The effect of custom carbon ankle-foot orthosis alignment on roll-over shape and center of pressure velocity

2020 ◽  
pp. 030936462097140
Author(s):  
Elizabeth Russell Esposito ◽  
Mitchell D Ruble ◽  
Andrea J Ikeda ◽  
Jason M Wilken
Keyword(s):  
Lower Limb ◽  
Sagittal Plane ◽  
Center Of Pressure ◽  
Heel Strike ◽  
Control Group ◽  
Foot Orthoses ◽  
Ankle Foot Orthosis ◽  
Ankle Foot Orthoses ◽  
Foot Orthosis ◽  
Center Of Pressure Velocity

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.

scholarly journals Safety and walking ability of KAFO users with the C-Brace® Orthotronic Mobility System, a new microprocessor stance and swing control orthosis

2016 ◽  
Vol 41 (1) ◽  
pp. 65-77 ◽  
Author(s):  
Eva Pröbsting ◽  
Andreas Kannenberg ◽  
Britta Zacharias
Keyword(s):  
Activities Of Daily Living ◽  
Lower Limb ◽  
Daily Living ◽  
Foot Orthoses ◽  
Evaluation Questionnaire ◽  
Ankle Foot Orthosis ◽  
Stance Control ◽  
Ankle Foot Orthoses ◽  
Locked Knee ◽  
Foot Orthosis

Background: There are clear indications for benefits of stance control orthoses compared to locked knee ankle foot orthoses. However, stance control orthoses still have limited function compared with a sound human leg. Objectives: The aim of this study was to evaluate the potential benefits of a microprocessor stance and swing control orthosis compared to stance control orthoses and locked knee ankle foot orthoses in activities of daily living. Study design: Survey of lower limb orthosis users before and after fitting of a microprocessor stance and swing control orthosis. Methods: Thirteen patients with various lower limb pareses completed a baseline survey for their current orthotic device (locked knee ankle foot orthosis or stance control orthosis) and a follow-up for the microprocessor stance and swing control orthosis with the Orthosis Evaluation Questionnaire, a new self-reported outcome measure devised by modifying the Prosthesis Evaluation Questionnaire for use in lower limb orthotics and the Activities of Daily Living Questionnaire. Results: The Orthosis Evaluation Questionnaire results demonstrated significant improvements by microprocessor stance and swing control orthosis use in the total score and the domains of ambulation ( p = .001), paretic limb health ( p = .04), sounds ( p = .02), and well-being ( p = .01). Activities of Daily Living Questionnaire results showed significant improvements with the microprocessor stance and swing control orthosis with regard to perceived safety and difficulty of activities of daily living. Conclusion: The microprocessor stance and swing control orthosis may facilitate an easier, more physiological, and safer execution of many activities of daily living compared to traditional leg orthosis technologies. Clinical relevance This study compared patient-reported outcomes of a microprocessor stance and swing control orthosis (C-Brace) to those with traditional knee ankle foot orthosis and stance control orthosis devices. The C-Brace offers new functions including controlled knee flexion during weight bearing and dynamic swing control, resulting in significant improvements in perceived orthotic mobility and safety.

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 An Improved Smart Ankle Foot Othosis Design Using Dual Fluid Power Cylinders

2010 ◽  
Vol 4 (2) ◽  
Author(s):  
Ricky Mehta ◽  
Eric L. Rohrs ◽  
Katarina F. Lipat ◽  
Evan C. Reed ◽  
Manish Paliwal
Keyword(s):  
Hydraulic Cylinder ◽  
Metatarsal Head ◽  
Foot Drop ◽  
Heel Strike ◽  
Neutral Position ◽  
Foot Orthoses ◽  
Ankle Foot Orthosis ◽  
Plantar Surface ◽  
Ankle Foot Orthoses ◽  
Foot Orthosis

To design a smart ankle-foot orthosis (SAFO) that improves upon current ankle-foot orthoses used to treat steppage gait. Current ankle-foot orthoses are subjected to significant stresses on the ankle region of the structure, causing discomfort and the possible failure of the AFO. Although these AFOs have a constant stiffness, they do not reduce the occurrence of slap foot, where the foot slaps on the ground rather than gradually lowering it. The SAFO is an active ankle-foot orthosis that allows the user’s foot to follow a normal gait cycle. It is designed to reduce stress at the ankle by allowing for movement of the foot beyond a 90 deg angle for plantarflexion. The hinged ankle-foot orthosis is incorporated with a novel dual hydraulic-cylinder system, two tension springs, and force sensitive resistors. The force sensors are placed at the hallux, first metatarsal head, fifth metatarsal base, and heel. The foot movement actuation follows the force applied to the plantar surface of the foot during gait. The sensor outputs are fed to a signal processor and control interface to coordinate the motor actuation with the forces exerted by the user. The motor turns the screw attached to the hydraulic cylinders, which, thereby, control the orifice size by moving a plate in the cylinder, thus, changing the resistance. The cylinder filled with air will be pressurized during the lean phase, as the orifices will be closed and will provide power just as a spring would during the heel-off phase. After the heel strike, the resistance of the fluid-filled cylinder is decreased to slowly lower the foot. Once the foot is flat, the resistance of the fluid-filled cylinder is increased to keep the foot in a position to allow for toe clearance. During the heel-off event, the air-filled cylinder will assist the user with the power to push off. When toe-off occurs, the fluid-filled cylinder will decrease the resistance to allow the tension springs to bring the foot back to neutral position. To power the motor and sensors, a rechargeable battery pack is placed in a waist bag. The SAFO’s flexible design uses a novel combination of hydraulic-pneumatic cylinders to prevent foot drop, and restore the user’s sense of normalcy by providing late stance plantarflexion and a return to neutral position in early swing phase.

Content analysis of child user and carer perspectives of ankle–foot orthoses

2020 ◽  
pp. 030936462095290
Author(s):  
David Lahoud ◽  
Christine HE Teng ◽  
Erez Nusem ◽  
Joshua Burns ◽  
Cara Wrigley ◽  
...  
Keyword(s):  
Content Analysis ◽  
User Experience ◽  
Secondary Data ◽  
Foot Orthoses ◽  
Ankle Foot Orthosis ◽  
Online Platforms ◽  
Ankle Foot Orthoses ◽  
Data Points ◽  
Negative Feelings ◽  
Foot Orthosis

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.

scholarly journals Gastrocnemius operating length with ankle foot orthoses in cerebral palsy

2016 ◽  
Vol 41 (3) ◽  
pp. 274-285 ◽  
Author(s):  
Hwan Choi ◽  
Tishya Anne Leong Wren ◽  
Katherine Muterspaugh Steele
Keyword(s):  
Cerebral Palsy ◽  
Classification System ◽  
Daily Life ◽  
System Level ◽  
Foot Orthoses ◽  
Functional Classification ◽  
Ankle Foot Orthosis ◽  
Ankle Foot Orthoses ◽  
Children With Cerebral Palsy ◽  
Foot Orthosis

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.

scholarly journals A Model to Predict the Effect of Ankle Joint Misalignment on Calf Band Movement in Ankle-Foot Orthoses

2007 ◽  
Vol 31 (1) ◽  
pp. 76-87 ◽  
Author(s):  
Stefania Fatone ◽  
Andrew H. Hansen
Keyword(s):  
Ankle Joint ◽  
Walking Speed ◽  
Sagittal Plane ◽  
Plantar Flexion ◽  
Dimensional Model ◽  
Ankle Foot Orthosis ◽  
Ankle Joints ◽  
Ankle Foot Orthoses ◽  
Foot Orthosis ◽  
Anterior Posterior

Accurate alignment of anatomical and mechanical joint axes is one of the major biomechanical principles pertaining to articulated orthoses, yet knowledge of the potential effects of axis misalignment is limited. The purpose of this project was to model the effects of systematic linear (proximal-distal and anterior-posterior) misalignments of single axis mechanical ankle joints in an ankle-foot orthosis (AFO) in order to determine the degree and direction of calf band travel that would occur over a functional range of motion. Sagittal plane misalignments of the ankle joint centres of an AFO were simulated using a simple two-dimensional model for both a range of ankle angles and a typical able-bodied ankle kinematic curve for self-selected normal walking speed. The model assumed that no movement occurred between the foot and the foot-plate of the AFO. The model predicted that for anterior (positive horizontal) misalignments, dorsiflexion movements would cause the calf band to travel proximally (i.e., up the leg) and plantar flexion movements would cause the calf band to travel distally (i.e., down the leg). The opposite was predicted for posterior (negative horizontal) misalignments. Proximal (positive vertical) misalignments would cause only distal movements of the calf band while distal (negative vertical) misalignments would cause only proximal movements of the calf band. Anterior-posterior misalignments were found to have a much larger effect on the amount of calf band travel than proximal-distal misalignments.

The effect of tuning ankle foot orthoses–footwear combination on the gait parameters of children with cerebral palsy

2012 ◽  
Vol 37 (2) ◽  
pp. 95-107 ◽  
Author(s):  
Nicola Eddison ◽  
Nachiappan Chockalingam
Keyword(s):  
Cerebral Palsy ◽  
Foot Orthoses ◽  
Ankle Foot Orthosis ◽  
Gait Parameters ◽  
Ankle Foot Orthoses ◽  
Children With Cerebral Palsy ◽  
Within Subjects ◽  
Kinetics Of ◽  
Kinematics And Kinetics ◽  
Foot Orthosis

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.

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
Keyword(s):  
Carbon Fibre ◽  
Gait Cycle ◽  
Test Procedure ◽  
The Other ◽  
Foot Orthoses ◽  
Mechanical Stiffness ◽  
Ankle Foot Orthosis ◽  
Ankle Foot Orthoses ◽  
Structural Concept ◽  
Foot Orthosis

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.

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. 

Comparison of ankle–foot orthoses with plantar flexion stop and plantar flexion resistance in the gait of stroke patients: A randomized controlled trial

2018 ◽  
Vol 42 (5) ◽  
pp. 544-553 ◽  
Author(s):  
Sumiko Yamamoto ◽  
Souji Tanaka ◽  
Naoyuki Motojima
Keyword(s):  
Controlled Trial ◽  
Plantar Flexion ◽  
Upper Body ◽  
Foot Orthoses ◽  
Stroke Patients ◽  
Subacute Phase ◽  
Ankle Foot Orthosis ◽  
Randomized Controlled ◽  
Ankle Foot Orthoses ◽  
Foot Orthosis

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.

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