A three centre study of the variability of ankle foot orthoses due to fabrication and grade of polypropylene

2004 ◽  
Vol 28 (2) ◽  
pp. 175-182 ◽  
Author(s):  
P. Convery ◽  
R.J. Greig ◽  
R.S. Ross ◽  
S. Sockalingam
Keyword(s):  
Plantar Flexion ◽  
Bending Stiffness ◽  
Flexural Stiffness ◽  
Foot Orthoses ◽  
Centre Study ◽  
Significant Difference ◽  
Ankle Foot Orthoses ◽  
The Difference ◽  
Plaster Models

This study investigates if fabrication techniques employed at different orthotic centres affect the characteristics of the manufactured plastic orthoses.Plaster models were formed from the same master mould. The thickness and bending stiffness of the supplied polypropylene sheets were measured prior to fabrication.An orthotic technician at each of the 3 orthotic centres manufactured 4 homopolymer and 4 copolymer polypropylene ankle-foot orthoses (AFOs), following each centre's fabrication practice. Another technician at one of the orthotic centres manufactured an additional 4 homopolymer and 4 copolymer AFOs. The thickness, the dorsiflexion stiffness and plantar-flexion stiffness of the 32 fabricated AFOs were monitored and compared.Analysis of the results suggests: Copolymer polypropylene sheets are supplied marginally thicker than homopolymer polypropylene sheets The difference between the thickness of the 16 copolymer and 16 homopolymer AFOs was not significant. The thickness of the AFOs manufactured in copolymer was less consistent than homopolymer. Dorsiflexion stiffness of the copolymer AFOs was less consistent than homopolymer AFOs. Although the bending stiffness of the copolymer and homopolymer sheets differed significantly, there was no significant difference between the dorsiflexion stiffness of the copolymer and homopolymer AFOs. Plantarflexion stiffness was consistent for both the copolymer and the homopolymer AFOs and there was no significant difference between the plantarflexion stiffness of the copolymer and homopolymer AFOs. The thickness and flexural stiffness of the AFOs manufactured by 2 technicians at the same centre did not differ.These results are useful benchmarks for the flexural stiffness of AFOs.

Passive-dynamic ankle–foot orthosis replicates soleus but not gastrocnemius muscle function during stance in gait: Insights for orthosis prescription

2016 ◽  
Vol 40 (5) ◽  
pp. 606-616 ◽  
Author(s):  
Elisa S Arch ◽  
Steven J Stanhope ◽  
Jill S Higginson
Keyword(s):  
Plantar Flexion ◽  
Knee Kinematics ◽  
Musculoskeletal Model ◽  
Bending Stiffness ◽  
Foot Orthoses ◽  
Plantar Flexor ◽  
Dynamic Simulations ◽  
Ankle Foot Orthosis ◽  
Ankle Foot Orthoses ◽  
Foot Orthosis

Background: Passive-dynamic ankle–foot orthosis characteristics, including bending stiffness, should be customized for individuals. However, while conventions for customizing passive-dynamic ankle–foot orthosis characteristics are often described and implemented in clinical practice, there is little evidence to explain their biomechanical rationale. Objectives: To develop and combine a model of a customized passive-dynamic ankle–foot orthosis with a healthy musculoskeletal model and use simulation tools to explore the influence of passive-dynamic ankle–foot orthosis bending stiffness on plantar flexor function during gait. Study design: Dual case study. Methods: The customized passive-dynamic ankle–foot orthosis characteristics were integrated into a healthy musculoskeletal model available in OpenSim. Quasi-static forward dynamic simulations tracked experimental gait data under several passive-dynamic ankle–foot orthosis conditions. Predicted muscle activations were calculated through a computed muscle control optimization scheme. Results: Simulations predicted that the passive-dynamic ankle–foot orthoses substituted for soleus but not gastrocnemius function. Induced acceleration analyses revealed the passive-dynamic ankle–foot orthosis acts like a uniarticular plantar flexor by inducing knee extension accelerations, which are counterproductive to natural knee kinematics in early midstance. Conclusion: These passive-dynamic ankle–foot orthoses can provide plantar flexion moments during mid and late stance to supplement insufficient plantar flexor strength. However, the passive-dynamic ankle–foot orthoses negatively influenced knee kinematics in early midstance. Clinical relevance Identifying the role of passive-dynamic ankle–foot orthosis stiffness during gait provides biomechanical rationale for how to customize passive-dynamic ankle–foot orthoses for patients. Furthermore, these findings can be used in the future as the basis for developing objective prescription models to help drive the customization of passive-dynamic ankle–foot orthosis characteristics.

scholarly journals The effects of ankle-foot orthoses with plantar flexion stop and plantar flexion resistance using rocker-sole shoes on stroke gait: A randomized-controlled trial

2021 ◽  
Vol 67 (4) ◽  
pp. 449-461
Author(s):  
Aliyeh Daryabor ◽  
Gholamreza Aminian ◽  
Mokhtar Arazpour ◽  
Mina Baniasad ◽  
Sumiko Yamamoto
Keyword(s):  
Controlled Trial ◽  
Plantar Flexion ◽  
Three Dimensional ◽  
Chronic Phase ◽  
Controlled Study ◽  
Foot Orthoses ◽  
Randomized Controlled ◽  
Ankle Foot Orthoses ◽  
Spatiotemporal Parameters ◽  
Single Support Phase

Objectives: This study aims to evaluate the effect of two ankle-foot orthoses (AFOs), AFO with plantar flexion stop (AFO-PlfS), and AFO with plantar flexion resistance (AFO-PlfR), while wearing standard shoes and rocker-sole shoes. Patients and methods: Between November 2017 and July 2018, in this randomized-controlled study, a total of 20 stroke patients (8 males, 12 females; mean age: 48.1 years; range, 33 to 65 years) in chronic phase were randomized to AFO groups (AFO-PlfS group, n=10 and AFO-PlfR group, n=10). Each group received the allocated AFO along with two kinds of shoes (standard shoe and rocker shoe) for a two-week adaptation. Two effects were separately evaluated: The orthotic effect and rocker shoe effect were defined as the evaluation of using an AFO wearing standard shoe compared to only standard shoe, and evaluation of using an AFO wearing rocker shoe compared to an AFO wearing standard shoe, respectively. The gait of each group was measured by three-dimensional motion analysis. Results: A significant orthotic effect was found in both AFO groups in spatiotemporal parameters and maximum ankle dorsiflexion in the single-support phase. Additionally, the AFO-PlfR group showed a significant improvement in the parameters related to the first rocker of gait, but not for AFO-PlfS group concerning the orthotic effect. The rocker shoe effect was found in significant reduction of peak ankle plantar flexor moment and power ankle generation during preswing for both AFO groups. Conclusion: According to the orthotic effect, an AFO-PlfR can create better function in the improvement of parameters related to the first rocker. Although a rocker shoe can facilitate rollover for weight progression in the third rocker of gait, it cannot make a strong push-off function in stroke survivors.

scholarly journals Stiffness control in posterior-type plastic ankle-foot orthoses: Effect of ankle trimline Part 1: A device for measuring ankle moment

1996 ◽  
Vol 20 (2) ◽  
pp. 129-131 ◽  
Author(s):  
T. Sumiya ◽  
Y. Suzuki ◽  
T. Kasahara
Keyword(s):  
Plantar Flexion ◽  
Foot Orthoses ◽  
Static Force ◽  
High Reproducibility ◽  
Ankle Moment ◽  
Low Viscosity ◽  
Ankle Foot Orthoses ◽  
Flexion Moment ◽  
Stiffness Control

A device was developed to measure the dorsi- and plantar flexion moment of plastic ankle-foot orthoses when deflected. It is operated by manually controlling a lever which is used to apply a nearly static force. Various orthoses can be classified according to the characteristics of the correcting force measured by this device. Simplicity and high reproducibility are the major advantages. However, to obtain measurements approximating the characteristics of orthoses under wearing conditions its use is restricted to orthoses made of low-viscosity materials.

scholarly journals OrthoRehab: Development of a New Methodology for the Comparison Study Between Different Types of Ankle–Foot Orthoses in Foot Dysfunction

2021 ◽  
Vol 2 ◽  
Author(s):  
Cláudia Quaresma ◽  
Barbara Lopes ◽  
Jorge Jacinto ◽  
Tiago Robalo ◽  
Mariana Matos ◽  
...  
Keyword(s):  
Plantar Flexion ◽  
Decision Support Tool ◽  
Clinical Decision ◽  
Rehabilitation Medicine ◽  
Gait Pattern ◽  
Real Problem ◽  
Foot Orthoses ◽  
Support Tool ◽  
Ankle Foot Orthoses ◽  
User Friendly

Foot dysfunction is one of the most likely consequences of rheumatoid arthritis and stroke. It is characterized by severe changes in the gait pattern due to a significant increase in the plantar flexion. Some of these dysfunctions can be compensated by using an ankle–foot orthosis. However, the clinical decision about which orthosis best suits the patient creates a real problem for physicians/therapists.Purpose: The main goal of this paper is to present a quantitative support tool that can assist the physicians/therapists in deciding which orthosis is most suitable for each subject.Methodology: In order to achieve such goal, a platform named OrthoRehab was developed, and it was tested in three conditions: without any orthosis and with two different ankle–foot orthoses. The data were acquired in the Gait Laboratory of Rehabilitation Medicine Center of Alcoitão using a VICON NEXUS 1.8.5® motion capture system that allows the capturing of kinematic and kinetic data.Results: The results reveal that OrthoRehab is a user-friendly, easy to apply tool that analyzes very relevant data for the clinical staff.Conclusion: The developed decision support tool, OrthoRehab, offers a quantitative analysis and provides insight to which orthosis achieves the best performance in comparison with the patient's gait pattern with no orthosis.

scholarly journals Comparative trials on hybrid walking systems for people with paraplegia: An analysis of study methodology

1999 ◽  
Vol 23 (3) ◽  
pp. 260-273 ◽  
Author(s):  
M. J. Ijzerman ◽  
G. Baardman ◽  
H. J. Hermens ◽  
P. H. Veltink ◽  
H. B. K. Boom ◽  
...  
Keyword(s):  
Study Design ◽  
Statistical Power ◽  
Outcome Measurement ◽  
Interval Estimation ◽  
Interrupted Time Series ◽  
Foot Orthoses ◽  
User Friendliness ◽  
Ankle Foot Orthoses ◽  
The Difference ◽  
Comparative Trials

A new orthosis (SEPRIX) which combines user friendliness with low energy cost of walking has been developed and will be subject to a clinical comparison with conventional hip-knee-ankle-foot orthoses. In designing such comparative trials it was considered it may be worthwhile to use previous clinical studies as practical examples. A literature search was conducted in order to select all comparative trials which have studied two walking systems (hip-knee-ankle-foot orthoses) for patients with a complete thoracic lesion. Study population, intervention, study design, outcome measurement and statistical analyses were examined. Statistical power was calculated where possible. Of 12 selected studies, 7 were simple A-B comparisons, 2 A-B comparisons with a replication, 2 cross-over trials and 1 non-randomised parallel group design, the last of which was considered internally invalid due to severe confounding by indication. All A-B comparisons were considered internally invalid as well, since they have not taken into account that a comparison of two orthoses requires a control for aspecific effects (like test effects) which may cause a difference. Statistical power could only be examined in 4 studies and the highest statistical power achieved in one study was 47 %. It is concluded that statistical power was too low to be able to detect differences. Even analysis through interval estimation showed that the estimation of the difference was too imprecise to be useful. Since the majority of the surveyed papers have reported small studies (of only 4–6 patients), it is assumed that lack of statistical power is a more general problem. Three possibilities are discussed in order to enhance statistical power in comparative trials, i.e. multicentre studies, statistical pooling of results and improving the efficiency of study design by means of interrupted time series designs.

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.

Polypropylene Ankle Foot Orthoses to Overcome Drop-Foot Gait in Central Neurological Patients: A Mechanical and Functional Evaluation

2010 ◽  
Vol 34 (3) ◽  
pp. 293-304 ◽  
Author(s):  
Daan J. J. Bregman ◽  
Vincent De Groot ◽  
Peter Van Diggele ◽  
Hubert Meulman ◽  
Han Houdijk ◽  
...  
Keyword(s):  
Energy Cost ◽  
Stance Phase ◽  
Plantar Flexion ◽  
Functional Evaluation ◽  
Foot Orthoses ◽  
Drop Foot ◽  
Functional Benefit ◽  
Ankle Foot Orthoses ◽  
Neurological Patients ◽  
Energy Cost Of Walking

The aim of this study was to assess the functional effects and mechanical contribution of Ankle Foot Orthoses (AFO) prescribed to overcome drop-foot gait. We hypothesized that poor functional effects of the AFO relate to insufficient mechanical contribution of the AFO during the swing phase, or unwanted constraining of the ankle during the stance phase. In seven patients with Stroke or Multiple Sclerosis, we determined changes in energy cost of walking resulting from wearing an AFO, as a measure of the functional effects. In addition, an instrumented gait analysis was performed, and the mechanical AFO properties were measured, to calculate the mechanical contribution of the AFO. The AFO was sufficiently stiff to effectively support the foot in swing, without hampering the ankle during stance. For the whole group, there was a significant improvement in walking speed and energy cost (12%). However, the AFO had no functional benefit in terms of a reduced energy cost of walking for three patients, who coherently demonstrated no pathological plantar flexion during swing without their AFO. We conclude that functional benefit from the AFO was only found when the mechanical AFO characteristics met the need to support the patients‘ mechanical deficiencies.

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.

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