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Todros, Silvia, Carlo Biz, Pietro Ruggieri, and Piero G. Pavan. "Experimental Analysis of Plantar Fascia Mechanical Properties in Subjects with Foot Pathologies." Applied Sciences 11, no. 4 (2021): 1517. http://dx.doi.org/10.3390/app11041517.
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Plantar Fascia (PF) is a fibrous tissue that plays a key role in supporting the foot arch; it can be affected by several pathologies that can alter foot biomechanics. The present study aims at investigating the mechanical behavior of PF and evaluating possible correlations between mechanical properties and specific pathologies, namely diabetes and plantar fibromatosis (Ledderhose syndrome). PF samples were obtained from 14 human subjects, including patients with Ledderhose syndrome, patients affected by diabetes and healthy subjects. Mechanical properties of PF tissues were evaluated on three samples from each subject, by cyclic uniaxial tensile tests up to 10% of maximum strain and stress relaxation tests for 300 s, in hydrated conditions at room temperature. In tensile tests, PF exhibits non-linear stress–strain behavior, with a higher elastic modulus (up to 25–30 MPa) in patients affected by Ledderhose syndrome and diabetes with respect to healthy subjects (elastic modulus 10 ÷ 14 MPa). Stress-relaxation tests show that PF of patients affected by Ledderhose syndrome and diabetes develop more intense viscous phenomena. The results presented in this work represent the first experimental data on the tensile mechanical propertied of PF in subjects with foot diseases and can provide an insight on foot biomechanics in pathological conditions.
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Teater, Rachel H., Kristine M. Fischenich, Benjamin B. Wheatley, et al. "Assessment of the compressive and tensile mechanical properties of materials used in the Jaipur Foot prosthesis." Prosthetics and Orthotics International 42, no. 5 (2018): 511–17. http://dx.doi.org/10.1177/0309364618767143.
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Background: Designed by Dr. Sethi, the Jaipur Foot prosthesis is ideally suited for amputees in developing countries as it utilizes locally sourced, biodegradable, inexpensive materials and is focused on affordability and functionality. To date, however, no data have been reported on the material properties of the foot components. Objectives: The goal of this work was to evaluate mechanical properties of the Jaipur Foot components to guide foot design and manufacturing and reduce weight. Study Design: Experimental. Methods: Mechanical testing was conducted on two types of woods (ardu and cheed), microcellular rubber, tire cord, cushion compound, tread compound, and skin-colored rubber. Each material was subjected to testing in either tension or compression based on its location and function in the foot. Samples were tested before and after vulcanization. Two-sample t-tests were used to assess statistical differences. Results: Cheed compressed perpendicular to the grain had a significantly higher modulus of elasticity than ardu ( p < 0.05); however, cheed had a higher density. Vulcanization significantly increased the modulus of skin-colored rubber, cushion compound, and tread compound ( p < 0.05) and decreased the moduli of both microcellular rubber and tire cord ( p < 0.05). Conclusion: The material property results from this study provide information for computer modeling to assess material construction on overall foot mechanics for design optimization. Ardu wood was ideal based on the desire to reduce weight, and the tire cord properties serve well to hold the foot together. Clinical relevance With new knowledge on the material properties of the components of the Jaipur Foot, future design modifications and standardized fabrication can be realized, making the Jaipur Foot more available on a global scale.
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Han, Dianlei, Rui Zhang, Hua Zhang, Zhenyu Hu, and Jianqiao Li. "Mechanical Performances of Typical Robot Feet Intruding into Sands." Energies 13, no. 8 (2020): 1867. http://dx.doi.org/10.3390/en13081867.
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Four kinds of feet with typical structures, referred to as the hemispherical foot, the semicylindrical foot, the rectangular foot and the circular foot, respectively, were designed and manufactured to study the foot–terrain interaction mechanics for legged robots. Three kinds of quartz sand were selected to study how particle size, shape and compactness affected the physical properties of the substrate and the intrusion performance of mechanical feet. The media with smaller particle sizes had higher bulk densities and lower angles of stability, but no obvious rule was found for particle shapes of quartz sand with different sizes. The intrusion resistive forces and pressures of the hemispherical foot on these three kinds of quartz sand were all less compared with the other three mechanical feet. The particle disturbance areas and motion trends were compared under these four kinds of mechanical feet using discrete element method simulations. The intrusion resistive forces of these mechanical feet first increased and then decreased with the increasing particle sizes of the quartz sand. Moreover, the intrusion resistive forces of these mechanical feet on spherical particles were smaller compared with irregular particles. The corresponding resistive forces of the mechanical feet were characterized based on the compactness of the quartz sand. According to the intrusion test data, the classic pressure–sinkage model was modified, and the relationships between intrusion resistive force and mechanical foot depth were obtained.
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Walke, K. M. "Mechanical Properties of Materials Used For Prosthetic Foot: A Review." IOSR Journal of Mechanical and Civil Engineering 17, no. 01 (2017): 61–65. http://dx.doi.org/10.9790/1684-17010026165.
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Jia, Yu Zhuo, and Jin Long Xu. "Study on Shallow Embedded Column Foot of Reactive Powder Concrete Pole Mechanical Properties." Applied Mechanics and Materials 680 (October 2014): 167–70. http://dx.doi.org/10.4028/www.scientific.net/amm.680.167.
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According to the existing specifications, design shallow embedded column foot of 500kV self-supporting partially prestressed reactive powder concrete pole, and perform numerical simulation of column foot stress under actual working condition by using finite element analysis software ANSYS WORKBENCH. The main research is capitals load-displacement curve, changes in stress along the height, plane section, the change in cross section of the stress problems between adjacent. The results show that shallow embedded column foot has good mechanical properties. It can well transmit larger axial pressure, pulling resistance and horizontal force generated by top load of RPC pole. Shallow embedded column foot in operation conditions higher safety level, can be used in 500kV transmission line.
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Major, Matthew J., Joel Scham, and Michael Orendurff. "The effects of common footwear on stance-phase mechanical properties of the prosthetic foot-shoe system." Prosthetics and Orthotics International 42, no. 2 (2017): 198–207. http://dx.doi.org/10.1177/0309364617706749.
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Background:Prosthetic feet are prescribed based on their mechanical function and user functional level. Subtle changes to the stiffness and hysteresis of heel, midfoot, and forefoot regions can influence the dynamics and economy of gait in prosthesis users. However, the user’s choice of shoes may alter the prosthetic foot-shoe system mechanical characteristics, compromising carefully prescribed and rigorously engineered performance of feet.Objectives:Observe the effects of footwear on the mechanical properties of the prosthetic foot-shoe system including commonly prescribed prosthetic feet.Study design:Repeated-measures, Mechanical characterization.Methods:The stiffness and energy return was measured using a hydraulic-driven materials test machine across combinations of five prosthetic feet and four common shoes as well as a barefoot condition.Results:Heel energy return decreased by an average 4%–9% across feet in all shoes compared to barefoot, with a cushioned trainer displaying the greatest effect. Foot designs that may improve perceived stability by providing low heel stiffness and rapid foot-flat were compromised by the addition of shoes.Conclusion:Shoes altered prosthesis mechanical characteristics in the sagittal and frontal planes, suggesting that shoe type should be controlled or reported in research comparing prostheses. Understanding of how different shoes could alter certain gait-related characteristics of prostheses may aid decisions on footwear made by clinicians and prosthesis users.Clinical relevanceShoes can alter function of the prosthetic foot-shoe system in unexpected and sometimes undesirable ways, often causing similar behavior across setups despite differences in foot design, and prescribing clinicians should carefully consider these effects on prosthesis performance.
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FONTANELLA, CHIARA GIULIA, ARTURO NICOLA NATALI, and EMANUELE LUIGI CARNIEL. "NUMERICAL ANALYSIS OF THE FOOT IN HEALTHY AND DEGENERATIVE CONDITIONS." Journal of Mechanics in Medicine and Biology 17, no. 06 (2017): 1750095. http://dx.doi.org/10.1142/s0219519417500956.
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The aim of this work is the development of a 3D numerical model of the foot that allows evaluating the influence of degenerative phenomena on the foot mechanical functionality. Such degenerative phenomena induce histo-morphological alterations and significant modification of the plantar soft tissue mechanical properties, as stiffening and lower damping capabilities. The finite element model of the foot is developed starting from the analysis of biomedical images. Different constitutive models define the mechanical response of the biological tissues. Because of the major role of plantar soft tissue in the here proposed analysis, a specific visco-hyperelastic constitutive formulation is provided considering the typical features of the tissue mechanics, as geometric and material non linearity, almost incompressible behavior and time-dependent phenomena. Constitutive parameters are identified by the analysis of experimental data from in vitro and in vivo mechanical tests, leading to the identification of a range of constitutive parameters for healthy and degenerative conditions. Numerical analyses are developed to investigate the influence of the progression of the degeneration on the distribution of stress and of strain within foot tissues during static standing. Numerical results show the increase of stress values with the appearance of degenerative conditions, showing the typical stiffening phenomenon. The mechanical response of the plantar soft tissue during specific loading condition and the influence of degenerative phenomena on foot mechanics can be evaluated with numerical analysis.
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Ker, R. F., M. B. Bennett, R. McN Alexander, and R. C. Kester. "Foot Strike and the Properties of the Human Heel Pad." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 203, no. 4 (1989): 191–96. http://dx.doi.org/10.1243/pime_proc_1989_203_038_01.
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Many force-plate records of human locomotion show an impulse (the foot strike) shortly after ground contact. The authors' hypothesis is that this results from the rapid deceleration of a mass (the ‘effective foot’) under forces which compress the heel pad. The quantitative implications are investigated through an illustrative calculation. The observations used are (a) the peak force reached in foot strike (b) the vertical velocity of the foot immediately before ground contact and (c) the properties of the heel pad in compression. Data for (a) and (b) are available in the literature; measurements for (c) are presented here. The deductions are: (a) the time taken to reach peak force is about 5.4 ms, which agrees with published measurements; (b) the mass of the effective foot is about 3.6 kg. The effective foot thus includes a substantial portion of the leg: this seems reasonable. The models used for the calculations clarify the relationship between the foot strike and the shock wave, which it generates.
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Sheehan, Conor, and Elaine Figgins. "A comparison of mechanical properties between different percentage layups of a single-style carbon fibre ankle foot orthosis." Prosthetics and Orthotics International 41, no. 4 (2016): 364–72. http://dx.doi.org/10.1177/0309364616652015.
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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.
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Taş, Serkan, Nezehat Özgül Ünlüer, and Feza Korkusuz. "Morphological and mechanical properties of plantar fascia and intrinsic foot muscles in individuals with and without flat foot." Journal of Orthopaedic Surgery 26, no. 3 (2018): 230949901880248. http://dx.doi.org/10.1177/2309499018802482.
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Purpose: Many musculoskeletal disorders are associated with over-pronated foot and decreased medial longitudinal arch (MLA) height. Foot intrinsic muscles and plantar fascia (PF) are the primary structures that support MLA. An important reason for the over-pronated foot and the reduction in the MLA height may be the morphological characteristics of the foot intrinsic muscles and PF as well as changes in their mechanical properties. The aim of the present study is to investigate the morphologic structure and mechanical properties of PF, flexor hallucis brevis (FHB), flexor digitorum brevis (FDB), and abductor hallucis (AbH) muscles in individuals with flat foot and to compare the results with those of healthy individuals. Methods: The study included 80 participants, 40 with flat foot and 40 with normal foot posture. The foot posture of the participants was assessed using the Foot Posture Index. PF, FHB, FDB, and AbH thickness and stiffness were measured with an ultrasonography device using a linear ultrasonography probe. Results: Individuals with flat foot had higher AbH thickness compared to individuals with normal foot posture ( p < 0.001), whereas both groups were similar in terms of PF ( p = 0.188), FHB ( p = 0.627), and FDB ( p = 0.212) thickness. Stiffness values of the assessed tissues were similar in both groups ( p > 0.05). Conclusion: AbH thickness was higher in individuals with flat foot; however, PF, FHB, and FDB thickness were similar in both groups. In addition, our results suggest that foot posture is not related to the stiffness of the assessed tissues.
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Arangio, George A., Chaorong Chen, and Wangdo Kim. "Effect of Cutting the Plantar Fascia on Mechanical Properties of the Foot." Clinical Orthopaedics and Related Research 339 (June 1997): 227–31. http://dx.doi.org/10.1097/00003086-199706000-00031.
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Jeryo, Abbas H., Jumaa S. Chiad, and Wajdi S. Abbod. "Boosting Mechanical Properties of Orthoses - Foot Ankle by Adding Carbon Nanotube Particles." Materials Science Forum 1039 (July 20, 2021): 518–36. http://dx.doi.org/10.4028/www.scientific.net/msf.1039.518.
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In this process, optimum laminating properties were used in producing prosthesis and orthoses were researched and selected based on high yield, ultimate stresses, stresses of bending and fatigue properties. The process of the optimal selection is the Response Surface Methodology (RSM), which has been used to reach two parameters: reinforcement perlon fiber and percent of multi-strand carbon MWCNT nanotube combined with the matrix resin. The response surface methodology is a combination of mathematician and statistic techniques which are used for experimental model building and analysis of problems. This technique revealed 13 separate laminations samples with a percentage of separate Perlon layers No. and MWCNT Wt %. Tests were conducted for all lamination materials as defined in RSM methods and rendered by vacuum system, including fatigue tests for the ideal laminating material as opposed to laminations developed in the prior study (three Tensile test, Bending test and Fatigue tests according to the ASTM D638 and D790 respectively). Tests from the system version 10.0.2 of Design Expert found lamination (10 perlon layers and 0.75% of MWCNTs) to be the best according to overall yield, ultimate and bending loads in the 12 other laminations. Fatigue eventually revealed that constraints were applied to the stamina tension (2,66, 1,66) for optimum lamination, relative to ten perlon lamination layers and 424 lamination respectively.
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Chanda, Arnab, and Stephen McClain. "Mechanical Modeling of Healthy and Diseased Calcaneal Fat Pad Surrogates." Biomimetics 4, no. 1 (2019): 1. http://dx.doi.org/10.3390/biomimetics4010001.
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The calcaneal fat pad is a major load bearing component of the human foot due to daily gait activities such as standing, walking, and running. Heel and arch pain pathologies such as plantar fasciitis, which over one third of the world population suffers from, is a consequent effect of calcaneal fat pad damage. Also, fat pad stiffening and ulceration has been observed due to diabetes mellitus. To date, the biomechanics of fat pad damage is poorly understood due to the unavailability of live human models (because of ethical and biosafety issues) or biofidelic surrogates for testing. This also precludes the study of the effectiveness of preventive custom orthotics for foot pain pathologies caused due to fat pad damage. The current work addresses this key gap in the literature with the development of novel biofidelic surrogates， which simulate the in vivo and in vitro compressive mechanical properties of a healthy calcaneal fat pad. Also, surrogates were developed to simulate the in vivo mechanical behavior of the fat pad due to plantar fasciitis and diabetes. A four-part elastomeric material system was used to fabricate the surrogates, and their mechanical properties were characterized using dynamic and cyclic load testing. Different strain (or displacement) rates were tested to understand surrogate behavior due to high impact loads. These surrogates can be integrated with a prosthetic foot model and mechanically tested to characterize the shock absorption in different simulated gait activities, and due to varying fat pad material property in foot pain pathologies (i.e., plantar fasciitis, diabetes, and injury). Additionally, such a foot surrogate model, fitted with a custom orthotic and footwear, can be used for the experimental testing of shock absorption characteristics of preventive orthoses.
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Ielapi, Alessio, Malcolm Forward, and Matthieu De Beule. "Computational and experimental evaluation of the mechanical properties of ankle foot orthoses: A literature review." Prosthetics and Orthotics International 43, no. 3 (2019): 339–48. http://dx.doi.org/10.1177/0309364618824452.
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Background: Ankle foot orthoses are external medical devices applied around the ankle joint area to provide stability to patients with neurological, muscular, and/or anatomical disabilities, with the aim of restoring a more natural gait pattern. Study design: This is a literature review. Objectives: To provide a description of the experimental and computational methods present in the current literature for evaluating the mechanical properties of the ankle foot orthoses. Methods: Different electronic databases were used for searching English-language articles realized from 1990 onward in order to select the newest and most relevant information available. Results: A total of 46 articles were selected, which describe the different experimental and computational approaches used by research groups worldwide. Conclusion: This review provides information regarding processes adopted for the evaluation of mechanical properties of ankle foot orthoses, in order to both improve their design and gain a deeper understanding of their clinical use. The consensus drawn is that the best approach would be represented by a combination of advanced computational models and experimental techniques, capable of being used to optimally mimic real-life conditions. Clinical relevance In literature, several methods are described for the mechanical evaluation of ankle foot orthoses (AFOs); therefore, the goal of this review is to guide the reader to use the best approach in the quantification of the mechanical properties of the AFOs and to help gaining insight in the prescription process.
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Stransky, J. J., J. H. Roese, and K. G. Watterston. "Soil Properties and Pine Growth Affected by Site Preparation after Clearcutting." Southern Journal of Applied Forestry 9, no. 1 (1985): 40–43. http://dx.doi.org/10.1093/sjaf/9.1.40.
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Abstract A pine-hardwood sawtimber stand in southeast Texas was clearcut in September 1972. Random plots were burned, chopped, KG-bladed, or left untreated. In the spring of 1974, 1-0 loblolly pine seedlings (Pinus taeda L.) were handplanted at 8 by 10 foot spacing. Data from soil samples, taken from the 0-5 inch depth before clearcutting and 1, 3, and 5 years after site preparation showed that burning appeared to have changed soil nutrient levels the least. Of the two mechanical treatments, KG-blading altered the chemical composition of the soil most, probably because topsoil organic matter was removed. Planted pines survived and grew best on mechanically prepared areas, producing 1.5 to 3.3 times more cubic-foot volume per acre than either of the other treatments by the end of the eighth year.
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Parekh, Selene, Samuel Adams, James Nunley, et al. "Mechanically Superior Molybdenum Rhenium (MoRe®) Alloy provides an advanced option for Foot and Ankle Implants." Foot & Ankle Orthopaedics 3, no. 3 (2018): 2473011418S0037. http://dx.doi.org/10.1177/2473011418s00376.
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Category: Other Introduction/Purpose: One of the most common complications in orthopaedic surgery of the foot and ankle is nonunion or delayed union and bone or implant fractures. Although foot and ankle surgery has improved dramatically over the past decades primarily due to the development of better techniques, little progress has been made in the development of new materials for implants. Titanium, the most commonly used alloy for foot and ankle implants, has limited strength and is notch-sensitive so repetitive stress leads to fatigue failure of implants and limits design options. Better materials with optimized biomechanical properties could result in the development of superior foot and ankle implants and surgical techniques. The mechanical properties of Molybdenum-Rhenium (MoRe®), a promising new alloy for foot and ankle implants were tested. Methods: Standard test methods (ASTM 1717) were performed to evaluate the mechanical properties of Molybdenum Rhenium (MoRe®) alloy compared to Titanium (Ti-6Al-4 V, ASTM F136-13 annealed bar, Ti-ELI). Results: MoRe® is composed purely (99.99%) of molybdenum and rhenium and does not contain Nickel. Molybdenum is found in food and is a cofactor to the enzymes xanthine oxidase and sulfite oxidase, which are essential to bone and connective tissue metabolism. Rhenium is an inert metal with no biological affect. Mechanical testing showed MoRe to be superior to Titanium: Yield Strength: MoRe® 280ksi, Titanium 115ksi, Ultimate Tensile Strength: MoRe® 300ksi, Titanium 125 ksi. Elongation and Reduction in Area: MoRe® 13%, 50%, respectively; Titanium 10%, 25%. Recoil: MoRe® <2%, Titanium 6%. Hardness Range: MoRe® 280-800HV, Titanium 350-400HV. Max Run-Out Load Bent Rod: MoRe® 4.0 mm rod 350 N, Titanium 5.5 mm rod 150 N. Decrease in Max Run-Out Load Bent, Unbent, Re-bent Rod: MoRe® -9%, Titanium -17%. Conclusion: The MoRe® alloy, with its advantageous mechanical properties, offers great promise for the design of a new generation of smaller, stronger and more fatigue resistant foot and ankle implants, resulting in less soft tissue disruption, quicker recovery and better outcomes for patients.
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Bregman, Daan J. J., Vincent De Groot, Peter Van Diggele, Hubert Meulman, Han Houdijk, and Jaap Harlaar. "Polypropylene Ankle Foot Orthoses to Overcome Drop-Foot Gait in Central Neurological Patients: A Mechanical and Functional Evaluation." Prosthetics and Orthotics International 34, no. 3 (2010): 293–304. http://dx.doi.org/10.3109/03093646.2010.495969.
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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.
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Chun Qi Zheng, Shin-Min Song, and G. E. O. Widera. "Foot force distribution of walking machine with consideration of terrain properties." Journal of Terramechanics 29, no. 4-5 (1992): 497–514. http://dx.doi.org/10.1016/0022-4898(92)90050-t.
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KAJIWARA, Heizo, and Tsutomu EZUMI. "3D3-03 A Basic Research on Mechanical Properties of Joints of the foot." Proceedings of the JSME Symposium on Welfare Engineering 2006 (2006): 263–64. http://dx.doi.org/10.1299/jsmewes.2006.263.
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Qiu, Qin Er, Qiu Li Hu, and Yao Dong Gu. "Experimental Study on Mechanical Properties of Sole Materials of Aerobics Sports Shoes." Advanced Materials Research 341-342 (September 2011): 77–79. http://dx.doi.org/10.4028/www.scientific.net/amr.341-342.77.
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The purpose of this study was to understand damping and anti-slip properties of the Reebok and the Huakang shoes, evaluate the mechanical effect of those aerobics sports shoes as well. From the biomechanical test, almost all mean pressure, average impulse and average pressure of the Reebok and the Huakang was less than the bare foot condition on "shoes - ground", but the average pressure, average impulse and average pressure of the Reebok shoes was slightly higher than the Huakang shoes. Meanwhile, the damping mechanics indexes do not exist significant differences (P＞0.05). It’s friction coefficient tests show that dynamic or static friction coefficient of the Reebok is superior than the Huakang, and dynamic or static friction coefficient does exist significant differences (P＜0.05).
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Kobayashi, Toshiki, Fan Gao, Nicholas LeCursi, K. Bo Foreman, and Michael S. Orendurff. "Effect of Shoes on Stiffness and Energy Efficiency of Ankle-Foot Orthosis: Bench Testing Analysis." Journal of Applied Biomechanics 33, no. 6 (2017): 460–63. http://dx.doi.org/10.1123/jab.2016-0309.
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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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Darwish, Heba, Zeinab Abdel-Megied, and Adel El Geiheini. "Physical Mechanical Properties of Medical Socks Proposed for Diabetic Foot Syndrome Sampled from the Market." Autex Research Journal 19, no. 1 (2019): 17–25. http://dx.doi.org/10.1515/aut-2018-0018.
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Abstract Diabetic disease and its chronic complications is a public health problem that affects millions of people all over the world. Feet diabetics need private care by using appropriate shoes and socks, to avoid friction, sweating and high temperature. Diabetic socks have to attain an effective thermal comfort and higher appraisal performance. To achieve these conditions, the diabetic socks have to attain comfortable fit, no pressure points or seams on fingers, suitable size, classified as spring-summer or autumn-winter and also to avoid high temperature. The specifications of the diabetic socks sold in the market consist of its material combination, size and chemical treatments. No definite physical mechanical properties of diabetic socks are proposed. Diabetic socks taken from the market, with appropriate price, were evaluated for both thermal and non-thermal properties. The tested samples demonstrate a great variability’s in the fabric construction and properties. By analyzing the tested socks, the proposed values concerning the properties of diabetic socks for summer and winter are introduced. Moreover, relative geometrical mean of thermal comfort properties was proposed for determining a global measure of diabetic sock properties.
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M. Takhakh, Ayad, and Saif M. Abbas. "Manufacturing and analysis of carbon fiber knee ankle foot orthosis." International Journal of Engineering & Technology 7, no. 4 (2018): 2236. http://dx.doi.org/10.14419/ijet.v7i4.17315.
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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.
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Kadhum, Murtaza, Mu-Huan Lee, Jan Czernuszka, and Chris Lavy. "An Analysis of the Mechanical Properties of the Ponseti Method in Clubfoot Treatment." Applied Bionics and Biomechanics 2019 (March 25, 2019): 1–11. http://dx.doi.org/10.1155/2019/4308462.
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Congenital clubfoot is a complex pediatric foot deformity, occurring in approximately 1 in 1000 live births and resulting in significant disability, deformity, and pain if left untreated. The Ponseti method of manipulation is widely recognized as the gold standard treatment for congenital clubfoot; however, its mechanical aspects have not yet been fully explored. During the multiple manipulation-casting cycles, the tendons and ligaments on the medial and posterior aspect of the foot and ankle, which are identified as the rate-limiting tissues, usually undergo weekly sequential stretches, with a plaster of Paris cast applied after the stretch to maintain the length gained. This triggers extracellular matrix remodeling and tissue growth, but due to the viscoelastic properties of tendons and ligaments, the initial strain size, rate, and loading history will affect the relaxation behavior and mechanical strength of the tissue. To increase the efficiency of the Ponseti treatment, we discuss the theoretical possibilities of decreasing the size of the strain step and interval of casting and/or increasing the overall number of casts. This modification may provide more tensile stimuli, allow more time for remodeling, and preserve the mechanical integrity of the soft tissues.
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M. Abbas, S. "Effects of Composite Material Layers on the Mechanical Properties for Partial Foot Prosthetic Socket." Al-Nahrain Journal for Engineering Sciences 21, no. 2 (2018): 253–58. http://dx.doi.org/10.29194/njes21020253.
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DANESI, VALENTINA, LUCA CRISTOFOLINI, MATEUSZ MARIA JUSZCZYK, PAOLO ERANI, and MARCO VICECONTI. "MECHANICAL PROPERTIES OF THE HUMAN METATARSAL BONES." Journal of Mechanics in Medicine and Biology 12, no. 04 (2012): 1250062. http://dx.doi.org/10.1142/s0219519412005034.
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Despite the incidence of metatarsal fractures and the associated risk of significant disability, little is known about the biomechanical properties (strength and stiffness) of metatarsal bones. In most cases a single metatarsal bone (first, second and fifth) has been investigated. An extensive investigation of the biomechanical properties of the metatarsal bones is essential in the understanding and prevention of metatarsal injuries. Entire sets of metatarsal bones from four feet were tested. The first foot was used to fine-tune the testing set-ups. To measure the stiffness, each metatarsal bone was subjected to non-destructive four-point-bending in the sagittal and transverse planes, axial compression and torsion. Strain was measured at two locations. To measure the strength, each metatarsal bone was tested to failure in torsion. Significant differences (p < 0.0001) existed among the stiffness of the five metatarsal bones: (i) in torsion the first metatarsal bone was 2–3 times stiffer than the others; (ii) in four-point-bending and axial compression this difference was less pronounced than in torsion; (iii) differences were smaller among the other metatarsal bones; (iv) the second metatarsal bone was less stiff than the third and fourth in bending. The second, third and fourth metatarsal bones were stiffer in the sagittal than in the transverse plane (p < 0.0001). Conversely, there was no significant difference between the two planes of bending for the first and fifth bones. During destructive testing, all metatarsal bones exhibited a linear elastic behavior and brittle failure. The torsional strength at failure ranged between 1.9 Nm and 6.9 Nm. The first metatarsal bone was stronger than all the others. Stiffness in different loading conditions and failure were measured and compared for all metatarsal bones. These data corroborate previous biomechanical studies concerning the role and load sharing of the different metatarsal bones.
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Berge,, Jocelyn S., Glenn K. Klute,, and Joseph M. Czerniecki,. "Mechanical Properties of Shock-Absorbing Pylons Used in Transtibial Prostheses." Journal of Biomechanical Engineering 126, no. 1 (2004): 120–22. http://dx.doi.org/10.1115/1.1645865.
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Prosthetic manufacturers have developed shock-absorbing pylons to attenuate the transient forces of foot-ground contact in order to supplement the residual capacity of lower limb amputees. The purpose of this study was to measure the elastic and damping properties of two frequently prescribed pylons (the ICON™ Shock Pylon and the Mercury TT Pyramid Pylon) at frequencies enveloping those observed during gait using pseudo-static compressive and dynamic cyclic testing methods. Results showed that the spring constants were linear functions of deformation (ranging from 74 to 110 N/mm and 91 to 157 N/mm for the ICON and the TT Pylons, respectively) while the damping force was a function of the square root of velocity combined with a coulomb element (1.6x˙0.5+21 and 7.4x˙0.5+102 N for the ICON and the TT Pylon, respectively).
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Gao, Fan, William Carlton, and Susan Kapp. "Effects of joint alignment and type on mechanical properties of thermoplastic articulated ankle-foot orthosis." Prosthetics and Orthotics International 35, no. 2 (2011): 181–89. http://dx.doi.org/10.1177/0309364611409617.
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Background: Articulated or hinged ankle-foot orthosis (AFO) allow more range of motion. However, quantitative investigation on articulated AFO is still sparse.Objective: The objective of the study was to quantitatively investigate effects of alignment and joint types on mechanical properties of the thermoplastic articulated AFO.Study design: Tamarack dorsiflexion assist flexure joints with three durometers (75, 85 and 95) and free motion joint were tested. The AFO joint was aligned with the center of the motor shaft (surrogate ankle joint), 10 mm superior, inferior, anterior and posterior with respect to the motor shaft center.Methods: The AFO was passively moved from 20° plantar flexion to 15° dorsiflexion at a speed of 10°/s using a motorized device. Mechanical properties including index of hysteresis, passive resistance torque and quasi-static stiffness (at neutral, 5°, 10° and 15° in plantar flexion) were quantified.Results: Significant effects of joint types and joint alignment on the mechanical properties of an articulated thermoplastic AFO were revealed. Specifically, center alignment showed minimum resistance and stiffness while anterior and posterior alignment showed significantly higher resistance and stiffness. The dorsiflexion assist torques at neutral position ranged from 0.69 ± 0.09 to 1.88 ± 0.10 Nm.Conclusions: Anterior and posterior alignment should be avoided as much as possible.Clinical relevanceThe current study suggested that anterior and posterior alignment be avoided as much as possible in clinical practice due to potential skin irritation and increase in stress around the ankle joint.
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Zahn, Peter K., and Timothy J. Brennan. "Incision-induced Changes in Receptive Field Properties of Rat Dorsal Horn Neurons." Anesthesiology 91, no. 3 (1999): 772. http://dx.doi.org/10.1097/00000542-199909000-00030.
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Background To learn more about pain mechanisms produced by surgery, responses of wide dynamic range (WDR) and high threshold (HT) dorsal horn neurons were studied before and after an incision. For this study, an incision was made in a mechanically insensitive area of the receptive field (RF) of the dorsal horn neuron in the plantar aspect of the foot and changes in mechanical response properties were studied. Methods Action potentials from single dorsal horn neurons were recorded in halothane anesthetized rats and these neurons were characterized as WDR or HT. Changes in background activity and responses to a variety of mechanical stimuli adjacent to the incision, distant to the injury, and in areas throughout the hindquarters were recorded. Results Fifty neurons were recorded (29 WDR, 21 HT cells); only nine of these had a sustained increase in background activity after incision. Marked decreases in threshold to von Frey filaments applied adjacent to the wound occurred in 9 of 28 WDR neurons but in none of 21 HT cells. Von Frey filament thresholds distant to the incision were largely not changed. A blunt mechanical stimulus activated 18 of 22 WDR neurons when applied directly on the incision. HT cells were largely not excited by this mechanical stimulus after incision. The RF to pinch was enlarged in 31 neurons to include areas outside the injury. Pinch RFs of both WDR and HT cells expanded. Conclusion These results suggest that incisions in mechanically insensitive areas of the RF of dorsal horn neurons produced little change in background activity; expansion of pinch RFs outside the injury was common. Changing a mechanically insensitive area of the RF of WDR neurons to a mechanically sensitive area by an incision could contribute to pain behaviors that indicate primary mechanical hyperalgesia in behavioral studies.
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Lewis, M. Anthony, Hyo-Kyung Lee, and Aftab Patla. "Foot Placement Selection Using Non-geometric Visual Properties." International Journal of Robotics Research 24, no. 7 (2005): 553–61. http://dx.doi.org/10.1177/0278364905055419.
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Arangio, George A., Chaorong Chen, and Eric P. Salathé. "Effect of Varying Arch Height with and Without the Plantar Fascia on the Mechanical Properties of the Foot." Foot & Ankle International 19, no. 10 (1998): 705–9. http://dx.doi.org/10.1177/107110079801901010.
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A biomechanical model was used to calculate the mechanical properties of the foot at a load of 683 newtons, while changing arch height with and without the plantar fascia. An increase in arch height from 20 mm to 60 mm decreased predicted vertical displacement of the foot from 11.8 mm to 5.5 mm with the plantar fascia intact and from 13.5 mm to 7.5 mm without the plantar fascia. The amount of horizontal elongation decreased from 8.6 mm to 8.4 mm with the plantar fascia and increased from 9.8 mm to 11.7 mm without. A 60-mm arch height yielded a 40% increase in horizontal elongation and a 36% increase in vertical displacement when the plantar fascia was cut, whereas a 20-mm arch height yielded a 13% increase in horizontal elongation and a 14% increase in vertical displacement. A change in arch height from 20 mm to 60 mm increased stiffness of the foot with and without the plantar fascia.
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Adiputra, Dimas, Nurhazimah Nazmi, Irfan Bahiuddin, et al. "A Review on the Control of the Mechanical Properties of Ankle Foot Orthosis for Gait Assistance." Actuators 8, no. 1 (2019): 10. http://dx.doi.org/10.3390/act8010010.
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In the past decade, advanced technologies in robotics have been explored to enhance the rehabilitation of post-stroke patients. Previous works have shown that gait assistance for post-stroke patients can be provided through the use of robotics technology in ancillary equipment, such as Ankle Foot Orthosis (AFO). An AFO is usually used to assist patients with spasticity or foot drop problems. There are several types of AFOs, depending on the flexibility of the joint, such as rigid, flexible rigid, and articulated AFOs. A rigid AFO has a fixed joint, and a flexible rigid AFO has a more flexible joint, while the articulated AFO has a freely rotating ankle joint, where the mechanical properties of the AFO are more controllable compared to the other two types of AFOs. This paper reviews the control of the mechanical properties of existing AFOs for gait assistance in post-stroke patients. Several aspects that affect the control of the mechanical properties of an AFO, such as the controller input, number of gait phases, controller output reference, and controller performance evaluation are discussed and compared. Thus, this paper will be of interest to AFO researchers or developers who would like to design their own AFOs with the most suitable mechanical properties based on their application. The controller input and the number of gait phases are discussed first. Then, the discussion moves forward to the methods of estimating the controller output reference, which is the main focus of this study. Based on the estimation method, the gait control strategies can be classified into subject-oriented estimations and phase-oriented estimations. Finally, suggestions for future studies are addressed, one of which is the application of the adaptive controller output reference to maximize the benefits of the AFO to users.
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Lin, Kuang-Wei, Chia-Jung Hu, Wen-Wen Yang, et al. "Biomechanical Evaluation and Strength Test of 3D-Printed Foot Orthoses." Applied Bionics and Biomechanics 2019 (December 7, 2019): 1–8. http://dx.doi.org/10.1155/2019/4989534.
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Foot orthoses (FOs) are commonly used as interventions for individuals with flatfoot. Advances in technologies such as three-dimensional (3D) scanning and 3D printing have facilitated the fabrication of custom FOs. However, few studies have been conducted on the mechanical properties and biomechanical effects of 3D-printed FOs. The purposes of this study were to evaluate the mechanical properties of 3D-printed FOs and determine their biomechanical effects in individuals with flexible flatfoot. During mechanical testing, a total of 18 FO samples with three orientations (0°, 45°, and 90°) were fabricated and tested. The maximum compressive load and stiffness were calculated. During a motion capture experiment, 12 individuals with flatfoot were enrolled, and the 3D-printed FOs were used as interventions. Kinematic and kinetic data were collected during walking by using an optical motion capture system. A one-way analysis of variance was performed to compare the mechanical parameters among the three build orientations. A paired t-test was conducted to compare the biomechanical variables under two conditions: walking in standard shoes (Shoe) and walking in shoes embedded with FOs (Shoe+FO). The results indicated that the 45° build orientation produced the strongest FOs. In addition, the maximum ankle evertor and external rotator moments under the Shoe+FO condition were significantly reduced by 35% and 16%, respectively, but the maximum ankle plantar flexor moments increased by 3%, compared with the Shoe condition. No significant difference in ground reaction force was observed between the two conditions. This study demonstrated that 3D-printed FOs could alter the ankle joint moments during gait.
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Pankova, B., T. Koudelka, K. Pavelka, M. Janura, and K. Jelen. "EXPLOITATION OF STEREOPHOTOGRAMMETRIC MEASUREMENT OF A FOOT IN ANALYSIS OF PLANTAR PRESSURE DISTRIBUTION." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences III-5 (June 6, 2016): 153–58. http://dx.doi.org/10.5194/isprsannals-iii-5-153-2016.
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Stereophotogrammetry as a method for the surface scanning can be used to capture some properties of the human body parts. The objective of this study is to quantify the foot stress distribution in 3D during its quasi-static stand using a footprint into an imprinting material when knowing its mechanical properties. One foot of a female, having the mass of 65kg, was chosen for the FEM foot model construction. After obtaining her foot imprint to the dental imprinting material, its positive plaster cast was created, whose surface was possible to scan using stereophotogrammetry. The imprint surface digital model was prepared with the help of the Konica-Minolta Vivid 9i triangulation scanner. This procedure provides the measured object models in a high resolution. The resulting surface mesh of the foot imprint involved 9.600 nodes and 14.000 triangles, approximately, after reduction due to the FEM analysis. Simulation of foot imprint was solved as the 3D time dependent nonlinear mechanical problem in the ADINA software. The sum of vertical reactions calculated at the contact area nodes was 320.5 N, which corresponds to the mass of 32.67 kg. This value is in a good agreement with the subject half weight – the load of one foot during its quasi-static stand. The partial pressures resulting from this mathematical model match the real pressures on the interface of the foot and imprinting material quite closely. Principally, these simulations can be used to assess the contact pressures in practical cases, e.g., between a foot and its footwear.
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Pankova, B., T. Koudelka, K. Pavelka, M. Janura, and K. Jelen. "EXPLOITATION OF STEREOPHOTOGRAMMETRIC MEASUREMENT OF A FOOT IN ANALYSIS OF PLANTAR PRESSURE DISTRIBUTION." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences III-5 (June 6, 2016): 153–58. http://dx.doi.org/10.5194/isprs-annals-iii-5-153-2016.
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Stereophotogrammetry as a method for the surface scanning can be used to capture some properties of the human body parts. The objective of this study is to quantify the foot stress distribution in 3D during its quasi-static stand using a footprint into an imprinting material when knowing its mechanical properties. One foot of a female, having the mass of 65kg, was chosen for the FEM foot model construction. After obtaining her foot imprint to the dental imprinting material, its positive plaster cast was created, whose surface was possible to scan using stereophotogrammetry. The imprint surface digital model was prepared with the help of the Konica-Minolta Vivid 9i triangulation scanner. This procedure provides the measured object models in a high resolution. The resulting surface mesh of the foot imprint involved 9.600 nodes and 14.000 triangles, approximately, after reduction due to the FEM analysis. Simulation of foot imprint was solved as the 3D time dependent nonlinear mechanical problem in the ADINA software. The sum of vertical reactions calculated at the contact area nodes was 320.5 N, which corresponds to the mass of 32.67 kg. This value is in a good agreement with the subject half weight – the load of one foot during its quasi-static stand. The partial pressures resulting from this mathematical model match the real pressures on the interface of the foot and imprinting material quite closely. Principally, these simulations can be used to assess the contact pressures in practical cases, e.g., between a foot and its footwear.
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Mohamad Noor, Mohd Zulkifli, Mohamad Anas Mohd Azmi, Mohd Shaiful Zaidi Mad Desa, Mohd Bijarimi Mat Piah, and Azizan Ramli. "The Thermal Properties of Polyurethane/Neoprene Blends on Prosthetic Foot." Materials Science Forum 990 (May 2020): 106–10. http://dx.doi.org/10.4028/www.scientific.net/msf.990.106.
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Neoprene reinforced polymer has become an attraction in current research and development of new material blend. In this invention, neoprene was chosen to be enhance to polyurethane because of their superior properties that possess extraordinary mechanical, electrical, optical and thermal properties on prosthetic foot. In this research, polyurethane was chosen due to good rigidity, easy processing and low cost. The reinforcement polyurethane with neoprene is expected to improve the properties of polyurethane. The objective of this research was conducted to investigate the effect of neoprene contents on thermal properties of polyurethane reinforced neoprene on prosthetic foot. The effect of neoprene on thermal properties neoprene reinforced polyurethane was analysed in term of its thermal stability by thermal gravimetric analysis (TGA). Moreover, the visual of small topographic details on the surface of polyurethane/neoprene blends will be examined by scanning electron microscope (SEM). Based on result, the thermal properties show the great enhancement at high neoprene contents which is 1.0wt%. The thermal stability of polyurethane reinforced neoprene improves when the temperature where decomposition starts to occurs are higher than decomposition temperature of pure polyurethane. Then, thermal conductivity of polyurethane shows the great improvement after the addition of neoprene. Lastly, the smooth surface and visible of sheets pattern on surface represent the present of neoprene disperse into polymer that enhance brittleness. Thus, the presence of neoprene has clearly enhanced the thermal stability of the polyurethane. Table 1 shows formulation of neoprene and polyurethane.
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TAŞ, Serkan. "Investigation of Morphological and Mechanical Properties of Foot Intrinsic Muscles in Overweight and Obese Females." Turkiye Klinikleri Journal of Health Sciences 3, no. 3 (2018): 214–19. http://dx.doi.org/10.5336/healthsci.2018-62369.
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Parker, D., G. Cooper, S. Pearson, et al. "A device for characterising the mechanical properties of the plantar soft tissue of the foot." Medical Engineering & Physics 37, no. 11 (2015): 1098–104. http://dx.doi.org/10.1016/j.medengphy.2015.08.008.
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Ling, Hang-yin, Pong-chi Choi, Yong-ping Zheng, and Kin-tak Lau. "Extraction of mechanical properties of foot plantar tissues using ultrasound indentation associated with genetic algorithm." Journal of Materials Science: Materials in Medicine 18, no. 8 (2007): 1579–86. http://dx.doi.org/10.1007/s10856-007-3025-6.
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Gao, Fan, and Gary G. Bedard. "Effects of Materials, Reinforcement, and Heat Treatment on Thermoplastic Solid Ankle-Foot Orthosis Mechanical Properties." JPO Journal of Prosthetics and Orthotics 25, no. 3 (2013): 143–50. http://dx.doi.org/10.1097/jpo.0b013e31829c163d.
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Faulí, Angel Camp, Cristina Llobell Andrés, Norberto Porta Rosas, Maria José Fernández, Enrique Montiel Parreño, and César Orgilés Barceló. "Physical Evaluation of Insole Materials Used to Treat the Diabetic Foot." Journal of the American Podiatric Medical Association 98, no. 3 (2008): 229–38. http://dx.doi.org/10.7547/0980229.
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Background: The selection of materials for the production of multilayer insoles for diabetic feet is a difficult task owing to the lack of technical information about these materials. Therefore, objective criteria were established for the selection of these materials. Methods: Mechanical- and comfort-related tests for the mechanical characterization of different materials and their combinations were considered. These tests were conducted according to standardized test methods for polymeric cellular materials. Results: Criteria for the use of cellular materials were obtained. The properties of accommodation, cushioning, and filling materials were established and the most adequate polymer nature for each of the three applications was identified. Variables that affect the properties of these material combinations were studied. Conclusions: These test results will allow podiatrists to select insoles in a more objective way, thus achieving a more successful treatment for diabetic foot-related injuries. (J Am Podiatr Med Assoc 98(3): 229–238, 2008)
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Han, Xiaoli, Jian Dai, Wei Qian, Baolong Li, Yuanjun Jin, and Ting Jiang. "Effect of column foot tenon on behavior of larch column base joints based on concrete plinth." BioResources 15, no. 3 (2020): 6648–67. http://dx.doi.org/10.15376/biores.15.3.6648-6667.
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The wooden columns in timber structures of ancient buildings have column foot tenons of various sizes. The main reason for these differences is their use for different roof loads. Six full-scale specimens with different sizes of column foot tenon were designed and manufactured. The tree species used for the specimens was larch. The quasi-static test was conducted on the specimens that were used in timber structures of ancient buildings. The effects of column foot tenon size on the mechanical properties of larch wooden columns were studied. The moment-rotational angle hysteretic curves, moment-rotational angle skeleton curves, ductility, stiffness degradation, energy dissipation capacity, slippages between the wooden column and the plinth, and the damage of the column foot tenons were examined. The test results showed that the column foot tenon played an important role in the mechanical behavior of the wooden column under low-cycle reversed cyclic loading. The rotation of the column foot tenon improved the energy dissipation capacity of the wooden column. As the rotational angle of the column base increased, the column foot tenon had different degrees of damage. Different sizes of column foot tenon had their own advantages and hysteretic behavior.
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Shu, Min, Yi Yang Li, and Xing Zhi Liao. "Study on Volleyball Athletes Foot Pressure Acquisition Method." Applied Mechanics and Materials 303-306 (February 2013): 274–79. http://dx.doi.org/10.4028/www.scientific.net/amm.303-306.274.
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How to improve training records and skill level, and try to minimize sports injury at the same time, has increasingly become the focus of Volleyball Professional Training Design. This paper puts forward a method to acquire the foot pressure information of volleyball athlete. By utilizing PVDF film which has the advantages of fast response, high sensitivity, good mechanical properties etc., the array of pressure sensors and signal conditioning circuit have been designed and produced. Tested, this method can accurately in real time acquire volleyball athlete’s foot dynamic pressure distribution information.
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Kelly, Luke A., Dominic J. Farris, Andrew G. Cresswell, and Glen A. Lichtwark. "Intrinsic foot muscles contribute to elastic energy storage and return in the human foot." Journal of Applied Physiology 126, no. 1 (2019): 231–38. http://dx.doi.org/10.1152/japplphysiol.00736.2018.
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The human foot is uniquely stiff to enable forward propulsion, yet also possesses sufficient elasticity to act as an energy store, recycling mechanical energy during locomotion. Historically, this dichotomous function has been attributed to the passive contribution of the plantar aponeurosis. However, recent evidence highlights the potential for muscles to modulate the energetic function of the foot actively. Here, we test the hypothesis that the central nervous system can actively control the foot’s energetic function, via activation of the muscles within the foot’s longitudinal arch. We used a custom-built loading apparatus to deliver cyclical loads to human feet in vivo, to deform the arch in a manner similar to that observed in locomotion. We recorded foot motion and forces, alongside muscle activation and ultrasound images from flexor digitorum brevis (FDB), an intrinsic foot muscle that spans the arch. When active, the FDB muscle fascicles contracted in an isometric manner, facilitating elastic energy storage in the tendon, in addition to the energy stored within the plantar aponeurosis. We propose that the human foot is akin to an active suspension system for the human body, with mechanical and energetic properties that can be actively controlled by the central nervous system. NEW & NOTEWORTHY The human foot is renowned for its ability to recycle mechanical energy during locomotion, contributing up to 17% of the energy required to power a stride. This mechanism has long been considered passive in nature, facilitated by the elastic ligaments within the arch of the foot. In this paper, we present the first direct evidence that the intrinsic foot muscles also contribute to elastic energy storage and return within the human foot. Isometric contraction of the flexor digitorum brevis muscle tissue facilitates tendon stretch and recoil during controlled loading of the foot. The significance of these muscles has been greatly debated by evolutionary biologists seeking to understand the origins of upright posture and gait, as well as applied and clinical scientists. The data we present here show a potential function for these muscles in contributing to the energetic function of the human foot.
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Banerjee, Shib Sundar, and Srivasta Ananthan. "STUDY OF THE BILATERAL ASYMMETRY OF PLANTAR MECHANICAL PROPERTIES AS A BIOMARKER FOR THE DIFFERENTIATION OF DIABETIC CONDITION." Biomedical Sciences Instrumentation 57, no. 2 (2021): 114–20. http://dx.doi.org/10.34107/yhpn9422.04114.
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Diabetes mellitus is a globally prevalent metabolic disease which results in altered plantar mechanical properties and foot ulcer. In this study, the bilateral asymmetry of mechanical properties for plantar soft tissue is investigated in healthy and diabetic conditions. Myotonometric signals are acquired from sub-metatarsal region of the plantar faces of healthy subjects and patients with varied diabetic age. Mechanical parameters such as dynamic stiffness and logarithmic decrement are extracted from the recorded signal. The asymmetry indices between right and left feet are computed. Statistical analysis shows that the spatial pattern of dynamic stiffness and logarithmic decrement varies significantly between healthy and diabetic subjects. The asymmetry index of dynamic stiffness in the fifth sub-metatarsal head can differentiate between healthy subjects and patients with both high and low diabetic age (p<0.05). The asymmetry index of logarithmic decrement is found to vary significantly between the healthy subjects and patients with higher diabetic age (p<0.05). These results indicate that bilateral asymmetry of myotonometric parameters can be exploited as a possible biomarker to differentiate diabetic patients from healthy subjects and can aid in the early detection of foot ulcer.
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Khartabil, Ahmad, and Samer Al Martini. "Fresh and Mechanical Properties of Sustainable Concrete Using Recycled Aggregates." Key Engineering Materials 803 (May 2019): 239–45. http://dx.doi.org/10.4028/www.scientific.net/kem.803.239.
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In the last few decades, the United Arab Emirates (UAE) witnessed rapid development in the construction industry. It was recently emphasized to adopt sustainability practice in all aspects related to construction. The recent sustainable practice that was enforced by Dubai Municipality in construction field is “greening the concrete” by solely replacing the Portland Cement with supplementary cementitious materials (SCMs), such as grand granulated blast furnace slag (GGBS) and fly ash. On the other hand, the use of recycled aggregates can also contribute to the greening of concrete and to the reduction of carbon foot print from the construction industry in the UAE. Consequently, it is significant to study the suitability of local available recycled aggregate and their effect on concrete fresh and hardened properties, in order to expand the current practice. The recycled aggregates, used in this investigation, are obtained from a local recycled aggregates plant in Abu Dhabi using concrete from demolished buildings in Abu Dhabi. The natural aggregates in concrete mixtures were replaced by recycled aggregates with the following percentages: 20%, 40%, 60% and 100%. The concrete parameters investigated are mainly the slump retention, rheology and compressive strength. The results are analyzed to arrive to pertinent conclusions for the utilization of concrete with recycled aggregates in different types of construction projects.
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Banga, Harish Kumar, Parveen Kalra, Rajendra M. Belokar, and Rajesh Kumar. "Customized design and additive manufacturing of kids’ ankle foot orthosis." Rapid Prototyping Journal 26, no. 10 (2020): 1677–85. http://dx.doi.org/10.1108/rpj-07-2019-0194.
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Purpose The purpose of this study is improvement of human gait by customized design of ankle foot orthosis (AFO). An has been the most frequently used orthosis in children with cerebral palsy. AFOs are designed to boost existing features or to avoid depression or traumatize muscle contractures. The advantages of AFO’s utilized for advancement in human walk attributes for the improvement in foot deformities patients or youngsters with spastic loss of motion. In this research on the customized design of AFO's to improve gait, there are limitations during walking of foot drop patients. In children with foot drops, specific AFOs were explicitly altered to improve parity and strength which are beneficial to walking positions. Design/methodology/approach This study proposes the customized design of AFOs using computerized and additive manufacturing for producing advances to alter the design and increase comfort for foot drop patients. Structuring the proposed design fabricated by using additive manufacturing and restricted material, the investigation was finalized at the Design Analysis Software (ANSYS). The system that performs best under investigation can additionally be printed using additive manufacturing. Findings The results show that the customized design of AFOs meets the patient’s requirements and could also be an alternative solution to the existing AFO design. The biomechanical consequences and mechanical properties of additive manufactured AFOs have been comparable to historically synthetic AFOs. While developing the novel AFO designs, the use of 3D printing has many benefits, including stiffness and weight optimization, to improve biomechanical function and comfort. To defeat the issues of foot drop patients, a customized AFO is used to improve the human gait cycle with new material and having better mechanical properties. Originality/value This research work focuses on the biomechanical impacts and mechanical properties of customized 3D-printed AFOs and compares them to traditionally made AFOs. Customized AFO design using 3D printing has numerous potential advantages, including new material with lightweight advancement, to improve biomechanical function and comfort. Normally, new applications mean an incremental collection of learning approximately the behavior of such gadgets and blending the new design, composite speculation and delivered substance production. The test results aim to overcome the new AFO structure issues and display the limited components and stress examination. The outcome of the research is the improved gait cycle of foot drop patients.
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Malyshev, Aleksey Y., and Pavel M. Balaban. "Identification of Mechanoafferent Neurons in Terrestrial Snail: Response Properties and Synaptic Connections." Journal of Neurophysiology 87, no. 5 (2002): 2364–71. http://dx.doi.org/10.1152/jn.00185.2001.
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In this study, we describe the putative mechanosensory neurons, which are involved in the control of avoidance behavior of the terrestrial snail Helix lucorum. These neurons, which were termed pleural ventrolateral (PlVL) neurons, mediated part of the withdrawal response of the animal via activation of the withdrawal interneurons. Between 15 and 30 pleural mechanosensory neurons were located on the ventrolateral side of each pleural ganglion. Intracellular injection of neurobiotin revealed that all PlVL neurons sent their axons into the skin nerves. The PlVL neurons had no spontaneous spike activity or fast synaptic potentials. In the reduced “CNS-foot” preparations, mechanical stimulation of the skin covering the dorsal surface of the foot elicited spikes in the PlVL neurons without any noticeable prepotential activity. Mechanical stimulus-induced action potentials in these cells persisted in the presence of high-Mg2+/zero-Ca2+ saline. Each neuron had oval-shaped receptive field 5–20 mm in length located on the dorsal surface of the foot. Partial overlapping of the receptive fields of different neurons was observed. Intracellular stimulation of the PlVL neurons produced excitatory inputs to the parietal and pleural withdrawal interneurons, which are known to control avoidance behavior. The excitatory postsynaptic potentials (EPSPs) in the withdrawal interneurons were induced in 1:1 ratio to the PlVL neuron spikes, and spike-EPSP latency was short and highly stable. These EPSPs also persisted in the high-Mg2+/high-Ca2+ saline, suggesting monosynaptic connections. All these data suggest that PlVL cells were the primary mechanosensory neurons.
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Rome, K. "A study of the properties of materials used in podiatry." Journal of the American Podiatric Medical Association 81, no. 2 (1991): 73–83. http://dx.doi.org/10.7547/87507315-81-2-73.
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This study was performed to provide insight into the functioning of a selection of materials used in the fabrication of orthoses. A series of mechanical and physical tests was performed on five materials, under strict laboratory conditions. The results demonstrate that the polyurethane foams are the most promising material in the design of foot orthoses. The results also suggest that an agglomeration of properties, not just one specific property, can influence the behavior of materials.
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Xu, Weichen, Binbin Zhang, Yu Deng, et al. "Corrosion of rail tracks and their protection." Corrosion Reviews 39, no. 1 (2020): 1–13. http://dx.doi.org/10.1515/corrrev-2020-0069.
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Abstract Rapid development of railway industry makes safety increasingly important. Wear, contact-impact, fatigue and corrosion are important factors initiating rail track degradation from the beginning, while corrosion attracts far less attention than other issues. Direct corrosion cost due to railway corrosion in China was 18.88 billion RMB, so corrosion definitely deserves more attention. This work has reviewed studies focussing exclusively on rail corrosion, including corrosion forms, protection and detection technologies. General corrosion on large rail surface is not limiting, while crevice corrosion between rail and liner, resulting in thinning of rail foot, is regarded significant but overlooked. Moreover, reciprocating micro-motion between rail foot and liner mechanically assists the ongoing of crevice corrosion. However, it was mentioned in very few reports and not investigated extensively. Coating and surface modification may be applied for mitigation of rail track corrosion. The weakness of coating is poor mechanical properties, while surface modification, including thermal spraying and laser cladding, may be a better way. Development of novel steel is another effective method, but loss of mechanical properties becomes obstacles for practical applications. Ultrasonic and infrared have been applied for detection, while more advanced technologies are promising. Suggestions are made on specific research topics in this field.