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

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. 

2017 ◽  
Vol 33 (6) ◽  
pp. 460-463 ◽  
Author(s):  
Toshiki Kobayashi ◽  
Fan Gao ◽  
Nicholas LeCursi ◽  
K. Bo Foreman ◽  
Michael S. Orendurff

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.


1997 ◽  
Vol 21 (3) ◽  
pp. 210-221 ◽  
Author(s):  
G. Baardman ◽  
M. J. Ijzerman ◽  
H. J. Hermen ◽  
P. H. Veltink ◽  
H. B. K. Boom ◽  
...  

The effect of reciprocally linking the hip hinges of a hip-knee-ankle-foot orthosis on standing performance was studied in a comparative trial of the Advanced Reciprocating Gait Orthosis (ARGO) and an ARGO in which the Bowden cable was removed (A_GO). Six male subjects with spinal cord injury (SCI) at T4 to T12 level participated in the study, which was conducted using a single case experimental design. Standing balance, the ability to handle balance disturbances (standing stability), and the performance of a functional hand task during standing were assessed in both orthosis configurations in the order A_GO-ARGO-A_GO-ARGO. No significant differences with respect to standing performance were found for the two orthosis configurations. However, the results indicate that the crutch force needed for maintaining balance during various tasks, especially for quiet standing with two crutches, may be much higher in the orthosis without Bowden cable. Therefore, it is very likely that the reciprocal hip joint link in the ARGO provides a substantial and clinically relevant reduction of upper body effort required for standing under functional conditions.


2020 ◽  
pp. 030936462095290
Author(s):  
David Lahoud ◽  
Christine HE Teng ◽  
Erez Nusem ◽  
Joshua Burns ◽  
Cara Wrigley ◽  
...  

Background: The evaluation of ankle–foot orthoses is primarily focused on biomechanical performance, with comparatively less studies pertaining to users’ quality of life and experiential factors. Objectives: To investigate how child users regard acquisition and use of ankle–foot orthoses through the perspectives of child users, parents/carers and practitioners. Study design: Inductive content analysis of secondary data. Methods: Child user and parent/carer perspectives, as communicated by them and by practitioners, were collected from online platforms and formal publications. Data and themes were analysed through an inductive approach. Investigator triangulation was used to increase trustworthiness and reduce bias. Results: We found and analysed 223 data points from 30 informal online platforms and 15 formal publications. These data clustered into five key themes relating to user experience with ankle–foot orthoses, including materials, structure, aesthetics, service and impact. Child users had mixed opinions about ankle–foot orthoses, reporting satisfaction with the functional improvements resulting from ankle–foot orthosis wear, while noting negative feelings from the experience of acquiring and using the device. Conclusion: This research suggests that considering the five themes in ankle–foot orthosis provision could improve the child user experience, inform future ankle–foot orthosis design, and improve clinical outcomes.


2016 ◽  
Vol 41 (3) ◽  
pp. 274-285 ◽  
Author(s):  
Hwan Choi ◽  
Tishya Anne Leong Wren ◽  
Katherine Muterspaugh Steele

Background:Many individuals with cerebral palsy wear ankle foot orthoses during daily life. Orthoses influence joint motion, but how they impact muscle remains unclear. In particular, the gastrocnemius is commonly stiff in cerebral palsy. Understanding whether orthoses stretch or shorten this muscle during daily life may inform orthosis design and rehabilitation.Objectives:This study investigated the impact of different ankle foot orthoses on gastrocnemius operating length during walking in children with cerebral palsy.Study design:Case series, within subject comparison of gastrocnemius operating length while walking barefoot and with two types of ankle foot orthoses.Methods:We performed gait analyses for 11 children with cerebral palsy. Each child was fit with two types of orthoses: a dynamic ankle foot orthosis (Cascade dynamic ankle foot orthosis) and an adjustable dynamic response ankle foot orthosis (Ultraflex ankle foot orthosis). Musculoskeletal modeling was used to quantify gastrocnemius musculotendon operating length and velocity with each orthosis.Results:Walking with ankle foot orthoses could stretch the gastrocnemius more than barefoot walking for some individuals; however, there was significant variability between participants and orthoses. At least one type of orthosis stretched the gastrocnemius during walking for 4/6 and 3/5 of the Gross Motor Functional Classification System Level I and III participants, respectively. AFOs also reduced peak gastrocnemius lengthening velocity compared to barefoot walking for some participants, with greater reductions among the Gross Motor Functional Classification System Level III participants. Changes in gastrocnemius operating length and lengthening velocity were related to changes in ankle and knee kinematics during gait.Conclusion:Ankle foot orthoses impact gastrocnemius operating length during walking and, with proper design, may assist with stretching tight muscles in daily life.Clinical relevanceDetermining whether ankle foot orthoses stretch tight muscles can inform future orthotic design and potentially provide a platform for integrating therapy into daily life. However, stretching tight muscles must be balanced with other goals of orthoses such as improving gait and preventing bone deformities.


2012 ◽  
Vol 37 (2) ◽  
pp. 95-107 ◽  
Author(s):  
Nicola Eddison ◽  
Nachiappan Chockalingam

Background:There are a wide variety of ankle foot orthoses used in clinical practice which are characterised by their design, the material used and the stiffness of that material. Changing any of these three components will alter the effect of the ankle foot orthosis on gait.Objectives:The purpose of this article is to provide an overview on the available research on ankle foot orthosis–footwear combination tuning on the gait characteristics of children with cerebral palsy through a structured review.Study Design:Literature review.Methods:A thorough search of previous studies published in English was conducted within all major databases using relevant phrases without any limits for the dates. These searches were then supplemented by tracking all key references from the appropriate articles identified including hand searching of published books where relevant.Results:To date, there are 947 papers in the literature pertaining to the study of ankle foot orthosis. Of these, 153 investigated the use of ankle foot orthosis for children with cerebral palsy. All the studies included in this review were of a within-subjects design and the evidence levels were generally low.Conclusions:The overall results suggested that ankle foot orthosis–footwear combination tuning has the potential to improve the kinematics and kinetics of gait in children with cerebral palsy. However, the review highlights a lack of well-designed and adequately powered studies.Clinical relevanceWhile the research described in this article indicates an improvement in the gait of children with cerebral palsy following tuning of their ankle foot orthosis–footwear combination, there is still a paucity of research with quantitative data on the effects of kinematics and kinetics of ankle foot orthosis–footwear combination tuning, comparing untuned ankle foot orthosis–footwear combinations with tuned ankle foot orthosis–footwear combination. Furthermore, current research does not identify the effect of tuning on energy efficiency.


2004 ◽  
Vol 28 (1) ◽  
pp. 44-48 ◽  
Author(s):  
R. E. Major ◽  
P. J. Hewart ◽  
A. M. Macdonald

There are many reasons why a rigid ankle foot orthosis (AFO) may be prescribed. In some cases it is desirable that the rigidity is sufficient to maintain a constant ankle position throughout the gait cycle. There is a need to determine a design of cosmetic, lightweight AFO that provides the necessary stiffness whilst being acceptable to the patient, encouraging continued wear with the resultant benefits. This paper describes an investigation of AFO resistance to dorsiflexion, comparing the stiffness of an AFO with forward trim lines, two designs of reinforced AFOs and an AFO with forward trim lines and an external ankle strap. One reinforced AFO had corrugations moulded in the polypropylene around the ankle, the other had carbon fibre inserts attached to the inside of the polypropylene. The emphasis was on testing the mechanical stiffness of the four AFO designs: the test procedure did not mimic the patterns of AFO loading during gait. Each design was tested in the same manner by the same examiner. The AFO with forward trimlines and an ankle strap displayed similar stiffness to the carbon fibre reinforced AFO and both were stiffer than the other two designs.


2018 ◽  
Vol 42 (5) ◽  
pp. 544-553 ◽  
Author(s):  
Sumiko Yamamoto ◽  
Souji Tanaka ◽  
Naoyuki Motojima

Background: The effect of plantar flexion resistance of ankle–foot orthoses on the ankle and knee joints is well known, but its effect on the hip joint and upper body movement during the gait of stroke patients remains unclear. Objectives: To compare the effect of an ankle–foot orthosis with plantar flexion stop and an ankle–foot orthosis with plantar flexion resistance on the gait of stroke patients in the subacute phase. Study design: Randomized controlled trial. Methods: A total of 42 stroke patients (mean age = 59.9 ± 10.9 years, 36 men and 4 women) in the subacute phase were randomized to each ankle–foot orthosis group in a parallel controlled trial with no blinding. Patients received gait training from physiotherapists using the specified ankle–foot orthosis for 2 weeks. Shod gait without an ankle–foot orthosis before training and gait with an ankle–foot orthosis after training were measured by three-dimensional motion analysis. Results: A total of 20 patients were analyzed in each group. Significant differences were found in pelvic and thoracic tilt angles between the two groups. Compared with the gait without an ankle–foot orthosis, the pelvis showed forward tilt when patients walked with an ankle–foot orthosis with plantar flexion stop, and the thorax showed decreased forward tilt when the patients walked with an ankle–foot orthosis with plantar flexion resistance. Conclusion: The difference in ankle–foot orthosis function in sagittal plantar flexion resistance affected the alignment of the upper body and the pelvis during the gait of stroke patients in the subacute phase. Clinical relevance Maintaining upright posture is important in gait rehabilitation. The findings of this study suggest that the ankle–foot orthosis with plantar flexion resistance facilitated better alignment of the upper body and pelvis during the gait of stroke patients in subacute phase. This type of ankle–foot orthosis could be beneficial for patients with malalignment of the upper body and pelvis.


2013 ◽  
Vol 38 (2) ◽  
pp. 148-154 ◽  
Author(s):  
Angelika Zissimopoulos ◽  
Stefania Fatone ◽  
Steven Gard

Background: One intervention often used to address physical impairments post stroke is an ankle–foot orthosis. Ankle–foot orthoses may improve walking speed, stride length, and gait pattern. However, effects on balance, crucial for safe ambulation, are thus far inconclusive. One aspect of balance shown to contribute to functional ability is self-efficacy. Self-efficacy, defined as the belief in one’s ability to succeed in particular situations, has been shown to be more strongly associated with activity and participation (as defined by the International Classification of Functioning, Disability, and Health) than physical performance measures of gait or balance. Objectives: We investigated whether self-efficacy, or balance confidence when referred to in the context of balance capabilities, is improved with ankle–foot orthosis use. Study design: Repeated measures study design. Methods: Balance confidence was measured using the Activities-specific Balance Confidence Scale in 15 persons with chronic poststroke hemiplegia, with and without their regular ankle–foot orthosis. Results: Activities-specific Balance Confidence Scale scores were significantly higher ( p ≤ 0.01) for the ankle–foot orthosis condition compared to no ankle–foot orthosis. Conclusions: One mechanism by which ankle–foot orthosis use may influence balance is improved balance confidence. Future work should explore the specific mechanisms underlying this improvement in self-efficacy. Clinical relevance Self-efficacy may be an important factor to consider when evaluating functioning post stroke. Rehabilitative interventions that improve balance confidence may help restore participation and overall functioning in pathological populations, particularly in the fall-prone poststroke population. Study results provide evidence for improvements in balance confidence with ankle–foot orthosis use.


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