scholarly journals A new structural concept in moulded fixed ankle foot orthoses and comparison of the bending stiffness of four constructions

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.

2016 ◽  
Vol 41 (4) ◽  
pp. 364-372 ◽  
Author(s):  
Conor Sheehan ◽  
Elaine Figgins

Background:Currently, a range of ‘off-the-shelf’ ankle foot orthoses are used in clinical practice, of various functions and designs. Their use relates to immediate control over mild conditions.Objectives:To investigate the properties of carbon fibre ankle foot orthoses at different percentage layups and provide a comparison of these through assessment of the (1) elastic properties, (2) deflection about the ankle (including the calculation of stiffness) and (3) failure under compressive forces (dorsiflexion).Study design:Experimental, bench test.Methods:Literature was reviewed to derive a suitable bench test for mechanical testing of ankle foot orthoses. Two universal Instron machines were used to apply the necessary forces. A pilot device was utilised to establish the range of forces appropriate to confirm the setup chosen was effective. Each test was then carried out on nine ankle foot orthoses (3 × 3 different percentage layups).Results:All nine devices had their elastic properties deduced. Stiffness exhibited greater resistance in tension, with angular deflection being greatest in the ‘Lite’ set and least in the Rigid. Failure occurred mainly due to fracture, proximally on the strut; however, this was not consistent among the devices.Conclusion:Results confirmed the properties expected of carbon fibre ankle foot orthoses were consistent. This can now be related to functionality and therefore specific device prescription options.Clinical relevanceThis article attempts to increase the understanding and develop the area of mechanically testing ankle foot orthoses. This was achieved by comparing carbon fibre at different percentage layups on an identical design and their resultant structural properties. This article outlines a clear and simple setup for obtaining repeatable results.


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.


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. 


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.


2020 ◽  
pp. 030936462097140
Author(s):  
Elizabeth Russell Esposito ◽  
Mitchell D Ruble ◽  
Andrea J Ikeda ◽  
Jason M Wilken

Background: Maintaining an optimal rolling of the foot over the ground is thought to increase the stability and efficiency of pathologic gait. Ankle-foot orthoses are often prescribed to improve gait mechanics in individuals with lower extremity injuries; however, their design may compromise how the foot rolls over the ground. Objectives: The aim of this study was to investigate the effects of the sagittal plane ankle-foot orthosis alignment on roll-over shape and center of pressure velocity in individuals with lower limb reconstructions. Study design: Randomized cross-over study with a control group comparison. Methods: In total, 12 individuals with lower limb reconstruction who used a custom carbon ankle-foot orthosis and 12 uninjured controls underwent gait analysis. Ankle-foot orthosis users were tested in their clinically-provided ankle-foot orthosis alignment, with an alignment that was 3° more plantarflexed, and with an alignment that was 3° more dorsiflexed. Components of roll-over shape and center of pressure velocity were calculated from heel strike on the ankle-foot orthosis limb to contralateral heel strike. Results: Roll-over shape radius was not affected by 3° changes to alignment and was not significantly different from controls. Aligning the ankle-foot orthosis in more dorsiflexion than clinically provided resulted in a smaller peak center of pressure velocity that occurred later in stance. Conclusion: Individuals using custom carbon ankle-foot orthoses can accommodate 3° alterations in the dorsiflexion or plantarflexion alignment.


2019 ◽  
Vol 43 (4) ◽  
pp. 453-458 ◽  
Author(s):  
Joshua Young ◽  
Sally Jackson

Background: Ankle-foot orthoses may be used in pre-ambulatory children with cerebral palsy; however, their effect on the acquisition of walking is unknown. This case report aims to evaluate the effect of an ankle-foot orthosis–footwear combination on the acquisition of walking in a single subject with cerebral palsy. Case Description and Methods: This study reports the orthotic management of a single child with spastic bilateral cerebral palsy over a 15-month period, during which time the ability to independently stand and walk was acquired. Custom rigid ankle-foot orthoses were prescribed. Gait speed and Edinburgh Visual Gait Score were assessed with and without the orthoses. Findings and Outcomes: The subject developed the ability to stand and walk using an ankle-foot orthosis–footwear combination with a walker frame, and to a limited extent without a walker frame. The subject remained unable to take independent steps unless wearing the ankle-foot orthosis–footwear combination. Clinically significant differences in gait speed and Edinburgh Visual Gait Score were observed. Conclusion: An ankle-foot orthosis–footwear combination may aid the development of independent walking in some children with cerebral palsy. Further research on the effects of orthoses on the acquisition of walking ability in children with cerebral palsy is needed. Clinical relevance Custom rigid ankle-foot orthoses combined with footwear may aid the development of independent standing and walking in some children with bilateral spastic cerebral palsy. This intervention may be considered in clinical practice and future research in this patient group.


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