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.

scholarly journals Studies Examining the Efficacy of Ankle Foot Orthoses should Report Activity Level and Mechanical Evidence

2010 ◽  
Vol 34 (3) ◽  
pp. 327-335 ◽  
Author(s):  
Jaap Harlaar ◽  
Merel Brehm ◽  
Jules G. Becher ◽  
Daan J. J. Bregman ◽  
Jaap Buurke ◽  
...  
Keyword(s):  
Treatment Algorithm ◽  
Relevant Information ◽  
Current Treatment ◽  
Activity Level ◽  
Walking Ability ◽  
Foot Orthoses ◽  
Level Of Evidence ◽  
Levels Of Evidence ◽  
Ankle Foot Orthoses

Ankle Foot Orthoses (AFOs) to promote walking ability are a common treatment in patients with neurological or muscular diseases. However, guidelines on the prescription of AFOs are currently based on a low level of evidence regarding their efficacy. Recent studies aiming to demonstrate the efficacy of wearing an AFO in respect to walking ability are not always conclusive. In this paper it is argued to recognize two levels of evidence related to the ICF levels. Activity level evidence expresses the gain in walking ability for the patient, while mechanical evidence expresses the correct functioning of the AFO. Used in combination for the purpose of evaluating the efficacy of orthotic treatment, a conjunct improvement at both levels reinforces the treatment algorithm that is used. Conversely, conflicting outcomes will challenge current treatment algorithms and the supposed working mechanism of the AFO. A treatment algorithm must use relevant information as an input, derived from measurements with a high precision. Its result will be a specific AFO that matches the patient's needs, specified by the mechanical characterization of the AFO footwear combination. It is concluded that research on the efficacy of AFOs should use parameters from two levels of evidence, to prove the efficacy of a treatment algorithm, i.e., how to prescribe a well-matched AFO.

scholarly journals Forces and moments in knee–ankle–foot orthoses while walking on irregular surfaces: A case series study

2013 ◽  
Vol 38 (2) ◽  
pp. 104-113 ◽  
Author(s):  
Jan Andrysek ◽  
Susan Klejman ◽  
John Kooy
Keyword(s):  
Knee Flexion ◽  
Real Life ◽  
Case Series ◽  
Assistive Devices ◽  
Foot Orthoses ◽  
Irregular Surfaces ◽  
Case Series Study ◽  
Peak Knee ◽  
Ankle Foot Orthoses ◽  
Series Study

Background: Kinetic data provide important information about the mobility performance of individuals with lower limb impairments and their assistive devices; however, there is limited understanding of this in real-life environments. Objective: To evaluate the effect of real-life irregular surfaces on forces and moments in knee–ankle–foot orthoses. Methods: In this case series study, a load cell was used to measure the forces and moments at the knee joint of knee–ankle–foot orthoses of individuals with unilateral muscle weakness as a result of poliomyelitis while walking on different ground surfaces and at different speeds. Results: Significantly higher shear forces and external peak knee flexion moments were found when walking on irregular surfaces. In individual cases, certain irregular ground conditions elicited large increases in peak flexion moments (>50%) when compared to walking on smooth level ground. Forces and moments were significantly higher at faster walking speeds. Conclusions: Higher external peak knee flexion moments during the stance phase suggest that greater demands for support and stability are placed on individuals and their assistive devices when negotiating real-life ground surfaces. Clinical relevance This study demonstrates that walking on irregular surfaces alters the loads placed on knee–ankle–foot orthoses and that the requirements for knee stabilization increase. This has important clinical implications on the design, prescription, and use of such devices given the structural and functional demands placed on them.

scholarly journals OrthoRehab: Development of a New Methodology for the Comparison Study Between Different Types of Ankle–Foot Orthoses in Foot Dysfunction

2021 ◽  
Vol 2 ◽  
Author(s):  
Cláudia Quaresma ◽  
Barbara Lopes ◽  
Jorge Jacinto ◽  
Tiago Robalo ◽  
Mariana Matos ◽  
...  
Keyword(s):  
Plantar Flexion ◽  
Decision Support Tool ◽  
Clinical Decision ◽  
Rehabilitation Medicine ◽  
Gait Pattern ◽  
Real Problem ◽  
Foot Orthoses ◽  
Support Tool ◽  
Ankle Foot Orthoses ◽  
User Friendly

Foot dysfunction is one of the most likely consequences of rheumatoid arthritis and stroke. It is characterized by severe changes in the gait pattern due to a significant increase in the plantar flexion. Some of these dysfunctions can be compensated by using an ankle–foot orthosis. However, the clinical decision about which orthosis best suits the patient creates a real problem for physicians/therapists.Purpose: The main goal of this paper is to present a quantitative support tool that can assist the physicians/therapists in deciding which orthosis is most suitable for each subject.Methodology: In order to achieve such goal, a platform named OrthoRehab was developed, and it was tested in three conditions: without any orthosis and with two different ankle–foot orthoses. The data were acquired in the Gait Laboratory of Rehabilitation Medicine Center of Alcoitão using a VICON NEXUS 1.8.5® motion capture system that allows the capturing of kinematic and kinetic data.Results: The results reveal that OrthoRehab is a user-friendly, easy to apply tool that analyzes very relevant data for the clinical staff.Conclusion: The developed decision support tool, OrthoRehab, offers a quantitative analysis and provides insight to which orthosis achieves the best performance in comparison with the patient's gait pattern with no orthosis.

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 Using the Edinburgh Visual Gait Score to Compare Ankle-Foot Orthoses, Sensorimotor Orthoses and Barefoot Gait Pattern in Children with Cerebral Palsy

Children ◽  
2020 ◽  
Vol 7 (6) ◽  
pp. 54 ◽  
Author(s):  
Clare MacFarlane ◽  
Wayne Hing ◽  
Robin Orr
Keyword(s):  
Cerebral Palsy ◽  
Gait Analysis ◽  
Gait Pattern ◽  
Spastic Diplegia ◽  
Foot Orthoses ◽  
Gait Quality ◽  
Spastic Quadriplegia ◽  
Ankle Foot Orthoses ◽  
Children With Cerebral Palsy ◽  
Gait Score

Gait analysis is one aspect of evaluation in ambulatory children with cerebral palsy (CP). Ankle-foot orthoses (AFOs) improve gait and alignment through providing support. An alternative and under-researched orthosis are sensomotoric orthoses (SMotOs). The Edinburgh Visual Gait Score (EVGS) is a valid observational gait analysis scale to measure gait quality. The aim of this study was to use the EVGS to determine what effect AFOs and SMotOs have on gait in children with CP. The inclusion criteria were: mobilizing children with a CP diagnosis, no surgery in the past six weeks, and currently using SMotOs and AFOs. Eleven participants were videoed walking 5 m (any order) barefoot, in SMotOs and AFOs. Of the participants (age range 3–13 years, mean 5.5 ± 2.9), two were female and six used assistive devices. Seven could walk barefoot. Participants had spastic diplegia (4), spastic quadriplegia (6), and spastic dystonic quadriplegia (1). Gross Motor Functional Classification System (GMFCS) levels ranged I–IV. The total score for SMotOs (7.62) and AFOs (14.18) demonstrated improved gait when wearing SMotOs (no significant differences between barefoot and AFOs). SMotOs may be a viable option to improve gait in this population. Additional study is required but SMotOs may be useful in clinical settings.

scholarly journals Classification of Ankle Joint Stiffness during Walking to Determine the Use of Ankle Foot Orthosis after Stroke

2021 ◽  
Vol 11 (11) ◽  
pp. 1512
Author(s):  
Yusuke Sekiguchi ◽  
Keita Honda ◽  
Dai Owaki ◽  
Shin-Ichi Izumi
Keyword(s):  
Ankle Joint ◽  
Joint Stiffness ◽  
Hierarchical Cluster ◽  
Gait Pattern ◽  
Foot Orthoses ◽  
Gait Patterns ◽  
Ankle Foot Orthosis ◽  
Ankle Foot Orthoses ◽  
Foot Orthosis

Categorization based on quasi-joint stiffness (QJS) may help clinicians select appropriate ankle foot orthoses (AFOs). The objectives of the present study were to classify the gait pattern based on ankle joint stiffness, also called QJS, of the gait in patients after stroke and to clarify differences in the type of AFO among 72 patients after stroke. Hierarchical cluster analysis was used to classify gait patterns based on QJS at least one month before the study, which revealed three distinct subgroups (SGs 1, 2, and 3). The proportion of use of AFOs, articulated AFOs, and non-articulated AFOs were significantly different among SGs 1–3. In SG1, with a higher QJS in the early and middle stance, the proportion of the patients using articulated AFOs was higher, whereas in SG3, with a lower QJS in both stances, the proportion of patients using non-articulated AFOs was higher. In SG2, with a lower QJS in the early stance and higher QJS in the middle stance, the proportion of patients using AFOs was lower. These findings indicate that classification of gait patterns based on QJS in patients after stroke may be helpful in selecting AFO. However, large sample sizes are required to confirm these results.

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.

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