Assessment of Mechanical Characteristics of Ankle-Foot Orthoses

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Amanda Wach ◽  
Linda McGrady ◽  
Mei Wang ◽  
Barbara Silver-Thorn
Keyword(s):  
Energy Storage ◽  
Functional Outcomes ◽  
Mechanical Characteristics ◽  
Leaf Spring ◽  
Clinical Test ◽  
Foot Orthoses ◽  
Ankle Motion ◽  
Compressive Stiffness ◽  
Ankle Foot Orthoses ◽  
Insight Into

Recent designs of ankle-foot orthoses (AFOs) have been influenced by the increasing demand for higher function from active individuals. The biomechanical function of the individual and device is dependent upon the underlying mechanical characteristics of the AFO. Prior mechanical testing of AFOs has primarily focused on rotational stiffness to provide insight into expected functional outcomes; mechanical characteristics pertaining to energy storage and release have not yet been investigated. A pseudostatic bench testing method is introduced to characterize compressive stiffness, device deflection, and motion of solid-ankle, anterior floor reaction, posterior leaf spring, and the intrepid dynamic exoskeletal orthosis (IDEO) AFOs. Each of these four AFOs, donned over a surrogate limb, were compressively loaded at different joint angles to simulate the foot-shank orientation during various subphases of stance. In addition to force–displacement measurements, deflection of each AFO strut and rotation of proximal and supramalleolar segments were analyzed. Although similar compressive stiffness values were observed for AFOs designed to reduce ankle motion, the corresponding strut deflection profile differed based on the respective fabrication material. For example, strut deflection of carbon-fiber AFOs resembled column buckling. Expanded clinical test protocols to include quantification of AFO deflection and rotation during subject use may provide additional insight into design and material effects on performance and functional outcomes, such as energy storage and release.

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.

Mechanical problem in 3D printed ankle-foot orthoses with function of energy storage

2018 ◽  
Author(s):  
Chien-Hsien Yeh ◽  
Yi-Chun Tsai ◽  
Fong-Chin Su ◽  
Li-Chieh Kuo ◽  
Kai Chang ◽  
...  
Keyword(s):  
Energy Storage ◽  
Foot Orthoses ◽  
Mechanical Problem ◽  
Ankle Foot Orthoses ◽  
3D Printed

scholarly journals Effects of Ankle Foot Orthoses on the Gait Patterns in Children with Spastic Bilateral Cerebral Palsy: A Scoping Review

Children ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 903
Author(s):  
Diogo Ricardo ◽  
Maria Raposo ◽  
Eduardo Cruz ◽  
Raul Oliveira ◽  
Filomena Carnide ◽  
...  
Keyword(s):  
Cerebral Palsy ◽  
Scientific Data ◽  
Cochrane Library ◽  
Leaf Spring ◽  
Foot Orthoses ◽  
Gait Patterns ◽  
Functional Scores ◽  
Ankle Foot Orthoses ◽  
Pathological Gait ◽  
The Impact

Background: Cerebral palsy (CP) is the most common cause of motor disability in children and can cause severe gait deviations. The sagittal gait patterns classification for children with bilateral CP is an important guideline for the planning of the rehabilitation process. Ankle foot orthoses should improve the biomechanical parameters of pathological gait in the sagittal plane. Methods: A systematic search of the literature was conducted to identify randomized controlled trials (RCT) and controlled clinical trials (CCT) which measured the effect of ankle foot orthoses (AFO) on the gait of children with spastic bilateral CP, with kinetic, kinematic, and functional outcomes. Five databases (Pubmed, Scopus, ISI Web of SCIENCE, SciELO, and Cochrane Library) were searched before February 2020. The PEDro Score was used to assess the methodological quality of the selected studies and alignment with the Cochrane approach was also reviewed. Prospero registration number: CRD42018102670. Results: We included 10 studies considering a total of 285 children with spastic bilateral CP. None of the studies had a PEDro score below 4/10, including five RCTs. We identified five different types of AFO (solid; dynamic; hinged; ground reaction; posterior leaf spring) used across all studies. Only two studies referred to a classification for gait patterns. Across the different outcomes, significant differences were found in walking speed, stride length and cadence, range of motion, ground force reaction and joint moments, as well as functional scores, while wearing AFO. Conclusions: Overall, the use of AFO in children with spastic bilateral CP minimizes the impact of pathological gait, consistently improving some kinematic, kinetic, and spatial-temporal parameters, and making their gait closer to that of typically developing children. Creating a standardized protocol for future studies involving AFO would facilitate the reporting of new scientific data and help clinicians use their clinical reasoning skills to recommend the best AFO for their patients.

Effect of Postoperative Early Ankle Motion Exercise Using Hinged Ankle-Foot Orthoses in Clubfoot

2005 ◽  
Vol 25 (4) ◽  
pp. 529-532 ◽  
Author(s):  
Yoko Miura ◽  
Makoto Kamegaya ◽  
Takashi Saisu ◽  
Hideshige Moriya
Keyword(s):  
Foot Orthoses ◽  
Ankle Motion ◽  
Ankle Foot Orthoses ◽  
Motion Exercise

scholarly journals The role of rigid and hinged polypropylene ankle-foot-orthoses in the management of cerebral palsy: a case study

1988 ◽  
Vol 12 (3) ◽  
pp. 129-135 ◽  
Author(s):  
E. A. Middleton ◽  
G. R. B. Hurley ◽  
J. S. McIlwain
Keyword(s):  
Cerebral Palsy ◽  
Reaction Force ◽  
Force Plate ◽  
Spastic Cerebral Palsy ◽  
Foot Orthoses ◽  
Ankle Motion ◽  
Ankle Foot Orthosis ◽  
Ankle Foot Orthoses ◽  
The Subject ◽  
Foot Orthosis

Ankle-foot orthoses are commonly used in the treatment of spastic cerebral palsy to hold the foot in a position conducive to a more functional gait. This study, utilizing quantitative biomechanical techniques, evaluates the effects of a rigid ankle-foot orthosis and a hinged ankle-foot orthosis on spastic cerebral palsy gait. The subject was a 4.5 year old female diagnosed as spastic diplegic cerebral palsied shortly after birth. Testing involved collection of kinematic coordinate data employing a WATSMART video system and ground reaction force' data using a Kistler force plate. Jensen's (1978) photogrammetric method was used to estimate body segment inertial parameters. The hinged ankle-foot orthosis was found to be more effective than the rigid ankle-foot orthosis. The subject exhibited a more natural ankle motion during the stance phase of gait, greater symmetry of segmental lower extremity motion, and decreased knee moments during stance while wearing a hinged ankle-foot orthosis.

scholarly journals Effects of the heel-to-toe rocker sole on walking in able-bodied persons

2013 ◽  
Vol 37 (6) ◽  
pp. 429-435 ◽  
Author(s):  
Mokhtar Arazpour ◽  
Stephen W Hutchins ◽  
Farhad T Ghomshe ◽  
Fahimeh Shaky ◽  
Masome V Karami ◽  
...  
Keyword(s):  
Stance Phase ◽  
Frontal Plane ◽  
Random Order ◽  
Ankle Arthrodesis ◽  
Foot Orthoses ◽  
Ankle Motion ◽  
Ankle Foot Orthoses ◽  
Spatial Parameters ◽  
Adult Volunteers ◽  
Support Phase

Background and aim: The most commonly prescribed external shoe modification is the use of rocker soles. The aim of this study was to evaluate the effect of a heel-to-toe rocker sole profile on specific temporal–spatial parameters and the kinematics of walking when added to footwear. Method: Seventeen healthy adult volunteers participated in this study. For each subject, gait analysis was performed under two conditions that were tested in a random order: walking with either a baseline shoe with a flat sole or a modified shoe adapted with a heel-to-toe rocker sole. Results: Significant differences were observed between rocker sole conditions during initial double-limb support and second double-limb support during stance phase. In frontal plane movement, significant differences were observed between the rocker sole conditions but only during second double-limb support phase. Conclusions: This heel-to-toe rocker sole may be useful for patients with conditions such as ankle arthrodesis or for use with ankle–foot orthoses where limited ankle motion is required. Clinical relevance The heel-to-toe rocker sole may be useful for conditions including ankle arthrodesis and for use with solid ankle–foot orthoses but may not be suitable for patients with reduced balance or an unstable posture.

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