Poster 60: Impact of the Ankle-Foot Orthoses on 3D Ankle Joint Rotation in Children with Spastic CP

PM&R ◽  
2009 ◽  
Vol 1 ◽  
pp. S129-S130
Author(s):  
Frederick T. Klingbeil ◽  
Xue-Cheng Liu ◽  
Elizabeth Moberg-Wolff
Keyword(s):  
Ankle Joint ◽  
Foot Orthoses ◽  
Joint Rotation ◽  
Ankle Foot Orthoses

An Orthotic Joint Design for Enhancing Ankle Mobility With Ankle Foot Orthoses Use

2020 ◽  
Vol 14 (4) ◽  
Author(s):  
Eileen Baker ◽  
Philip Voglewede ◽  
Thomas Current ◽  
Barbara Silver-Thorn
Keyword(s):  
Ankle Joint ◽  
Initial Contact ◽  
Walking Ability ◽  
Foot Orthoses ◽  
The Novel ◽  
Drop Foot ◽  
Current Form ◽  
Ankle Foot Orthoses ◽  
Ankle Mobility ◽  
Mobility Impaired

Abstract Articulated ankle foot orthoses (AFOs) are prescribed to treat drop-foot, a common neuromuscular weakness observed after a stroke. These assistive devices prevent the toe from dragging during swing (drop-foot) by providing a resistive moment at the ankle. However, existing ankle joint designs for articulated AFOs introduce additional gait pathologies as they also constrain ankle mobility during stance. A novel ankle joint for AFOs to prevent drop-foot during swing and improve ankle mobility during stance was developed, thereby reducing compensatory knee motion during stance. The design intent was to mimic the unconstrained kinematic response of a nonpathologic ankle at initial contact while preventing drop-foot during swing. The design incorporated two modes of operation: locked during swing for support and unlocked during stance for enhanced range of motion. Proof of concept testing with able-bodied subjects was conducted to test walking ability over level ground based on kinetic and kinematic parameters. The comparative tests confirmed the ability of the novel design to prevent drop-foot and its potential for enhanced ankle mobility during stance. Preliminary results indicate that the novel ankle joint should be refined to facilitate smooth and consistent unlocking but can be safely used in its current form with mobility impaired individuals.

Comparison of gait between healthy participants and persons with spinal cord injury when using the advanced reciprocating gait orthosis

2015 ◽  
Vol 40 (2) ◽  
pp. 287-293 ◽  
Author(s):  
Mokhtar Arazpour ◽  
Mahmoud Joghtaei ◽  
Mahmood Bahramizadeh ◽  
Monireh Ahmadi Bani ◽  
Stephen W Hutchins ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Range Of Motion ◽  
Ankle Joint ◽  
Step Length ◽  
Foot Orthoses ◽  
Normal Walking ◽  
Cord Injury ◽  
Ankle Foot Orthoses ◽  
Spatial Parameters

Background:The advanced reciprocating gait orthosis (ARGO) has a rigid structure which provides restricted movement at the hip, knee, and ankle joints and incorporates a pelvic section with an extended section in the lumbar region. Healthy subjects, when walking with an RGO in situ, could feasibly demonstrate the level of limitation in movement imposed by ARGO-assisted ambulation.Objective:The aim of this study was to compare the function of the advanced reciprocating gait orthosis when fitted with the dorsiflexion-assist ankle–foot orthoses on temporal–spatial parameters and kinematics of walking in both able-bodied people and those with spinal cord injury.Study design:Quasi experimental design.Methods:Data were acquired from six able-bodied and four spinal cord injury subjects who used an advanced reciprocating gait orthosis which incorporated dorsiflexion-assist ankle–foot orthoses. Kinematics and temporal–spatial parameters were calculated and compared.Results:All able-bodied individuals walked with speeds which were only approximately one-third that of when walking without an orthosis. The mean step length and cadence were both reduced by 48% and 6%, respectively. There were significant differences in hip, knee, and ankle joint range of motions between normal walking and walking with the advanced reciprocating gait orthosis both in able-bodied subjects and patients with spinal cord injury. There were also significant differences in the speed of walking, cadence, step length, hip range of motion, and ankle range of motion when using the advanced reciprocating gait orthosis between the two groups.Conclusion:Temporal–spatial parameters and lower limb sagittal plane kinematics of walking were altered compared to normal walking, especially when spinal cord injury subjects walked with the advanced reciprocating gait orthosis compared to the able-bodied subjects.Clinical relevanceTo produce an improvement in RGO function, an increase in walking performance should involve attention to improvement of hip, knee, and ankle joint kinematics, which differs significantly from normal walking.

A methodology for the customization of hinged ankle-foot orthoses based on in vivo helical axis calculation with 3D printed rigid shells

2020 ◽  
pp. 095441192098154
Author(s):  
Carlo Ferraresi ◽  
Carlo De Benedictis ◽  
Loris Bono ◽  
Federica Del Gaudio ◽  
Laura Ferrara ◽  
...  
Keyword(s):  
Ankle Joint ◽  
Motion Artifact ◽  
Lower Limbs ◽  
Helical Axis ◽  
Foot Orthoses ◽  
Kinematics Analysis ◽  
Motor Tasks ◽  
Ankle Foot Orthoses ◽  
Kinematic Analyses

This study aims to develop techniques for ankle joint kinematics analysis using motion capture based on stereophotogrammetry. The scope is to design marker attachments on the skin for a most reliable identification of the instantaneous helical axis, to be targeted for the fabrication of customized hinged ankle-foot orthoses. These attachments should limit the effects of the experimental artifacts, in particular the soft-tissue motion artifact, which affect largely the accuracy of any in vivo ankle kinematics analysis. Motion analyses were carried out on two healthy subjects wearing customized rigid shells that were designed through 3D scans of the subjects’ lower limbs and fabricated by additive manufacturing. Starting from stereophotogrammetry data collected during walking and dorsi-plantarflexion motor tasks, the instantaneous and mean helical axes of ankle joint were calculated. The customized shells matched accurately the anatomy of the subjects and allowed for the definition of rigid marker clusters that improved the accuracy of in vivo kinematic analyses. The proposed methodology was able to differentiate between subjects and between the motor tasks analyzed. The observed position and dispersion of the axes were consistent with those reported in the literature. This methodology represents an effective tool for supporting the customization of hinged ankle-foot orthoses or other devices interacting with human joints functionality.

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.

scholarly journals Ankle muscle responses during perturbed walking with blocked ankle joints

2019 ◽  
Vol 121 (5) ◽  
pp. 1711-1717 ◽  
Author(s):  
Mark Vlutters ◽  
Edwin H. F. van Asseldonk ◽  
Herman van der Kooij
Keyword(s):  
Ankle Joint ◽  
Balance Control ◽  
Muscle Length ◽  
Joint Rotation ◽  
Long Latency ◽  
Ankle Joints ◽  
Ankle Foot Orthoses ◽  
Ankle Muscle ◽  
Length Changes ◽  
Muscle Responses

The ankle joint muscles can contribute to balance during walking by modulating the center of pressure and ground reaction forces through an ankle moment. This is especially effective in the sagittal plane through ankle plantar- or dorsiflexion. If the ankle joints were to be physically blocked to make an ankle strategy ineffective, there would be no functional contribution of these muscles to balance during walking, nor would these muscles generate afferent output regarding ankle joint rotation. Consequently, ankle muscle activation for the purpose of balance control would be expected to disappear. We have performed an experiment in which subjects received anteroposterior pelvis perturbations during walking while their ankle joints could not contribute to the balance recovery. The latter was realized by physically blocking the ankle joints through a pair of modified ankle-foot orthoses. In this article we present the lower limb muscle activity responses in reaction to these perturbations. Of particular interest are the tibialis anterior and gastrocnemius medialis muscles, which could not contribute to the balance recovery through the ankle joint or encode muscle length changes caused by ankle joint rotation. Yet, these muscles showed long-latency responses, ~100 ms after perturbation onset. The response amplitudes were dependent on the perturbation magnitude and direction, as well as the state of the leg. The results imply that ankle muscle responses can be evoked without changes in proprioceptive information of those muscles through ankle rotation. This suggest a more centralized regulation of balance control, not strictly related to the ankle joint kinematics. NEW & NOTEWORTHY Walking human subjects received forward-backward perturbations at the pelvis while wearing “pin-shoes,” a pair of modified ankle-foot orthoses that physically blocked ankle joint movement and reduced the base of support of each foot to a single point. The lower leg muscles showed long-latency perturbation-dependent activity changes, despite having no functional contributions to balance control through the ankle joint and not having been subjected to muscle length changes through ankle joint rotation.

A three-dimensional model to assess the effect of ankle joint axis misalignments in ankle–foot orthoses

2014 ◽  
Vol 40 (2) ◽  
pp. 240-246 ◽  
Author(s):  
Stefania Fatone ◽  
William Brett Johnson ◽  
Kerice Tucker
Keyword(s):  
Ankle Joint ◽  
Three Dimensional ◽  
Foot Orthoses ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Ankle Foot Orthosis ◽  
Joint Axis ◽  
Ankle Foot Orthoses ◽  
Foot Orthosis

Background: Misalignment of an articulated ankle–foot orthosis joint axis with the anatomic joint axis may lead to discomfort, alterations in gait, and tissue damage. Theoretical, two-dimensional models describe the consequences of misalignments, but cannot capture the three-dimensional behavior of ankle–foot orthosis use. Objectives: The purpose of this project was to develop a model to describe the effects of ankle–foot orthosis ankle joint misalignment in three dimensions. Study design: Computational simulation. Methods: Three-dimensional scans of a leg and ankle–foot orthosis were incorporated into a link segment model where the ankle–foot orthosis joint axis could be misaligned with the anatomic ankle joint axis. The leg/ankle–foot orthosis interface was modeled as a network of nodes connected by springs to estimate interface pressure. Motion between the leg and ankle–foot orthosis was calculated as the ankle joint moved through a gait cycle. Results: While the three-dimensional model corroborated predictions of the previously published two-dimensional model that misalignments in the anterior -posterior direction would result in greater relative motion compared to misalignments in the proximal -distal direction, it provided greater insight showing that misalignments have asymmetrical effects. Conclusions: The three-dimensional model has been incorporated into a freely available computer program to assist others in understanding the consequences of joint misalignments. Clinical relevance Models and simulations can be used to gain insight into functioning of systems of interest. We have developed a three-dimensional model to assess the effect of ankle joint axis misalignments in ankle–foot orthoses. The model has been incorporated into a freely available computer program to assist understanding of trainees and others interested in orthotics.

scholarly journals Gait evaluation of the advanced reciprocating gait orthosis with solid versus dorsi flexion assist ankle foot orthoses in paraplegic patients

2012 ◽  
Vol 37 (2) ◽  
pp. 161-167 ◽  
Author(s):  
Monireh Ahmadi Bani ◽  
Mokhtar Arazpour ◽  
Farhad Tabatabai Ghomshe ◽  
Mohammad Ebrahim Mousavi ◽  
Stephen William Hutchins
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Ankle Joint ◽  
Neurological Injury ◽  
Foot Orthoses ◽  
Gait Parameters ◽  
Cord Injury ◽  
Ankle Foot Orthoses ◽  
Quasi Experimental ◽  
The Mean

Background:Mechanical orthoses are used for standing and walking after neurological injury. Most orthoses such as the advanced reciprocating gait orthosis typically use solid ankle–foot orthoses.Objectives:The goal of this study was to test the effects of ankle dorsiflexion assistance in patients with spinal cord injury when ambulating with an advanced reciprocating gait orthosis compared to walking with fixed ankles.Study Design:Quasi-experimental.Methods:Four patients with spinal cord injury were fitted with an advanced reciprocating gait orthosis equipped with solid and dorsiflexion assist-type ankle–foot orthoses and walked at their self-selected speed. Joint angles and spatial–temporal parameters were measured and analyzed.Results:The mean walking speed and stride length were both significantly increased along with cadence by the volunteer subjects when ambulating using the advanced reciprocating gait orthosis fitted with dorsiflexion assist ankle–foot orthoses compared to the advanced reciprocating gait orthosis with solid ankle–foot orthoses. The mean ankle joint ranges of motion were significantly increased when walking with the advanced reciprocating gait orthosis with dorsiflexion assist ankle–foot orthoses compared to when using the advanced reciprocating gait orthosis with the solid ankle–foot orthoses. Knee joint ranges of motion were reduced, and hip joint ranges of motion were increased but not significantly.Conclusion:The advanced reciprocating gait orthosis fitted with the dorsiflexion assist ankle–foot orthoses had the effect of improving gait parameters when compared to the advanced reciprocating gait orthosis with solid ankle–foot orthoses.Clinical relevanceThe advanced reciprocating gait orthosis with dorsiflexion assist ankle–foot orthoses has the potential to improve hip and ankle joint kinematics and the temporal–spatial parameters of gait in spinal cord injury patients’ walking.

scholarly journals Individual stiffness optimization of dorsal leaf spring ankle–foot orthoses in people with calf muscle weakness is superior to standard bodyweight-based recommendations

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Niels F. J. Waterval ◽  
Merel-Anne Brehm ◽  
Jaap Harlaar ◽  
Frans Nollet
Keyword(s):  
Muscle Weakness ◽  
Energy Cost ◽  
Activity Level ◽  
Calf Muscle ◽  
Leaf Spring ◽  
Foot Orthoses ◽  
Ankle Foot Orthoses ◽  
The Individual ◽  
Optimal Stiffness ◽  
Walking Energy Cost

Abstract Background In people with calf muscle weakness, the stiffness of dorsal leaf spring ankle–foot orthoses (DLS-AFO) needs to be individualized to maximize its effect on walking. Orthotic suppliers may recommend a certain stiffness based on body weight and activity level. However, it is unknown whether these recommendations are sufficient to yield the optimal stiffness for the individual. Therefore, we assessed whether the stiffness following the supplier’s recommendation of the Carbon Ankle7 (CA7) dorsal leaf matched the experimentally optimized AFO stiffness. Methods Thirty-four persons with calf muscle weakness were included and provided a new DLS-AFO of which the stiffness could be varied by changing the CA7® (Ottobock, Duderstadt, Germany) dorsal leaf. For five different stiffness levels, including the supplier recommended stiffness, gait biomechanics, walking energy cost and speed were assessed. Based on these measures, the individual experimentally optimal AFO stiffness was selected. Results In only 8 of 34 (23%) participants, the supplier recommended stiffness matched the experimentally optimized AFO stiffness, the latter being on average 1.2 ± 1.3 Nm/degree more flexible. The DLS-AFO with an experimentally optimized stiffness resulted in a significantly lower walking energy cost (− 0.21 ± 0.26 J/kg/m, p < 0.001) and a higher speed (+ 0.02 m/s, p = 0.003). Additionally, a larger ankle range of motion (+ 1.3 ± 0.3 degrees, p < 0.001) and higher ankle power (+ 0.16 ± 0.04 W/kg, p < 0.001) were found with the experimentally optimized stiffness compared to the supplier recommended stiffness. Conclusions In people with calf muscle weakness, current supplier’s recommendations for the CA7 stiffness level result in the provision of DLS-AFOs that are too stiff and only achieve 80% of the reduction in energy cost achieved with an individual optimized stiffness. It is recommended to experimentally optimize the CA7 stiffness in people with calf muscle weakness in order to maximize treatment outcomes. Trial registration Nederlands Trial Register 5170. Registration date: May 7th 2015. http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=5170.

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