  
Nicholas LeCursi ◽  
K. Bo Foreman ◽  
Michael S. Orendurff
Keyword(s):  
Mechanical Properties ◽  
Energy Efficiency ◽  
Lower Limb ◽  
Plantar Flexion ◽  
Foot Orthoses ◽  
Testing Device ◽  
Ankle Foot Orthosis ◽  
Ankle Foot Orthoses ◽  
Bench Testing ◽  
Foot Orthosis

Understanding the mechanical properties of ankle-foot orthoses (AFOs) is important to maximize their benefit for those with movement disorders during gait. Though mechanical properties such as stiffness and/or energy efficiency of AFOs have been extensively studied, it remains unknown how and to what extent shoes influence their properties. The aim of this study was to investigate the effect of shoes on stiffness and energy efficiency of an AFO using a custom mechanical testing device. Stiffness and energy efficiency of the AFO were measured in the plantar flexion and dorsiflexion range, respectively, under AFO-alone and AFO-Shoe combination conditions. The results of this study demonstrated that the stiffness of the AFO-Shoe combination was significantly decreased compared to the AFO-alone condition, but no significant differences were found in energy efficiency. From the results, we recommend that shoes used with AFOs should be carefully selected not only based on their effect on alignment of the lower limb, but also their effects on overall mechanical properties of the AFO-Shoe combination. Further study is needed to clarify the effects of differences in shoe designs on AFO-Shoe combination mechanical properties.

scholarly journals Impact of ankle-foot orthoses on gait 1 year after lower limb surgery in children with bilateral cerebral palsy

2018 ◽  
Vol 43 (1) ◽  
pp. 12-20 ◽  
Author(s):  
Ingrid Skaaret ◽  
Harald Steen ◽  
Terje Terjesen ◽  
Inger Holm
Keyword(s):  
Cerebral Palsy ◽  
Gait Analysis ◽  
Lower Limb ◽  
Three Dimensional ◽  
Foot Orthoses ◽  
Important Improvement ◽  
Gait Dysfunction ◽  
Ankle Foot Orthoses ◽  
Profile Score ◽  
Lower Limb Surgery

Background: Different types of ankle-foot orthoses are commonly used following lower limb surgery in children with bilateral spastic cerebral palsy. After three-dimensional gait analysis 1 year postoperatively, many children are recommended continued use of ankle-foot orthoses. Objectives: Our aims were to quantify the impact of ankle-foot orthoses on gait 1 year postoperatively and evaluate predictors for clinically important improvement. Study design: Prospective cohort study. Methods: A total of 34 ambulating children with bilateral cerebral palsy, with mean age 11 years (range 6–17), comprising 12 girls and 22 boys, were measured with three-dimensional gait analysis preoperatively (barefoot) and 1 year postoperatively (barefoot and with ankle-foot orthoses). Outcome was evaluated using gait profile score, key kinematic, kinetic and temporal–spatial variables in paired sample comparisons. Logistic regression was used to evaluate predictors for clinically important improvement with orthoses (⩾1.6° change in gait profile score). Results: Walking barefoot 1 year postoperatively, major improvements were seen in gait profile score and key variables. With ankle-foot orthoses, there were significantly improved step length and velocity, additional moderate reduction/improvement in gait profile score and knee moments and decreased stance ankle dorsiflexion compared to barefoot. Children using ground reaction ankle-foot orthoses ( n = 14) decreased stance knee flexion from 13.9° walking barefoot to 8.2° with orthoses. High gait profile score and more gait dysfunction preoperatively were significant predictors of clinically important improvement walking with orthoses. Conclusion: The results indicate improved gait function walking with ankle-foot orthoses versus barefoot 1 year after lower limb surgery. Stronger impact of ankle-foot orthoses was found in children with more pronounced gait dysfunction preoperatively. Clinical relevance The 1-year postoperative three-dimensional gait analysis is a useful method to assess treatment outcome after lower limb surgery in children with bilateral cerebral palsy and could also guide clinicians whether further treatment with ankle-foot orthoses is indicated, using clinically important differences as thresholds to evaluate their impact on gait.

Carbon Fiber Based Twisted and Coiled Artificial Muscles (TCAMs) for Powered Ankle-Foot Orthoses (AFO)

2021 ◽  
Author(s):  
Parth Kotak ◽  
Jason Wilken ◽  
Kirsten Anderson ◽  
Caterina Lamuta
Keyword(s):  
Carbon Fiber ◽  
Low Cost ◽  
Input Voltage ◽  
Input Power ◽  
Artificial Muscles ◽  
Specific Work ◽  
Foot Orthoses ◽  
Ankle Foot Orthoses ◽  
Low Cost Manufacturing

Abstract Ankle foot orthoses (AFOs) control the position and motion of the ankle, compensate for weakness, and correct deformities. AFOs can be classified as passive or powered. Powered AFOs overcome the limitations of passive AFOs by adapting their performance to meet a variety of requirements. However, the actuators currently used to power AFOs are typically heavy, bulky, expensive, or limited to laboratory settings. Thus, there is a strong need for lightweight, inexpensive, and flexible actuators for powering AFOs. In this technical brief, Carbon Fiber/Silicone Rubber (CF/SR) Twisted and Coiled Artificial Muscles (TCAMs) are proposed as novel actuators for powered AFOs. CF/SR TCAMs can lift up to 12,600 times their weight with an input power of only 0.025 W cm-1 and are fabricated from inexpensive materials through a low-cost manufacturing process. Additionally, they can provide a specific work of 758 J kg-1 when an input voltage of 1.64 V cm-1 is applied. A mechanical characterization of CF/SR TCAMs in terms of length/tension, tension/velocity, and active-passive length/tension is presented, and results are compared with the performance of skeletal muscles. A gait analysis demonstrates that CF/SR TCAMs can provide the performance required to supplement lower limb musculature and replicate the gait cycle of a healthy subject. Therefore, the preliminary results provided in this brief are a stepping stone for a dynamic AFO powered by CF/SR TCAMs.

Ankle–foot orthosis alignment affects running mechanics in individuals with lower limb injuries

2019 ◽  
Vol 43 (3) ◽  
pp. 316-324
Author(s):  
Kelly A Schmidtbauer ◽  
E Russell Esposito ◽  
Jason M Wilken
Keyword(s):  
Lower Extremity ◽  
Lower Limb ◽  
Knee Extensor ◽  
Design Parameters ◽  
Foot Orthoses ◽  
Lower Limb Injury ◽  
Limb Injuries ◽  
Peak Knee ◽  
Ankle Foot Orthoses ◽  
Running Mechanics

Background: Individuals with severe lower extremity injuries often require ankle–foot orthoses to return to normal activities. Ankle–foot orthoses alignment is a key consideration during the clinical fitting process and may be particularly important during dynamic activities such as running. Objective: To investigate how 3° changes in sagittal plane ankle–foot orthoses alignment affect running mechanics. Study design: Controlled laboratory study. Methods: Twelve participants with unilateral lower limb injury ran overground and lower extremity running mechanics were assessed. Participants wore their passive-dynamic ankle–foot orthoses in three alignments: clinically fit neutral, 3° plantarflexed from clinically fit neutral, and 3° dorsiflexed from clinically fit neutral. Results: The 3° changes in sagittal alignment significantly influenced ankle mechanics during running. The plantarflexed alignment significantly decreased the peak ankle plantarflexor moment, peak knee extensor moment, and peak ankle and knee power absorption and generation compared to more dorsiflexed alignments. Alignment also altered footstrike angle, with dorsiflexed alignments associated with a more dorsiflexed footstrike pattern and plantarflexed alignments toward a more plantarflexed footstrike pattern. However, alignment did not influence loading rate. Conclusion: Small changes in ankle–foot orthoses alignment significantly altered running mechanics, including footstrike angle, and knee extensor moments. Understanding how ankle–foot orthoses design parameters affect running mechanics may aid the development of evidence-based prescription guidelines and improve function for ankle–foot orthoses users who perform high-impact activities. Clinical relevance Understanding how ankle–foot orthoses alignment impacts biomechanics should be a consideration when fitting passive-dynamic devices for higher impact activities, such as running. Individual running styles, including footstrike patterns, may be affected by small changes in alignment.

Effect of ankle-foot orthoses on trunk sway and lower limb intersegmental coordination in children with bilateral cerebral palsy

2012 ◽  
Vol 5 (3) ◽  
pp. 171-179 ◽  
Author(s):  
Marc Degelean ◽  
Ludo De Borre ◽  
Patrick Salvia ◽  
Karine Pelc ◽  
Eric Kerckhofs ◽  
...  
Keyword(s):  
Cerebral Palsy ◽  
Lower Limb ◽  
Foot Orthoses ◽  
Intersegmental Coordination ◽  
Ankle Foot Orthoses ◽  
Trunk Sway

Computational and experimental evaluation of the mechanical properties of ankle foot orthoses: A literature review

2019 ◽  
Vol 43 (3) ◽  
pp. 339-348
Author(s):  
Alessio Ielapi ◽  
Malcolm Forward ◽  
Matthieu De Beule
Keyword(s):  
Mechanical Properties ◽  
Literature Review ◽  
English Language ◽  
Computational Models ◽  
Real Life ◽  
Relevant Information ◽  
Gait Pattern ◽  
Foot Orthoses ◽  
Ankle Foot Orthoses ◽  
Gaining Insight

Background: Ankle foot orthoses are external medical devices applied around the ankle joint area to provide stability to patients with neurological, muscular, and/or anatomical disabilities, with the aim of restoring a more natural gait pattern. Study design: This is a literature review. Objectives: To provide a description of the experimental and computational methods present in the current literature for evaluating the mechanical properties of the ankle foot orthoses. Methods: Different electronic databases were used for searching English-language articles realized from 1990 onward in order to select the newest and most relevant information available. Results: A total of 46 articles were selected, which describe the different experimental and computational approaches used by research groups worldwide. Conclusion: This review provides information regarding processes adopted for the evaluation of mechanical properties of ankle foot orthoses, in order to both improve their design and gain a deeper understanding of their clinical use. The consensus drawn is that the best approach would be represented by a combination of advanced computational models and experimental techniques, capable of being used to optimally mimic real-life conditions. Clinical relevance In literature, several methods are described for the mechanical evaluation of ankle foot orthoses (AFOs); therefore, the goal of this review is to guide the reader to use the best approach in the quantification of the mechanical properties of the AFOs and to help gaining insight in the prescription process.

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