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Sample records for players wear shoes

  1. The influence of shoe drop on the kinematics and kinetics of children tennis players.

    Science.gov (United States)

    Herbaut, Alexis; Chavet, Pascale; Roux, Maxime; Guéguen, Nils; Gillet, Christophe; Barbier, Franck; Simoneau-Buessinger, Emilie

    2016-11-01

    This study investigated the immediate effects of reducing the shoe drop (i.e. the difference between the heel and the forefoot height) on the kinematics and kinetics of the lower extremities of children tennis players performing a tennis-specific movement. Thirteen children tennis players performed a series of simulated open stance forehands wearing 3 pairs of shoes differing only in the drop: 0 (D0), 6 (D6) and the control condition of 12 mm (D12). Two embedded forceplates and a motion capture system were used to analyse the ground reaction forces and ankle and knee joint angles and moments of the leading lower limb. In D6 compared with D12, the peak impact force was reduced by 24% (p = .004) and the ankle was less dorsiflexed at foot strike (p = .037). In D0 compared with D12, the peak impact force was reduced by 17% (p = .049), the ankle was less dorsiflexed at foot strike (p = .045) and the knee was more flexed at foot strike (p = .007). In addition, 4 out of 13 participants (31%) presented a forefoot strike pattern for some of the trials in D0. No difference was observed across shoe conditions for the peak knee extensor moment (p = .658) or the peak ankle plantarflexor moment (p = .071). The results provide preliminary data supporting the hypothesis that for children tennis players, using a 6-mm lower shoe drop might reduce heel impact forces and thus limit potentially impact-related injuries.

  2. Influence of dorsiflexion shoes on neuromuscular fatigue of the plantar flexors after combined tapping-jumping exercises in volleyball players.

    Science.gov (United States)

    Lapole, Thomas; Ahmaidi, Said; Gaillien, Benjamin; Leprêtre, Pierre-Marie

    2013-07-01

    Dorsiflexion shoes could be useful to increase jumping performance. The aim of the present study was to investigate the impact of wearing shoes inducing moderate dorsiflexion (2°) on neuromuscular fatigue induced by volleyball exercises involving multiple stretch-shortening cycles. Squat jump (SJ) and countermovement jump (CMJ) performance, and plantar flexors isometric voluntary and evoked contractile properties were assessed in 10 unfamiliarized trained volleyball players before and after a 10-minute intensive combined tapping-jumping volleyball exercise performed, in blinded randomized conditions, with neutral (0°) or moderate dorsiflexion (2°). No significant difference was observed on SJ performance in neutral and moderate dorsiflexion conditions. However, CMJ height was initially lower with 2° dorsiflexion compared with 0° (p volleyball exercise also induced a significant decrease in maximal voluntary contraction (p volleyball players.

  3. Adherence to wearing therapeutic shoes among people with diabetes: a systematic review and reflections

    Directory of Open Access Journals (Sweden)

    Jarl G

    2016-08-01

    Full Text Available Gustav Jarl,1,2 Lars-Olov Lundqvist2 1Department of Prosthetics and Orthotics, Faculty of Medicine and Health, 2University Health Care Research Center, Faculty of Medicine and Health, Örebro University, Örebro, Sweden Introduction: Therapeutic shoes are prescribed to prevent diabetic foot ulcers, but adherence to wearing the shoes is often poor.  Aim: The aim of this study was to review the literature on factors that are associated with adherence to wearing therapeutic shoes and construct a model of adherence to aid future research and development in the field. Methods: We conducted a systematic search in PubMed, CINAHL, and PsycINFO for quantitative studies on factors associated with adherence to wearing therapeutic shoes among people with diabetes. Results: Six studies were included in the review. The studies focused mainly on patient-, therapy-, and condition-related adherence factors. There is some evidence (three to five studies that sex, diabetes duration, and ulcer history are not associated with adherence. The evidence for or against the other factors was weak (only one or two studies or conflicting. Conclusion: There is no conclusive evidence for using any factor to predict adherence to wearing therapeutic shoes, but there is some evidence against using certain factors for predicting adherence. Future studies should include a broader range of factors, including health system and social/economic factors, and they should investigate perceived costs and benefits of wearing therapeutic shoes in comparison with other shoes or no shoes. A seesaw model is presented illustrating the complex phenomenon of adherence. Further research is needed to identify factors associated with adherence to wearing therapeutic shoes, to enable the development of interventions to improve adherence and thereby reduce ulceration rates among people with diabetic foot complications.Keywords: Patient compliance, shoes, foot ulcer, diabetic foot, diabetes

  4. SPORTS SHOES PURCHASE INTENTION AMONG MALAYSIAN VOLLEYBALL PLAYERS VS. NON-VOLLEYBALL PLAYERS: A CONCEPTUAL PAPER

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    GOH PIN SIANG

    2013-12-01

    Full Text Available The purpose of this study is to advance the understanding of volleyball players’ purchase intention toward sport shoes by investigating the relationship between the independent variables (endorsement, advertising, pricing and electronic word-of-mouth and purchase intention. Descriptive research and causal research will be used as the research design, thus questionnaire and experimentation will be used to obtain data. Primary data in this study is attained by distributing the questionnaire to the Malaysian volleyball players throughout several volleyball tournament venues in Malaysia. The experiment will be conducted by comparing two groups of respondents, including volleyball players and non-volleyball players. This study is limited to several independent variables such as endorsement, advertising, pricing and electronic word-of-mouth. This study is significant for marketers for solving the challenges faced in the sport industry. It also helps to identify consumers’ purchase preferences for sport shoes. The marketer would understand more about their targeted customers’ intentions to purchase, thus the sport industry related with sport marketing in Malaysia might gain more profit.

  5. Effects of high heeled shoes wearing experience and heel height on human standing balance and functional mobility.

    Science.gov (United States)

    Hapsari, Vaniessa Dewi; Xiong, Shuping

    2016-01-01

    This study aimed to examine the effects of high heeled shoes (HHS) wearing experience and heel height on human standing balance and functional mobility. Thirty young and healthy females (ten experienced and twenty inexperienced HHS wearers) participated in a series of balance tests when they wore shoes of four different heel heights: 1 cm (flat), 4 cm (low), 7 cm (medium) and 10 cm (high). Experimental results show that regardless of the wearing experience, the heel elevation induces more effort from lower limb muscles (particularly calf muscles) and results in worse functional mobility starting at 7 cm heel height. While the heel height increased to 10 cm, the standing balance also becomes worse. Experienced HHS wearers do not show significantly better overall performance on standing balance and functional mobility than inexperienced controls, even though they have better directional control (76.8% vs. 74.4%) and larger maximum excursion (93.3% vs. 89.7%). To maintain standing balance, experienced wearers exert less effort on tibialis anterior, vastus lateralis and erector spinae muscles at the cost of more intensive effort from gastrocnemius medialis muscle. Many women wear high heeled shoes (HHS) to increase female attractiveness. This study shows that HHS induce more muscular effort and worse human standing balance and functional mobility, especially when heel height reaches 10 cm. HHS wearing experience only provides certain advantages to wearers on limits of stability in terms of larger maximum excursion and better directional control.

  6. Post-marathon wearing of Masai Barefoot Technology shoes facilitates recovery from race-induced fatigue: an evaluation utilizing a visual analog scale

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    Nakagawa K

    2014-12-01

    Full Text Available Kento Nakagawa, Takashi Obu, Kazuyuki KanosueFaculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan Purpose: To investigate the potential benefit of post-race wearing of unstable shoes (Masai Barefoot Technology [MBT] on recovery from marathon race–induced fatigue.Patients and methods: Forty-five runners who participated in a full marathon race were divided into three groups: 1 MBT shoes, 2 trail running shoes, and 3 control (CON. Participants ran a full marathon with their own running shoes, and then put on the assigned shoes immediately after the race. They continued to wear the assigned shoes for the ensuing 3 days. The CON group wore their usual shoes. Estimates of post-race fatigue were made by the participants on questionnaires that utilized a visual analog scale. Estimates were made just after the race, as well as for the next 3 days.Results: The subjective fatigue of the MBT group was lower than that of the CON (P<0.05 or trail running shoe groups (P<0.05 on day 3.Conclusion: MBT shoe intervention can promote recovery from the fatigue induced by running a full marathon.Keywords: footwear, VAS, full marathon

  7. Exercise clothing and shoes

    Science.gov (United States)

    ... wear form-fitting, stretchy clothing for activities like: Running Biking Advanced yoga/Pilates Swimming You may be ... Make sure your shoes fit your activity. For running, buy running shoes. They are light, flexible, and ...

  8. Women's musculoskeletal foot conditions exacerbated by shoe wear: an imaging perspective.

    Science.gov (United States)

    Goud, Ajay; Khurana, Bharti; Chiodo, Christopher; Weissman, Barbara N

    2011-04-01

    The predominance of several musculoskeletal foot conditions in women are largely the result of biomechanical alterations caused by ill-fitting shoes. In particular, the altered biomechanics (associated with high-heeled shoes and shoes with a narrowed toe box) has been linked to the genesis of hallux valgus, hammer toe deformity, Haglund syndrome, metatarsal stress fracture, Freiberg infraction, and Morton neuroma. In reviewing the imaging findings of several of these conditions, we emphasize the role of radiographs, special radiographic views, and the utility of more costly studies, such as magnetic resonance imaging.

  9. Does wearing unstable shoes reduce low back pain and disability in nurses? A randomized controlled pilot study.

    Science.gov (United States)

    Vieira, Edgar R; Brunt, Denis

    2016-02-01

    To evaluate if wearing unstable shoes reduces low back pain and disability in nurses. A randomized controlled trial. Hospitals and homecare. A total of 20 matched female registered nurses with low back pain. The mean (standard deviation) age was 31 years (5) for the control and 34 years (6) for the intervention group; height was 161 cm (5) and 165 cm (7), respectively. The intervention group received unstable shoes at Week 2 to wear for at least 36 h/week for a month. The Oswestry Low Back Pain Disability Questionnaire and a visual analogue pain scale. The mean (standard deviation) pain level was 6 (1) at baseline vs. 6 (2) at Week 6 for the control group, and 5 (1) vs. 1 (1) for the intervention group. The mean (standard deviation) disability level was 31% (9) at baseline vs. 28% (7) at Week 6 for the control, and 27% (12) vs. 13% (5) for the intervention group. There were no significant changes over time on pain or disability levels for the control group. The intervention group reported lower levels of pain on Weeks 4 (mean difference ⩾-1.4, p ⩽ 0.009) and 6 (mean difference ⩾-3.1, p back pain and disability in nurses and might be helpful as part of the back pain rehabilitation process. © The Author(s) 2015.

  10. Foot pronation is not associated with increased injury risk in novice runners wearing a neutral shoe : a 1-year prospective cohort study

    NARCIS (Netherlands)

    Nielsen, Rasmus Oestergaard; Buist, Ida; Parner, Erik Thorlund; Nohr, Ellen Aagaard; Sorensen, Henrik; Lind, Martin; Rasmussen, Sten

    2014-01-01

    Objective To investigate if running distance to first running-related injury varies between foot postures in novice runners wearing neutral shoes. Design A 1-year epidemiological observational prospective cohort study. Setting Denmark. Participants A total of 927 novice runners equivalent to 1854 fe

  11. A preliminary case study of the effect of shoe-wearing on the biomechanics of a horse’s foot

    Directory of Open Access Journals (Sweden)

    Olga Panagiotopoulou

    2016-07-01

    Full Text Available Horse racing is a multi-billion-dollar industry that has raised welfare concerns due to injured and euthanized animals. Whilst the cause of musculoskeletal injuries that lead to horse morbidity and mortality is multifactorial, pre-existing pathologies, increased speeds and substrate of the racecourse are likely contributors to foot disease. Horse hooves have the ability to naturally deform during locomotion and dissipate locomotor stresses, yet farriery approaches are utilised to increase performance and protect hooves from wear. Previous studies have assessed the effect of different shoe designs on locomotor performance; however, no biomechanical study has hitherto measured the effect of horseshoes on the stresses of the foot skeleton in vivo. This preliminary study introduces a novel methodology combining three-dimensional data from biplanar radiography with inverse dynamics methods and finite element analysis (FEA to evaluate the effect of a stainless steel shoe on the function of a Thoroughbred horse’s forefoot during walking. Our preliminary results suggest that the stainless steel shoe shifts craniocaudal, mediolateral and vertical GRFs at mid-stance. We document a similar pattern of flexion-extension in the PIP (pastern and DIP (coffin joints between the unshod and shod conditions, with slight variation in rotation angles throughout the stance phase. For both conditions, the PIP and DIP joints begin in a flexed posture and extend over the entire stance phase. At mid-stance, small differences in joint angle are observed in the PIP joint, with the shod condition being more extended than the unshod horse, whereas the DIP joint is extended more in the unshod than the shod condition. We also document that the DIP joint extends more than the PIP after mid-stance and until the end of the stance in both conditions. Our FEA analysis, conducted solely on the bones, shows increased von Mises and Maximum principal stresses on the forefoot phalanges

  12. Temperature Changes on the Foot during Pregnancy Affected by Wearing Biomechanical Shoes

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    Martin Zvonar

    2016-02-01

    Full Text Available Introduction: Everyone needs to walk; however, many people have problems with walking caused by non-standard condition or function of their feet, which in some cases can be easily recognized by thermography methods. The question is which internal actors can influence plantar temperature. 20 pregnant women from Czech and Slovak Republic in early stage of pregnancy, aged from 24 to 38 years old were included in the research. In this research, we followed the course of temperature-rested feet and feet after exercise for pregnant mothers in the different trimesters of pregnancy. Our task during the experimental research was to verify the functionality of special shoes. When we examined the temperatures of left and right sole in pregnant women, we noticed significant differences between right and left leg on 1 % level of statistical significance. Body weight gain is directly proportional with increased pressure on future mother’s sole. Increased body weight and pressure on the sole connected with it increases blood flow of the tissue. More blood flowing increases the friction and the temperature of the sole. Surprisingly, from second to third trimester we noticed decrease in temperature after walking.

  13. Factores de rendimiento en el desplazamiento del tenista influenciados por el calzado. (Performance factors on tennis player displacements influenced by the shoes.

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    Salvador Llana Belloch

    2009-04-01

    Full Text Available ResumenLos desplazamientos laterales son de gran importancia en el tenis. Sin embargo, no ha sido publicado ningún estudio sobre el efecto del calzado sobre el rendimiento en este tipo de movimientos. En el estudio participaron 5 jugadores habituales de tenis y se analizaron 10 calzados comerciales de tenis. El movimiento estudiado consistió en un desplazamiento lateral con parada y cambio de sentido, registrándose las fuerzas mediante una plataforma dinamométrica Dinascan-IBV y grabándose el movimiento con dos cámaras de vídeo S-VHS Panasonic WV-BL600. Los resultados de los ANOVAs realizados mostraron que algunas de las variables analizadas eran dependientes del calzado (p Abstract Sideward cutting movements are very important in tennis. However, no studies on their effect on performance have been published. 5 tennis players (age 21.5 ± 0.8, weight 75.2 ± 2.8 kg, height, 1.78 ± 0.05 m participated in the study on a voluntary basis and 10 tennis shoes were analysed. Subjects perform a sideward cutting movement. An extensometric force plate (Dinascan-IBV was used to record the kinetic variables and 2 video cameras (Panasonic-WV-BL600 were utilized for the kinematic variables. ANOVA results showed several variables as shoe-dependent (p

  14. Contact allergens in shoe leather among patients with foot eczema

    NARCIS (Netherlands)

    van Coevorden, AM; Coenraads, PJ; Pas, HH; van der Valk, PGM

    2002-01-01

    Some patients with relapsing foot eczema and a shoe leather allergy, who fail to show positive results with standard series and shoe wear screening tray patch testing, do not respond to the use of hypoallergenic shoe leather. We assume that relevant allergens are present in hypoallergenic shoe leath

  15. Influence of shoe midsole hardness on plantar pressure distribution in four basketball-related movements.

    Science.gov (United States)

    Lam, Wing-Kai; Ng, Wei Xuan; Kong, Pui Wah

    2017-01-01

    This study examined how shoe midsole hardness influenced plantar pressure in basketball-related movements. Twenty male university basketball players wore customized shoes with hard and soft midsoles (60 and 50 Shore C) to perform four movements: running, maximal forward sprinting, maximal 45° cutting and lay-up. Plantar loading was recorded using an in-shoe pressure measuring system, with peak pressure (PP) and pressure time integral (PTI) extracted from 10 plantar regions. Compared with hard shoes, subjects exhibited lower PP in one or more plantar regions when wearing the soft shoes across all tested movements (Ps < 0.05). Lower PTI was also observed in the hallux for 45° cutting, and the toes and forefoot regions during the first step of lay-up in the soft shoe condition (Ps < 0.05). In conclusion, using a softer midsole in the forefoot region may be a plausible remedy to reduce the high plantar loading experienced by basketball players.

  16. Acing common skin problems in tennis players.

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    Basler, R S; Garcia, M A

    1998-12-01

    The following measures can help prevent skin disorders in tennis players: wearing properly fitted shoes to avoid tennis toe, talon noir, and calluses; applying lubricants to protect against blisters and chafing; washing skin thoroughly to reduce the risk of acne mechanica; and wearing a hat and sunscreen to guard against photoinjury. 'Stringer's fingers' can be prevented by breaking the habit of adjusting the racket strings after each point. Should these disorders become troublesome, conservative treatments are usually effective. For example, calluses may be carefully pared, and pain from a subungual hemorrhage can be relieved by piercing the toenail with a hot paper clip.

  17. Oxygen Consumption While Standing with Unstable Shoe Design

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    Gasser Benedikt A.

    2014-09-01

    Full Text Available Purpose. This study explored the effects of unstable shoe design on oxygen consumption. Methods. Oxygen consumption (VO2 and heart rate (HR were measured in 16 individuals while barefoot, wearing unstable shoes (Masai Barefoot Technology and wearing conventional sport shoes while standing and walking on a treadmill and for 5 individuals while walking around a 400 m track. Results. When wearing the MBT shoes, a significant (p < 0.01 increase of 9.3 ± 5.2% in VO2 was measured while standing quietly for 6 min. No differences in VO2 and HR were observed between the MBT shoes or weight-adjusted conventional shoes (to match the weight of the MBT shoes while walking on a treadmill. However, significant increases (p < 0.01 in VO2 (4.4 ± 8.2% and HR (3.6 ± 7.3% were observed for the MBT shoes compared with being barefoot. No significant differences in VO2 and HR were recorded while walking around a 400 m track either with MBT shoes, weight-adjusted conventional shoes or barefoot. Nonetheless, a comparison of the MBT shoes with barefoot revealed a tendency for VO2 to be higher when wearing the MBT shoes (7.1 ± 6.5%, p < 0.1 although HR was not significantly affected. Conclusions. The unstable shoe design predominantly effects oxygen consumption while standing, most likely due to increased muscle activity of the lower extremities.

  18. Parents: Avoid Kids Foot Problems with the Right Shoes

    Science.gov (United States)

    ... to the tip of the big toe. Tight shoes can cause blisters, corns and calluses on your child’s toes, blisters on the back of the heels or worse, ingrown nails, which can become infected. ... nail. Shoes wear out Shoes lose their shock absorption over ...

  19. KINETIC ASSESSMENT OF GOLF SHOE OUTER SOLE DESIGN FEATURES

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    Rosemary J. Dyson

    2009-12-01

    Full Text Available This study assessed human kinetics in relation to golf shoe outer sole design features during the golf swing using a driver club by measuring both within the shoe, and beneath the shoe at the natural grass interface. Three different shoes were assessed: metal 7- spike shoe, alternative 7-spike shoe, and a flat soled shoe. In-shoe plantar pressure data were recorded using Footscan RS International pressure insoles and sampling at 500 Hz. Simultaneously ground reaction force at the shoe outer sole was measured using 2 natural grass covered Kistler force platforms and 1000 Hz data acquisition. Video recording of the 18 right-handed golfers at 200 Hz was undertaken while the golfer performed 5 golf shots with his own driver in each type of shoe. Front foot (nearest to shot direction maximum vertical force and torque were greater than at the back foot, and there was no significant difference related to the shoe type. Wearing the metal spike shoe when using a driver was associated with more torque generation at the back foot (p < 0. 05 than when the flat soled shoe was worn. Within shoe regional pressures differed significantly with golf shoe outer sole design features (p < 0.05. Comparison of the metal spike and alternative spike shoe results provided indications of the quality of regional traction on the outer sole. Potential golf shoe outer sole design features and traction were presented in relation to phases of the golf swing movement. Application of two kinetic measurement methods identified that moderated (adapted muscular control of foot and body movement may be induced by golf shoe outer sole design features. Ground reaction force measures inform comparisons of overall shoe functional performance, and insole pressure measurements inform comparisons of the underfoot conditions induced by specific regions of the golf shoe outer sole

  20. Validity of the SenseWear Armband to assess energy expenditure during intermittent exercise and recovery in rugby union players.

    Science.gov (United States)

    Zanetti, Sara; Pumpa, Kate L; Wheeler, Keane W; Pyne, David B

    2014-04-01

    Portable wearable devices that assess energy expenditure during intermittent exercise and recovery would be useful in team sports. Fourteen state-level male rugby union players (mean ± SD: age, 22 ± 4 years; body mass, 88.8 ± 11.2 kg; height, 1.81 ± 0.07 m, body fat, 18 ± 6%) participated in this study. Energy expenditure was measured by the SenseWear Armband (SWA) and validated against indirect calorimetry as the criterion measure during a 42-minute rugby-specific intermittent exercise test and an immediate postexercise 10-minute recovery period. Energy expenditure measurements from indirect calorimetry and the SWA were only moderately correlated during both the exercise test (r = 0.55, ±0.34; mean, ±90% confidence limits) and recovery period (r = 0.58, ±0.33). The SWA estimate of energy expenditure during exercise was unclear, with a mean bias of -1.9% (±5.3%), and during recovery energy expenditure was overestimated, with a mean bias of 17% (±12%) at the mean estimated energy expenditure. Typical error of SWA energy expenditure estimates expressed as a coefficient of variation (±90% confidence interval) was 10% (8-16%) during exercise and 19% (14-30%) during recovery. The SWA did not provide a valid measure of energy expenditure during rugby-specific intermittent exercise or 10-minute postexercise recovery. Further improvements are required in the performance of the SWA before it can be used routinely in intermittent sports and provide worthwhile information in relation to workloads of athletes for sport scientists and coaches.

  1. Mechanics of jazz shoes and their effect on pointing in child dancers.

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    Fong Yan, Alycia; Smith, Richard; Vanwanseele, Benedicte; Hiller, Claire

    2012-07-01

    There has been little scientific investigation of the impact of dance shoes on foot motion or dance injuries. The pointed (plantar-flexed) foot is a fundamental component of both the technical requirements and the traditional aesthetic of ballet and jazz dancing. The aims of this study were to quantify the externally observed angle of plantar flexion in various jazz shoes compared with barefoot and to compare the sagittal plane bending stiffness of the various jazz shoes. Sixteen female recreational child dancers were recruited for 3D motion analysis of active plantar flexion. The jazz shoes tested were a split-sole jazz shoe, full-sole jazz shoe, and jazz sneaker. A shoe dynamometer measured the stiffness of the jazz shoes. The shoes had a significant effect on ankle plantar flexion. All jazz shoes significantly restricted the midfoot plantar flexion angle compared with the barefoot condition. The split-sole jazz shoe demonstrated the least restriction, whereas the full-sole jazz shoe the most midfoot restriction. A small restriction in metartarsophalangeal plantar flexion and a greater restriction at the midfoot joint were demonstrated when wearing stiff jazz shoes. These restrictions will decrease the aesthetic of the pointed foot, may encourage incorrect muscle activation, and have an impact on dance performance.

  2. The Relationship of Foot Shape and Sensitivity to Comfort of Shoe-Inserts

    Science.gov (United States)

    1998-07-30

    including such maladies as patellofemoral disorders, shin splints, Achilles tendinitis , plantar fasciitis and various stress fractures. Lower limb...anatomic malalignment; muscle-tendon imbalances of strength, endurance, or flexibility; shoe wear; surface; and pre-existent disease states

  3. Rotational and peak torque stiffness of rugby shoes.

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    Ballal, Moez S; Usuelli, Federico Giuseppe; Montrasio, Umberto Alfieri; Molloy, Andy; La Barbera, Luigi; Villa, Tomaso; Banfi, Giuseppe

    2014-09-01

    Sports people always strive to avoid injury. Sports shoe designs in many sports have been shown to affect traction and injury rates. The aim of this study is to demonstrate the differing stiffness and torque in rugby boots that are designed for the same effect. Five different types of rugby shoes commonly worn by scrum forwards were laboratory tested for rotational stiffness and peak torque on a natural playing surface generating force patterns that would be consistent with a rugby scrum. The overall internal rotation peak torque was 57.75±6.26 Nm while that of external rotation was 56.55±4.36 Nm. The Peak internal and external rotational stiffness were 0.696±0.1 and 0.708±0.06 Nm/deg respectively. Our results, when compared to rotational stiffness and peak torques of football shoes published in the literature, show that shoes worn by rugby players exert higher rotational and peak torque stiffness compared to football shoes when tested on the same natural surfaces. There was significant difference between the tested rugby shoes brands. In our opinion, to maximize potential performance and lower the potential of non-contact injury, care should be taken in choosing boots with stiffness appropriate to the players main playing role. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Effects of an unstable shoe construction on balance in women aged over 50 years

    DEFF Research Database (Denmark)

    Ramstrand, Nerrolyn; Thuesen, Anna Helena; Nielsen, Dennis Brandborg;

    2010-01-01

    BACKGROUND: Shoes with an unstable sole construction are commonly used as a therapeutic tool by physiotherapists and are widely available from shoe and sporting goods retailers. The aim of this study was to investigate the effects of using an unstable shoe (Masai Barefoot Technology) on standing...... balance, reactive balance and stability limits. METHODS: Thirty-one subjects agreed to participate in the study and underwent balance tests on three different occasions. After test occasion one (baseline) 20 subjects received Masai Barefoot Technology shoes and were requested to wear them as much...

  5. Shoe allergic contact dermatitis.

    Science.gov (United States)

    Matthys, Erin; Zahir, Amir; Ehrlich, Alison

    2014-01-01

    Foot dermatitis is a widespread condition, affecting men and women of all ages. Because of the location, this condition may present as a debilitating problem to those who have it. Allergic contact dermatitis involving the feet is frequently due to shoes or socks. The allergens that cause shoe dermatitis can be found in any constituent of footwear, including rubber, adhesives, leather, dyes, metals, and medicaments. The goal of treatment is to identify and minimize contact with the offending allergen(s). The lack of product information released from shoe manufacturers and the continually changing trends in footwear present a challenge in treating this condition. The aim of this study is to review the current literature on allergic contact shoe dermatitis; clinical presentation, allergens, patch testing, and management will be discussed. PubMed and MEDLINE databases were used for the search, with a focus on literature updates from the last 15 years.

  6. 提高军官常服皮鞋穿着与视觉舒适性探讨%A Study on the Comfort and Wear of Military Leather Shoes

    Institute of Scientific and Technical Information of China (English)

    梁高勇; 秦蕾; 王修行; 来侃; 薛喜东; 孙润军

    2012-01-01

    The foot data, shoes fancy, weight and sports performance is studied in this paper, thus we obtain a unanimous data. So it is beneficial for military leather shoes development and production.%本文通过军人脚型测量分析、军鞋审美取向调查分析、军鞋重量与运动性能试验分析等探讨研究,获得了脚型、式样、重量等相关数据,对于新式军鞋研究、生产和使用具有一定的参考作用。

  7. Shoes and Orthotics for Diabetics

    Science.gov (United States)

    ... wrong kind of shoes or from poorly fitting shoes can lead to blisters, calluses and ulcers, not only in the insensitive foot but also in feet with no evidence of neuropathy. It is highly recommended that shoe fitting for patients with any loss of sensation ...

  8. Estimating center of pressure and center of mass patterns in stroke subjects during daily life activities using force sensing shoes

    NARCIS (Netherlands)

    van Meulen, Fokke; Reenalda, Jasper; Nikamp-Simons, Corien Diana Maria; Buurke, Jaap; Veltink, Petrus H.

    2014-01-01

    The aim of this study is to evaluate center of pressure and center of mass movement patterns in stroke patients, during activities of daily living while wearing instrumented shoes containing force sensors and inertial sensors. The use of instrumented shoes enables the measurement of balance

  9. Rocker shoe, minimalist shoe, and standard running shoe : A comparison of running economy

    NARCIS (Netherlands)

    Sobhani, Sobhan; Bredeweg, Steven; Dekker, Rienk; Kluitenberg, Bas; van den Heuvel, Edwin; Hijmans, Juha; Postema, Klaas

    2014-01-01

    Objectives: Running with rocker shoes is believed to prevent lower limb injuries. However, it is not clear how running in these shoes affects the energy expenditure. The purpose of this study was, therefore, to assess the effects of rocker shoes on running economy in comparison with standard and min

  10. Rocker shoe, minimalist shoe, and standard running shoe : A comparison of running economy

    NARCIS (Netherlands)

    Sobhani, Sobhan; Bredeweg, Steven; Dekker, Rienk; Kluitenberg, Bas; van den Heuvel, Edwin; Hijmans, Juha; Postema, Klaas

    Objectives: Running with rocker shoes is believed to prevent lower limb injuries. However, it is not clear how running in these shoes affects the energy expenditure. The purpose of this study was, therefore, to assess the effects of rocker shoes on running economy in comparison with standard and

  11. Immediate effect of Masai Barefoot Technology shoes on knee joint moments in women with knee osteoarthritis.

    Science.gov (United States)

    Tateuchi, Hiroshige; Taniguchi, Masashi; Takagi, Yui; Goto, Yusuke; Otsuka, Naoki; Koyama, Yumiko; Kobayashi, Masashi; Ichihashi, Noriaki

    2014-01-01

    Footwear modification can beneficially alter knee loading in patients with knee osteoarthritis. This study evaluated the effect of Masai Barefoot Technology shoes on reductions in external knee moments in patients with knee osteoarthritis. Three-dimensional motion analysis was used to examine the effect of Masai Barefoot Technology versus control shoes on the knee adduction and flexion moments in 17 women (mean age, 63.6 years) with radiographically confirmed knee osteoarthritis. The lateral and anterior trunk lean values, knee flexion and adduction angles, and ground reaction force were also evaluated. The influence of the original walking pattern on the changes in knee moments with Masai Barefoot Technology shoes was evaluated. The knee flexion moment in early stance was significantly reduced while walking with the Masai Barefoot Technology shoes (0.25±0.14Nm/kgm) as compared with walking with control shoes (0.30±0.19 Nm/kgm); whereas the knee adduction moment showed no changes. Masai Barefoot Technology shoes did not increase compensatory lateral and anterior trunk lean. The degree of knee flexion moment in the original walking pattern with control shoes was correlated directly with its reduction when wearing Masai Barefoot Technology shoes by multiple linear regression analysis (adjusted R2=0.44, PBarefoot Technology shoes reduced the knee flexion moment during walking without increasing the compensatory trunk lean and may therefore reduce external knee loading in women with knee osteoarthritis.

  12. Effect of Finishing on Heat and Moisture Transfer Properties of Lining Leather for Shoes

    OpenAIRE

    角田, 由美子

    2016-01-01

      Leather lining for shoes was made from unfinished and pigment-finished glutaraldehyde-tanned leather and chrome-tanned leather prepared from pig skin. The effect of the different treatments on the heat and moisture transfer properties of the lining leather was investigated at 20℃ and 65% RH using an apparatus that simulates the microclimate of the shoes. The apparatus was developed by modeling the conditions expected during actual shoe wearing.  1. The water absorption, water vapour permeab...

  13. The effect of field condition and shoe type on lower extremity injuries in American Football.

    Science.gov (United States)

    Iacovelli, Jaclyn Nicole; Yang, Jingzhen; Thomas, Geb; Wu, Hongqian; Schiltz, Trisha; Foster, Danny T

    2013-08-01

    Considerable improvement has been made in football field surfaces and types of shoe, yet relatively few epidemiological studies have investigated their roles in the risk of football injuries. This study examined the effects of field surface, surface condition and shoe type on the likelihood of lower extremity football injuries. Deidentified data from 188 players from one division I university football team during the 2007-2010 seasons were analysed. Lower extremity injury rate and rate ratio, along with 95% confidence limits, were calculated by football activity, playing surface condition and shoe type. A total of 130 lower extremity injuries were sustained, with an overall lower extremity injury rate of 33.5/10 000 athlete-sessions. The lower extremity injury rate was 2.61 times higher when the surface condition was abnormal compared with when the surface condition was normal. During games, the risk for lower extremity injury was 3.34 times higher (95% CI 1.70 to 6.56) on artificial turf compared with natural grass. However, this trend was not statistically significant in practice sessions. Furthermore, neither the number of shoe cleats nor the height of the shoe top was statistically associated with risk of lower extremity injuries. Football players who played on artificial turf or when the surface condition was abnormal were susceptible to lower extremity injuries. Evidence from this study suggests that further research into playing surfaces and shoe types may provide fruitful opportunities to reduce injuries to collegiate football players.

  14. Dielectric and electrical hazard shoes.

    Science.gov (United States)

    Hoagland, Hugh

    2011-04-01

    With OSHA early documents falling on the side of EH shoes for electrical work, companies would do well to consider them for all electrical workers and other workers exposed to electrical hazards or damp locations. These shoes rarely add more than $5 to the cost of the shoe and have been known to save lives. They should be considered for low-voltage (shoes provide this type of protection and are the preferred step potential PPE option in both OSHA 1910.269 and NFPA 70E.

  15. Exclusive wearing of shoes of impregnated cloth by an adolescent girl during a cold winter: late effects in osseous tomo-scintigraphy and in magnetic resonance imaging; Froid hivernal et port exclusif de chaussures de sport en tissu par une adolescente: effets tardifs en tomoscintigraphie osseuse et en resonance magnetique nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Als, C.; Marugg, S. [Medical Imaging Luzern, Lucerne (Switzerland); Als, C. [Zithaklinic, Service de Medecine Nucleaire, Grand-Duche de Luxembourg (Luxembourg)

    2009-10-15

    We present a rare clinical case of a 14-year-old adolescent girl from central Switzerland with an algoneurodystrophy of the left foot and leg 6 months after grade I frostbite(s) of the feet. After 6 months of constant pain of the digits, not attenuated by non steroid anti-inflammatory drugs, MRI of the feet reveals a predominantly left-sided and distal medullary edema, limited to the phalanges. Bone scintigraphy shows a predominantly left-sided diffuse feet hypoperfusion, coupled with an increased bone uptake of the left leg at late images. Inadequate life-style of adolescents, i.e., exclusively wearing shoes made of cloth and not of leather - even with temperatures below 0 Celsius degree in winter - might be a cause of chronic pain of foot digits. This is a rare demonstration of late effects of cold on foot digits by combined MRI and bone scintigraphy. Algoneurodystrophy in children and adolescents is an under diagnosed clinical entity. (authors)

  16. Effect of shoe type on descending a curb.

    Science.gov (United States)

    George, Juff; Heller, Michelle; Kuzel, Michael

    2012-01-01

    The aim of this study was to evaluate the effect of shoe type on the performance of women during curb descent. Performance during curb stepping may be explained by biomechanical research that has evaluated the kinematics of overground walking and stair ascent and descent. Studies have reported that women exhibit performance differences when wearing high heels, flip flops and sneakers during overground walking and stair ascent and descent. Thus, in addition to features of the curb, the type of shoe being worn may also affect performance. Although several studies have investigated curb stepping, no known studies have investigated the effects of different types of footwear on curb descent performance. This research was conducted in a real-world environment where participants wore three different types of shoes and performed a series of activities that involved curb stepping. The subjects were videotaped while descending a curb, allowing for observation of changes in gait parameters. Results of this study indicate that wearing high heels leads to performance differences as compared to wearing flip flops or sneakers.

  17. Effect of shoes containing nanosilica particles on knee valgus in active females during landing

    Directory of Open Access Journals (Sweden)

    Zahra Bassiri

    2015-01-01

    Full Text Available Objective(s: The effect of silica nanoparticles (SNPs in sport shoes outsoles on the  parameters related to anterior cruciate ligament (ACL Injury has not been investigated. The aim of this study was to investigate the effect of shoes outsole containing a composite of thermoplastic elastomer based on styrene-butadiene and silica nanoparticles (TPEN shoe on Knee Valgus Angle (KVA as a risk factor of ACL injuries during landing Materials and Methods: Fourteen active healthy women without knee injuries and disorders performed bilateral drop jump (DJ and single leg drop landing (SLL tasks in barefoot, wearing shoes fabricated with polyvinyl chloride outsole (PVC shoe and TPEN shoes conditions , randomly. The knee valgus angle values of right and left legs were calculated in the landing conditions. Two factors repeated measures ANOVA were used to investigate the effect of landing and footwear conditions on KVA of right and left legs.  Results: For both left and right limbs, the KVA was at maximum and minimum values during landing with barefoot and TPEN shoes, respectively. PVC shoe significantly reduced the knee valgus by 3.84% in left and 4.18% in right knee (P

  18. Influence of basketball shoe mass, outsole traction, and forefoot bending stiffness on three athletic movements.

    Science.gov (United States)

    Worobets, Jay; Wannop, John William

    2015-09-01

    Prior research has shown that footwear can enhance athletic performance. However, public information is not available on what basketball shoe properties should be selected to maximise movement performance. Therefore, the purpose of the study was to investigate the influence of basketball shoe mass, outsole traction, and forefoot bending stiffness on sprinting, jumping, and cutting performance. Each of these three basketball shoe properties was systematically varied by ± 20% to produce three shoe conditions of varying mass, three conditions of varying traction, and three conditions of varying bending stiffness. Each shoe was tested by 20 recreational basketball players completing maximal effort sprints, vertical jumps, and a cutting drill. Outsole traction had the largest influence on performance, as the participants performed significantly worse in all tests when traction was decreased by 20% (p < 0.001), and performed significantly better in the cutting drill when traction was increased by 20% (p = 0.005). Forefoot bending stiffness had a moderate effect on sprint and cutting performance (p = 0.013 and p = 0.016 respectively) and shoe mass was found to have no effect on performance. Therefore, choosing a shoe with relatively high outsole traction and forefoot bending stiffness should be prioritised, and less concern should be focused on selecting the lightest shoe.

  19. Walking Shoes: Features and Fit

    Science.gov (United States)

    ... be snug, not tight. If you're a woman with wide feet, consider men's or boys' shoes, which are cut a bit larger through the heel and the ball of the foot. Walk in the shoes before buying them. They should feel comfortable right away. Make sure your heel fits snugly in ...

  20. The effects of shoes with a rounded soft sole in the anterior-posterior direction on leg joint angle and muscle activity.

    Science.gov (United States)

    Demura, Tomohiro; Demura, Shin-ichi

    2012-09-01

    This study examines the effect of these shoes on the leg joint angle and muscle activity during walking. Ten healthy young male adults (mean age: 24.1±4.3 years) walked on a walkway while wearing one of three kinds of shoes with a rounded soft sole in the anterior-posterior direction (Stretch Walker: SW, mass: 440 g), MBT (Masai Barefoot Technology; similar to the SW in form and material, mass: 600 g), and flat-bottomed shoes (FS, mass: 420 g)). After familiarizing themselves with the shoes, subjects walked twenty laps on the walkway, which was about 40 m long (mean speed: 4.1 km/h). After a sufficient rest, they repeated this with the other shoes. During walking, the volume of muscle discharge was measured once every 2 laps. The mean value of the 10 measurements was used as the evaluation variable for integral values and joint angle, while the right foot touched the ground twice. In conclusion, the range of leg movement during walking was smaller when wearing shoes with a rounded soft sole in the anterior-posterior direction (SW and MBT) than when wearing normal shoes (FS). However, the effects of the SW and MBT on leg muscle activity during walking differ little from wearing the normal shoes during a leisurely 10-min walk. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. The influence of revised high-heeled shoes on foot pressure and center of pressure during standing in young women.

    Science.gov (United States)

    Bae, Young-Hyeon; Ko, Mansoo; Lee, Suk Min

    2015-12-01

    [Purpose] Revised high-heeled shoes were developed to minimize foot deformities by reducing excessive load on the forefoot during walking or standing in adult females, who frequently wear standard high-heeled shoes. Specifically, this study aimed to investigate the effects of revised high-heeled shoes on foot pressure distribution and center of pressure distance during standing in adult females. [Subjects and Methods] Twelve healthy adult females were recruited to participate in this study. Foot pressures were obtained under 3 conditions: barefoot, in revised high-heeled shoes, and in standard 7-cm high-heeled shoes. Foot pressure was measured using the Tekscan HR mat scan system. One-way repeated analysis of variance was used to compare the foot pressure distribution and center of pressure distance under these 3 conditions. [Results] The center of pressure distance between the two lower limbs and the fore-rear distribution of foot pressure were significantly different for the 3 conditions. [Conclusion] Our findings support the premise that wearing revised high-heeled shoes seems to provide enhanced physiologic standing posture compared to wearing standard high-heeled shoes.

  2. The Effect of Training in Minimalist Running Shoes on Running Economy.

    Science.gov (United States)

    Ridge, Sarah T; Standifird, Tyler; Rivera, Jessica; Johnson, A Wayne; Mitchell, Ulrike; Hunter, Iain

    2015-09-01

    The purpose of this study was to examine the effect of minimalist running shoes on oxygen uptake during running before and after a 10-week transition from traditional to minimalist running shoes. Twenty-five recreational runners (no previous experience in minimalist running shoes) participated in submaximal VO2 testing at a self-selected pace while wearing traditional and minimalist running shoes. Ten of the 25 runners gradually transitioned to minimalist running shoes over 10 weeks (experimental group), while the other 15 maintained their typical training regimen (control group). All participants repeated submaximal VO2 testing at the end of 10 weeks. Testing included a 3 minute warm-up, 3 minutes of running in the first pair of shoes, and 3 minutes of running in the second pair of shoes. Shoe order was randomized. Average oxygen uptake was calculated during the last minute of running in each condition. The average change from pre- to post-training for the control group during testing in traditional and minimalist shoes was an improvement of 3.1 ± 15.2% and 2.8 ± 16.2%, respectively. The average change from pre- to post-training for the experimental group during testing in traditional and minimalist shoes was an improvement of 8.4 ± 7.2% and 10.4 ± 6.9%, respectively. Data were analyzed using a 2-way repeated measures ANOVA. There were no significant interaction effects, but the overall improvement in running economy across time (6.15%) was significant (p = 0.015). Running in minimalist running shoes improves running economy in experienced, traditionally shod runners, but not significantly more than when running in traditional running shoes. Improvement in running economy in both groups, regardless of shoe type, may have been due to compliance with training over the 10-week study period and/or familiarity with testing procedures. Key pointsRunning in minimalist footwear did not result in a change in running economy compared to running in traditional footwear

  3. The effect of different shoes on functional mobility and energy expenditure in post-stroke hemiplegic patients using ankle-foot orthosis.

    Science.gov (United States)

    Farmani, Farzad; Mohseni Bandpei, Mohammad Ali; Bahramizadeh, Mahmood; Aminian, Gholamreza; Nikoo, Mohammad Reza; Sadeghi-Goghari, Mohammad

    2016-10-01

    Ankle-foot orthoses could be utilized both with and without shoes. While several studies have shown that ankle-foot orthoses improve gait abilities in hemiplegic patients, it remains unclear whether they should be used with shoes or without. The study purpose was to compare the effect of standard shoes and rocker shoes on functional mobility in post-stroke hemiplegic patients utilizing ankle-foot orthosis. Randomized clinical study. Thirty post-stroke hemiplegic patients participated in this study randomly assigned to two groups. Group I received standard shoes + ankle-foot orthosis and group II were provided with rocker shoes + ankle-foot orthosis. Their functional mobility and energy expenditure parameters including timed up and go, timed up stairs, timed down stairs, preferred walking speed, and oxygen (O2) cost (mL/kg/m) were measured. In group I, no significant changes were seen in outcome measures after wearing standard shoes. While in group II, O2 cost and timed up and go time significantly decreased, and preferred walking speed increased when patients wore rocker shoes. Also, there was a significant difference between rocker shoes and standard shoes in improvement of timed up and go, preferred walking speed, and O2 cost. When patients using ankle-foot orthosis wore rocker shoes, their functional mobility improved and oxygen cost diminished. Also, rocker shoes was significantly more effective than standard shoes in improving functional mobility parameters. This study suggests that in post-stroke hemiplegic patients using ankle-foot orthosis, wearing rocker shoes can lead to much more improved functional mobility and decreased energy expenditure compared to ankle-foot orthosis only. Thus, in stroke patients, the combination of ankle-foot orthosis-rocker shoes is recommended for both rehabilitation programs and ankle-foot orthosis efficacy investigations. © The International Society for Prosthetics and Orthotics 2015.

  4. Little Lucy's Shoe

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Little Lucy is blue, She lost a nice shoe,What can little Lucy do?Go and buy another shoe.这首童谣读起来是不是很朗朗上口?blue,shoe.do非常押韵。现在.就请你试著将它译成中文E—mail或邮寄给我们吧,“最佳小诗人”等着你!

  5. Shod wear and foot alignment in clinical gait analysis.

    Science.gov (United States)

    Louey, Melissa Gar Yee; Sangeux, Morgan

    2016-09-01

    Sagittal plane alignment of the foot presents challenges when the subject wears shoes during gait analysis. Typically, visual alignment is performed by positioning two markers, the heel and toe markers, aligned with the foot within the shoe. Alternatively, software alignment is possible when the sole of the shoe lies parallel to the ground, and the change in the shoe's sole thickness is measured and entered as a parameter. The aim of this technical note was to evaluate the accuracy of visual and software foot alignment during shod gait analysis. We calculated the static standing ankle angles of 8 participants (mean age: 8.7 years, SD: 2.9 years) wearing bilateral solid ankle foot orthoses (BSAFOs) with and without shoes using the visual and software alignment methods. All participants were able to stand with flat feet in both static trials and the ankle angles obtained in BSAFOs without shoes was considered the reference. We showed that the current implementation of software alignment introduces a bias towards more ankle dorsiflexion, mean=3°, SD=3.4°, p=0.006, and proposed an adjusted software alignment method. We found no statistical differences using visual alignment and adjusted software alignment between the shoe and shoeless conditions, p=0.19 for both. Visual alignment or adjusted software alignment are advised to represent foot alignment accurately.

  6. A COMPARISON OF GOLF SHOE DESIGNS HIGHLIGHTS GREATER GROUND REACTION FORCES WITH SHORTER IRONS

    Directory of Open Access Journals (Sweden)

    Paul Worsfold

    2007-12-01

    Full Text Available In an effort to reduce golf turf damage the traditional metal spike golf shoe has been redesigned, but shoe-ground biomechanical evaluations have utilised artificial grass surfaces. Twenty-four golfers wore three different golf shoe traction designs (traditional metal spikes, alternative spikes, and a flat-soled shoe with no additional traction when performing shots with a driver, 3 iron and 7 iron. Ground action forces were measured beneath the feet by two natural grass covered force platforms. The maximum vertical force recorded at the back foot with the 3 iron and 7 iron was 0.82 BW (body weight and at the front foot 1.1 BW approximately in both the metal spike and alternative spike golf shoe designs. When using the driver these maximal vertical values were 0.49 BW at the back foot and 0.84 BW at the front foot. Furthermore, as performance of the backswing and then downswing necessitates a change in movement direction the range of force generated during the complete swing was calculated. In the metal spike shoe the vertical force generated at the back foot with both irons was 0.67 BW and at the front foot 0.96 BW with the 3 iron and 0.92 BW with the 7 iron. The back foot vertical force generated with the driver was 0.33 BW and at the front foot 0.83 BW wearing the metal spike shoe. Results indicated the greater force generation with the irons. When using the driver the more horizontal swing plane associated with the longer club reduced vertical forces at the back and front foot. However, the mediolateral force generated across each foot in the metal and alternative spike shoes when using the driver was greater than when the irons were used. The coefficient of friction was 0. 62 at the back and front foot whichever shoe was worn or club used

  7. How to Select the Right Athletic Shoes

    Science.gov (United States)

    ... a running shoe may help prevent shin splints, tendinitis, heel pain, stress fractures and other overuse syndromes. ... a running/sports shoe help prevent shin splints, tendinitis, heel pain, stress fractures and other overuse syndromes. ...

  8. Wuxia's Children Shoes sole: Touching Children's Heart

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Wuxia Children shoes sole company, founded in 1998, is the first professional children shoes sole business in Wenzhou city. It is located in Huanglong Commercial Center,Wenzhou city, Zhejiang province.

  9. A case of contact dermatitis to dimethylfumarate in shoes identified in Italy

    Directory of Open Access Journals (Sweden)

    Franca Davanzo

    2010-12-01

    Full Text Available The present paper describes a case of shoe contact dermatitis from DMF identified by the Poison Control Centre of Milan (PCCM, Italy, in 2009. A 35 year old woman was affected by irritant reactions while wearing shoes contaminated with DMF. Exposure to these shoes was limited to a 8 hour period and was not repeated. In the following days the patient suffered feet blistering and swelling limited to the area in contact with shoe vamp. Topical application of cortisone did not prevent development of bullous eczema. After 20 days from exposure, the lesions were healed but the skin remained red, dry and very sensitive. Chemical analyses of shoes quantified an average concentration of DMF of 383 mg/kg. The patient refused to be patch tested. The observation here reported confirm that DMF should be considered a possible causal agent in shoe contact dermatitis. Documentation of cases exposed to this chemical provide a relevant support to characterize clinical manifestations and to identifying contaminated articles.

  10. 2007 World Shoes Forum in Biejing

    Institute of Scientific and Technical Information of China (English)

    Feng Yuan

    2007-01-01

    @@ 2007 Beijing Forum on World Shoes Industry opened grandly on 9th October.It is approved by Ministry of Commerce,sponsored by Trade Development Bureau of Ministry of Commerce,Pengrun International Fashion Centre,organizing committee of China International Shoes Fair,and assisted by Leather Association of Shenzhen,management committee of China Western Shoes garden of Chengdu.

  11. The effect of the heel- to- toe rocker shoe on moments of ankle joint and temporal-spatial of gait in female student

    Directory of Open Access Journals (Sweden)

    masoomeh Veiskarami

    2015-01-01

    Full Text Available Background : Rocker shoes are the most commonly prescribed external therapeutic shoe modification and are used for treatment of the ankle and midfoot problems. The aim of this study was to assesse the effects of the heel- to-toe rocker shoes on temporal-spatial and ankle joint moments in sagital and frontal plane. Materials and Methods: In this quasi-exprimental study, three-dimentional gait analysis was carried out on 20 healthy university female students with normal normal gait pattern selected by convenience sampling method. A Vicon 470 system(Oxford Metrix, U.K. consisting of 6 cameras operating at 60Hz and kistler forceplate (A9286 was used.The paired samples T test was used to statistical analysis. Results: The results showed that there is no significant change in temporal-spatial parameters while wearing this modified shoe ,but the ankle moments while wearing rocker shoes in sagittal plane was significantly less than that while wearing traditional shoes(p=0.002 but in frontal plane significantly increased(p=0.007. Conclusion: Based on the current findings the major benefits of this modified shoe appear to be significantly restricted sagital plane moments with maintenance of walking speed so the loads on ankle joint and achilles tendon reduced, but increases frontal plain moments which leads to increase of mediolateral instability of ankle joint.

  12. Biomechanical simulation of high-heeled shoe donning and walking.

    Science.gov (United States)

    Yu, Jia; Cheung, Jason Tak-Man; Wong, Duo Wai-Chi; Cong, Yan; Zhang, Ming

    2013-08-09

    Footwear serves to protect the foot in various activities, to enhance athletic performance in sports and in many cases to fulfill aesthetic and cultural needs of urban society. Most women like wearing high-heeled shoes (HHS) for the benefit of sensuous attractiveness, while foot problems are often associated. Computational modeling based on finite element (FE) analysis is a useful tool for deep understanding of foot and footwear biomechanics and incorporating footwear with foot in the model is the prerequisite. In this study, a three-dimensional FE model of coupled foot-ankle-shoe complex and preceding gait simulation were established. Interfacial contact simulation was employed to complete the donning process of foot and shoe upper contact. Three major stance phases namely heel strike, midstance and push off were simulated to investigate the biomechanical response of high-heeled shod walking. It was found that the contact pressure at all metatarsophalangeal (MTP) joints intensified and reached their maximum at push off phase during locomotion, meanwhile the first MTP had the largest magnitude. The first and fifth MTP joints had larger movements in transverse plane among all MTP joints, indicating that these two joints bended more significantly by toe box restraint during locomotion. The dorsal contact pressure at the first toe increased by four times from heel strike to push off. The established HHS donning and walking simulation in this study proved the versatility and promising potential of computational approach for realistic biomechanical evaluation and optimization of footwear design in a virtual environment.

  13. Shoe concerns and foot problems of wearers of safety footwear.

    Science.gov (United States)

    Marr, S J; Quine, S

    1993-05-01

    In Australia workers in many industries are required to wear safety footwear (footwear incorporating a steel toe cap). An investigation of the problems reported by 321 workers (70 per cent male) employed in a broad range of work activities and required to wear safety footwear was conducted in 1990 and 1991. Respondents were interviewed by a professionally trained podiatrist using a structured questionnaire followed by a foot examination. An extremely high percentage (91 per cent) of subjects reported one or more foot problems (which were verified by the podiatrist), and most considered that the safety footwear either caused the problem or adversely affected an existing foot condition. The main shoe concerns reported were excessive heat (65 per cent of all respondents), inflexible soles (52 per cent), weight (48 per cent) and pressure from steel toe cap (47 per cent). Certain gender differences were identified. General recommendations are made.

  14. Patient compliance and effect of orthopaedic shoes

    DEFF Research Database (Denmark)

    Philipsen, A B; Ellitsgaard, N; Krogsgaard, M R

    1999-01-01

    Orthopaedic shoes are individually handmade after a prescription from an orthopaedic surgeon, hence relatively expensive. Bad compliance is mentioned in the literature but not investigated. In order to evaluate patient compliance and the effect of orthopaedic shoes, 85 patients who were prescribed...... orthopaedic shoes at the authors' department during a 3 year period received a questionnaire concerning relief of symptoms and daily use of the shoes. The answers from 74 patients were correlated to the prescription procedure and the degree of medical follow-up. Only 60 of 74 patients used their shoes. Some...... were checked by the orthopaedic surgeon after delivery of the shoes. In conclusion the authors believe there is a great need for information to be given to the patients about the functions and limitations of orthopaedic shoes and that every patient should be offered a control check-up by the surgeon...

  15. COMPARATIVE STUDY OF 4 WEEKS OF DYNAMIC B ALANCE TRAINING PROGRAM IN COLLEGIATE FOOTBALL PLAYERS: RANDOMIZED CLINICAL TRIAL

    Directory of Open Access Journals (Sweden)

    Nisha

    2015-03-01

    Full Text Available BACKGROUND: Balance is highly integrative dynamic process involving coordination of multiple neurological pathways that allows for the maintenance of the COG over BOS . Football players often perform lower extremity passing , shooting , twisting , cutting and dribbling skills while wearing shoes , these actions require body to be in the equilibrium position to perform the task . This leads to t he conclusion of the great importance of the ability of balance in football . AIMS: 1 . To study the effect of 4 week multidirectional balance board training on dynamic balance in football players . 2 . To study the effect of 4 week Both Sides Up ball training on dynamic balance in football players . 3 . To compare the effect of multidirectional balance board training program and BOSU ball training program on dynamic balance in football players . STUDY DESIGN: Randomized Clinical trial . METHODS: Total of 60 competitive badminton players with age group between18 - 25 were recruited in this study . The participants were allocated into 2 groups viz ., Group A (multidirectional balance board training and Group B (BOSU ball Training for a period of 4 we eks . Participants were test for SEBT and vertical jump test on first day and after 4 weeks of balance training . STATISTICAL ANALYSIS: Student t test , Chi - Square Test . RESULTS: The data analysis and statistical inference showed that , after 4 weeks of balanc e training there was improvement in dynamic balance in both the groups but there was no significant difference in dynamic balance between two groups . As seen by difference in the SEBT and VJT scores pre and post training with p<0 . 001 . CONCLUSION: 4 weeks balance training using BOSU and multidirectional balance board is effective in improving dynamic balance and vertical jump performance in football players and also can be used as a component of multifaceted training to improve dynamic balance and game skills

  16. Increased Athletic Performance in Lighter Basketball Shoes: Shoe or Psychology Effect?

    Science.gov (United States)

    Mohr, Maurice; Trudeau, Matthieu B; Nigg, Sandro R; Nigg, Benno M

    2016-01-01

    To determine the effect of shoe mass on performance in basketball-specific movements and how this affects changes if an athlete is aware or not of the shoe's mass relative to other shoes. In an experimental design, 22 male participants were assigned to 2 groups. In the "aware" group, differences in the mass of the shoes were disclosed, while participants in the other group were blinded to the mass of shoes. For both groups lateral shuffle-cut and vertical-jump performances were quantified in 3 different basketball-shoe conditions (light, 352 ± 18.4 g; medium, 510 ± 17 g; heavy, 637 ± 17.7 g). A mixed ANOVA compared mean shuffle-cut and vertical-jump performances across shoes and groups. For blinded participants, perceived shoe-weight ratings were collected and compared across shoe conditions using a Friedman 2-way ANOVA. In the aware group, performance in the light shoes was significantly increased by 2% (vertical jump 2%, P performance across shoes. Differences in performance of the aware participants were most likely due to psychological effects such as positive and negative expectancies toward the light and heavy shoes, respectively. These results underline the importance for coaches and shoe manufacturers to communicate the performance-enhancing benefits of products or other interventions to athletes to optimize their performance outcome.

  17. Spatial and temporal gait characteristics of elderly individuals during backward and forward walking with shoes and barefoot.

    Science.gov (United States)

    Elboim-Gabyzon, Michal; Rotchild, Shira

    2017-02-01

    Backward walking (BW) is an inherent component of mobility and function in daily activities, particularly indoors, when it is more likely that a person is barefoot. No studies to date have compared the spatio-temporal characteristics of BW with and without shoes in elderly individuals. This study compared spatio-temporal measures of BW and forward walking (FW) among elderly individuals while barefoot or wearing shoes. Forty-seven elderly individuals (13 men and 34 women, 76.7±7.7years of age) were evaluated. Participants were requested to walk at a comfortable, self-selected pace across the GAITRite(®) walkway for three trials under each of four conditions: walking forward (FW) and BW wearing their own comfortable low-heeled walking shoes and FW and BW walking without shoes. Gait speed, stride length and cadence were significantly reduced in BW versus FW, with an increase in double limb support (DLS), both with and without shoes. Barefoot BW resulted in significantly increased gait speed and cadence, and decreased DLS compared to BW with shoes. BW stride length was not affected by footwear. While barefoot FW was also associated with a significant increase in cadence and decrease in DLS time compared to walking with shoes, it decreased stride length and had no detrimental effect on gait speed. Assessment of the spatio-temporal parameters of walking barefoot and with shoes during FW and BW can contribute to our understanding of the ability of elderly individuals to adapt to changing walking conditions, and should be included in the assessment of functional mobility of elderly individuals.

  18. Wear Modalities and Mechanisms of the Mining Non-asbestos Composite Brake Material

    Science.gov (United States)

    Bao, Jiusheng; Yin, Yan; Zhu, Zhencai; Tong, Minming; Lu, Yuhao; Peng, Yuxing

    2013-08-01

    The mining brake material is generally made of composite materials and its wear has important influences on the braking performance of disc brakes. In order to improve the braking reliability of mine hoisters, this paper did some tribological investigations on the mining brake material to reveal its wear modalities and mechanisms. The mining non-asbestos brake shoe and 16Mn steel were selected as braking pairs and tested on a pad-on-disc friction tester. And a SEM was used to observe the worn surface of the brake shoe. It is shown that the non-asbestos brake material has mainly five wear modalities: adhesive wear, abrasive wear, cutting wear, fatigue wear and high heat wear. At the front period of a single braking the wear modality is mainly composed of some light mechanical wear such as abrasive, cutting and point adhesive. With the temperature rising at the back period it transforms to some heavy mechanical wear such as piece adhesive and fatigue. While in several repeated brakings once the surface temperature rises beyond the thermal-decomposition point of the bonding material, the strong destructive high heat wear takes leading roles on the surface. And a phenomenon called friction catastrophe (FC) occurs easily, which as a result causes a braking failure. It is considered that the friction heat has important influences on the wear modalities of the brake material. And the reduction of friction heat must be an effective technical method for decreasing wear and avoiding braking failures.

  19. Examining the degree of pain reduction using a multielement exercise model with a conventional training shoe versus an ultraflexible training shoe for treating plantar fasciitis.

    Science.gov (United States)

    Ryan, Michael; Fraser, Scott; McDonald, Kymberly; Taunton, Jack

    2009-12-01

    Plantar fasciitis is a common injury to the plantar aponeurosis, manifesting as pain surrounding its proximal insertion at the medial calcaneal tubercle. Pain is typically worse in the morning when getting out of bed, and may subside after the tissue is sufficiently warmed up. For running-based athletes and individuals who spend prolonged periods of time on their feet at work, plantar fasciitis may become recalcitrant to conservative treatments such as ice, rest, and anti-inflammatory medication. Exercise-based therapies have received only limited attention in the literature for this common problem, yet they are becoming increasingly validated for pain relief and positive tissue remodeling at other sites of similar soft-tissue overuse injury. This study reports on pain outcomes in individuals experiencing chronic plantar fasciitis while wearing a shoe with an ultraflexible midsole (Nike Free 5.0) (FREE) versus a conventional training (CON) shoe in a 12-week multielement exercise regimen, and after a 6-month follow-up. Adults with >or= 6-month history of painful heel pain were recruited and randomly assigned to wear 1 of the 2 shoes. All subjects completed the same exercise protocol. A visual analogue scale item tracked peak pain in the preceding 24 hours taken at baseline, 6- and 12-week points, and at the 6-month follow-up. Twenty-one subjects completed the program (9 FREE; 12 CON). Both groups reported significant improvements in pain by the 6-month follow-up, and the FREE group reported an overall reduced level of pain throughout the study as a result of lower mean pain scores at the midpoint and post-test compared with the CON group. The exercise regimen employed in this study appears to reduce pain associated with chronic plantar fasciitis, and in doing so, the Nike 5.0 shoe may result in reductions in pain earlier than conventional running shoes.

  20. Serious eye injury in badminton players.

    Science.gov (United States)

    Kelly, S P

    1987-10-01

    Serious eye injury can occur in badminton players and may become more frequent. The causes and nature of such injuries in this sport in six patients are discussed. All were playing competitive doubles matches. Penetrating eye injury due to a shattered glass spectacle lens occurred. Players should be advised not to wear spectacles with glass lenses. Ocular protection in this sport is desirable, and the forward player should hold the racket in front of the face.

  1. know where the shoe pinches

    Institute of Scientific and Technical Information of China (English)

    周立

    2003-01-01

    英语对话: A:I now know where the shoe pinches for you.It is your husband who should be to blame for your son’s wrong doings. B:That’s why we have been at loggerheads with each other quite a lot re- cently.They all get on my nerves. A:Maybe you can talk sense into him and tell him the consequences. B:Everything I say falls on a deaf ear.

  2. Multibody Dynamic Stress Simulation of Rigid-Flexible Shovel Crawler Shoes

    Directory of Open Access Journals (Sweden)

    Samuel Frimpong

    2016-06-01

    Full Text Available Electric shovels are used in surface mining operations to achieve economic production capacities. The capital investments and operating costs associated with the shovels deployed in the Athabasca oil sands formation are high due to the abrasive conditions. The shovel crawler shoes interact with sharp and abrasive sand particles, and, thus, are subjected to high transient dynamic stresses. These high stresses cause wear and tear leading to crack initiation, propagation and premature fatigue failure. The objective of this paper is to develop a model to characterize the crawler stresses and deformation for the P&H 4100C BOSS during propel and loading using rigid-flexible multi-body dynamic theory. A 3-D virtual prototype model of the rigid-flexible crawler track assembly and its interactions with oil sand formation is simulated to capture the model dynamics within multibody dynamics software MSC ADAMS. The modal and stress shapes and modal loads due to machine weight for each flexible crawler shoes are generated from finite element analysis (FEA. The modal coordinates from the simulation are combined with mode and stress shapes using modal superposition method to calculate real-time stresses and deformation of flexible crawler shoes. The results show a maximum von Mises stress value of 170 MPa occurring in the driving crawler shoe during the propel motion. This study provides a foundation for the subsequent fatigue life analysis of crawler shoes for extending crawler service life.

  3. Effect of soccer shoe upper on ball behaviour in curve kicks

    Science.gov (United States)

    Ishii, Hideyuki; Sakurai, Yoshihisa; Maruyama, Takeo

    2014-08-01

    New soccer shoes have been developed by considering various concepts related to kicking, such as curving a soccer ball. However, the effects of shoes on ball behaviour remain unclear. In this study, by using a finite element simulation, we investigated the factors that affect ball behaviour immediately after impact in a curve kick. Five experienced male university soccer players performed one curve kick. We developed a finite element model of the foot and ball and evaluated the validity of the model by comparing the finite element results for the ball behaviour immediately after impact with the experimental results. The launch angle, ball velocity, and ball rotation in the finite element analysis were all in general agreement with the experimental results. Using the validated finite element model, we simulated the ball behaviour. The simulation results indicated that the larger the foot velocity immediately before impact, the larger the ball velocity and ball rotation. Furthermore, the Young's modulus of the shoe upper and the coefficient of friction between the shoe upper and the ball had little effect on the launch angle, ball velocity, and ball rotation. The results of this study suggest that the shoe upper does not significantly influence ball behaviour.

  4. Multivariate Multiscale Entropy Applied to Center of Pressure Signals Analysis: An Effect of Vibration Stimulation of Shoes

    Directory of Open Access Journals (Sweden)

    Jiann-Shing Shieh

    2012-11-01

    Full Text Available Falls are unpredictable accidents and resulting injuries can be serious to the elderly. A preventative solution can be the use of vibration stimulus of white noise to improve the sense of balance. In this work, a pair of vibration shoes were developed and controlled by a touch-type switch which can generate mechanical vibration noise to stimulate the patient’s feet while wearing the shoes. In order to evaluate the balance stability and treatment effect of vibrating insoles in these shoes, multivariate multiscale entropy (MMSE algorithm is applied to calculate the relative complexity index of reconstructed center of pressure (COP signals in antero-posterior and medio-lateral directions by the multivariate empirical mode decomposition (MEMD. The results show that the balance stability of 61.5% elderly subjects is improved after wearing the developed shoes, which is more than 30.8% using multiscale entropy. In conclusion, MEMD-enhanced MMSE is able to distinguish the smaller differences between before and after the use of vibration shoes in both two directions, which is more powerful than the empirical mode decomposition (EMD-enhanced MSE in each individual direction.

  5. Eye Wear

    Science.gov (United States)

    Eye wear protects or corrects your vision. Examples are Sunglasses Safety goggles Glasses (also called eyeglasses) Contact ... jobs and some sports carry a risk of eye injury. Thousands of children and adults get eye ...

  6. The Changing Fate of Cloth Shoes

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    ONE day I found by chance one of my old photos taken 30 years ago. In it I was still a serious 17-year-old girl with my hair in two short braids and dressed in a blue cloth coat, brown corduroys and a pair of black cloth shoes each fastened by a strap at the side My eyes fixed on the shoes and lingered for quite a long time. A smile quietly crawled over my lips. Isn't it the fashionable "little girl's shoe" which is expected to prevail in the market this year?

  7. Dream for a Pair of Shoes

    Institute of Scientific and Technical Information of China (English)

    江大洪; 章思英

    2005-01-01

    The boy was 1.7 meters tall when he just started his third year at primary school. As his feet had outgrown even Father's shoes,his parents had to look up and down the streets for size-46 shoes. At 16,he shot to a height of 2.2 meters,and no store or market in the whole of China had stock of size-53 shoes for his big feet. The parents watched rather alarmingly their son shooting up wildly like a sapling.

  8. KIDNEY ANOMALIES: HORSE SHOE KIDNEY

    Directory of Open Access Journals (Sweden)

    Hemalatha

    2015-03-01

    Full Text Available INTRODUCTION : Horse Shoe Kidney was first recognized during an autopsy by De Carpi in 1521. This anomaly consists of two distinct renal masses lying vertically on either side of the midline and connected at their respective lower poles by a parenchymatous or fibrous isthmus that crosses the mid pl ane of the body. This isthmus lies at the level of 4th lumbar vertebra just beneath the origin of inferior mesenteric artery in about 40% of cases. Fusion of upper poles instead of the lower poles results in a n inverted horse Shoe Kidney which constitute 5 - 10% of ail Horse - Shoe kidneys , (i.e. in 95% of HSK , fusion is at lower poles. HSK is found more commonly in males by a 2 : 1 margin. AIM OF STUDY : An attempt has been made to know the various anomalies . The study has been taken up with the fond hope of helping the clinician , sonologist , and surgeons during their routine work. To apply this knowledge to the incoming post graduates in their research works. EMBRIOLOGICAL BASIS & KDNEY : The abnormality originates between 4th and 6th weeks of gestation , after the ureteral bud has entered the renal blastema. Boyden (1931 postulated that at the 14mm stage (4.5 weeks the developing metanephric masses lie close to one another , any disturbance in their relationship may result in joining at their inferior poles. A slight alteration in the position of the umbilical or common iliac artery could change the orientation of migrating kidneys thus leading to contact and fusion. In 1941 Dees (Nation 1945 , Bell 1946 , Gleen 1959 , Campbell 1970 described horse - shoe kidney di sease occurrence in 0.25% of the population or about 1 in 400. OBSERVATION : In the present study 176 specimens of kidneys were studied out of which 40 were fetal specimens and the rest were adult specimens consisting of both cadaveric and sonograms. The ad ult specimens from cadavers were 76 and 60 from sonograms. MATERIAL & METHODS : Abdomen is opened ; superficial viscera and

  9. Ground reaction forces in ballet dancers landing in flat shoes versus pointe shoes.

    Science.gov (United States)

    Walter, Heather L; Docherty, Carrie L; Schrader, John

    2011-06-01

    Reports in the literature suggest an abundance of lower extremity injuries in ballet dancers; however, few studies have identified the underlying causes of these injuries. Excessive ground reaction forces and shoe type are two potential contributing factors. Eighteen collegiate female ballet majors volunteered for this study. Each participant performed 12 trials of a basic ballet jump, six trials in flat shoes and 6 trials in pointe shoes, landing on a force plate. Ground reaction force (Newtons) and jump height (centimeters) were assessed for each trial. The mean ground reaction force and jump height for each shoe condition was used for statistical analysis. Two dependent t-tests were conducted to determine differences between the shoe types, one for ground reaction force and one for jump height. Alpha level was set at p < .05. We found that the ground reaction force was significantly higher when landing in flat shoes than in pointe shoes (p = .003). There was no significant difference in jump height between the two shoe conditions. This leads us to believe that the increase in ground reaction force was produced primarily by the shoe type.

  10. Veto players

    NARCIS (Netherlands)

    Warntjen, Andreas; Dowding, Keith

    2010-01-01

    Veto players are political actors whose consent is necessary to adopt a new policy. Put otherwise, they have veto power which allows them to prevent a change to the status quo. The concept is crucial to the influential veto player theory developed by George Tsebelis. Building on earlier work in form

  11. Veto players

    NARCIS (Netherlands)

    Warntjen, Andreas; Dowding, Keith

    2010-01-01

    Veto players are political actors whose consent is necessary to adopt a new policy. Put otherwise, they have veto power which allows them to prevent a change to the status quo. The concept is crucial to the influential veto player theory developed by George Tsebelis. Building on earlier work in form

  12. Erosions in the foot at baseline are predictive of orthopaedic shoe use after 10 years of treat to target therapy in patients with recent onset rheumatoid arthritis

    NARCIS (Netherlands)

    S.A. Bergstra (Sytske Anne); I.M. Markusse (Iris M.); G. Akdemir (Gülşah); H.K. Ronday; K.H. Han (K. Huub); W.F. Lems (Willem); P.J.S.M. Kerstens; R. van Den Berg (Rosaline); R. Landewé (Robert); C.F. Allaart (Cornelia)

    2016-01-01

    textabstractThe objective of this study is to investigate if foot joint damage due to rheumatoid arthritis (RA) can predict whether patients will start wearing orthopaedic shoes (OS) within 10 years after treatment start. Data from recent onset RA patients with 10 years follow-up from the BeSt (Dutc

  13. Classification and mass production technique for three-quarter shoe insoles using non-weight-bearing plantar shapes.

    Science.gov (United States)

    Sun, Shuh-Ping; Chou, Yi-Jiun; Sue, Chun-Chia

    2009-07-01

    We have developed a technique for the mass production and classification of three-quarter shoe insoles via a 3D anthropometric measurement of full-size non-weight-bearing plantar shapes. The plantar shapes of fifty 40-60-year-old adults from Taiwan were categorized and, in conjunction with commercially available flat or leisure shoe models, three-quarter shoe-insole models were generated using a CAD system. Applying a rapid prototype system, these models were then used to provide the parameters for manufacturing the shoe insoles. The insoles developed in this study have been classified into S, M and L types that offer user-friendly options for foot-care providers. We concluded that these insoles can mate tightly with the foot arch and disperse the pressure in the heel and forefoot over the foot arch. Thus, practically, the pressure difference over the plantar region can be minimised, and the user can experience comfort when wearing flat or leisure shoes.

  14. Tooth wear

    Directory of Open Access Journals (Sweden)

    Tušek Ivan

    2014-01-01

    Full Text Available Tooth wear is the loss of dental hard tissue that was not caused by decay and represents a common clinical problem of modern man. In the etiology of dental hard tissue lesions there are three dominant mechanisms that may act synergistically or separately:friction (friction, which is caused by abrasion of exogenous, or attrition of endogenous origin, chemical dissolution of dental hard tissues caused by erosion, occlusal stress created by compression and flexion and tension that leads to tooth abfraction and microfracture. Wear of tooth surfaces due to the presence of microscopic imperfections of tooth surfaces is clinically manifested as sanding veneers. Tribology, as an interdisciplinary study of the mechanisms of friction, wear and lubrication at the ultrastructural level, has defined a universal model according to which the etiopathogenesis of tooth wear is caused by the following factors: health and diseases of the digestive tract, oral hygiene, eating habits, poor oral habits, bruxism, temporomandibular disorders and iatrogenic factors. Attrition and dental erosion are much more common in children with special needs (Down syndrome. Erosion of teeth usually results from diseases of the digestive tract that lead to gastroesophageal reflux (GER of gastric juice (HCl. There are two basic approaches to the assessment of the degree of wear and dental erosion. Depending on the type of wear (erosion, attrition, abfraction, the amount of calcium that was realised during the erosive attack could be determined qualitatively and quantitatively, or changes in optical properties and hardness of enamel could be recorded, too. Abrasion of teeth (abrasio dentium is the loss of dental hard tissue caused by friction between the teeth and exogenous foreign substance. It is most commonly provoked by prosthetic dentures and bad habits, while its effect depends on the size of abrasive particles and their amount, abrasive particle hardness and hardness of tooth

  15. Shoes versus sneakers in toddler ambulation.

    Science.gov (United States)

    Gould, N

    1985-10-01

    The purpose of this study was to determine the relative values and differences between shoes and sneakers for young children just learning to walk. In phase 1 of the study, 79 toddlers (47 females and 32 males), ranging in age from 11 months to 3 years, were carefully measured for footwear. Only 15 toddlers (19%) could be properly fitted in the medium-width sneakers that are currently available on the market. The majority of the measured toddlers required widths greater than D, and to accommodate these wider feet, it was necessary to fit them with longer sneakers than they actually needed otherwise, thus making ambulation a bit more difficult and clumsy. In phase 2, eight toddlers, randomly selected except for sex (four male and four female), ranging in age from 11 to 16 months who had been ambulating 2 weeks to 5 months, were tagged with an identifying letter and videotaped in four walking situations: sneakers on tile, shoes on tile, sneakers on rugging, and shoes on rugging. Four hours of video taping was edited down to one-half hour. Twenty-three observers (orthopaedic surgeons, pediatricians, and shoe fitters) carefully reviewed the tape on multiple occasions and came to the following conclusions: better fit, stance, gait, cadence, and stability were noted with shoes in all the toddlers and in all situations. Falls were three times more frequent in sneakers as compared to shoes on tile surfaces and five times more frequent on rugging. It was concluded that the slight economic advantage of sneakers over shoes was not that great to warrant jeopardizing the capabilities of the toddler in the earliest stages of ambulation.

  16. Messuosasto Minna Parikka Shoes Oy:lle

    OpenAIRE

    2013-01-01

    Opinnäytetyöni aiheena on messuosaston suunnittelu Minna Parikka Shoes Oy:lle. Nykyään messurakenteiden ja -kalusteiden suunnitteluun ei ole panostettu, vaan on käytetty messujärjestäjien tarjoamia hylly- ja huonekaluratkaisuja. Messuosastot ovat olleet kooltaan noin viisi neliötä, eikä niillä ole saavutettu suurta näkyvyyttä. Minna Parikka Shoes Oy osallistuu vuosittain ainakin neljille eri messuille ympäri maailman. Messuosaston suunnittelun lähtökohtana on eri maiden messuihin sovel...

  17. Fluid pressures at the shoe-floor-contaminant interface during slips: effects of tread and implications on slip severity.

    Science.gov (United States)

    Beschorner, Kurt E; Albert, Devon L; Chambers, April J; Redfern, Mark S

    2014-01-22

    Previous research on slip and fall accidents has suggested that pressurized fluid between the shoe and floor is responsible for initiating slips yet this effect has not been verified experimentally. This study aimed to (1) measure hydrodynamic pressures during slipping for treaded and untreaded conditions; (2) determine the effects of fluid pressure on slip severity; and (3) quantify how fluid pressures vary with instantaneous resultant slipping speed, position on the shoe surface, and throughout the progression of the slip. Eighteen subjects walked on known dry and unexpected slippery floors, while wearing treaded and untreaded shoes. Fluid pressure sensors, embedded in the floor, recorded hydrodynamic pressures during slipping. The maximum fluid pressures (mean+/-standard deviation) were significantly higher for the untreaded conditions (124+/-75 kPa) than the treaded conditions (1.1+/-0.29 kPa). Maximum fluid pressures were positively correlated with peak slipping speed (r=0.87), suggesting that higher fluid pressures, which are associated with untreaded conditions, resulted in more severe slips. Instantaneous resultant slipping speed and position of sensor relative to the shoe sole and walking direction explained 41% of the fluid pressure variability. Fluid pressures were primarily observed for untreaded conditions. This study confirms that fluid pressures are relevant to slipping events, consistent with fluid dynamics theory (i.e. the Reynolds equation), and can be modified with shoe tread design. The results suggest that the occurrence and severity of unexpected slips can be reduced by designing shoes/floors that reduce underfoot fluid pressures. © 2013 Published by Elsevier Ltd.

  18. Effect of hoof boots and toe-extension shoes on the forelimb kinetics of horses during walking.

    Science.gov (United States)

    Amitrano, Fernando N; Gutierrez-Nibeyro, Santiago D; Schaeffer, David J

    2016-05-01

    OBJECTIVE To determine and compare the effect of hoof boots (HBs) and shoes with a toe extension on stance duration, ground reaction force, and sole length in contact with the ground in nonlame horses during walking. ANIMALS 6 nonlame Standardbreds. PROCEDURES Force plate gait analyses of the forelimbs were performed while the horses were walking barefoot before manipulation of feet (baseline), while the horses were walking fitted with HBs, while the horses were walking shod with toe-extension shoes, and while the horses were walking barefoot after shoe removal. Horses underwent radiography of both forelimb feet to determine the sole length in contact with the ground when barefoot, wearing HBs, and shod with toe-extension shoes. Stance duration, ground reaction force, and sole length were compared among the various walking sessions. RESULTS Compared with baseline findings, stance duration increased significantly when horses were fitted with HBs (7%) or toe-extension shoes (5%). Peak forelimb ground reaction force was similar among walking sessions; however, time of braking force peak was significantly greater during the stance phase only when horses wore HBs. Also, the sole length in contact with the ground was significantly longer in horses fitted with HBs (14.3 cm) or shod with the toe-extension shoes (17.6 cm), compared with that for one of the barefoot hooves (12.7 cm). CONCLUSIONS AND CLINICAL RELEVANCE In nonlame horses, use of HBs prolonged the stance time and time of braking force peak, which is indicative of a slower deceleration phase during limb impact with the ground. Also, the use of HBs prolonged the deceleration phase of the stride and increased the sole length in contact with the ground.

  19. The effects of cycling shoe stiffness on forefoot pressure.

    Science.gov (United States)

    Jarboe, Nathan Edward; Quesada, Peter M

    2003-10-01

    Plantar pressure data were recorded in two different shoe types to determine the effect of cycling shoe stiffness on peak plantar forefoot pressure in cyclists. Two pairs of shoes of the same size and manufacturer, identical except for outsole material and stiffness, were tested. Shoe stiffness measurements were collected under controlled conditions and in two different configurations using a dynamic hydraulic tensile testing machine. Measurements of plantar pressure were done using Pedar capacitive-based sensor insoles while subjects pedaled in a seated position at a controlled power output. Power output was set at a constant value of 400 W across all subjects by a magnetic resistance trainer unit. The pressure distribution in carbon-fiber-composite shoes during cycling was compared to cycling shoes made with plastic soles. Carbon fiber shoes presented stiffness values 42% and 550% higher than plastic shoes in longitudinal bending and three-point bending, respectively. The shoes made with carbon fiber produced peak plantar pressures 18% higher than those of plastic design (121 kPa vs. 103 kPa, p = .005). Competitive or professional cyclists suffering from metatarsalgia or ischemia should be especially careful when using carbon fiber cycling shoes because the shoes increase peak plantar pressure, which may aggravate these foot conditions.

  20. EFFECTS OF UNSTABLE SHOES ON ENERGY COST DURING TREADMILL WALKING AT VARIOUS SPEEDS

    Directory of Open Access Journals (Sweden)

    Keiji Koyama

    2012-12-01

    Full Text Available In recent years, shoes having rounded soles in the anterior- posterior direction have been commercially introduced, which are commonly known as unstable shoes (US. However, physiological responses during walking in US, particularly at various speeds, have not been extensively studied to date. The purpose of this study was to investigate the effect of wearing unstable shoes while walking at low to high speeds on the rate of perceived exertion (RPE, muscle activation, oxygen consumption (VO2, and optimum speed. Healthy male adults wore US or normal walking shoes (WS, and walked at various speeds on a treadmill with no inclination. In experiment 1, subjects walked at 3, 4, 5, 6, and 7 km·h-1 (duration, 3 min for all speeds and were recorded on video from the right sagittal plane to calculate the step length and cadence. Simultaneously, electromyogram (EMG was recorded from six different thigh and calf muscles, and the integrated EMG (iEMG was calculated. In experiment 2, RPE, heart rate and VO2 were measured with the walking speed being increased from 3.6 to 7.2 km·h-1 incrementally by 0.9 km·h-1 every 6 min. The optimum speed, defined by the least oxygen cost, was calculated from the fitted quadratic relationship between walking speed and oxygen cost. Wearing US resulted in significantly longer step length and lower cadence compared with WS condition at any given speed. For all speeds, iEMG in the medial gastrocnemius and soleus muscles, heart rate, and VO2 were significantly higher in US than WS. However, RPE and optimum speed (US, 4.75 ± 0.32 km·h-1; WS, 4. 79 ± 0.18 km·h-1 did not differ significantly between the two conditions. These results suggest that unstable shoes can increase muscle activity of lower legs and energy cost without influencing RPE and optimum speed during walking at various speeds

  1. Does "transition shoe" promote an intermediate biomechanical condition compared to running in conventional shoe and in reduced protection condition?

    Science.gov (United States)

    da Silva Azevedo, Ana Paula; Mezêncio, Bruno; Valvassori, Raísa; Mochizuki, Luis; Amadio, Alberto Carlos; Serrão, Júlio Cerca

    2016-05-01

    This study evaluated if running in a "transition shoe" commercially available results in intermediate mechanical load upon lower extremities compared to conventional shoe and minimalist shoe/barefoot. Kinematic and kinetic parameters while running in different shoe conditions were compared. Fourteen runners (12 men, 2 women; age=28.4±7.3 years), inexperienced in minimalist shoes and barefoot running, ran on an instrumented treadmill within four experimental conditions (conventional shoe - CS, transition shoe - TrS, minimalist shoe - MS, and barefoot - BF). Running was performed at 9km/h for 10min in each experimental condition. Vertical ground reaction force (VGRF) and two-dimensional kinematic variables of lower limbs (both legs) were recorded. Nine data acquisitions (10s) were conducted for each footwear condition. Transition shoe lead to significant changes in VGRF variables related to impact control, while kinematic parameters were little affected. The TrS had smaller first peak of VGRF (Fy1) than CS (p≤0.001) and higher than MS (p=0.050) and BF (p≤0.001). Time to first peak of VGRF (tFy1) of TrS was smaller than CS (p≤0.001) and higher than MS (p≤0.001) and BF (p≤0.001). The TrS and MS induced to lesser knee flexion (prunning shoe to minimalist shoe/barefoot.

  2. Epidemiology of High-Heel Shoe Injuries in U.S. Women: 2002 to 2012.

    Science.gov (United States)

    Moore, Justin Xavier; Lambert, Brice; Jenkins, Gabrielle P; McGwin, Gerald

    2015-01-01

    The purpose of the present study was to investigate the epidemiology of high-heel-related injuries among a nationally representative population of women in the United States and to analyze the demographic differences within this group. The data used in the present study were collected from the Consumer Product Safety Commission's National Electronic Injury Surveillance System. A total of 3294 injuries, representing an estimated 123,355 high-heel-related injuries, were treated in emergency departments within the United States from 2002 to 2012. The overall rate of high-heel-related injuries for the study was 7.32 per 100,000 females (95% confidence interval 7.08 to 7.56). The injury rate was greatest for young adult females, with the greatest rates observed for those aged 20 to 29 years (18.38 per 100,000 females) and those aged 30 to 39 years (11.07 per 100,000 females). The results from the present study suggest that high-heel-related injuries have nearly doubled during the 11-year period from 2002 to 2012. Injuries from high heels are differential by body region, with most injuries occurring as sprains and strains to the foot and ankle. Although high heels might be stylish, from a health standpoint, it could be worthwhile for females and those interested in wearing high heels to understand the risks of wearing high-heeled shoes and the potential harm that precarious activities in high-heeled shoes can cause. The results of the present study can be used in the development of a prospective cohort study to investigate the risk of injury from high-heeled shoes, accounting for the exposure time and studying differences in demographics (e.g., age and race).

  3. Corrective shoes for children: a survey of current practice.

    Science.gov (United States)

    Staheli, L T; Giffin, L

    1980-01-01

    A survey of shoe-prescribing practices for children was taken among pediatricians, orthopaedists, pediatric orthopaedists, and podiatrists. Opinions differed significantly regarding the usefulness of shoe modifications for common pediatric lower limb and foot problems. Parents' attitudes toward children's shoes were also surveyed. Pediatricians and pediatric orthopaedists tended to prescribe corrective shoes less often than did orthopaedists and podiatrists. High topped shoes are not necessary to promote normal foot development, in the opinion of 85% of those surveyed; however, high topped shoes were often recommended for infants because they slip off less easily. Preferences for Thomas heels, scaphoid pads, reverse lasts, straight lasts, wedges, torque heels, and shoe lifts for problems including flexible flat feet, metatarsus adductus, intoeing, bow legs, knock knees, and leg length inequalities were delineated among the four groups treating children's feet. The authors conclude that whereas studies show that shoe modifications are of questionable value in the problems discussed, corrective shoes are often prescribed when regular shoes would be more appropriate and economical.

  4. Stiffness Effects in Rocker-Soled Shoes: Biomechanical Implications

    Science.gov (United States)

    Su, Pei-Fang; Chung, Chia-Hua; Hsia, Chi-Chun; Chang, Chih-Han

    2017-01-01

    Rocker-soled shoes provide a way to reduce the possible concentration of stress, as well as change movement patterns, during gait. This study attempts to examine how plantar force and spatio-temporal variables are affected by two rocker designs, one with softer and one with denser sole materials, by comparing them with the barefoot condition and with flat-soled shoes. Eleven subjects’ gait parameters during walking and jogging were recorded. Our results showed that compared with barefoot walking, plantar forces were higher for flat shoes while lower for both types of rocker shoes, the softer-material rocker being the lowest. The plantar force of flat shoes is greater than the vertical ground reaction force, while that of both rocker shoes is much less, 13.87–30.55% body weight. However, as locomotion speed increased to jogging, for all shoe types, except at the second peak plantar force of the denser sole material rocker shoes, plantar forces were greater than for bare feet. More interestingly, because the transmission of force was faster while jogging, greater plantar force was seen in the rocker-soled shoes with softer material than with denser material; results for higher-speed shock absorption in rocker-soled shoes with softer material were thus not as good. In general, the rolling phenomena along the bottom surface of the rocker shoes, as well as an increase in the duration of simultaneous curve rolling and ankle rotation, could contribute to the reduction of plantar force for both rocker designs. The possible mechanism is the conversion of vertical kinetic energy into rotational kinetic energy. To conclude, since plantar force is related to foot-ground interface and deceleration methods, rocker-design shoes could achieve desired plantar force reduction through certain rolling phenomena, shoe-sole stiffness levels, and locomotion speeds. PMID:28046009

  5. Effect of motion control running shoes compared with neutral shoes on tibial rotation during running.

    Science.gov (United States)

    Rose, Alice; Birch, Ivan; Kuisma, Raija

    2011-09-01

    To determine whether a motion control running shoe reduces tibial rotation in the transverse plane during treadmill running. An experimental study measuring tibial rotation in volunteer participants using a repeated measures design. Human Movement Laboratory, School of Health Professions, University of Brighton. Twenty-four healthy participants were tested. The group comprised males and females with size 6, 7, 9 and 11 feet. The age range for participants was 19 to 31 years. The total range of proximal tibial rotation was measured using the Codamotion 3-D Movement Analysis System. A one-tailed paired t-test indicated a statistically significant decrease in the total range of proximal tibial rotation when a motion control shoe was worn (mean difference 1.38°, 95% confidence interval 0.03 to 2.73, P=0.04). There is a difference in tibial rotation in the transverse plane between a motion control running shoe and a neutral running shoe. The results from this study have implications for the use of supportive running shoes as a form of injury prevention. Copyright © 2010 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

  6. [The shoe industry and the musculoskeletal system].

    Science.gov (United States)

    Bazzini, Giacomo; Capodaglio, Edda Maria; Mancin, Donatella

    2012-01-01

    Shoes factory workers are engaged in ripetitive tasks, often performed in constrained postures and in concomitance of force applied, which result in increased risk of musculoskeletal disorders. Risk assessment and ergonomic interventions are part of the on-site prevention program, which should pertain also to gender and age differences. Health and safety issues can be adequately faced by an active epidemiological surveillance complemented by ergonomics.

  7. 3D Tracking via Shoe Sensing

    Directory of Open Access Journals (Sweden)

    Fangmin Li

    2016-10-01

    Full Text Available Most location-based services are based on a global positioning system (GPS, which only works well in outdoor environments. Compared to outdoor environments, indoor localization has created more buzz in recent years as people spent most of their time indoors working at offices and shopping at malls, etc. Existing solutions mainly rely on inertial sensors (i.e., accelerometer and gyroscope embedded in mobile devices, which are usually not accurate enough to be useful due to the mobile devices’ random movements while people are walking. In this paper, we propose the use of shoe sensing (i.e., sensors attached to shoes to achieve 3D indoor positioning. Specifically, a short-time energy-based approach is used to extract the gait pattern. Moreover, in order to improve the accuracy of vertical distance estimation while the person is climbing upstairs, a state classification is designed to distinguish the walking status including plane motion (i.e., normal walking and jogging horizontally, walking upstairs, and walking downstairs. Furthermore, we also provide a mechanism to reduce the vertical distance accumulation error. Experimental results show that we can achieve nearly 100% accuracy when extracting gait patterns from walking/jogging with a low-cost shoe sensor, and can also achieve 3D indoor real-time positioning with high accuracy.

  8. 3D Tracking via Shoe Sensing.

    Science.gov (United States)

    Li, Fangmin; Liu, Guo; Liu, Jian; Chen, Xiaochuang; Ma, Xiaolin

    2016-10-28

    Most location-based services are based on a global positioning system (GPS), which only works well in outdoor environments. Compared to outdoor environments, indoor localization has created more buzz in recent years as people spent most of their time indoors working at offices and shopping at malls, etc. Existing solutions mainly rely on inertial sensors (i.e., accelerometer and gyroscope) embedded in mobile devices, which are usually not accurate enough to be useful due to the mobile devices' random movements while people are walking. In this paper, we propose the use of shoe sensing (i.e., sensors attached to shoes) to achieve 3D indoor positioning. Specifically, a short-time energy-based approach is used to extract the gait pattern. Moreover, in order to improve the accuracy of vertical distance estimation while the person is climbing upstairs, a state classification is designed to distinguish the walking status including plane motion (i.e., normal walking and jogging horizontally), walking upstairs, and walking downstairs. Furthermore, we also provide a mechanism to reduce the vertical distance accumulation error. Experimental results show that we can achieve nearly 100% accuracy when extracting gait patterns from walking/jogging with a low-cost shoe sensor, and can also achieve 3D indoor real-time positioning with high accuracy.

  9. Creative Design of Double Safety Shoes Mechanisms

    Science.gov (United States)

    Cheng, Hong Yih

    This paper is to synthesize the double safety shoes mechanisms of elevators for prompting passenger's safety. A systematic design methodology including type synthesis and mechanism skeletons technology is also presented based on the design requirements and design constraints. The design requirements include to avoiding from collision between shoes, and shoe can be pulled out independently not to drag the door. The design constraints are proposed for assigning link types and kinematic relations. An existing mechanism, which is designed with six links and seven joints, is investigated by mechanism kinematics and structure sketch to establish the topological structure. According to the creative method, all of the possible kinematic chains with the numbers of the vertices and edges are enumerated. Then the linkage numbers are assigned skillfully to the edges, and one of the kinematic pairs, for example, revolute pair, prismatic pair, and rolling pair, is chosen for every vertices. So every kinematic chain can be stretched out several particularized chains. Several mechanism skeletons are also sketched.

  10. Shoe collar height effect on athletic performance, ankle joint kinematics and kinetics during unanticipated maximum-effort side-cutting performance.

    Science.gov (United States)

    Lam, Gilbert Wing Kai; Park, Eun Jung; Lee, Ki-Kwang; Cheung, Jason Tak-Man

    2015-01-01

    Side-step cutting manoeuvres comprise the coordination between planting and non-planting legs. Increased shoe collar height is expected to influence ankle biomechanics of both legs and possibly respective cutting performance. This study examined the shoe collar height effect on kinematics and kinetics of planting and non-planting legs during an unanticipated side-step cutting. Fifteen university basketball players performed maximum-effort side-step cutting to the left 45° direction or a straight ahead run in response to a random light signal. Seven successful cutting trials were collected for each condition. Athletic performance, ground reaction force, ankle kinematics and kinetics of both legs were analysed using paired t-tests. Results indicated that high-collar shoes resulted in less ankle inversion and external rotation during initial contact for the planting leg. The high-collar shoes also exhibited a smaller ankle range of motion in the sagittal and transverse planes for both legs, respectively. However, no collar effect was found for ankle moments and performance indicators including cutting performance time, ground contact time, propulsion ground reaction forces and impulses. These findings indicated that high-collar shoes altered ankle positioning and restricted ankle joint freedom movements in both legs, while no negative effect was found for athletic cutting performance.

  11. A method to investigate the effect of shoe-hole size on surface marker movement when describing in-shoe joint kinematics using a multi-segment foot model.

    Science.gov (United States)

    Bishop, Chris; Arnold, John B; Fraysse, Francois; Thewlis, Dominic

    2015-01-01

    To investigate in-shoe foot kinematics, holes are often cut in the shoe upper to allow markers to be placed on the skin surface. However, there is currently a lack of understanding as to what is an appropriate size. This study aimed to demonstrate a method to assess whether different diameter holes were large enough to allow free motion of marker wands mounted on the skin surface during walking using a multi-segment foot model. Eighteen participants underwent an analysis of foot kinematics whilst walking barefoot and wearing shoes with different size holes (15 mm, 20mm and 25 mm). The analysis was conducted in two parts; firstly the trajectory of the individual skin-mounted markers were analysed in a 2D ellipse to investigate total displacement of each marker during stance. Secondly, a geometrical analysis was conducted to assess cluster deformation of the hindfoot and midfoot-forefoot segments. Where movement of the markers in the 15 and 20mm conditions were restricted, the marker movement in the 25 mm condition did not exceed the radius at any anatomical location. Despite significant differences in the isotropy index of the medial and lateral calcaneus markers between the 25 mm and barefoot conditions, the differences were due to the effect of footwear on the foot and not a result of the marker wands hitting the shoe upper. In conclusion, the method proposed and results can be used to increase confidence in the representativeness of joint kinematics with respect to in-shoe multi-segment foot motion during walking.

  12. Experimental Study of Heat Dissipation in Indoor Sports Shoes

    OpenAIRE

    Dessing, O.; A.J. Jansen; Leihitu, C.; Overhage, D.

    2014-01-01

    As indoor sports shoes are intensively used in a warm and sweaty environment for periods of up to three consecutive hours, the built-up heat inside is insufficiently released causing warm and perspiring feet. This results in an increased chance of blisters and skin irritations. Experimental research on the ventilation properties of the shoe was done using a controlled heat source, digital thermometer and thermo-graphic camera. A representative set of five volley- and handball shoes were subje...

  13. [The functional sport shoe parameter "torsion" within running shoe research--a literature review].

    Science.gov (United States)

    Michel, F I; Kälin, X; Metzger, A; Westphal, K; Schweizer, F; Campe, S; Segesser, B

    2009-12-01

    Within the sport shoe area torsion is described as the twisting and decoupling of the rear-, mid- and forefoot along the longitudinal axis of the foot. Studies have shown that running shoes restrict the torsion of the foot and thus they increase the pronation of the foot. Based on the findings, it is recommended to design running shoes, which allow the natural freedom of movement of the foot. The market introduction of the first torsion concept through adidas(R) took place in 1989. Independently of the first market introduction, only one epidemiological study was conducted in the running shoe area. The study should investigate the occurrence of Achilles tendon problems of the athletes running in the new "adidas Torsion(R) shoes". However, further studies quantifying the optimal region of torsionability concerning the reduction of injury incidence are still missing. Newer studies reveal that the criterion torsion only plays a secondary roll regarding the buying decision. Moreover, athletes are not able to perceive torsionability as a discrete functional parameter. It is to register, that several workgroups are dealing intensively with the detailed analysis of the foot movement based on kinematic multi-segment-models. However, scientific as well as popular scientific contributions display that the original idea of the torsion concept is still not completely understood. Hence, the "inverse" characteristic is postulated. The present literature review leads to the deduction that the functional characteristics of the torsion concept are not fully implemented within the running shoe area. This implies the necessity of scientific studies, which investigate the relevance of a functional torsion concept regarding injury prevention based on basic and applied research. Besides, biomechanical studies should analyse systematically the mechanism and the effects of torsion relevant technologies and systems.

  14. Effects of different shoe-lacing patterns on the biomechanics of running shoes.

    Science.gov (United States)

    Hagen, Marco; Hennig, Ewald M

    2009-02-01

    In the present study, we examined the influence of shoe lacing on foot biomechanics in running. Twenty experienced rearfoot runners ran in six different lacing conditions across a force platform at a speed of 3.3 m . s(-1). Foot pronation during contact, tibial acceleration, and plantar pressure distribution of the right leg were recorded. The test conditions differed in the number of laced eyelets (1, 2, 3, 6 or 7) and in lacing tightness (weak, regular or strong). The results show reduced loading rates (P running shoe features and is likely to reduce the risk of lower limb injury.

  15. Relationship Between Agility Tests and Short Sprints: Reliability and Smallest Worthwhile Difference in National Collegiate Athletic Association Division-I Football Players.

    Science.gov (United States)

    Mann, J Bryan; Ivey, Pat A; Mayhew, Jerry L; Schumacher, Richard M; Brechue, William F

    2016-04-01

    The Pro-Agility test (I-Test) and 3-cone drill (3-CD) are widely used in football to assess quickness in change of direction. Likewise, the 10-yard (yd) sprint, a test of sprint acceleration, is gaining popularity for testing physical competency in football players. Despite their frequent use, little information exists on the relationship between agility and sprint tests as well the reliability and degree of change necessary to indicate meaningful improvement resulting from training. The purpose of this study was to determine the reliability and smallest worthwhile difference (SWD) of the I-Test and 3-CD and the relationship of sprint acceleration to their performance. Division-I football players (n = 64, age = 20.5 ± 1.2 years, height = 185.2 ± 6.1 cm, body mass = 107.8 ± 20.7 kg) performed duplicate trials in each test during 2 separate weeks at the conclusion of a winter conditioning period. The better time of the 2 trials for each week was used for comparison. The 10-yd sprint was timed electronically, whereas the I-Test and 3-CD were hand timed by experienced testers. Each trial was performed on an indoor synthetic turf, with players wearing multicleated turf shoes. There was no significant difference (p > 0.06) between test weeks for the I-Test (4.53 ± 0.35 vs. 4.54 ± 0.31 seconds), 3-CD (7.45 ± 0.06 vs. 7.49 ± 0.06 seconds), or 10-yd sprint (1.85 ± 0.12 vs. 1.84 ± 0.12 seconds). The intraclass correlation coefficients (ICC) for 3-CD (ICC = 0.962) and 10-yd sprint (ICC = 0.974) were slightly higher than for the I-Test (ICC = 0.914). These values lead to acceptable levels of the coefficient of variation for each test (1.2, 1.2, and 1.9%, respectively). The SWD% indicated that a meaningful improvement due to training would require players to decrease their times by 6.6% for I-Test, 3.7% for 3-CD, and 3.8% for 10-yd sprint. Performance in agility and short sprint tests are highly related and reliable in college football players, providing quantifiable

  16. Wearing gloves in the hospital

    Science.gov (United States)

    ... gloves; PPE - wearing gloves; Nosocomial infection - wearing gloves; Hospital acquired infection - wearing gloves ... Wearing gloves in the hospital helps prevent the spread of germs. This helps protect both patients and health care workers from infection.

  17. Comparative wear mapping techniques

    DEFF Research Database (Denmark)

    Alcock, J.; Sørensen, Ole Toft; Jensen, S.

    1996-01-01

    Pin-on-disc tests of tungsten carbide pins against silicon carbide discs were performed and wear rate, mechanism and friction maps constructed. Correlations were observed between the wear mode and the friction of the pin-disc interface, and between the qualitative incidence of disruptive wear...

  18. SensorShoe: Mobile Gait Analysis for Parkinson's Disease Patients

    NARCIS (Netherlands)

    Kauw-A-Tjoe, R.; Thalen, J.; Marin-Perianu, M.; Havinga, P.J.M.

    2007-01-01

    We present the design and initial evaluation of a mobile gait analysis system, SensorShoe. The target user group is represented by Parkinson's Disease patients, which need continuous assistance with the physical therapy in their home environment. SensorShoe analyses the gait by using a low-power sen

  19. SensorShoe: Mobile Gait Analysis for Parkinson's Disease Patients

    NARCIS (Netherlands)

    Havinga, P.J.M.; Kauw-A-Tjoe, R.G.; Marin-Perianu, M.; Thalen, J.P.

    2007-01-01

    We present the design and initial evaluation of a mobile gait analysis system, SensorShoe. The target user group is represented by Parkinson's Disease patients, which need continous assistance with the physical therapy in their home environment. SensorShoe analyses the gait by using a low-power sens

  20. 49 CFR 229.79 - Third rail shoes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Third rail shoes. 229.79 Section 229.79..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Electrical System § 229.79 Third rail shoes. When locomotives are equipped with both third rail and overhead...

  1. 49 CFR 229.81 - Emergency pole; shoe insulation.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Emergency pole; shoe insulation. 229.81 Section... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Electrical System § 229.81 Emergency pole; shoe insulation. (a) Each locomotive equipped with a pantograph...

  2. Wear Debris Analysis:Fundamental Principle of Wear-Graphy

    Institute of Scientific and Technical Information of China (English)

    陈铭; 王伟华; 殷勇辉; 王成焘

    2004-01-01

    A new wear-graphy technology was developed, which can simultaneously identify the shape and composition of wear debris, for both metals and non-metals.The fundamental principles of the wear-graphy system and its wear-gram system are discussed here.A method was developed to distribute wear debris on a slide uniformly to reduce overlapping of wear debris while smearing.The composition identification analyzes the wear debris using the scanning electron microscope (SEM) energy spectrum, infrared-thermal imaging and X-ray imaging technology.A wear debris analysis system based on database techniques is demonstrated, and a visible digitized wear-gram is acquired based on the information of wear debris with image collection and processing of the wear debris.The method gives the morphological characteristics of the wear debris, material composition identification of the wear debris, intelligent recognition of the wear debris, and storage and management of wear debris information.

  3. In-shoe plantar tri-axial stress profiles during maximum-effort cutting maneuvers.

    Science.gov (United States)

    Cong, Yan; Lam, Wing Kai; Cheung, Jason Tak-Man; Zhang, Ming

    2014-12-18

    Soft tissue injuries, such as anterior cruciate ligament rupture, ankle sprain and foot skin problems, frequently occur during cutting maneuvers. These injuries are often regarded as associated with abnormal joint torque and interfacial friction caused by excessive external and in-shoe shear forces. This study simultaneously investigated the dynamic in-shoe localized plantar pressure and shear stress during lateral shuffling and 45° sidestep cutting maneuvers. Tri-axial force transducers were affixed at the first and second metatarsal heads, lateral forefoot, and heel regions in the midsole of a basketball shoe. Seventeen basketball players executed both cutting maneuvers with maximum efforts. Lateral shuffling cutting had a larger mediolateral braking force than 45° sidestep cutting. This large braking force was concentrated at the first metatarsal head, as indicated by its maximum medial shear stress (312.2 ± 157.0 kPa). During propulsion phase, peak shear stress occurred at the second metatarsal head (271.3 ± 124.3 kPa). Compared with lateral shuffling cutting, 45° sidestep cutting produced larger peak propulsion shear stress (463.0 ± 272.6 kPa) but smaller peak braking shear stress (184.8 ± 181.7 kPa), of which both were found at the first metatarsal head. During both cutting maneuvers, maximum medial and posterior shear stress occurred at the first metatarsal head, whereas maximum pressure occurred at the second metatarsal head. The first and second metatarsal heads sustained relatively high pressure and shear stress and were expected to be susceptible to plantar tissue discomfort or injury. Due to different stress distribution, distinct pressure and shear cushioning mechanisms in basketball footwear might be considered over different foot regions.

  4. Analysis of walking improvement with dynamic shoe insoles, using two accelerometers

    Science.gov (United States)

    Tsuruoka, Yuriko; Tamura, Yoshiyasu; Shibasaki, Ryosuke; Tsuruoka, Masako

    2005-07-01

    The orthopedics at the rehabilitation hospital found that disorders caused by sports injuries to the feet or caused by lower-back are improved by wearing dynamic shoe insoles, these improve walking balance and stability. However, the relationship of the lower-back and knees and the rate of increase in stability were not quantitatively analyzed. In this study, using two accelerometers, we quantitatively analyzed the reciprocal spatiotemporal contributions between the lower-back and knee of patients with left lower-back pain by means of Relative Power Contribution Analysis. When the insoles were worn, the contribution of the left and right knee relative to the left lower-back pain was up to 26% ( panalysis of the left and right knee decreased by up to 67% ( p<0.05). This shows an increase in stability.

  5. Contact allergy in Indonesian patients with foot eczema attributed to shoes

    NARCIS (Netherlands)

    Febriana, S. A.; Soebono, H.; Coenraads, P. J.; Schuttelaar, M. L. A.

    2015-01-01

    BackgroundShoe dermatitis is a form of contact dermatitis resulting from exposure to shoes. Allergens and types of shoes responsible may vary depending on manufacturing techniques, climatic conditions and indigenous traditions. This study focuses primarily on as yet unexplored shoe dermatitis cases

  6. Effect of rocker shoes on plantar pressure pattern in healthy female runners

    NARCIS (Netherlands)

    Sobhani, Sobhan; van den Heuvel, Edwin; Bredeweg, Steven; Kluitenberg, Bas; Postema, Klaas; Hijmans, Juha M.; Dekker, Rienk

    2014-01-01

    Rocker profile shoes (rocker shoes) are one of the treatment options of metatarsalgia and forefoot stress fractures. The efficacy of rocker shoes in unloading the forefoot pressure has been shown in walking. In running, however, the effect of rocker shoes on forefoot pressure is unknown. Eighteen he

  7. Plantar pressure relief in the diabetic foot using forefoot offloading shoes

    NARCIS (Netherlands)

    S.A. Bus; R.W.M. van Deursen; R.V. Kanade; M. Wissink; E.A. Manning; J.G. van Baal; K.G. Harding

    2009-01-01

    Purpose: Forefoot offloading shoes (FOS) are commonly used in clinical practice for treatment of plantar forefoot ulcers in the diabetic foot. The aim of this study was to assess the offloading efficacy of four different FOS models in comparison with a cast shoe and control shoe. Methods: In-shoe pl

  8. Polymer wear evaluation

    DEFF Research Database (Denmark)

    Lagerbon, Mikkel; Sivebæk, Ion Marius

    2012-01-01

    the safety of the patients. Prediction of the wear of polymers is complicated by the low thermal conductivity of this kind of material. It implies that any acceleration of testing conditions by increased contact pressure and/or sliding velocity will make the polymer fail due to exaggerated heat buildup......Polymer wear plays an increasing role in manufacturing of machine parts for e.g. medical devices. Some of these have an expected lifetime of five to eight years during which very little wear of the components is acceptable. Too much wear compromises the dosage accuracy of the device and thereby....... This is not the kind of wear observed in medical devices. In the present work a method was developed capable of evaluating the wear progression in polymer-polymer contacts. The configuration of the setup is injection moulded specimens consisting of an upper part having a toroid shape and a lower flat part. The sliding...

  9. Polymer wear evaluation

    DEFF Research Database (Denmark)

    Lagerbon, Mikkel; Sivebæk, Ion Marius

    2012-01-01

    Polymer wear plays an increasing role in manufacturing of machine parts for e.g. medical devices. Some of these have an expected lifetime of five to eight years during which very little wear of the components is acceptable. Too much wear compromises the dosage accuracy of the device and thereby...... the safety of the patients. Prediction of the wear of polymers is complicated by the low thermal conductivity of this kind of material. It implies that any acceleration of testing conditions by increased contact pressure and/or sliding velocity will make the polymer fail due to exaggerated heat buildup....... This is not the kind of wear observed in medical devices. In the present work a method was developed capable of evaluating the wear progression in polymer-polymer contacts. The configuration of the setup is injection moulded specimens consisting of an upper part having a toroid shape and a lower flat part. The sliding...

  10. The effect of shoe design and lateral wedges on knee load and neuromuscular control in healthy subjects during walking

    DEFF Research Database (Denmark)

    Mølgaard, Carsten; Kersting, Uwe G.

    2014-01-01

    three-dimensional gait analysis. Barefoot walking, walking in a running shoe, an Oxford-type leather shoe, and a rocker shoe were analysed. The shoes were tested both with and without a 10-degree full-length laterally wedged insole. Results: There were significant shoe wedge interactions on the first...

  11. Dentofacial trauma and players' attitude towards mouthguard use in field hockey: a systematic review and meta-analysis.

    NARCIS (Netherlands)

    Vucic, S.; Drost, R.W.; Ongkosuwito, E.M.; Wolvius, E.B.

    2016-01-01

    BACKGROUND: Dentofacial injuries are a risk while playing field hockey. Wearing mouthguards is recommended. OBJECTIVE: To synthesise findings on the prevalence and characteristics of dentofacial injuries sustained by field hockey players. We also investigated the prevalence of regular mouthguard use

  12. Children sport shoes--a systematic review of current literature.

    Science.gov (United States)

    Walther, Markus; Herold, Dirk; Sinderhauf, Angela; Morrison, Robert

    2008-01-01

    The child's foot is clearly distinct from the adult foot in its functional anatomy and ability to cope with pressure. This requires special considerations in the development of a children's sport shoe. Medical and sport science databases were thoroughly searched for studies pertaining to the anatomy and biomechanics of children's feet during their development. With the data found, a list of requirements for the children's shoe was compiled. Small children should have a sports shoe, which is as flexible as their own foot. The small impact forces during their sports activities make extra cushioning superfluous. During school age the connective tissue gains stability. The growing amount of sports activities, much of which is performed on hard indoor surfaces, enhances the need for cushioning. At the same time there is a growing necessity for adequate mechanical stimuli to help the muscles and bones develop. The strength of the connective tissue and the flexibility of the joints reach adult levels by the age of 15. In small shoes, the displacement of proportions can lead to improper positioning of the flex zone and thereby causing harmful stress on the foot. Cushioning elements are often oversized. Considering the wide range of anatomy in the child's foot, it is advisable to produce children's shoes in different widths. The child's foot differs in anatomy and function from the adult foot. Children sport shoes should meet the child specific requirement.

  13. The effect of shoe design and lateral wedging on knee loading

    DEFF Research Database (Denmark)

    Mølgaard, Carsten; Kersting, Uwe G.

    -dimensional gait analysis. Barefoot walking, walking in a running shoe, an Oxford-type leather shoe, and a rocker shoe were analyzed. The shoes were tested both with and without a 10-degree full length laterally wedged insole. Results: Similar, significant reductions in the peak knee adduction moment with lateral...... wedges were observed in all three types of shoes. However, differences between shoe design were of similar magnitude as the effect of laterally wedged insoles. Only marginal changes in muscle activity for lateral hamstrings during barefoot toe-out walking and gastrocnemius when using the Oxford wedged...

  14. A systematic review of the methodological quality and extent to which evaluation studies measure the usability of orthopaedic shoes

    NARCIS (Netherlands)

    Jannink, MJA; van Dijk, H; de Vries, J; Groothoff, JW; Lankhorst, GJ

    2004-01-01

    Objective: To determine the methodological quality of studies evaluating orthopaedic shoes and orthopaedic shoe provisions. To what extent do studies evaluating orthopaedic shoes prescribed for patients with degenerative disorders of the foot, rheumatoid arthritis, diabetes mellitus and neurological

  15. READY-TO-WEAR CONTENT

    National Research Council Canada - National Science Library

    Erik J Martin

    2014-01-01

      Welcome to the age of wearable tech, where everyday attire from wristbands and eyeglasses to shirts and shoes are transformed into cutting-edge computers designed to receive, transmit, and display...

  16. A comparative mechanical analysis of the pointe shoe toe box. An in vitro study.

    Science.gov (United States)

    Cunningham, B W; DiStefano, A F; Kirjanov, N A; Levine, S E; Schon, L C

    1998-01-01

    Dancing en pointe requires the ballerina to stand on her toes, which are protected only by the pointe shoe toe box. This protection diminishes when the toe box loses its structural integrity. The objectives of this study were 1) to quantify the comparative structural static and fatigue properties of the pointe shoe toe box, and 2) to evaluate the preferred shoe characteristics as determined by a survey of local dancers. Five different pointe shoes (Capezio, Freed, Gaynor Minden, Leo's, and Grishko) were evaluated to quantify the static stiffness, static strength, and fatigue properties (cycles to failure) of the shoes. Under axial loading conditions, the Leo's shoe demonstrated the highest stiffness level, and the Freed shoe exhibited the least strength. Under vertical loading conditions, the Leo's and Freed shoes demonstrated the highest stiffness levels, and the Gaynor Minden and Freed shoes exhibited the highest strength. Fatigue testing highlighted the greatest differences among the five shoes, with the Gaynor Minden demonstrating the highest fatigue life. Dancers rated the top five shoe characteristics, in order of importance, as fit, comfort, box/platform shape, vamp shape, and durability and indicated that the "best" shoe is one that "feels right" and permits artistic maneuvers, not necessarily the strongest or most durable shoe.

  17. Patients’ expectations and actual use of custom-made orthopaedic shoes

    NARCIS (Netherlands)

    Netten, van Jaap J.; Jannink, Michiel J.A.; Hijmans, Juha M.; Geertzen, Jan H.B.; Postema, Klaas

    2010-01-01

    Objective: To investigate the association between patients’ expectations and the actual use of custom-made orthopaedic shoes. - Design: A prospective cohort study with internal comparison. - Setting: Twelve orthopaedic shoe companies. - Patients: During six months, consecutive patients who were p

  18. Biomechanics of slow running and walking with a rocker shoe.

    Science.gov (United States)

    Sobhani, Sobhan; Hijmans, Juha; van den Heuvel, Edwin; Zwerver, Johannes; Dekker, Rienk; Postema, Klaas

    2013-09-01

    Evidence suggests a link between the loading of the Achilles tendon and the magnitude of the ankle internal plantar flexion moment during late stance of gait, which is clinically relevant in the management of Achilles tendinopathy. Some studies showed that rocker shoes can reduce the ankle internal plantar flexion moment. However, the existing evidence is not conclusive and focused on walking and scarce in running. Sixteen healthy runners participated in this study. Lower extremity kinetics, kinematics and electromyographic (EMG) signals of triceps surae and tibialis anterior were quantified for two types of shoes during running and walking. The peak ankle plantar flexion moment was reduced significantly in late stance of running (0.27 Nm/kg; prunning and walking with the rocker shoe (prunning and walking. A significant delay of the EMG peak, approximately 2% (prunning and walking. The peak amplitude of tibialis anterior was significantly increased (64.7 μV, prunning and walking in healthy people.

  19. [The shoe industry: from productive reality to risk individualization].

    Science.gov (United States)

    Saretto, Gianni; Dulio, Sergio

    2012-01-01

    This article describes in detail each stage of the shoe manufacturing process: design, cutting and shearing, sewing and trimming, assemblage, sole preparation, finishing, packaging and stocking, shoe manufacturing with synthetic materials. It will then discuss new technologies and their impact on the improvement of the worker's health, safety and convenience. A definition of the shoe parts and of the materials and machinery employed in its production will be provided, as well as a synthesis of the occupational hazards involved in each department. Although dealing with competitors who can take advantage of low-cost production and lack of concern for labour protection and environmental issues, the industry should always take great care of topics such as innovation and automation, but also workplace health and safety, while pushing the limits of that technological advance which companies have to face.

  20. Impact attenuation properties of jazz shoes alter lower limb joint stiffness during jump landings.

    Science.gov (United States)

    Fong Yan, Alycia; Smith, Richard M; Hiller, Claire E; Sinclair, Peter J

    2017-05-01

    To quantify the impact attenuation properties of the jazz shoes, and to investigate the in-vivo effect of four jazz shoe designs on lower limb joint stiffness during a dance-specific jump. Repeated measures. A custom-built mechanical shoe tester similar to that used by athletic shoe companies was used to vertically impact the forefoot and heel region of four different jazz shoe designs. Additionally, dancers performed eight sautés in second position in bare feet and the shoe conditions. Force platforms and 3D-motion capture were used to analyse the joint stiffness of the midfoot, ankle, knee and hip during the jump landings. Mechanical testing of the jazz shoes revealed significant differences in impact attenuation characteristics among each of the jazz shoe designs. Gross knee and midfoot joint stiffness were significantly affected by the jazz shoe designs in the dancers' jump landings. The tested jazz shoe designs altered the impact attenuating capacity of jump landing technique in dancers. The cushioned jazz shoes are recommended particularly for injured dancers to reduce impact on the lower limb. Jazz shoe design should consider the impact attenuation properties of the forefoot region, due to the toe-strike landing technique in dance movement. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  1. Modified distal shoe appliance--fabrication and clinical performance.

    Science.gov (United States)

    Gujjar, Kumar Raghav; Indushekar, K R; Amith, H V; Sharma, Shefali Li

    2012-01-01

    When the primary second molar is prematurely lost, mesial movement and migration of the permanent first molar often occurs. This is one of the most difficult problems of the developing dentition confronted by pediatric dentists. Use of a space maintainer that will guide the permanent first molar into its normal position is indicated. In cases with bilateral premature loss of primary molars, the conventional design of distal shoe poses a variety of problems and, therefore, necessitates a customized design for the eruption guidance of permanent first molars. The purpose of this case report is to discuss an innovative design of a distal shoe appliance, which was used with good clinical results.

  2. Protective Equipment and Player Characteristics Associated With the Incidence of Sport-Related Concussion in High School Football Players

    Science.gov (United States)

    McGuine, Timothy A.; Hetzel, Scott; McCrea, Michael; Brooks, M. Alison

    2015-01-01

    Background The incidence of sport-related concussion (SRC) in high school football is well documented. However, limited prospective data are available regarding how player characteristics and protective equipment affect the incidence of SRC. Purpose To determine whether the type of protective equipment (helmet and mouth guard) and player characteristics affect the incidence of SRC in high school football players. Design Cohort study; Level of evidence, 2. Methods Certified athletic trainers (ATs) at each high school recorded the type of helmet worn (brand, model, purchase year, and recondition status) by each player as well as information regarding players’ demographics, type of mouth guard used, and history of SRC. The ATs also recorded the incidence and days lost from participation for each SRC. Incidence of SRC was compared for various helmets, type of mouth guard, history of SRC, and player demographics. Results A total of 2081 players (grades 9–12) enrolled during the 2012 and/or 2013 football seasons (2287 player-seasons) and participated in 134,437 football (practice or competition) exposures. Of these players, 206 (9%) sustained a total of 211 SRCs (1.56/1000 exposures). There was no difference in the incidence of SRC (number of helmets, % SRC [95% CI]) for players wearing Riddell (1171, 9.1% [7.6%–11.0%]), Schutt (680, 8.7% [6.7%–11.1%]), or Xenith (436, 9.2% [6.7%–12.4%]) helmets. Helmet age and recondition status did not affect the incidence of SRC. The rate of SRC (hazard ratio [HR]) was higher in players who wore a custom mouth guard (HR = 1.69 [95% CI, 1.20–2.37], P football players. Players who had sustained an SRC within the previous 12 months were more likely to sustain an SRC than were players without a history of SRC. Sports medicine providers who work with high school football players need to realize that factors other than the type of protective equipment worn affect the risk of SRC in high school players. PMID:25060072

  3. Foot motion in children shoes: a comparison of barefoot walking with shod walking in conventional and flexible shoes.

    Science.gov (United States)

    Wolf, Sebastian; Simon, Jan; Patikas, Dimitrios; Schuster, Waltraud; Armbrust, Petra; Döderlein, Leonhard

    2008-01-01

    The increased prevalence for flatfoot and hallux valgus in modern societies may be the consequence of inadequate footwear in childhood. Based on the assumption that barefoot walking represents the best condition for the development of a healthy foot the objective of this study was to monitor the influence of commercial footwear on children's foot motion during walking. Furthermore, an attempt was made to reduce this influence by changing the physical properties of standard footwear. Children's barefoot motion pattern was monitored by a marker-based optical 3D-tracking method using a multi-segment foot model. In the study's first stage, barefoot walking was compared to walking with a commercial product. In the second stage it was compared to both, the pattern with the commercial product and with the shoe modified on the basis of the findings of the first stage of the study. Eighteen children (8.2+/-0.7 years old) with no foot deformity and with the same shoe size were recruited for this study. It was found that tibio-talar ROM increased in the commercial shoe (26.6 degrees ) compared to the barefoot condition (22.5 degrees , p=0.001) whereas the medial arch changes for push-off were diminished since the variation in arch length was reduced from 9.9% (barefoot) to 5.9% (shoe, pstudy shows that slimmer and more flexible children's shoes do not change foot motion as much as conventional shoes and therefore should be recommended not only for children in this age but for healthy children in general.

  4. Optical wear monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Kidane, Getnet S; Desilva, Upul P.; He, Chengli; Ulerich, Nancy H.

    2016-07-26

    A gas turbine includes first and second parts having outer surfaces located adjacent to each other to create an interface where wear occurs. A wear probe is provided for monitoring wear of the outer surface of the first part, and includes an optical guide having first and second ends, wherein the first end is configured to be located flush with the outer surface of the first part. A fiber bundle includes first and second ends, the first end being located proximate to the second end of the optical guide. The fiber bundle includes a transmit fiber bundle comprising a first plurality of optical fibers coupled to a light source, and a receive fiber bundle coupled to a light detector and configured to detect reflected light. A processor is configured to determine a length of the optical guide based on the detected reflected light.

  5. Engineering specification and system design for CAD/CAM of custom shoes. Phase 5: UMC involvement (January 1, 1989 - June 30, 1989)

    Science.gov (United States)

    Bao, Han P.

    1989-01-01

    The CAD/CAM of custom shoes is discussed. The solid object for machining is represented by a wireframe model with its nodes or vertices specified systematically in a grid pattern covering its entire length (point-to-point configuration). Two sets of data from CENCIT and CYBERWARE were used for machining purposes. It was found that the indexing technique (turning the stock by a small angle then moving the tool on a longitudinal path along the foot) yields the best result in terms of ease of programming, savings in wear and tear of the machine and cutting tools, and resolution of fine surface details. The work done using the LASTMOD last design system results in a shoe last specified by a number of congruent surface patches of different sizes. This data format was converted into a form amenable to the machine tool. It involves a series of sorting algorithms and interpolation algorithms to provide the grid pattern that the machine tool needs as was the case in the point to point configuration discussed above. This report also contains an in-depth treatment of the design and production technique of an integrated sole to complement the task of design and manufacture of the shoe last. Clinical data and essential production parameters are discussed. Examples of soles made through this process are given.

  6. Does Wearing Textured Insoles during Non-class Time Improve Proprioception in Professional Dancers?

    Science.gov (United States)

    Steinberg, N; Tirosh, O; Adams, R; Karin, J; Waddington, G

    2015-11-01

    This study sought to determine whether textured insoles inserted in the sports shoes of young dancers improved their inversion and eversion ankle movement discrimination. 26 ballet dancers (14 female, 12 male) from the Australian Ballet School, ages 14-19 years, were divided into 2 groups according to sex and class levels. During the first 4 weeks, the first intervention group (GRP1) was asked to wear textured insoles in their sports shoes during non-class periods, and the second intervention group (GRP2) followed standard practice. In the next 4 weeks, GRP2 was asked to wear the textured insoles and GRP1 did not wear the textured insoles. Participants were tested pre-intervention, after 4 weeks, and at 8 weeks for both inversion and eversion ankle discrimination. In both inversion and eversion testing positions, interaction was found between the 2 groups and the 3 testing times (pproprioceptive system arising from textured insoles worn for 4 weeks was sufficient to improve the ankle proprioception of ballet dancers, in both inversion and eversion movements.

  7. Effects of shoe sole hardness on plantar pressure and comfort in older people with forefoot pain.

    Science.gov (United States)

    Lane, Tamara J; Landorf, Karl B; Bonanno, Daniel R; Raspovic, Anita; Menz, Hylton B

    2014-01-01

    Plantar forefoot pain is common in older people and is related to increased peak pressures under the foot during gait. Variations in the hardness of the shoe sole may therefore influence both the magnitude of loading under the foot and the perceived comfort of the shoe in this population. The aim of this investigation was to determine the effect of varying shoe sole hardness on plantar pressures and comfort in older people with forefoot pain. In-shoe plantar pressures under the forefoot, midfoot and rearfoot were recorded from 35 older people (mean age 73.2, SD 4.5 years) with current or previous forefoot pain using the pedar-X(®) system. Participants walked at their normal comfortable speed along an 8m walkway in shoes with three different levels of sole hardness: soft (Shore A25), medium (Shore A40) and hard (Shore A58). Shoe comfort was measured on a 100mm visual analogue scale. There were statistically significant differences in peak pressure of between 5% and 23% across the forefoot, midfoot and rearfoot (phard-soled shoe registered the highest peak pressures and the soft-soled shoe the lowest peak pressures. However, no differences in comfort scores across the three shoe conditions were observed. These findings demonstrate that as shoe sole hardness increases, plantar pressure increases, however this does not appear to have a significant effect on shoe comfort.

  8. Effect Of Running Shoes on Foot Impact During Running

    CERN Document Server

    Nassif, Henry

    2016-01-01

    Running is part of almost every sport, and requires a great amount of stamina, endurance, mental toughness and overall strength. At every step, the foot experiences ground reaction forces necessary to support the motion of the body. With the advancements in shoe technology, running shoes have grown in popularity among runners, as well as non-runners, because they reduce the risk of injuries from the impact felt by the foot. The purpose of this report is to analyze the effect of running shoes on impact forces on the foot. This is achieved through the use of three force pads fixed at different locations on the foot The force measured by each sensor is then used to estimate the vertical ground reaction force, using the sensors' calibrations equations . Based on the ground reaction force, the effective mass corresponding to the momentum change occurring during the transient phase of the impact is estimated. The results show that running at 9 miles per hour without running shoes generates an effective mass of (14....

  9. The distal shoe space maintainer chairside fabrication and clinical performance.

    Science.gov (United States)

    Brill, Warren A

    2002-01-01

    The chairside-fabricated distal shoe appliance, with a stainless steel crown as the retainer, is an efficacious and cost-effective appliance for guiding the unerupted permanent first molar into position after premature loss or extraction of the second primary molar. The fabrication technique is illustrated in this case report and data is presented on the success rate of the appliance.

  10. Effect of shoe type on plantar pressure: A gender comparison

    NARCIS (Netherlands)

    R.M. Queen; A.N. Abbey; J.I. Wiegerinck; J.C. Yoder; J.A. Nunley

    2010-01-01

    Despite the differences in materials, racing flats have begun to be used not only for racing, but also for daily training. As there are data suggesting a gender difference in overuse injuries in runners, shoe choice may affect loading patterns during running. The purpose was to determine differences

  11. Experimental Study of Heat Dissipation in Indoor Sports Shoes

    NARCIS (Netherlands)

    Dessing, O.; Jansen, A.J.; Leihitu, C.; Overhage, D.

    2014-01-01

    As indoor sports shoes are intensively used in a warm and sweaty environment for periods of up to three consecutive hours, the built-up heat inside is insufficiently released causing warm and perspiring feet. This results in an increased chance of blisters and skin irritations. Experimental research

  12. Biomechanics of slow running and walking with a rocker shoe

    NARCIS (Netherlands)

    Sobhani, Sobhan; Hijmans, Juha; van den Heuvel, Edwin; Zwerver, Johannes; Dekker, Rienk; Postema, Klaas

    2013-01-01

    Evidence suggests a link between the loading of the Achilles tendon and the magnitude of the ankle internal plantar flexion moment during late stance of gait, which is clinically relevant in the management of Achilles tendinopathy. Some studies showed that rocker shoes can reduce the ankle internal

  13. Shoe That Works As a Mobile Phone Inventecd

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    澳洲一名电脑工程师发明了一部鞋子手机,既能当鞋穿.又能当手机用。 A shoe that also works as a mobile phone has been invented by an Australian scientist, in a move reminiscent of spoof spy films.

  14. Comparative wear mapping techniques

    DEFF Research Database (Denmark)

    Alcock, J.; Sørensen, Ole Toft; Jensen, S.

    1996-01-01

    Pin surfaces were analysed by laser profilometry. Two roughness parameters, R(a) and the fractal dimension, were investigated as a first step towards methods of quantitative wear mechanism mapping. Both parameters were analysed for their relationship to the severity and prevalence of a mechanism....

  15. Are old running shoes detrimental to your feet? A pedobarographic study

    Directory of Open Access Journals (Sweden)

    Makwana Nilesh

    2011-08-01

    Full Text Available Abstract Background Footwear characteristics have been implicated in fatigue and foot pain. The recommended time for changing running shoes is every 500 miles. The aim of our study was to assess and compare plantar peak pressures and pressure time integrals in new and old running shoes. Findings This was a prospective study involving 11 healthy female volunteers with no previous foot and ankle problems. New running shoes were provided to the participants. Plantar pressures were measured using the Novel Pedar system while walking with new and participants' personal old running shoes. Plantar pressures were measured in nine areas of the feet. Demographic data, age of old running shoes, Body Mass Index (BMI, peak pressures and pressure-time integral were acquired. The right and left feet were selected at random and assessed separately. Statistical analysis was done using the paired t test to compare measurements between old and new running shoes. The mean peak pressures were higher in new running shoes (330.5 ± 79.6 kiloPascals kPa when compared to used old running shoes (304 ± 58.1 kPa (p = 0.01. The pressure-time integral was significantly higher in the new running shoes (110 ± 28.3 kPa s compared to used old running shoes (100.7 ± 24.0 kPa s (p = 0.01. Conclusion Plantar pressure measurements in general were higher in new running shoes. This could be due to the lack of flexibility in new running shoes. The risk of injury to the foot and ankle would appear to be higher if running shoes are changed frequently. We recommend breaking into new running shoes slowly using them for mild physical activity.

  16. Assessment of wear facets produced by the ACTA wear machine

    DEFF Research Database (Denmark)

    Benetti, Ana R; Larsen, Liselotte; Dowling, Adam H

    2016-01-01

    OBJECTIVE: To investigate the use of a three-dimensional (3D) digital scanning method in determining the accuracy of the wear performance parameters of resin-based composites (RBCs) determined using a two-dimensional (2D) analogue methodology following in-vitro testing in an Academisch Centrum...... an assessment of the potential of the experimental RBC formulations for clinical usage. CONCLUSION: The 3D technique allowed for the assessment of mean maximum wear depth and mean total volumetric wear which enables tribological analyses of the wear facet and therefore the wear mechanisms operative. Employing...... profilers is useful when screening potential new RBC formulations for the restoration of posterior dentition....

  17. Tibia and fibula fractures in soccer players.

    Science.gov (United States)

    Boden, B P; Lohnes, J H; Nunley, J A; Garrett, W E

    1999-01-01

    We performed a retrospective review of 31 athletes who sustained a fracture of the lower leg from a direct blow while playing soccer. Fifteen fractures involved both the tibia and fibula 11 only the tibia, and 5 only the fibula. Information was collected using a standardized questionnaire. The mean follow-up from the time of injury was 30 months. Injuries typically occurred in young, competitive athletes during game situations. The mechanisms were broadly classified into several categories: contact during a slide tackle (13, 42%), a collision with the goalkeeper (8, 26%), two opposing players colliding while swinging for a loose ball (7, 23%), or a player being kicked by a standing opponent (3, 10%). The majority of fractures (26, 90%) occurred while the athletes were wearing shin guards. The point of impact was with the shin guard prior to the fracture in 16 cases (62%). Return to competitive soccer averaged 40 weeks for combined tibia and fibula fractures, 35 weeks for isolated tibia fractures, and 18 weeks for isolated fibula fractures. Injuries were associated with a high incidence of major complications (12 out of 31, 39%), especially in concurrent tibia and fibula fractures (8 out of 15, 50%). These findings suggest that lower leg fractures in soccer players are serious injuries, often necessitating a prolonged recovery time. In addition, this study questions the ability of shin guards to protect against fractures.

  18. In-shoe plantar pressure distribution during running on natural grass and asphalt in recreational runners.

    Science.gov (United States)

    Tessutti, Vitor; Trombini-Souza, Francis; Ribeiro, Ana Paula; Nunes, Ana Luiza; Sacco, Isabel de Camargo Neves

    2010-01-01

    The type of surface used for running can influence the load that the locomotor apparatus will absorb and the load distribution could be related to the incidence of chronic injuries. As there is no consensus on how the locomotor apparatus adapts to loads originating from running surfaces with different compliance, the objective of this study was to investigate how loads are distributed over the plantar surface while running on natural grass and on a rigid surface--asphalt. Forty-four adult runners with 4+/-3 years of running experience were evaluated while running at 12 km/h for 40 m wearing standardised running shoes and Pedar insoles (Novel). Peak pressure, contact time and contact area were measured in six regions: lateral, central and medial rearfoot, midfoot, lateral and medial forefoot. The surfaces and regions were compared by three ANOVAS (2 x 6). Asphalt and natural grass were statistically different in all variables. Higher peak pressures were observed on asphalt at the central (pasphalt: 342.3(76.3)kPa] and lateral rearfoot (pasphalt: 350.9(98.3)kPa] and lateral forefoot (pasphalt: 245.3(55.5)kPa]. For natural grass, contact time and contact area were significantly greater at the central rearfoot (p<0.001). These results suggest that natural grass may be a surface that provokes lighter loads on the rearfoot and forefoot in recreational runners.

  19. In-shoe plantar pressure measurement and analysis system based on fabric pressure sensing array.

    Science.gov (United States)

    Shu, Lin; Hua, Tao; Wang, Yangyong; Qiao Li, Qiao; Feng, David Dagan; Tao, Xiaoming

    2010-05-01

    Spatial and temporal plantar pressure distributions are important and useful measures in footwear evaluation, athletic training, clinical gait analysis, and pathology foot diagnosis. However, present plantar pressure measurement and analysis systems are more or less uncomfortable to wear and expensive. This paper presents an in-shoe plantar pressure measurement and analysis system based on a textile fabric sensor array, which is soft, light, and has a high-pressure sensitivity and a long service life. The sensors are connected with a soft polymeric board through conductive yarns and integrated into an insole. A stable data acquisition system interfaces with the insole, wirelessly transmits the acquired data to remote receiver through Bluetooth path. Three configuration modes are incorporated to gain connection with desktop, laptop, or smart phone, which can be configured to comfortably work in research laboratories, clinics, sport ground, and other outdoor environments. A real-time display and analysis software is presented to calculate parameters such as mean pressure, peak pressure, center of pressure (COP), and shift speed of COP. Experimental results show that this system has stable performance in both static and dynamic measurements.

  20. FEM modelling of shoes insoles components for standing and walking simulation

    Directory of Open Access Journals (Sweden)

    Braun Barbu

    2017-01-01

    Full Text Available The paper presents a research stage in which a new method applied for foot insoles components rapid prototyping was successfully tested in case of two young persons with small orthopaedic diseases. The research in this stage is focused on the FEA model analysis before and after prototyping, the model consisting in two sets of specific items to be inserted into the plantar supporters, with orthopaedic correction role. The simulation and testing was performed in condition of wearing shoes containing such of plantar supporters, when standing and walking, these situations being the most common. The main studied problem was to verify if the CAD modelled orthotic items to be prototyped should resist in case of static and dynamic loads, similar to those found in case of standing and walking. It was demonstrated a good correlation in terms of testing results before and after items prototyping, especially for the second person. Besides, it was demonstrated that the FEA analysis applied method could be successfully used to verify the prototyped orthotic items endurance and resistance.

  1. 节能耐磨型电梯导靴靴衬应用研究%Applied Research of Energy-saving and Wearable Sliding Guide Shoes of Elevator

    Institute of Scientific and Technical Information of China (English)

    罗丹; 杨勇; 曹智超; 肖化明

    2014-01-01

    Many sliding guide shoes of elevator are easy to wear. It leads to the elevator running unstable and jitter the common shoes friction coefifcient is too large, causing large friction and energy consumption in the process of running elevator. Therefore, it is of great practical signiifcance and application value to study the friction behavior and use the new composite material in the sliding guide shoes to reduce friction as to reduce energy consumption, improve wear resistance, extend service life and cut costs.%很多电梯使用的导靴靴衬存在容易磨损的问题,从而导致电梯运行中的抖动和不平稳现象,影响乘坐的舒适性。常用的靴衬材料摩擦系数偏大,造成电梯运行过程中摩擦力偏大,能耗增加。因此对这类电梯的导轨与导靴间的摩擦行为进行研究,将新型复合材料应用于电梯靴衬,实现减摩以降低能耗,提升靴衬的耐磨性,延长使用寿命,降低成本,具有较大的实际意义和应用价值。

  2. The Player Engagement Process

    DEFF Research Database (Denmark)

    Schoenau-Fog, Henrik

    2011-01-01

    Engagement is an essential element of the player experience, and the concept is described in various ways in the literature. To gain a more detailed comprehension of this multifaceted concept, and in order to better understand what aspects can be used to evaluate engaging game play and to design...... engaging user experiences, this study investigates one dimension of player engagement by empirically identifying the components associated with the desire to continue playing. Based on a description of the characteristics of player engagement, a series of surveys were developed to discover the components......, categories and triggers involved in this process. By applying grounded theory to the analysis of the responses, a process-oriented player engagement framework was developed and four main components consisting of objectives, activities, accomplishments and affects as well as the corresponding categories...

  3. Factors Affecting Ankle Support Device Usage in Young Basketball Players

    Directory of Open Access Journals (Sweden)

    Michael D. Cusimano

    2013-05-01

    Full Text Available This cross-sectional study explores factors affecting the decision of basketball players to wear ankle support devices (ASDs. A questionnaire regarding attitudes towards ASD usage was developed based on the Health Belief Model (HBM. The questionnaire assessed HBM perceptions (susceptibility, severity, benefits, and barriers and modifying factors (demographic, personal history of ankle injury, influence of coach to preventive action that may affect an athlete’s decision to wear ASDs. One hundred forty basketball players competing at the recreational, high school, or university levels completed the questionnaire, with the questionnaires being completed at the basketball gymnasium or at home. It was found that athletes whose coaches enforced ASD use were significantly more likely to wear them (OR: 35.71; 95% CI: 10.01, 127.36, as were athletes who perceived ankle injuries to be severe (OR: 2.77; 95% CI: 1.04, 7.37. Previous injury did not significantly increase the odds of using an ASD. The combined influence of coach enforcement and previous injury had the greatest effect on increasing ASD use. The largest barrier to ASD use was a lack of aesthetic appeal. Strategies aimed at increasing players’ willingness to wear ankle protection should be emphasized among coaches and parents as this may increase use of ASDs.

  4. Wear Resistance and Wear Mechanism of a Hot Dip Aluminized Steel in Sliding Wear Test

    Science.gov (United States)

    Xue, Zhiyong; Hao, Xiaoyang; Huang, Yao; Gu, Lingyun; Ren, Yu; Zheng, Ruipeng

    2016-12-01

    Sliding wear experiments were conducted on a hot dip aluminized steel to investigate its wear resistance and wear mechanism. The wear tests were also carried out on a hot dip galvanized steel and the base material (steel Q345) as a comparison. Results show that the wear resistance and hardness of the hot dip aluminized steel are significantly higher than that of the hot dip galvanized steel and the steel Q345 at room temperature. The better wear resistance of the hot dip aluminized steel attributes mainly to the formation of a transition layer containing abundant Fe-Al intermetallic compounds and the transformation of wear-resisting oxides during the friction process. The main phase in the transition layer is Fe2Al5. The thickness of the transition layer is about 90-120 μm. When the wear load increases from 3 N to 19 N, the wear type of the aluminized layer transform from adhesive wear (3 N) into abrasive wear (7 N) and finally into slight wear mixed with oxidation (higher than 11 N).

  5. TIRE WEAR MODELING

    Directory of Open Access Journals (Sweden)

    Rosen IVANOV

    2016-09-01

    Full Text Available On the basis of a known relationship, an enhanced model for specific tire wear per kilometer has been developed. It is appropriate for practical use - for evaluation of the influence of different factors. Two types of experiments have been carried out with a testing device - one without sideslip, but with a known longitudinal slip, and the other one with the same longitudinal slip but also with a known sideslip. As a result, the coefficients of the proportion of the developed model have been evaluated. After the model validation, an analytical investigation concerning the influence of tire pressure, sideslip and longitudinal slip on the tire wear has been carried out. The results are presented graphically.

  6. Engine oil wear resistance

    Directory of Open Access Journals (Sweden)

    A.N. Farhanah

    2015-03-01

    Full Text Available Lubricants play a vital role in an internal combustion engine to lubricate parts and help to protect and prolong the engine life. Lubricant also will help to reduce wear by creating lubricating film between the moving parts hence reduce metal-to-metal contacts. Engine oil from three different manufacturers with the same SAE viscosity grade available in market does not mean it will have the same lubricity for an engine. In this study, commercial mineral lubrication oil (SAE 10W-30 from three manufacturers was investigated to compare the lubrication performance at three different temperatures (40˚C, 70˚C and 100˚C in 60 minutes time duration by using four ball wear tester. The speed will be varied from 1000 rpm to 2500 rpm. Results show that all three lubricants have different lubricity performance; the smaller the wear scar, the better the lubricant since the lubricant can protect the moving surfaces from direct metal-to-metal contact occur.

  7. Human Behavior Recognition Using Foot Pressure Sensing Shoes

    Science.gov (United States)

    Sugimoto, Chika; Ozaki, Kenji; Ezoe, Ryosuke; Hosaka, Hiroshi; Yamato, Hiroyuki

    To recognize human behavior in unlimited environments, sensing shoes for measuring foot pressure distribution were developed. Seven pressure sensors were installed on an insole, and a measurement module was embedded in the shoe. An analysis for discriminating the user's movements from the foot pressure distribution was examined, considering the movements, walking, running, standing, sitting, going upstairs and downstairs, and cycling. These seven actions were discriminated using feature quantities such as the average, standard deviation, maximum, and difference deviation extracted from the data of three sensors by discriminant analysis. The evaluation results showed highly accurate behavior recognition based on foot pressure at some points. In addition, by canonical discriminant analysis, six discriminant functions which classify the seven actions with an accuracy of 100% were derived by using feature quantities extracted from five sensors. The results confirmed that discriminant analysis can be used for automatically recognizing human behaviors based on foot pressure data.

  8. Characterization of ground SBR scraps from shoe industry

    OpenAIRE

    Marinês Massarotto; Janaina da Silva Crespo; Ademir José Zattera; Mara Zeni

    2008-01-01

    Expanded poly(butadiene-co-styrene) (SBR), a residue of the shoe industry of Rio Grande do Sul, is a crosslinked material. For further utilization in recycling and reclaiming processes this residue was ground under ambient conditions. The obtained powder (SBR-r) was physically, thermally and chemically characterized and the results were analyzed as for its suitability for reuse methods. This characterization provides a better understanding of the SBR residue components, which may lead to econ...

  9. Pure mechanical wear loss measurement in corrosive wear

    Indian Academy of Sciences (India)

    Yanliang Huang; Xiaoxia Jiang; Sizuo Li

    2000-12-01

    The method for the measurement of the pure mechanical wear loss for 321 stainless steel, 1045 steel and pure iron in the study of the synergy between corrosion and wear was studied. The methods studied included the measurement in distilled water, by cathodic protection and by adding inhibitor KI, and all were compared with the wear loss in air. The experiment showed that the pure mechanical wear losses and friction coefficients obtained by the three methods were close to each other and can be used to calculate the various wear components in the study of the interaction of corrosion and wear, but the measurements in distilled water for pure iron and 1045 steel are not recommended due to their corrosion.

  10. The effect of shoe design and lateral wedging on knee loading

    DEFF Research Database (Denmark)

    Mølgaard, Carsten; Kersting, Uwe G.

    The increasing number of patients with developing osteoarthritis is accompanied by a growing scientific interest in non-operative early treatment strategies. It is generally believed that laterally wedged insoles can change the distribution of the knee loading, but the importance of footwear design......-dimensional gait analysis. Barefoot walking, walking in a running shoe, an Oxford-type leather shoe, and a rocker shoe were analyzed. The shoes were tested both with and without a 10-degree full length laterally wedged insole. Results: Similar, significant reductions in the peak knee adduction moment with lateral...... wedges were observed in all three types of shoes. However, differences between shoe design were of similar magnitude as the effect of laterally wedged insoles. Only marginal changes in muscle activity for lateral hamstrings during barefoot toe-out walking and gastrocnemius when using the Oxford wedged...

  11. Medial collateral ligament knee sprains in college football. Brace wear preferences and injury risk.

    Science.gov (United States)

    Albright, J P; Powell, J W; Smith, W; Martindale, A; Crowley, E; Monroe, J; Miller, R; Connolly, J; Hill, B A; Miller, D

    1994-01-01

    In this prospective, multiinstitutional analysis of medial collateral ligament sprains in college football players, we categorized 987 previously uninjured study subjects according to frequency of wearing preventive knee braces, studied the patterns by which 47 of 100 injuries occurred to unbraced knees, and identified several extrinsic, sport-specific risk factors shared for both braced and unbraced knees. The attendance, brace wear choice, position, string, and session of each participant were recorded daily; medial collateral ligament sprains were reported whenever tissue damage was confirmed. Both the likelihood of wearing braces and risk of injury without them was highly dependent on session (games/practices), position group (line, linebacker/tight end, skill), and string group (players/nonplayers). Subjects wearing braces often faced a high injury risk to their unbraced knees, a finding compatible with the opinion that braces were a necessary evil, best worn when concern over danger of injury outweighed desire for speed and agility. It is concluded that to avoid misinterpretations due to the confounding influence of brace wear selection bias, accurate investigation of daily brace wear patterns is required. Then, before considing the impact of preventive knee braces, a repartitioning of the data base is essential to assure that only similar groups will be compared.

  12. Are old running shoes detrimental to your feet? A pedobarographic study

    OpenAIRE

    Makwana Nilesh; Rethnam Ulfin

    2011-01-01

    Abstract Background Footwear characteristics have been implicated in fatigue and foot pain. The recommended time for changing running shoes is every 500 miles. The aim of our study was to assess and compare plantar peak pressures and pressure time integrals in new and old running shoes. Findings This was a prospective study involving 11 healthy female volunteers with no previous foot and ankle problems. New running shoes were provided to the participants. Plantar pressures were measured using...

  13. These Shoes Are Made for Walking: Sensitivity Performance Evaluation of Commercial Activity Monitors under the Expected Conditions and Circumstances Required to Achieve the International Daily Step Goal of 10,000 Steps.

    Directory of Open Access Journals (Sweden)

    Sandra O'Connell

    Full Text Available Physical activity is a vitally important part of a healthy lifestyle, and is of major benefit to both physical and mental health. A daily step count of 10,000 steps is recommended globally to achieve an appropriate level of physical activity. Accurate quantification of physical activity during conditions reflecting those needed to achieve the recommended daily step count of 10,000 steps is essential. As such, we aimed to assess four commercial activity monitors for their sensitivity/accuracy in a prescribed walking route that reflects a range of surfaces that would typically be used to achieve the recommended daily step count, in two types of footwear expected to be used throughout the day when aiming to achieve the recommended daily step count, and in a timeframe required to do so.Four commercial activity monitors were worn simultaneously by participants (n = 15 during a prescribed walking route reflective of surfaces typically encountered while achieving the daily recommended 10,000 steps. Activity monitors tested were the Garmin Vivofit ™, New Lifestyles' NL-2000 ™ pedometer, Withings Smart Activity Monitor Tracker (Pulse O2 ™, and Fitbit One ™.All activity monitors tested were accurate in their step detection over the variety of different surfaces tested (natural lawn grass, gravel, ceramic tile, tarmacadam/asphalt, linoleum, when wearing both running shoes and hard-soled dress shoes.All activity monitors tested were accurate in their step detection sensitivity and are valid monitors for physical activity quantification over the variety of different surfaces tested, when wearing both running shoes and hard-soled dress shoes, and over a timeframe necessary for accumulating the recommended daily step count of 10,000 steps. However, it is important to consider the accuracy of activity monitors, particularly when physical activity in the form of stepping activities is prescribed as an intervention in the treatment or prevention of a

  14. Friction and wear calculation methods

    CERN Document Server

    Kragelsky, I V; Kombalov, V S

    1981-01-01

    Friction and Wear: Calculation Methods provides an introduction to the main theories of a new branch of mechanics known as """"contact interaction of solids in relative motion."""" This branch is closely bound up with other sciences, especially physics and chemistry. The book analyzes the nature of friction and wear, and some theoretical relationships that link the characteristics of the processes and the properties of the contacting bodies essential for practical application of the theories in calculating friction forces and wear values. The effect of the environment on friction and wear is a

  15. Wear of polymers and composites

    CERN Document Server

    Abdelbary, Ahmed

    2015-01-01

    In the field of tribology, the wear behaviour of polymers and composite materials is considered a highly non-linear phenomenon. Wear of Polymers and Composites introduces fundamentals of polymers and composites tribology. The book suggests a new approach to explore the effect of applied load and surface defects on the fatigue wear behaviour of polymers, using a new tribometer and thorough experiments. It discusses effects of surface cracks, under different static and cyclic loading parameters on wear, and presents an intelligent algorithm, in the form of a neural network, to map the relations

  16. Protective equipment and player characteristics associated with the incidence of sport-related concussion in high school football players: a multifactorial prospective study.

    Science.gov (United States)

    McGuine, Timothy A; Hetzel, Scott; McCrea, Michael; Brooks, M Alison

    2014-10-01

    The incidence of sport-related concussion (SRC) in high school football is well documented. However, limited prospective data are available regarding how player characteristics and protective equipment affect the incidence of SRC. To determine whether the type of protective equipment (helmet and mouth guard) and player characteristics affect the incidence of SRC in high school football players. Cohort study; Level of evidence, 2. Certified athletic trainers (ATs) at each high school recorded the type of helmet worn (brand, model, purchase year, and recondition status) by each player as well as information regarding players' demographics, type of mouth guard used, and history of SRC. The ATs also recorded the incidence and days lost from participation for each SRC. Incidence of SRC was compared for various helmets, type of mouth guard, history of SRC, and player demographics. A total of 2081 players (grades 9-12) enrolled during the 2012 and/or 2013 football seasons (2287 player-seasons) and participated in 134,437 football (practice or competition) exposures. Of these players, 206 (9%) sustained a total of 211 SRCs (1.56/1000 exposures). There was no difference in the incidence of SRC (number of helmets, % SRC [95% CI]) for players wearing Riddell (1171, 9.1% [7.6%-11.0%]), Schutt (680, 8.7% [6.7%-11.1%]), or Xenith (436, 9.2% [6.7%-12.4%]) helmets. Helmet age and recondition status did not affect the incidence of SRC. The rate of SRC (hazard ratio [HR]) was higher in players who wore a custom mouth guard (HR = 1.69 [95% CI, 1.20-2.37], P football players. Players who had sustained an SRC within the previous 12 months were more likely to sustain an SRC than were players without a history of SRC. Sports medicine providers who work with high school football players need to realize that factors other than the type of protective equipment worn affect the risk of SRC in high school players. © 2014 The Author(s).

  17. Influence of high-heeled shoes on the sagittal balance of the spine and the whole body.

    Science.gov (United States)

    Weitkunat, Tim; Buck, Florian M; Jentzsch, Thorsten; Simmen, Hans-Peter; Werner, Clément M L; Osterhoff, Georg

    2016-11-01

    Wearing high heels is associated with chronic pain of the neck, lower back and knees. The mechanisms behind this have not been fully understood. The purpose of this study was to investigate the influence of high-heeled shoes on the sagittal balance of the spine and the whole body in non-habitual wearers of high heels. Lateral standing whole body low-dose radiographs were obtained from 23 female participants (age 29 ± 6 years) with and without high heels and radiological parameters describing the sagittal balance were quantified. These were analyzed for differences between both conditions in the total sample and in subgroups. Standing in high heels was associated with an increased femoral obliquity angle [difference (Δ) 3.0° ± 1.7°, p < 0.0001], and increased knee (Δ 2.4° ± 2.9°, p = 0.0009) and ankle flexion (Δ 38.7° ± 3.4°, p < 0.0001). The differences in C7 and meatus vertical axis, cervical and lumbar lordosis, thoracic kyphosis, spino-sacral angle, pelvic tilt, sacral slope, and spinal tilt were not significant. Individuals adapting with less-than-average knee flexion responded to high heels by an additional increase in cervical lordosis (Δ 5.8° ± 10.7° vs. 1.8° ± 5.3°). In all participants, wearing high heels led to increased flexion of the knees and to more ankle flexion. While some participants responded to high heels primarily through the lower extremities, others used increased cervical lordosis to adapt to the shift of the body's center of gravity. This could explain the different patterns of pain in the neck, lower back and knees seen in individuals wearing high heels frequently.

  18. A survey on the relationship between wedge heel of nurse shoes and hallux valgus%坡跟护士鞋与足拇外翻的相关性研究

    Institute of Scientific and Technical Information of China (English)

    胡婷

    2013-01-01

    Objective To investigate the relationship between the heel design of nurse shoes and the incidences of hallux valgus. The findings of this study will help clinical nurses to choose right shoes to keep the occupational safety. Methods To investigate 87 clinical nurses in different department through answering the questionnaire designed by the investigator. Results 63.2% clinical nurses felt squeezing wearing wedge heel of nurse shoes, 69% clinical nurses showed that wedge heel of nurse shoes could contribute the pain of the hallux joint. The working position and the extent of squeezing of shoes have positive relationship with the pain of po-darthrum (P<0.05), and the wedge heel has positive relationship with hallux valgus(P<0.01).Conclusion The result of the study demonstrated that the wedge heel of nurse shoes will cause hallux valgus. Therefore, wedge heel of the nurse shoes should not be de-signed for reducing the occurence of hallux valgus in clinical nurses.%目的研究护士鞋跟设计与诱发拇外翻的相关性,为临床护士选择合适的工作鞋从而改善护士职业安全提供依据。方法采用自行设计的调查问卷,对87例各科临床护士进行护士鞋跟设计对足部影响的调查。结果63.2%的护士认为坡跟护士鞋的鞋尖处感觉狭窄,认为工作时穿着坡跟护士鞋会感足趾关节疼痛的护士占69%,护士的工作状态、护士鞋对足趾挤压程度与坡跟鞋引起的足趾关节疼痛呈正相关(P<0.05),且坡跟鞋引起的足趾关节疼痛又与拇外翻发生呈正相关(P<0.01)。结论护士鞋坡跟设计增加了拇外翻病变的发生几率,针对护士群体,及护士特殊工作状态,应减少采取护士鞋坡跟设计,以改善临床护士的职业健康状况。

  19. The effect of shoe design and lateral wedges on knee load and neuromuscular control in healthy subjects during walking

    DEFF Research Database (Denmark)

    Mølgaard, Carsten Møller; Kersting, Uwe G.

    2013-01-01

    design/type on the effectiveness of lateral wedging has not been investigated so far. The Purpose of the present study was to explore alterations in knee loading due to lateral foot wedges in three different shoes. Methods: Thirteen healthy participants with no history of knee pain were tested using...... three-dimensional gait analysis. Barefoot walking, walking in a running shoe, an Oxford-type leather shoe, and a rocker shoe were analysed. The shoes were tested both with and without a 10-degree full-length laterally wedged insole. Results: There were significant shoe wedge interactions on the first...... and second peak knee adduction moments. However, the variability of this moment between shoe designs was of similar magnitude as the effect of laterally wedged insoles. Only marginal changes in muscle activity for gastrocnemius when walking with the wedged Oxford shoe were revealed. Conclusion: Lateral...

  20. Wear of micro end mills

    DEFF Research Database (Denmark)

    Bissacco, Giuliano; Hansen, Hans Nørgaard; De Chiffre, Leonardo

    2005-01-01

    This paper addresses the important issue of wear on micro end mills considering relevant metrological tools for its characterization and quantification. Investigation of wear on micro end mills is particularly difficult and no data are available in the literature. Small worn volumes cause large d...

  1. Factors influencing visor use among players in the National Hockey League (NHL

    Directory of Open Access Journals (Sweden)

    Micieli R

    2014-04-01

    Full Text Available Robert Micieli,1 Jonathan A Micieli21Faculty of Science and Engineering, York University, 2Department of Ophthalmology and Vision Science, University of Toronto, Toronto, ON, CanadaAbstract: Eye, orbital, and facial injuries are significant risks to National Hockey League (NHL players, and can be mitigated by the use of a partial visor – currently optional for all non-rookie players. The goal of the current study was to determine the overall use of visors among non-rookie NHL players in the 2013–2014 season and assess factors influencing their uptake. This was an observational, cross-sectional study using active NHL rosters and demographic information obtained from the official NHL website. Visor use was determined based on in-game video or images at two different time points in the 2013–2014 season. The use of visors during the 2013–2014 season was 75.2% among non-rookie players. When rookies were included, the overall use of visors was 77.8%. Compared to Canadian-born players, European players were significantly more likely to choose to wear a visor (odds ratio [OR] 3.48, 95% confidence interval [CI] 1.96–6.17. Players in the younger age-groups, particularly those younger than 24 years (OR 5.67, 95% CI 2.52–5.76 and those between 24 and 28 years (OR 2.18, 95% CI 1.23–3.87, were more likely to wear a visor compared to older players. Overall, visor use continues to grow in the NHL independently of new legislation, and is more likely in younger players and those of European origin.Keywords: ice hockey, facial protection, professional sports, eye injuries, safety

  2. [Infants wearing teething necklaces].

    Science.gov (United States)

    Taillefer, A; Casasoprana, A; Cascarigny, F; Claudet, I

    2012-10-01

    Numerous infants wear teething necklaces, a quack remedy with a real risk of strangulation or aspiration of small beads. Evaluate parental perceptions and beliefs about the use of teething necklaces and analyze parental knowledge about the associated dangers. Between March and July 2011, in three different pediatric units of a tertiary children's hospital and a general hospital in Toulouse and Montauban (southwest France), voluntary parents were invited to be interviewed about their child wearing a teething necklace. The interviews were conducted following an anthropological approach: they were recorded and then fully transcribed and analyzed. Parents were informed that the conversation was recorded. During the study period, 48 children were eligible. Eleven families refused to participate, 29 parents were interviewed face to face. The children's mean age was 14 years ± 7 months, the male:female ratio was equal to 0.8 (12 boys, 15 girls). The mean age of children when necklace wearing was started was equal to 4 ± 2 months. The mean mother's age was 31 ± 5 years and 33 ± 4 years for fathers. The parents' religion was mostly Catholic (60%). Teething necklaces were mainly made of amber (n=23). Sales information about the risks associated with the necklaces was for the most part absent (92%). The most frequent positive parental perceptions were analgesic properties and a soothing remedy (73%); a birth accessory and memory (64%); an esthetic accessory (60%); a protective amulet (60%); and an alternative or additional element to other traditional therapeutics (55%). The negative parental perceptions (n=4) were an unnecessary accessory, costume jewelry, a pure commercial abuse of a popular belief, a dangerous item with a risk of strangulation, and the absence of proof of its efficacy. Although parents concede that teeth eruption is benign, they fear its related symptoms. To a natural phenomenon a natural response: they use a necklace to satisfy the analogy. The

  3. Running with a minimalist shoe increases plantar pressure in the forefoot region of healthy female runners

    NARCIS (Netherlands)

    Bergstra, S. A.; Kluitenberg, B.; Dekker, R.; Bredeweg, S. W.; Postema, K.; Van den Heuvel, E. R.; Hijmans, J. M.; Sobhani, S.

    2015-01-01

    OBJECTIVES: Minimalist running shoes have been proposed as an alternative to barefoot running. However, several studies have reported cases of forefoot stress fractures after switching from standard to minimalist shoes. Therefore, the aim of the current study was to investigate the differences in pl

  4. GROUND REACTION FORCE DIFFERENCES BETWEEN RUNNING SHOES, RACING FLATS, AND DISTANCE SPIKES IN RUNNERS

    Directory of Open Access Journals (Sweden)

    Suzanna Logan

    2010-03-01

    Full Text Available Various shoes are worn by distance runners throughout a training season. This study measured the differences in ground reaction forces between running shoes, racing flats, and distance spikes in order to provide information about the potential effects of footwear on injury risk in highly competitive runners. Ten male and ten female intercollegiate distance runners ran across a force plate at 6.7 m·s-1 (for males and 5.7 m·s-1 (for females in each of the three types of shoes. To control for differences in foot strike, only subjects who exhibited a heel strike were included in the data analysis. Two repeated-measures ANOVAs with Tukey's post-hoc tests (p < 0.05 were used to detect differences in shoe types among males and females. For the males, loading rate, peak vertical impact force and peak braking forces were significantly greater in flats and spikes compared to running shoes. Vertical stiffness in spikes was also significantly greater than in running shoes. Females had significantly shorter stance times and greater maximum propulsion forces in racing flats compared to running shoes. Changing footwear between the shoes used in this study alters the loads placed on the body. Care should be taken as athletes enter different phases of training where different footwear is required. Injury risk may be increased since the body may not be accustomed to the differences in force, stance time, and vertical stiffness

  5. The use of the wooden shoe (Steward Clog) in treating laminitis.

    Science.gov (United States)

    Steward, Micheal L

    2010-04-01

    This article describes the use of the wooden shoe in the treatment of chronic laminitis. The shoe, designed to provide a solid base and full roller motion, offers mechanical advantages and enables reduction and redistribution of forces within the hoof capsule.

  6. Patients' expectations and actual use of custom-made orthopaedic shoes

    NARCIS (Netherlands)

    van Netten, Jaap J.; Jannink, Michiel J. A.; Hijmans, Juha M.; Geertzen, Jan H. B.; Postema, Klaas

    2010-01-01

    Objective: To investigate the association between patients' expectations and the actual use of custom-made orthopaedic shoes. Design: A prospective cohort study with internal comparison. Setting: Twelve orthopaedic shoe companies. Patients: During six months, consecutive patients who were provided w

  7. Occupational skin hazards and prevalence of occupational skin diseases in shoe manufacturing workers in Indonesia

    NARCIS (Netherlands)

    Febriana, Sri Awalia; Soebono, Hardyanto; Coenraads, Pieter-Jan

    Purpose Shoe manufacturing workers are exposed daily to an extensive range of potential physical and chemical occupational hazards. Shoe manufacturing in Indonesia is one of the industrial sectors that has shown sustained growth amongst the newly industrialized countries (NICs). In this study, we

  8. Analysis of Reference and Influence of Shoes Culture in the East and the West

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Abook once noted that: Shoes is the art that combines Lcommodity, spirit and materiallife. It not merely reflects aesthetic consciousness decided by world view and sense of worth, but also the time essence and the emotion expression of designer. After attentive contemplation, it should admit that the author holds deep understanding towards the culture of shoes.

  9. Switch wear leveling

    Science.gov (United States)

    Wu, Hunter; Sealy, Kylee; Gilchrist, Aaron

    2015-09-01

    An apparatus for switch wear leveling includes a switching module that controls switching for two or more pairs of switches in a switching power converter. The switching module controls switches based on a duty cycle control technique and closes and opens each switch in a switching sequence. The pairs of switches connect to a positive and negative terminal of a DC voltage source. For a first switching sequence a first switch of a pair of switches has a higher switching power loss than a second switch of the pair of switches. The apparatus includes a switch rotation module that changes the switching sequence of the two or more pairs of switches from the first switching sequence to a second switching sequence. The second switch of a pair of switches has a higher switching power loss than the first switch of the pair of switches during the second switching sequence.

  10. Low friction wear resistant graphene films

    Science.gov (United States)

    Sumant, Anirudha V.; Berman, Diana; Erdemir, Ali

    2017-02-07

    A low friction wear surface with a coefficient of friction in the superlubric regime including graphene and nanoparticles on the wear surface is provided, and methods of producing the low friction wear surface are also provided. A long lifetime wear resistant surface including graphene exposed to hydrogen is provided, including methods of increasing the lifetime of graphene containing wear surfaces by providing hydrogen to the wear surface.

  11. TPR鞋用材料%TPR shoe materials

    Institute of Scientific and Technical Information of China (English)

    郑玉婴

    2001-01-01

    The paper reports the composition, processing techniques, property and application performance, low temperature resistance and high strength of TPR materials. The materials can be used for different types of shoes.%分析了TPR鞋用材料的配方、工艺、性能.实验结果表明,该材料具有高弹性、耐低温、粘结强度牢等特点,适用于生产中高档运动鞋和旅游鞋鞋底.

  12. Tactile shoe inlays for high speed pressure monitoring

    DEFF Research Database (Denmark)

    Drimus, Alin; Mátéfi-Tempfli, Stefan

    2015-01-01

    pressure sensitive cells and the use of high speed electronics and multiplexing algorithms provides frame rates of 100 Hz. The sensors tolerate overloads while showing a consistent output. The developed prototypes show a high potential not only for robotics, but also for use in sensorised human prosthetics.......This work describes the development of flexible tactile sensor shoe inlays for humanoid robots. Their design is based on a sandwich structure of flexible layers with a thin sheet of piezoresistive rubber as main transducer element. The layout and patterning of top and bottom electrodes give 1024...

  13. Nasal cancer in the Northamptonshire boot and shoe industry.

    Science.gov (United States)

    Acheson, E D; Cowdell, R H; Jolles, B

    1970-02-14

    A survey of the incidence of nasal cancer in Northamptonshire during the period 1953 to 1967 is reported. Of the 46 patients with nasal cancer ascertained during the 15-year period 21 (19 males and 2 females) had been employed at some time in the boot and shoe industry. Five other cases diagnosed either before 1953 or after 1967 in persons who had worked in the boot and shoe industry in Northamptonshire were ascertained from various sources.The incidence of nasal cancer (all histological types considered together) was significantly higher in male boot and shoe operatives in Northamptonshire than in males of all occupational classes in the Cancer Register areas selected for comparison and in males working in other occupations in Northamptonshire. The excess incidence has recently given rise to the occurrence of between 1 and 2 new cases per annum in the Northamptonshire boot and shoe industry.The cases within the Northamptonshire industry occurred almost entirely in the relatively small number of workers who are exposed to the dust of the materials used in the manufacture of footwear.Possibly there are two carcinogenic factors in the industry-one related to the production of nasal adenocarcinoma, and the other to squamous and possibly other types of carcinoma in the nasal cavity and sinuses. This requires further study. Our best estimate of the latent period for the adenocarcinoma cases was 54.6 years, which is substantially longer than for the patients with squamous, transitional, and anaplastic tumours (41.7 years). We have no evidence to answer the question whether the facts are still present in the industrial environment, though undoubtedly the standards of hygiene in the industry has improved substantially since these men were first exposed.There is probably an increased risk of nasal adenocarcinoma in the footwear repairing industry, but this requires further study. Our evidence suggests that snuff taking should be considered as a possible contributory factor

  14. Investigation of Friction Behaviors of Brake Shoe Materials using Metallic Filler

    Directory of Open Access Journals (Sweden)

    E. Surojo

    2015-12-01

    Full Text Available Some vehicles use brake shoe made from semi-metallic materials. Semi-metallic brake shoes are made from a combination of metallic and non-metallic materials. Metallic particles are added in the formulation of brake shoe material to improve composites characteristics. In this paper, friction behaviors of brake shoe material using metallic filler were investigated. Machining chips of cast iron and copper wire of electric motor used were incorporated in composite as metallic fillers with amount 0, 2, and 4 vol. %. Friction testing was performed to measure coefficient of friction by pressing surface specimen against the surface of rotating disc. The results show that cast iron chip and Cu short wire have effect on increasing coefficient of friction of brake shoe material. They form contact plateau at contact surface. At contact surface, the Cu short wires which have parallel orientation to the sliding contact were susceptible to detach from the matrix.

  15. Orthosis-Shaped Sandals Are as Efficacious as In-Shoe Orthoses and Better than Flat Sandals for Plantar Heel Pain: A Randomized Control Trial.

    Directory of Open Access Journals (Sweden)

    Bill Vicenzino

    Full Text Available To investigate efficacy of a contoured sandal being marketed for plantar heel pain with comparison to a flat flip-flop and contoured in-shoe insert/orthosis.150 volunteers aged 50 (SD: 12 years with plantar heel pain (>4 weeks were enrolled after responding to advertisements and eligibility determined by telephone and at first visit. Participants were randomly allocated to receive commercially available contoured sandals (n = 49, flat flip-flops (n = 50 or over the counter, pre-fabricated full-length foot orthotics (n = 51. Primary outcomes were a 15-point Global Rating of Change scale (GROC: 1 = a very great deal worse, 15 = a very great deal better, 13 to 15 representing an improvement and the 20-item Lower Extremity Function Scale (LEFS on which participants rate 20 common weight bearing activities and activities of daily living on a 5-point scale (0 = extreme difficulty, 4 = no difficulty. Secondary outcomes were worst level of heel pain in the preceding week, and the foot and ankle ability measure. Outcomes were collected blind to allocation. Analyses were done on an intention to treat basis with 12 weeks being the primary outcome time of interest.The contoured sandal was 68% more likely to report improvement in terms of GROC compared to flat flip-flop. On the LEFS the contoured sandal was 61% more likely than flat flip-flop to report improvement. The secondary outcomes in the main reflected the primary outcomes, and there were no differences between contoured sandal and shoe insert.Physicians can have confidence in supporting a patient's decision to wear contoured sandals or in-shoe orthoses as one of the first and simple strategies to manage their heel pain.The Australian New Zealand Clinical Trials Registry ACTRN12612000463875.

  16. Tool wear mechanism in turning of novel wear-resisting aluminum bronze

    Institute of Scientific and Technical Information of China (English)

    倪东惠; 夏伟; 张大童; 郭国文; 邵明

    2003-01-01

    Tool wear and wear mechanism during the turning of a wear-resisting aluminum bronze have been stud-ied. Tool wear samples were prepared by using M2 high-speed steel and YW1 cemented carbide tools to turn a novelhigh strength, wear resisting aluminum bronze without coolant and lubricant. Adhesion of workpiece materials wasfound on tool's surface. Under the turning condition used in this study major wear mechanisms for turning aluminumbronze using M2 high-speed steel tool are diffusion wear, adhesive wear and plastic deformation and shear on thecrater. Partial melting of high-speed steel on the rake plays a role in the tool wear also. Major wear mechanisms forturning aluminum bronze using YW1 cemented carbide tool are diffusion wear, attrition wear and sliding wear. Tocontrol the machining temperature is essential to reduce tool wear.

  17. A Shoe-Embedded Piezoelectric Energy Harvester for Wearable Sensors

    Directory of Open Access Journals (Sweden)

    Jingjing Zhao

    2014-07-01

    Full Text Available Harvesting mechanical energy from human motion is an attractive approach for obtaining clean and sustainable electric energy to power wearable sensors, which are widely used for health monitoring, activity recognition, gait analysis and so on. This paper studies a piezoelectric energy harvester for the parasitic mechanical energy in shoes originated from human motion. The harvester is based on a specially designed sandwich structure with a thin thickness, which makes it readily compatible with a shoe. Besides, consideration is given to both high performance and excellent durability. The harvester provides an average output power of 1 mW during a walk at a frequency of roughly 1 Hz. Furthermore, a direct current (DC power supply is built through integrating the harvester with a power management circuit. The DC power supply is tested by driving a simulated wireless transmitter, which can be activated once every 2–3 steps with an active period lasting 5 ms and a mean power of 50 mW. This work demonstrates the feasibility of applying piezoelectric energy harvesters to power wearable sensors.

  18. A shoe-embedded piezoelectric energy harvester for wearable sensors.

    Science.gov (United States)

    Zhao, Jingjing; You, Zheng

    2014-07-11

    Harvesting mechanical energy from human motion is an attractive approach for obtaining clean and sustainable electric energy to power wearable sensors, which are widely used for health monitoring, activity recognition, gait analysis and so on. This paper studies a piezoelectric energy harvester for the parasitic mechanical energy in shoes originated from human motion. The harvester is based on a specially designed sandwich structure with a thin thickness, which makes it readily compatible with a shoe. Besides, consideration is given to both high performance and excellent durability. The harvester provides an average output power of 1 mW during a walk at a frequency of roughly 1 Hz. Furthermore, a direct current (DC) power supply is built through integrating the harvester with a power management circuit. The DC power supply is tested by driving a simulated wireless transmitter, which can be activated once every 2-3 steps with an active period lasting 5 ms and a mean power of 50 mW. This work demonstrates the feasibility of applying piezoelectric energy harvesters to power wearable sensors.

  19. Ground reaction force differences between running shoes, racing flats, and distance spikes in runners.

    Science.gov (United States)

    Logan, Suzanna; Hunter, Ian; J Ty Hopkins, J T; Feland, J Brent; Parcell, Allen C

    2010-01-01

    Various shoes are worn by distance runners throughout a training season. This study measured the differences in ground reaction forces between running shoes, racing flats, and distance spikes in order to provide information about the potential effects of footwear on injury risk in highly competitive runners. Ten male and ten female intercollegiate distance runners ran across a force plate at 6.7 m·s(-1) (for males) and 5.7 m·s(-1) (for females) in each of the three types of shoes. To control for differences in foot strike, only subjects who exhibited a heel strike were included in the data analysis. Two repeated-measures ANOVAs with Tukey's post-hoc tests (p force and peak braking forces were significantly greater in flats and spikes compared to running shoes. Vertical stiffness in spikes was also significantly greater than in running shoes. Females had significantly shorter stance times and greater maximum propulsion forces in racing flats compared to running shoes. Changing footwear between the shoes used in this study alters the loads placed on the body. Care should be taken as athletes enter different phases of training where different footwear is required. Injury risk may be increased since the body may not be accustomed to the differences in force, stance time, and vertical stiffness. Key pointsTo determine the differences in ground reaction forces between regular running shoes and competitive footwear, force plate data was obtained from 10 males (6.7 m·s(-1)) and 10 females (5.7 m·s(-1)) for each of three shoe types.Data from men and women were analyzed in two separate groups, and significant differences were found for various GRF components between the three types of shoes.The significant increases in GRF components in competitive footwear suggest that the body must deal with greater impact forces in these shoes than in running shoes at the same running speed.The results from this study warrant the recommendation that runners transition gradually from

  20. The effect of neoprene shorts on leg proprioception in Australian football players.

    Science.gov (United States)

    Cameron, Matthew L; Adams, Roger D; Maher, Chris G

    2008-06-01

    Our purpose was to assess the effect of wearing close-fitting neoprene shorts on swinging leg movement discrimination (MD) scores in elite level Australian Football players. Twenty players had their swinging leg MD assessed using the active movement extent discrimination apparatus (AMEDA), once wearing close-fitting neoprene and once wearing loose-fitting running shorts. Subjects were randomly allocated to one of the shorts conditions prior to repeating the test in the other condition. The AMEDA was used to assess the accuracy at which subjects judge the extent of a standing backward swinging leg movement corresponding to the late swing early stance phase of running. Each subject performed 40 movements made to one of five randomly set physical limits, and without the aid of vision made a judgment as to the perceived limit position. From the accuracy of these judgments, a movement discrimination (MD) score was calculated for each subject under each condition. Subjects were grouped as having low or high neuromuscular control, or ability to use proprioception when controlling active movements without vision, based on their loose-shorts MD score. Analysis was performed on the MD scores obtained for each limb from subjects in the two groups, under the two shorts-wearing conditions. There was no main effect of wearing close-fitting shorts when the cohort was treated as a whole. A significant interaction effect was obtained (F=17.027, p=0.0006) whereby the mean MD score of the low neuromuscular control ability group was improved when wearing neoprene shorts but was reduced for the high ability group. Wearing close-fitting neoprene shorts has a beneficial effect on leg swing judgment accuracy in subjects with low neuromuscular control ability. Conversely, leg swing judgment accuracy for subjects with high ability was reduced by wearing neoprene shorts.

  1. They shall wear fringes.

    Science.gov (United States)

    Sugar, M

    1999-01-01

    The multiple functions of clothes include utility, protection, rivalry, disguise, camouflage, display for seduction purposes, aggression, totemism, and status. Here the focus is on a decorative and distinctive hierarchical aspect of ancient dress, the tsitsit or fringes, whose original function is long absent, but that has endured for 3,500 years in Judaism. The beginning of their use beyond the totemic appears related to issues of changing identity from slavery to liberty, endowing noble status, exhibitionism, a symbol of identity, identification with the aggressor, a talisman, and potency. It is conceptualized that they became a symbol, or a specifier, that helped promote group cohesion in ex-slaves who were frightened, dependent, anxious, and not hopeful about their future. The tsitsit aided the development of a new identity and made all Israelites equal and noble to the observer. The durability of this symbol to the present is evident in its daily wear, as an accompaniment to daily prayers, as well as in its use as a burial shroud for males. It appears that the tsitsit have additional multiple functions. These are the promise of oral and genital satisfaction, and the pleasure of the after-life, superego warnings and control of sexual impulses, protection, survival value, and affirmation. Since they offer sublimation with acceptable gratification of instincts, the tsitsit have become ritualized and endure.

  2. Intelligent Detection of Drill Wear

    Science.gov (United States)

    Liu, T. I.; Chen, W. Y.; Anatharaman, K. S.

    1998-11-01

    Backpropagation neural networks (BPNs) were used for on-line detection of drill wear. The neural network consisted of three layers: input, hidden, and output. The input vector comprised drill size, feed rate, spindle speed, and eight features obtained by processing the thrust and torque signals. The output was the drill wear state which either usable or failure. Drilling experiments with various drill sizes, feed rates and spindle speeds were carried out. The learning process was performed effectively by utilising backpropagation with smoothing and an activation function slope. The on-line detection of drill wear states using BPNs achieved 100% reliability even when the drill size, feed rate and spindle speed were changed. In other words, the developed on-line drill wear detection systems have very high robustness and hence can be used in very complex production environments, such as flexible manufacturing systems.

  3. Active Learning for Player Modeling

    DEFF Research Database (Denmark)

    Shaker, Noor; Abou-Zleikha, Mohamed; Shaker, Mohammad

    2015-01-01

    Learning models of player behavior has been the focus of several studies. This work is motivated by better understanding of player behavior, a knowledge that can ultimately be employed to provide player-adapted or personalized content. In this paper, we propose the use of active learning for player...... experience modeling. We use a dataset from hundreds of players playing Infinite Mario Bros. as a case study and we employ the random forest method to learn mod- els of player experience through the active learning approach. The results obtained suggest that only part of the dataset (up to half the size...... of the full dataset) is necessary for the construction of accu- rate models that are as accurate as those constructed from the full dataset. This indicates the potential of the method and its benefits in cases when obtaining the data is expensive or time, storage or effort consuming. The results also indicate...

  4. Active Learning for Player Modeling

    DEFF Research Database (Denmark)

    Shaker, Noor; Abou-Zleikha, Mohamed; Shaker, Mohammad

    2015-01-01

    Learning models of player behavior has been the focus of several studies. This work is motivated by better understanding of player behavior, a knowledge that can ultimately be employed to provide player-adapted or personalized content. In this paper, we propose the use of active learning for player...... experience modeling. We use a dataset from hundreds of players playing Infinite Mario Bros. as a case study and we employ the random forest method to learn mod- els of player experience through the active learning approach. The results obtained suggest that only part of the dataset (up to half the size...... of the full dataset) is necessary for the construction of accu- rate models that are as accurate as those constructed from the full dataset. This indicates the potential of the method and its benefits in cases when obtaining the data is expensive or time, storage or effort consuming. The results also indicate...

  5. Influence of different safety shoes on gait and plantar pressure: a standardized examination of workers in the automotive industry.

    Science.gov (United States)

    Ochsmann, Elke; Noll, Ulrike; Ellegast, Rolf; Hermanns, Ingo; Kraus, Thomas

    2016-09-30

    Working conditions, such as walking and standing on hard surfaces, can increase the development of musculoskeletal complaints. At the interface between flooring and musculoskeletal system, safety shoes may play an important role in the well-being of employees. The aim of this study was to evaluate the effects of different safety shoes on gait and plantar pressure distributions on industrial flooring. Twenty automotive workers were individually fitted out with three different pairs of safety shoes ( "normal" shoes, cushioned shoes, and midfoot bearing shoes). They walked at a given speed of 1.5 m/s. The CUELA measuring system and shoe insoles were used for gait analysis and plantar pressure measurements, respectively. Statistical analysis was conducted by ANOVA analysis for repeated measures. Walking with cushioned safety shoes or a midfoot bearing safety shoe led to a significant decrease of the average trunk inclination (pindustrial accident, but in addition, safety shoes could be a long-term preventive instrument for maintaining health of the employees' musculoskeletal system, as they are able to affect gait parameters. Further research needs to focus on safety shoes in working situations.

  6. Wear resistance properties of austempered ductile iron

    Science.gov (United States)

    Lerner, Y. S.; Kingsbury, G. R.

    1998-02-01

    A detailed review of wear resistance properties of austempered ductile iron (ADI) was undertaken to examine the potential applications of this material for wear parts, as an alternative to steels, alloyed and white irons, bronzes, and other competitive materials. Two modes of wear were studied: adhesive (frictional) dry sliding and abrasive wear. In the rotating dry sliding tests, wear behavior of the base material (a stationary block) was considered in relationship to countersurface (steel shaft) wear. In this wear mode, the wear rate of ADI was only one-fourth that of pearlitic ductile iron (DI) grade 100-70-03; the wear rates of aluminum bronze and leaded-tin bronze, respectively, were 3.7 and 3.3 times greater than that of ADI. Only quenched DI with a fully martensitic matrix slightly outperformed ADI. No significant difference was observed in the wear of steel shafts running against ADI and quenched DI. The excellent wear performance of ADI and its countersurface, combined with their relatively low friction coefficient, indicate potential for dry sliding wear applications. In the abrasive wear mode, the wear rate of ADI was comparable to that of alloyed hardened AISI 4340 steel, and approximately one-half that of hardened medium-carbon AISI 1050 steel and of white and alloyed cast irons. The excellent wear resistance of ADI may be attributed to the strain-affected transformation of high-carbon austenite to martensite that takes place in the surface layer during the wear tests.

  7. The Delamination Theory of Wear

    Science.gov (United States)

    1974-09-01

    junctions, it is still based on the assumption that the deformation occurs at the asperities. Rabinowicz [14] advanced an adhesion theory of friction...shown that bronze particles were indeed bigger than steel particles. The compilation of wear particle sizes given by Rabinowicz [14] also indicates...Waterhouse [32] has shown that, in fact, fretting occurs by delamination. 6) Minimum Load for Loose Particle Formation Rabinowicz [14] found that no wear

  8. Effects of insoles and additional shock absorption foam on the cushioning properties of sport shoes.

    Science.gov (United States)

    Chiu, Hung-Ta; Shiang, Tzyy-Yuang

    2007-05-01

    The purpose of this study was to investigate the effects of insoles and additional shock absorption foam on the cushioning properties of various sport shoes with an impact testing method. Three commercial sport shoes were used in this study, and shock absorption foam (TPE5020; Vers Tech Science Co. Ltd., Taiwan) with 2-mm thickness was placed below the insole in the heel region for each shoe. Eight total impacts with potential energy ranged from 1.82 to 6.08 J were performed onto the heel region of the shoe. The order of testing conditions was first without insole, then with insole, and finally interposing the shock absorption foam for each shoe. Peak deceleration of the striker was measured with an accelerometer attached to the striker during impact. The results of this study seemed to show that the insole or additional shock absorption foam could perform its shock absorption effect well for the shoes with limited midsole cushioning. Further, our findings showed that insoles absorbed more, even up to 24-32% of impact energy under low impact energy. It seemed to indicate that insoles play a more important role in cushioning properties of sport shoes under a low impact energy condition.

  9. Cross-Domain Shoe Retrieval with a Semantic Hierarchy of Attribute Classification Network.

    Science.gov (United States)

    Zhan, Huijing; Shi, Boxin; Kot, Alex C

    2017-08-04

    Cross-domain shoe image retrieval is a challenging problem, because the query photo from the street domain (daily life scenario) and the reference photo in the online domain (online shop images) have significant visual differences due to the viewpoint and scale variation, self-occlusion, and cluttered background. This paper proposes the Semantic Hierarchy Of attributE Convolutional Neural Network (SHOE-CNN) with a three-level feature representation for discriminative shoe feature expression and efficient retrieval. The SHOE-CNN with its newly designed loss function systematically merges semantic attributes of closer visual appearances to prevent shoe images with the obvious visual differences being confused with each other; the features extracted from image, region, and part levels effectively match the shoe images across different domains. We collect a large-scale shoe dataset composed of 14341 street domain and 12652 corresponding online domain images with fine-grained attributes to train our network and evaluate our system. The top-20 retrieval accuracy improves significantly over the solution with the pre-trained CNN features.

  10. The fractal characterization of wear particles in relation to the wear status

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The topography and distribution of wear particles produced in the wear process containmuch information about the wear status. Fractal geometry is applied in this paper to describe thewear particle accumulation in order to characterize the wear status change. The sliding wear test isperformed on a pin-on-disc apparatus using steel disc and brass pin. The investigation resultsshow that wear particle accumulation presents a strong bi-fractal behavior. Also, the fractal dimen-sion varies in correspondence to the wear status change. A new fractal index characterizing thewear particle accumulation is put forward. The wear tests of brass pin demonstrate that the fractalindex is effective in describing the wear status change.

  11. Wear behaviour of Al 261

    Directory of Open Access Journals (Sweden)

    N. Mathan Kumar

    2016-03-01

    Full Text Available Al 2618 matrix material was mixed with the Silicon Nitride (Si3N4, Aluminium Nitride (AlN and Zirconium Boride (ZrB2 reinforced particles. AMC was synthesized successfully by the stir casting method with the various X-wt.% of reinforcements (X = 0,2,4,6,8. Tribological behaviour was studied in this composite with various temperature conditions. The working conditions were Temperature (°C, Load (N, Velocity (m/s and Sliding Distances (m. Before wear testing the mechanical behaviour has been analysed. EDAX was confirmed by the matrix material composition. The Al 2618 alloy and the reinforcement mixers were confirmed by the X-ray Diffraction analysis. Wear rate (mm3/m, Wear resistance (m/mm3, Specific Wear rate (m/Nm and Co-efficient of friction (μ were analysed with various conditions. The worn surfaces were analysed before and after wear testing by Scanning Electron Microscope (SEM. Influence of process parameters and Percentage of contribution were analysed by Taguchi and Analysis of Variance (ANOVA methods. Genetic Algorithm (GA was adopted for optimizing the best and mean of the wear rate and to identify the exact influence of input parameters.

  12. Critical component wear in heavy duty engines

    CERN Document Server

    Lakshminarayanan, P A

    2011-01-01

    The critical parts of a heavy duty engine are theoretically designed for infinite life without mechanical fatigue failure. Yet the life of an engine is in reality determined by wear of the critical parts. Even if an engine is designed and built to have normal wear life, abnormal wear takes place either due to special working conditions or increased loading.  Understanding abnormal and normal wear enables the engineer to control the external conditions leading to premature wear, or to design the critical parts that have longer wear life and hence lower costs. The literature on wear phenomenon r

  13. Plantar pressure relief in the diabetic foot using forefoot offloading shoes.

    Science.gov (United States)

    Bus, Sicco A; van Deursen, Robert W M; Kanade, Rajani V; Wissink, Marieke; Manning, Erik A; van Baal, Jeff G; Harding, Keith G

    2009-06-01

    Forefoot offloading shoes (FOS) are commonly used in clinical practice for treatment of plantar forefoot ulcers in the diabetic foot. The aim of this study was to assess the offloading efficacy of four different FOS models in comparison with a cast shoe and control shoe. In-shoe plantar pressures were measured during walking in each of the six footwear conditions in 24 neuropathic diabetic patients at high risk for plantar foot ulceration. For each of six foot regions, peak pressure, pressure-time integral, and force-time integral were calculated. Load transfer diagrams were developed to assess the footwear mechanisms of action. Perceived walking comfort was measured using a visual analogue scale (VAS). All comparisons between conditions were tested at Pheads and hallux regions were significantly reduced (by 38-58%) in all FOS models when compared with the control shoe. The FOS also relieved metatarsal head peak pressure to a significantly larger extent than the cast shoe (approximately 20%). The load transfer diagrams showed a major transfer of approximately 40% of forefoot load to the midfoot explaining the offloading efficacy of the FOS. Perceived walking comfort was significantly lower in the FOS (VAS score 2.7-5.9) when compared with the control shoe (VAS 8.2) and cast shoe (VAS 6.8). The data showed that all FOS models were effective in their primary goal, relieving forefoot pressure in at-risk neuropathic diabetic patients. Therefore, these shoes may be effective in offloading and healing plantar forefoot ulcers, although the low comfort scores should be considered as this may potentially affect adherence to treatment.

  14. The effect of shoe type on gait in forefoot strike runners during a 50-km run

    Directory of Open Access Journals (Sweden)

    Mark E. Kasmer

    2014-06-01

    Conclusion: More runners adopted a more posterior initial contact area after the 50-km run in the traditional shoe type than in the minimalist shoe type. The runners who adopted a more posterior initial contact area were more closely associated with an increased median frequency of the medial gastrocnemius, which suggests there may be a change in motor unit recruitment pattern during long-distance, sustained velocity running. The increased peak pressures observed in the medial forefoot in the minimalist shoe type may predispose to metatarsal stress fractures in the setting of improper training.

  15. The value of shoe size for prediction of the timing of the pubertal growth spurt

    Directory of Open Access Journals (Sweden)

    Verkerke Gijsbertus J

    2011-01-01

    Full Text Available Abstract Background Knowing the timing of the pubertal growth spurt of the spine, represented by sitting height, is essential for the prognosis and therapy of adolescent idiopathic scoliosis. There are several indicators that reflect growth or remaining growth of the patient. For example, distal body parts have their growth spurt earlier in adolescence, and therefore the growth of the foot can be an early indicator for the growth spurt of sitting height. Shoe size is a good alternative for foot length, since patients can remember when they bought new shoes and what size these shoes were. Therefore the clinician already has access to some longitudinal data at the first visit of the patient to the outpatient clinic. The aim of this study was to describe the increase in shoe size during adolescence and to determine whether the timing of the peak increase could be an early indicator for the timing of the peak growth velocity of sitting height. Methods Data concerning shoe sizes of girls and boys were acquired from two large shoe shops from 1991 to 2008. The longitudinal series of 242 girls and 104 boys were analysed for the age of the "peak increase" in shoe size, as well as the age of cessation of foot growth based on shoe size. Results The average peak increase in shoe size occurred at 10.4 years (SD 1.1 in girls and 11.5 years (SD 1.5 in boys. This was on average 1.3 years earlier than the average peak growth velocity of sitting height in girls, and 2.5 years earlier in boys. The increase in shoe size diminishes when the average peak growth velocity of sitting height takes place at respectively 12.0 (SD 0.8 years in girls, and 13.7 (SD 1.0 years in boys. Conclusions Present data suggest that the course of the shoe size of children visiting the outpatient clinic can be a useful first tool for predicting the timing of the pubertal growth spurt of sitting height, as a representative for spinal length. This claim needs verification by direct

  16. Characterization of ground SBR scraps from shoe industry

    Directory of Open Access Journals (Sweden)

    Marinês Massarotto

    2008-03-01

    Full Text Available Expanded poly(butadiene-co-styrene (SBR, a residue of the shoe industry of Rio Grande do Sul, is a crosslinked material. For further utilization in recycling and reclaiming processes this residue was ground under ambient conditions. The obtained powder (SBR-r was physically, thermally and chemically characterized and the results were analyzed as for its suitability for reuse methods. This characterization provides a better understanding of the SBR residue components, which may lead to economic and environmental advantages. The SBR-r (3548 mesh is composed by 22.2% of SBR and 77.8% of filler. The elastomeric fraction has 71.4% of crosslinked material. The results demonstrate that SBR can be recycled for use in microcellular composites.

  17. Low Power Shoe Integrated Intelligent Wireless Gait Measurement System

    Science.gov (United States)

    Wahab, Y.; Mazalan, M.; Bakar, N. A.; Anuar, A. F.; Zainol, M. Z.; Hamzah, F.

    2014-04-01

    Gait analysis measurement is a method to assess and identify gait events and the measurements of dynamic, motion and pressure parameters involving the lowest part of the body. This significant analysis is widely used in sports, rehabilitation as well as other health diagnostic towards improving the quality of life. This paper presents a new system empowered by Inertia Measurement Unit (IMU), ultrasonic sensors, piezoceramic sensors array, XBee wireless modules and Arduino processing unit. This research focuses on the design and development of a low power ultra-portable shoe integrated wireless intelligent gait measurement using MEMS and recent microelectronic devices for foot clearance, orientation, error correction, gait events and pressure measurement system. It is developed to be cheap, low power, wireless, real time and suitable for real life in-door and out-door environment.

  18. [Occupational risks of a shoe industry from the workers' perspective].

    Science.gov (United States)

    Luz, Fernanda Reinher da; Loro, Marli Maria; Zeitoune, Regina Célia Gollner; Kolankiewicz, Adriane Cristina Bernat; Rosanelli, Cleci Schmidt Piovesan

    2013-01-01

    This is a qualitative and descriptive study, which aimed to identify the occupational risks of a shoe industry, as well as the preventive measures taken against those risks, from the workers' perspective. The sample consisted of fifteen workers. Data were collected through semi-structured interviews and analyzed according to content analysis. The ethical aspects were respected and the research was approved by the Committee of Ethics in Research of the Northwest Regional University of Rio Grande do Sul. The results showed that the workers are aware of the risks of their work process, made use of safety measures for personal protection, and the company offers safety devices, informing and performing periodical visits to the sectors, aiming to develop educational actions.

  19. Fully casted soft power generating triboelectric shoe insole

    Science.gov (United States)

    Haque, Rubaiyet I.; Farine, Pierre-André; Briand, Danick

    2016-11-01

    Power generating soft triboelectric based shoe insole fully elastomeric and compatible with large-scale fabrication technique has been developed. During the process, film casting and stencil printing techniques were implemented to deposit/pattern elastomeric and soft/flexible materials, such as, polydimethylsiloxane (PDMS) and polyurethane (PU). Carbon- based elastomeric materials were used as electrodes, which were also film casted. The developed triboelectric generator (TENG) was capable of harnessing electrical power effectively from mechanical deformation of the system during walking or running activities. The performance of the device was tested for walking with frequency of 0.9±0.2 Hz. The power (rms value) of 0.25 mW was achieved for load resistance of 100 MΩ,, which corresponded to the power density (rms value) of 1.9 μW/cm2.

  20. Don't Wear Your New Shoes (Yet): Taking the Right Steps to Become a Successful Principal Investigator

    NARCIS (Netherlands)

    De Ridder, J.; Abeel, T.; Michaut, M.; Satagopam, V.P.; Gehlenborg, N.

    2013-01-01

    You finished your PhD, have been a postdoc for a while, and you start wondering, "What's next?" Suppose you come to the conclusion that you want to stay in academia, and move up the ladder to become a principal investigator (PI). How does one reach this goal given that academia is one of the most

  1. Don't Wear Your New Shoes (Yet: Taking the Right Steps to Become a Successful Principal Investigator.

    Directory of Open Access Journals (Sweden)

    Jeroen de Ridder

    2013-01-01

    Full Text Available You finished your PhD, have been a postdoc for a while, and you start wondering, “What's next?” Suppose you come to the conclusion that you want to stay in academia, and move up the ladder to become a principal investigator (PI. How does one reach this goal given that academia is one of the most competitive environments out there? And suppose you do manage to snatch your dream position, how do you make sure you hit the ground running? Here we report on the workshop “P2P - From Postdoc To Principal Investigator” that we organized at ISMB 2012 in Long Beach, California. The workshop addressed some of the challenges that many postdocs and newly appointed PIs are facing. Three experienced PIs, Florian Markowetz (Group Leader, Cambridge Research Institute, Cancer Research UK, Gary Bader (Associate Professor, The Donnelly Centre, University of Toronto, and Philip Bourne (Professor, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, provided insight into the transition from a trainee to PI and shared advice on how to make the best out it.

  2. Don't Wear Your New Shoes (Yet): Taking the Right Steps to Become a Successful Principal Investigator.

    OpenAIRE

    Jeroen de Ridder; Thomas Abeel; Magali Michaut; Satagopam, Venkata P; Nils Gehlenborg

    2013-01-01

    You finished your PhD, have been a postdoc for a while, and you start wondering, “What's next?” Suppose you come to the conclusion that you want to stay in academia, and move up the ladder to become a principal investigator (PI). How does one reach this goal given that academia is one of the most competitive environments out there? And suppose you do manage to snatch your dream position, how do you make sure you hit the ground running? Here we report on the workshop “P2P - From Postdoc To Pri...

  3. Don't Wear Your New Shoes (Yet): Taking the Right Steps to Become a Successful Principal Investigator

    NARCIS (Netherlands)

    De Ridder, J.; Abeel, T.; Michaut, M.; Satagopam, V.P.; Gehlenborg, N.

    2013-01-01

    You finished your PhD, have been a postdoc for a while, and you start wondering, "What's next?" Suppose you come to the conclusion that you want to stay in academia, and move up the ladder to become a principal investigator (PI). How does one reach this goal given that academia is one of the most co

  4. Use of orthopedic shoes in patients with degenerative disorders of the foot

    NARCIS (Netherlands)

    Jannink, Michiel J.; IJzerman, Maarten J.; Groothuis-Oudshoorn, Karin; Stewart, Roy E.; Groothoff, Johan W.; Lankhorst, Gustaaf J.

    2005-01-01

    Objectives: To study the actual use of orthopedic shoes by patients with degenerative foot disorders and to identify factors associated with use and nonuse, based on the parameters of the International Organization for Standardization definition of usability: effectiveness, efficiency, satisfaction,

  5. Threshold Based Indexing of Commercial Shoe Print to Create Reference and Recovery Images

    CERN Document Server

    Rathinavel, S

    2010-01-01

    One of the important evidence in a crime scene that is normally overlooked but very important evidence is shoe print as the criminal is normally unaware of the mask for this. In this paper we use image processing technique to process reference shoe images to make it index-able for a search from the database the shoe print impressions available in the commercial market. This is achieved first by converting the commercially available image through the process of converting them to gray scale then apply image enhancement and restoration techniques and finally do image segmentation to store the segmented parameter as index in the database storage. We use histogram method for image enhancement, inverse filtering for image restoration and threshold method for indexing. We use global threshold as index of the shoe print. The paper describes this method and simulation results are included to validate the method.

  6. The effects of high custom made shoes on gait characteristics and patient satisfaction in hemiplegic gait

    NARCIS (Netherlands)

    Eckhardt, Martine M.; Mulder, Mascha C. Borgerhoff; Horemans, Herwin L.; van der Woude, Luc H.; Ribbers, Gerard M.

    2011-01-01

    Objective: To determine the effects of a temporary high custom made orthopaedic shoe on functional mobility, walking speed, and gait characteristics in hemiplegic stroke patients. In addition, interference of attentional demands and patient satisfaction were studied. Design: Clinical experimental st

  7. The effects of high custom made shoes on gait characteristics and patient satisfaction in hemiplegic gait

    NARCIS (Netherlands)

    Eckhardt, Martine M; Mulder, Mascha C Borgerhoff; Horemans, Herwin L; van der Woude, Lucas; Ribbers, Gerard M

    2011-01-01

    OBJECTIVE: To determine the effects of a temporary high custom made orthopaedic shoe on functional mobility, walking speed, and gait characteristics in hemiplegic stroke patients. In addition, interference of attentional demands and patient satisfaction were studied. DESIGN: Clinical experimental st

  8. Multi-Player Quantum Games

    CERN Document Server

    Benjamin, S C; Benjamin, Simon C.; Hayden, Patrick M.

    2001-01-01

    Game theory is a mature field of applied mathematics. It formalizes the conflict between competing agents, and has found applications ranging from economics through to biology. Recently the first efforts have been made to introduce quantum information into game theory. For two-player games, it has been found that when the allowed `moves' are extended to include everything quantum mechanically possible, then the predominant strategies in the game can disappear, and only reappear if the players degrade the quantum coherence. Here we present the first study of quantum games with more than two players. We demonstrate that such games can exhibit `coherent' equilibrium strategies which have no analogue in classical games, or even in two-player quantum games. These equilibria are generally of a cooperative nature: quantum players can exploit their environment highly efficiently through the use of collaborative strategies.

  9. Exploiting Fashion Features for Floor Storage Systems in the Shoe Industry

    OpenAIRE

    Antonella Meneghetti

    2013-01-01

    Floor storage systems are used in the shoe industry to store fashion products of seasonal collections of low quantity and high variety. Since space is valuable and order picking must be sped up, stacking of shoeboxes should be optimized. The problem is modelled based on shoe features (model, type, colour, and size) and with the goal of forcing similar boxes into locations close to each other in order to improve workers’ ability to retrieve orders fast. The model is encoded in Constraint Logic...

  10. The effect of foot orthoses and in-shoe wedges during cycling: a systematic review

    OpenAIRE

    Yeo, Boon K; Bonanno, Daniel R

    2014-01-01

    Background The use of foot orthoses and in-shoe wedges in cycling are largely based on theoretical benefits and anecdotal evidence. This review aimed to systematically collect all published research on this topic, critically evaluate the methods and summarise the findings. Methods Study inclusion criteria were: all empirical studies that evaluated the effects of foot orthoses or in-shoe wedges on cycling; outcome measures that investigated physiological parameters, kinematics and kinetics of ...

  11. Calculation of wear (f.i. wear modulus) in the plastic cup of a hip joint prosthesis

    NARCIS (Netherlands)

    Ligterink, D.J.

    1975-01-01

    The wear equation is applied to the wear process in a hip joint prosthesis and a wear modulus is defined. The sliding distance, wear modulus, wear volume, wear area, contact angle and the maximum normal stress were calculated and the theoretical calculations applied to test results. During the wear

  12. Multiscale Modeling of Wear Degradation

    KAUST Repository

    Moraes, Alvaro

    2014-01-06

    Cylinder liners of diesel engines used for marine propulsion are naturally subjected to a wear process, and may fail when their wear exceeds a specified limit. Since failures often represent high economical costs, it is utterly important to predict and avoid them. In this work [4], we model the wear process using a pure jump process. Therefore, the inference goal here is to estimate: the number of possible jumps, its sizes, the coefficients and the shapes of the jump intensities. We propose a multiscale approach for the inference problem that can be seen as an indirect inference scheme. We found that using a Gaussian approximation based on moment expansions, it is possible to accurately estimate the jump intensities and the jump amplitudes. We obtained results equivalent to the state of the art but using a simpler and less expensive approach.

  13. Multiscale Modeling of Wear Degradation

    KAUST Repository

    Moraes, Alvaro

    2016-01-06

    Cylinder liners of diesel engines used for marine propulsion are naturally subjected to a wear process, and may fail when their wear exceeds a specified limit. Since failures often represent high economical costs, it is utterly important to predict and avoid them. In this work [4], we model the wear process using a pure jump process. Therefore, the inference goal here is to estimate: the number of possible jumps, its sizes, the coefficients and the shapes of the jump intensities. We propose a multiscale approach for the inference problem that can be seen as an indirect inference scheme. We found that using a Gaussian approximation based on moment expansions, it is possible to accurately estimate the jump intensities and the jump amplitudes. We obtained results equivalent to the state of the art but using a simpler and less expensive approach.

  14. Multiscale Modeling of Wear Degradation

    KAUST Repository

    Moraes, Alvaro

    2015-01-07

    Cylinder liners of diesel engines used for marine propulsion are naturally subjected to a wear process, and may fail when their wear exceeds a specified limit. Since failures often represent high economical costs, it is utterly important to predict and avoid them. In this work [4], we model the wear process using a pure jump process. Therefore, the inference goal here is to estimate: the number of possible jumps, its sizes, the coefficients and the shapes of the jump intensities. We propose a multiscale approach for the inference problem that can be seen as an indirect inference scheme. We found that using a Gaussian approximation based on moment expansions, it is possible to accurately estimate the jump intensities and the jump amplitudes. We obtained results equivalent to the state of the art but using a simpler and less expensive approach.

  15. Shoes alter the spring-like function of the human foot during running.

    Science.gov (United States)

    Kelly, Luke A; Lichtwark, Glen A; Farris, Dominic J; Cresswell, Andrew

    2016-06-01

    The capacity to store and return energy in legs and feet that behave like springs is crucial to human running economy. Recent comparisons of shod and barefoot running have led to suggestions that modern running shoes may actually impede leg and foot-spring function by reducing the contributions from the leg and foot musculature. Here we examined the effect of running shoes on foot longitudinal arch (LA) motion and activation of the intrinsic foot muscles. Participants ran on a force-instrumented treadmill with and without running shoes. We recorded foot kinematics and muscle activation of the intrinsic foot muscles using intramuscular electromyography. In contrast to previous assertions, we observed an increase in both the peak (flexor digitorum brevis +60%) and total stance muscle activation (flexor digitorum brevis +70% and abductor hallucis +53%) of the intrinsic foot muscles when running with shoes. Increased intrinsic muscle activation corresponded with a reduction in LA compression (-25%). We confirm that running shoes do indeed influence the mechanical function of the foot. However, our findings suggest that these mechanical adjustments are likely to have occurred as a result of increased neuromuscular output, rather than impaired control as previously speculated. We propose a theoretical model for foot-shoe interaction to explain these novel findings. © 2016 The Author(s).

  16. Effects of a minimalist shoe on running economy and 5-km running performance.

    Science.gov (United States)

    Fuller, Joel T; Thewlis, Dominic; Tsiros, Margarita D; Brown, Nicholas A T; Buckley, Jonathan D

    2016-09-01

    The purpose of this study was to determine if minimalist shoes improve time trial performance of trained distance runners and if changes in running economy, shoe mass, stride length, stride rate and footfall pattern were related to any difference in performance. Twenty-six trained runners performed three 6-min sub-maximal treadmill runs at 11, 13 and 15 km·h(-1) in minimalist and conventional shoes while running economy, stride length, stride rate and footfall pattern were assessed. They then performed a 5-km time trial. In the minimalist shoe, runners completed the trial in less time (effect size 0.20 ± 0.12), were more economical during sub-maximal running (effect size 0.33 ± 0.14) and decreased stride length (effect size 0.22 ± 0.10) and increased stride rate (effect size 0.22 ± 0.11). All but one runner ran with a rearfoot footfall in the minimalist shoe. Improvements in time trial performance were associated with improvements in running economy at 15 km·h(-1) (r = 0.58), with 79% of the improved economy accounted for by reduced shoe mass (P economy and 5-km running performance.

  17. Erosive Wear and Wear Mechanism of in situ TiCp/Fe Composites

    Institute of Scientific and Technical Information of China (English)

    Zhaojing LIU; Zhiliang NING; Fengzhen LI; Xiurong YAO; Shanzhi REN

    2005-01-01

    The base structure of in situ TiCP/Fe composites fabricated under industrial condition was changed by different heat treatments. Erosive wear tests were carried out and the results were compared with that of wear-resistant white cast iron. The results suggest that the wear resistance of the in situ TiCp/Fe composite is higher than that of wear-resistant white cast iron under the sand erosive wear condition. The wear mechanism of the wear-resistant white cast iron was a cycle process that base surface was worn and carbides were exposed, then carbides was broken and wear pits appeared. While the wear mechanism of in situ TiCp/Fe composite was a cycle process that base surface was worn and TiC grains were exposed and dropped. The wear resistance of in situ TiCp/Fe composite was lower than that of wear-resistant white cast iron under the slurry erosive wear condition. Under such circumstance,the material was not only undergone erosive wear but also electrochemistry erosion due to the contact with water in the medium. The wear behaviours can be a combination of two kinds of wear and the sand erosive wear is worse than slurry erosive wear.

  18. LOW HANDICAP GOLFERS GENERATE MORE TORQUE AT THE SHOE-NATURAL GRASS INTERFACE WHEN USING A DRIVER

    Directory of Open Access Journals (Sweden)

    Paul Worsfold

    2008-09-01

    Full Text Available The aim was to determine the rotational torque occurring at the shoe-natural grass interface during golf swing performance with different clubs, and to determine the influence of handicap and golf shoe design. Twenty-four golfers (8 low 0-7; 8 medium 8-14; and 8 high 15+ performed 5 shots with a driver, 3-iron and 7-iron when 3 shoes were worn: a modern 8 mm metal 7-spike shoe, an alternative 7-spike shoe and a flat soled shoe. Torque was measured at the front and back foot by grass covered force platforms in an outdoor field. Torque at the shoe- natural turf interface was similar at the front foot when using a driver, 3-iron and 7-iron with maximum mean torque (Tzmax 17-19 Nm and torque generation in the entire backswing and downswing approximately 40 Nm. At the back foot, torque was less than at the front foot when using the driver, 3-iron and 7-iron. At the back foot Tzmax was 6-7 Nm, and torque generation was 10-16 Nm, with a trend for greater torque generation when using the driver rather than the irons. The metal spike shoe allowed significantly more back foot torque generation when using a driver than a flat- soled shoe (p 0.05, although back foot mean torques generated tended to be greater for the metal spike shoe. The golf shot outcomes were similar for low, medium and high handicappers in both metal and alternative spike shoes (metal: 87%; 76%; 54%; alternative: 85%; 74%; 54% respectively. The better, low handicap golfers generated significantly more back foot torque (metal spike: 18.2 Nm; alternative: 15.8 Nm; p < 0.05 when using a driver. Further research should consider back foot shoe-grass interface demands during driver usage by low handicap and lighter body-weight golfers

  19. Metallurgical Design and Development of NASA Crawler/Transporter Tread Belt Shoe Castings

    Science.gov (United States)

    Parker, Donald S.

    2006-01-01

    The NASA Crawler/Transporters (CT-1 and CT-2) used to transport the Space Shuffles are one of the largest tracked vehicles in existence today. Two of these machines have been used to move space flight vehicles at Kennedy Space Center since the Apollo missions of the 1960's and relatively few modifications have been made to keep them operational. In September of 2003 during normal Crawler/Transporter operations cracks were observed along the roller pad surfaces of several tread belt shoes. Further examination showed 20 cracked shoes on CT-1 and 40 cracked shoes on CT-2 and a formal failure analysis investigation was undertaken while the cracked shoes were replaced. Six shoes were cross-sectioned with the fracture surfaces exposed and it was determined that the cracks were due to fatigue that initiated on the internal casting web channels at pre-existing casting defects and propagated through thickness both transgranularly and intergranularly between internal shrinkage cavities, porosity, and along austenitic and ferritic grain boundaries. The original shoes were cast during the 1960's using a modified 861330 steel with slightly higher levels of chromium, nickel and molybdenum followed by heat treatment to achieve a minimum tensile strength of 11 Oksi. Subsequent metallurgical analysis of the tread belt shoes after multiple failures showed excessive internal defects, alloy segregation, a nonuniform ferritic/ bainitic/martensitic microstructure, and low average tensile properties indicative of poor casting and poor heat-treatment. As a result, NASA funded an initiative to replace all of the tread belt shoes on both crawler/transporters along with a redesign of the alloy, manufacturing, and heat-treatment to create a homogeneous cast structure with uniform mechanical and metallurgical properties. ME Global, a wholly owned subsidiary of ME Elecmetal based in Minneapolis, MN was selected as manufacturing and design partner to develop the new shoes and this paper

  20. Should School Nurses Wear Uniforms?

    Science.gov (United States)

    Journal of School Health, 2001

    2001-01-01

    This 1958 paper questions whether school nurses should wear uniforms (specifically, white uniforms). It concludes that white uniforms are often associated with the treatment of ill people, and since many people have a fear reaction to them, they are not necessary and are even undesirable. Since school nurses are school staff members, they should…

  1. Tooth wear patterns in the deciduous dentition.

    Science.gov (United States)

    Warren, John J; Yonezu, Takuro; Bishara, Samir E

    2002-12-01

    Tooth wear is common in the deciduous dentition. A recent study suggests that tooth wear in the deciduous dentition is related to subsequent tooth wear in adults, so that early identification of factors related to tooth wear could be of long-term benefit. The purposes of this study were to describe patterns of tooth wear in the deciduous dentition and to relate tooth wear to occlusal characteristics and longitudinal dietary patterns. Data were collected as part of a longitudinal study of a cohort of children recruited at birth from Iowa hospitals. Stone casts were obtained in the deciduous dentition stage, and 355 children, 4 to 5 years old, met the selection criteria. Tooth wear was categorized for each tooth as none, mild, moderate, or severe, and related to occlusal characteristics and longitudinal data on fruit juice and soft drink consumption. All children exhibited some tooth wear on at least 1 tooth, and nearly 16% of them had at least 1 tooth with severe wear. Tooth wear was generally more severe in the maxillary arch and the anterior teeth. Severe tooth wear on the molars was significantly related to posterior crossbites, but severe tooth wear on the incisors was related to Class III canine relationships. There were no statistically significant relationships between tooth wear and soft drink or fruit juice consumption. Based on our results, we concluded that mild tooth wear is universal in the deciduous dentition, but only a few occlusal factors are related to severe tooth wear. Tooth wear was not related to any dietary patterns we investigated.

  2. Improvements of harrows wear resistance

    Directory of Open Access Journals (Sweden)

    Warouma Arifa

    2015-12-01

    Full Text Available Wear is the main reason for the loss of performance of the parts for agricultural machinery. It leads to the degradation of the soil working quality. This work aims to highlight the wear resistance of the harrows discs manufactured, consolidated and sharpened differently. The tests were conducted in the laboratory and the field of the Faculty of Exploitation and Repair of Agricultural Machinery of the State Technical University of Kirovograd (Ukraine in 2015. The technical equipment consists of devices for consolidation by electric discharge and for measurement the linear wear of discs, a harrow, a sand test bed, a tractor and discs made of different materials and technologies. Some parameterized were collected during the laboratory test each 5 ha and up to 20 ha of operation and in the fields each 30 ha until the time limit of exploitation. The Laboratory tests have shown that after twenty (20 ha of operation, the wear resistance of the experimental discs made of steel 65G and consolidated by electric discharge with simultaneous grinding (sharpening angle of 30° is 2.95 times higher than the discs in series made of steel 28MnB5. The field experiment gave the following results: According to agro technical requirements, the plowing depth limit of serial discs made of steel 28MnB5 was reached after an operating duration of 120 ha while for experimental discs made of steel 65G and consolidated by electric discharge with simultaneous grinding (sharpening angle of 30 degrees this duration is of 156 ha. The diameter wear limit of experimental discs was reached after an operating duration of 179 ha against 154 ha for the serial ones. Therefore, the new technology can be applied during the manufacture and / or the repair of the discs.

  3. Needs and challenges in precision wear measurement

    Energy Technology Data Exchange (ETDEWEB)

    Blau, P.J.

    1996-01-10

    Accurate, precise wear measurements are a key element in solving both current wear problems and in basic wear research. Applications range from assessing durability of micro-scale components to accurate screening of surface treatments and thin solid films. Need to distinguish small differences in wear tate presents formidable problems to those who are developing new materials and surface treatments. Methods for measuring wear in ASTM standard test methods are discussed. Errors in using alterate methods of wear measurement on the same test specimen are also described. Human judgemental factors are a concern in common methods for wear measurement, and an experiment involving measurement of a wear scar by ten different people is described. Precision in wear measurement is limited both by the capabilities of the measuring instruments and by the nonuniformity of the wear process. A method of measuring wear using nano-scale indentations is discussed. Current and future prospects for incorporating advanced, higher-precision wear measurement methods into standards are considered.

  4. Consideration of Wear Rates at High Velocities

    Science.gov (United States)

    2010-03-01

    tionally, the texts by Bayer [3; 4], Rabinowicz [30], and Stachowiak [32] thoroughly cover the topic of wear mechanisms. A summary of the material is...March 1976. 30. Rabinowicz , E. Friction and Wear of Metals. John Wiley & Sons, New York, 1995. 31. Saka, N., A. M. Eleiche, and N. P. Suh. “Wear of

  5. An Evaluation of High Velocity Wear

    Science.gov (United States)

    2007-03-01

    x10F~ -4 [18:18-19]. Authors such as Hutchings and Rabinowicz however, do not explicitly limit equation (12) to plastic wear. They suggest that...Surface Melting of Rotating Bands. Wear, Vol. 38, 235- 243 21. Rabinowicz , E. (1965). Friction and Wear of Materials (Second ed.). New York, NY

  6. The Edubox Learning Design Player

    NARCIS (Netherlands)

    Tattersall, Colin; Vogten, Hubert; Hermans, Henry

    2005-01-01

    Tattersall, C., Vogten, H. & Hermans, H. (2005). The Edubox Learning Design Player. In: Koper, R. & Tattersall, C., Learning Design: A Handbook on Modelling and Delivering Networked Education and Training (pp. 303-310). Berlin-Heidelberg: Springer Verlag.

  7. The Astro Learning Design Player

    NARCIS (Netherlands)

    Sharples, Paul; Wilson, Scott; Popat, Kris; Griffiths, David; Beauvoir, Phillip

    2010-01-01

    Sharples, Paul Wilson, S., Popat, K., Griffiths, D., Beauvoir, P. (2009) The Astro Learning Design Player. This software is distributed under the three clause BSD license, copyright TENCompetence Foundation

  8. The Edubox Learning Design Player

    NARCIS (Netherlands)

    Tattersall, Colin; Vogten, Hubert; Hermans, Henry

    2005-01-01

    Tattersall, C., Vogten, H. & Hermans, H. (2005). The Edubox Learning Design Player. In: Koper, R. & Tattersall, C., Learning Design: A Handbook on Modelling and Delivering Networked Education and Training (pp. 303-310). Berlin-Heidelberg: Springer Verlag.

  9. Detection of abnormalities in a human gait using smart shoes

    Science.gov (United States)

    Kong, Kyoungchul; Bae, Joonbum; Tomizuka, Masayoshi

    2008-03-01

    Health monitoring systems require a means for detecting and quantifying abnormalities from measured signals. In this paper, a new method for detecting abnormalities in a human gait is proposed for an improved gait monitoring system for patients with walking problems. In the previous work, we introduced a fuzzy logic algorithm for detecting phases in a human gait based on four foot pressure sensors for each of the right and left foot. The fuzzy logic algorithm detects the gait phases smoothly and continuously, and retains all information obtained from sensors. In this paper, a higher level algorithm for detecting abnormalities in the gait phases obtained from the fuzzy logic is discussed. In the proposed algorithm, two major abnormalities are detected 1) when the sensors measure improper foot pressure patterns, and 2) when the human does not follow a natural sequence of gait phases. For mathematical realization of the algorithm, the gait phases are dealt with by a vector analysis method. The proposed detection algorithm is verified by experiments on abnormal gaits as well as normal gaits. The experiment makes use of the Smart Shoes that embeds four bladders filled with air, the pressure changes in which are detected by pressure transducers.

  10. ERGONOMIC WORK ANALYSIS APPLICATION IN A SMALL SHOE BUSINESS

    Directory of Open Access Journals (Sweden)

    Aline Marian Callegaro

    2013-11-01

    Full Text Available This paper aims to presentthe results after conducting an Ergonomic Work Analysis (EWA in a smallbusiness located in Porto Alegre. The ergonomic intervention was performed basedon Guérin et al. (2001 and aimed to analyze the process organization and thelayout of the shoemaker workstations to provide improvements to these areas.The starting point was the account of the small shoe business owner’s need hadto hire one more shoemaker without increasing the company physical space. The EWAwas used focusing the work organization, how the flow of information ran fromthe entry of an order to the final stage of the product repairing. Thediagnosis showed the company main problems were related to the shop assistantsdependence on the shoemakers to provide budget information and delivery time tocustomers and the layout organization. Among the results, a temporal analysisof two company recurrent tasks was performed in order to ascertain possiblelosses related to the displacement and the search for material. A new layoutscheme was also proposed, aiming to organize the work stations, making easierthe stock, tools and equipment removal, providing a free space to make possiblethe hiring of the new shoemakers within the current company boundaries.

  11. The gearing function of running shoe longitudinal bending stiffness.

    Science.gov (United States)

    Willwacher, Steffen; König, Manuel; Braunstein, Björn; Goldmann, Jan-Peter; Brüggemann, Gert-Peter

    2014-07-01

    The purpose of the present study was to investigate whether altered longitudinal bending stiffness (LBS) levels of the midsole of a running shoe lead to a systematic change in lower extremity joint lever arms of the ground reaction force (GRF). Joint moments and GRF lever arms in the sagittal plane were determined from 19 male subjects running at 3.5 m/s using inverse dynamics procedures. LBS was manipulated using carbon fiber insoles of 1.9 mm and 3.2 mm thickness. Increasing LBS led to a significant shift of joint lever arms to a more anterior position. Effects were more pronounced at distal joints. Ankle joint moments were not significantly increased in the presence of higher GRF lever arms when averaged over all subjects. Still, two individual strategies (1: increase ankle joint moments while keeping push-off times almost constant, 2: decrease ankle joint moments and increase push-off times) could be identified in response to increased ankle joint lever arms that might reflect individual differences between subjects with respect to strength capacities or anthropometric characteristics. The results of the present study indicate that LBS systematically influences GRF lever arms of lower extremity joints during the push-off phase in running. Further, individual responses to altered LBS levels could be identified that could aid in finding optimum LBS values for a given individual. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Recognition of household and athletic activities using SmartShoe.

    Science.gov (United States)

    Edgar, S Ryan; Fulk, George D; Sazonov, Edward S

    2012-01-01

    The ability to provide real time feedback concerning a person's activity level and energy expenditure can be beneficial for improving activity levels of individuals. Examples include biofeedback systems used for body weight and physical activity management and biofeedback systems for rehabilitation of stroke patients. A critical aspect of any such system is being able to accurately classify data in real-time so that active and timely feedback can be provided. In the paper we demonstrate feasibility of real-time recognition of multiple household and athletic activities on a cell phone using the data collected by a wearable sensor system consisting of SmartShoe sensor and a wrist accelerometer. The experimental data were collected for multiple household and athletic activities performed by a healthy individual. The data was used to train two neural networks, one to be used primarily for sedentary individuals and one for more active individuals. Classification of household activities including ascending stairs, descending stairs, doing the dishes, vacuuming, and folding laundry, achieved 89.62% average accuracy. Classification of athletic activities such as jumping jacks, swing dancing, and ice skating, was performed with 93.13% accuracy. As proof of real-time processing on a mobile platform the trained neural network for healthy individuals was timed and required less than 4 ms to perform each feature vector construction and classification.

  13. Durability of running shoes with ethylene vinyl acetate or polyurethane midsoles.

    Science.gov (United States)

    Wang, Lin; Hong, Youlian; Li, Jing Xian

    2012-12-01

    Ethylene vinyl acetate and polyurethane are widely used materials for shoe midsoles. The present study investigated the durability of running shoes made from ethylene vinyl acetate and one type of polyurethane (polyurethane-1), which have similar hardness and density, and another type of polyurethane (polyurethane-2), which has high hardness/density. All shoes differed from one another only in terms of the midsole material used. Eight male runners participated in the present study and used the shoes to run 500 km (10 × 50 km). The cushioning and energy return characteristics of each shoe were measured using an impact tester before and after each 50-km run. The results showed that as the running distance increased, the peak force of midsole materials changed with different patterns. Ethylene vinyl acetate and polyurethane-1 showed greater cushioning than polyurethane-2 over 500 km (ethylene vinyl acetate, 918.2-968.0 N; polyurethane-1, 909.6-972.9 N; polyurethane-2, 983.0-1105.6 N). Polyurethane-1 showed greater cushioning from 200 km to 300 km compared with 0 km (0 km, 972.9 ± 66.3 N; 200 km, 909.6 ± 61.2 N; 250 km, 921.9 ± 51.2 N; 300 km, 924.6 ± 51.9 N). The cushioning of ethylene vinyl acetate shoes was diminished after 500 km compared with that at 0 km (968.0 ± 25.9 N vs. 921.1 ± 20.1 N). Ethylene vinyl acetate resulted in greater energy returns than polyurethane. Both foam category and hardness/density affected the critical biomechanical properties of running shoes.

  14. Sliding wear resistance of iron aluminides

    Indian Academy of Sciences (India)

    Garima Sharma; M Sundararaman; N Prabhu; G L Goswami

    2003-04-01

    Room temperature dry sliding wear behaviour of iron aluminides containing 28% aluminium and various amounts of chromium has been investigated using pin on disk wear tester. The aluminides were heat treated to have ordered 3 structure. It was found that wear rate of the aluminides increased with the increase of applied normal load and sliding speed. Wear resistance of the aluminides increased with increase in chromium content. SEM observation of the worn surface showed that the microcutting and microploughing were the dominant sliding wear mechanisms.

  15. The effects of common footwear on stance-phase mechanical properties of the prosthetic foot-shoe system.

    Science.gov (United States)

    Major, Matthew J; Scham, Joel; Orendurff, Michael

    2017-05-01

    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. Observe the effects of footwear on the mechanical properties of the prosthetic foot-shoe system including commonly prescribed prosthetic feet. Repeated-measures, Mechanical characterization. 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. 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. 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 relevance Shoes 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.

  16. Technical evaluation of a CAD system for orthopaedic shoe-upper design.

    Science.gov (United States)

    Lord, M; Foulston, J; Smith, P J

    1991-01-01

    Computer aided design is now employed routinely in the volume shoe trade. New styles are developed on a three-dimensional image of the last followed by automated pattern generation and engineering. It is suggested that such systems could be useful in the orthopaedic footwear industry although the different requirements for these bespoke products need careful consideration. A clinical trial has been conducted on the Shoemaster (Clarks Shoes) upper design system both to assess its technical capabilities and to consider its role in improvement of service and cosmetic appearance. This particular system works throughout on a three-dimensional representation of the shoe last, which offers particular advantages for integration with shape capture and reproduction. The report concentrates on the technical evaluation to assess (a) its ability to work with unusual last shapes dictated by medical requirements and (b) its potential for integration into a complete computer system for design of both shoe lasts and shoe uppers. The trial indicates that this particular system is promising in both respects.

  17. Design and evaluation of vibratory shoe on balance control for elderly subjects: technical note.

    Science.gov (United States)

    Aboutorabi, Atefeh; Arazpour, Mokhtar; Farahmand, Farzam; Bahramizadeh, Mahmood; Fadayevatan, Reza; Abdollahi, Ehsan

    2017-03-22

    Aging often results in a decline in somatosensory function, and such changes are associated with diminished motor performance. Input noise can enhance sensory and motor function through a mechanism known as stochastic resonance (SR). This paper describes the development and testing of a new vibrating shoe to possibly assist the elderly patients in controlling their balance and decreasing their falling risks. The new vibrating shoe was evaluated to ascertain its ability to generate appropriate random and nonlinear vibrations. The vibratory shoe performance in two young subjects with decreased foot sensation and two elderly subjects in different static and dynamic balance situations was also evaluated. The postural control, expressed by the stability index (SI), was significantly affected by SR in the older subjects. The vibrating motors could be recommended as a suitable solution for dynamic balance situations. Moreover, the new vibrating shoe could improve the age-related balance impairments in elderly subjects with balance deficiencies and others with impaired foot sensations. Implications for rehabilitations Older adults exhibited decreased postural stability. Noise signal improves sensation and proprioception in older people. New shoe with vibrating motors can operate in different dynamic situations.

  18. Wear prediction in a fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Boyle, E.J. [USDOE Morgantown Energy Technology Center, WV (United States); Rogers, W.A. [EG and G Washington Analytical Services Center, Inc., Morgantown, WV (United States)

    1993-06-01

    A procedure to model the wear of surfaces exposed to a fluidized bed is formulated. A stochastic methodology adapting the kinetic theory of gases to granular flows is used to develop an impact wear model. This uses a single-particle wear model to account for impact wear from all possible-particle collisions. An adaptation of a single-particle abrasion model to describe the effects of many abrading particles is used to account for abrasive wear. Parameters describing granular flow within the fluidized bed, necessary for evaluation of the wear expressions, are determined by numerical solution of the fluidized bed hydrodynamic equations. Additional parameters, describing the contact between fluidized particles and the wearing surface, are determined by optimization based on wear measurements. The modeling procedure was used to analyze several bubbling and turbulent fluidized bed experiments with single-tube and tube bundle configurations. Quantitative agreement between the measured and predicted wear rates was found, with some exceptions for local wear predictions. This work demonstrates a methodology for wear predictions in fluidized beds.

  19. Fluoridation and tooth wear in Irish adults.

    LENUS (Irish Health Repository)

    Burke, F M

    2010-10-01

    The aim of this study was to determine the prevalence of tooth wear in adults in Ireland and its relationship with water fluoridation. The National Survey of Adult Oral Health was conducted in 2000\\/2001. Tooth wear was determined using a partial mouth examination assessing the upper and lower anterior teeth. A total of 2456 subjects were examined. In this survey, increasing levels and severity of tooth wear were associated with ageing. Men were more affected by tooth wear and were more likely to be affected by severe tooth wear than women. It was found that age, and gender were significant predictors of tooth wear (P < 0.01). Overall, there was no significant relationship between fluoridation and tooth wear in this study.

  20. Wear of micro end mills

    DEFF Research Database (Denmark)

    Bissacco, Giuliano; Hansen, Hans Nørgaard; De Chiffre, Leonardo

    2005-01-01

    This paper addresses the important issue of wear on micro end mills considering relevant metrological tools for its characterization and quantification. Investigation of wear on micro end mills is particularly difficult and no data are available in the literature. Small worn volumes cause large...... deviations from the ideal micro tool shape, dramatically changing the cutting edge profile as well as rake and clearance angles. This critically affects the performance of the micro tool leading to increased cutting forces and micro tool deflections with detrimental effects on the accuracy of the machined...... part. For this investigation 200 microns end mills are considered. Visual inspection of the micro tools requires high magnification and depth of focus. 3D reconstruction based on scanning electron microscope (SEM) images and stereo-pair technique is foreseen as a possible method for quantification...

  1. Hydraulic System Wear Debris Analysis.

    Science.gov (United States)

    1982-08-03

    drawn. Each one-=L sample was drawn with a clean plastic pipette of one-mL capacity. The samples were placed in clean Ferrogram preparation bottles ...and from cavities in a block which held linear seals into sampling bottles . Several photographs of this debris , which was deposited on Ferro- grams...silicon in the glass overshadowed the elements of the wear debris . To overcome this difficulty, the Ferrogram should be pre- pared on a carbon-filled

  2. Frontal Lobe Function in Chess Players

    Directory of Open Access Journals (Sweden)

    Vahid Nejati

    2012-05-01

    Full Text Available Chess is considered as a cognitive game because of severe engagement of the mental resources during playing. The purpose of this study is evaluation of frontal lobe function of chess players with matched non-players. Wisconsin Card Sorting Test (WCST data showed no difference between the player and non-player groups in preservation error and completed categories but surprisingly showed significantly lower grade of the player group in correct response. Our data reveal that chess players dont have any preference in any stage of Stroop test. Chess players dont have any preference in selective attention, inhibition and executive cognitive function. Chess players' have lower shifting abilities than non-players.

  3. Differences in plantar loading between training shoes and racing flats at a self-selected running speed

    NARCIS (Netherlands)

    J.I. Wiegerinck; J. Boyd; J.C. Yoder; A.N. Abbey; J.A. Nunley; R.M. Queen

    2009-01-01

    The purpose of this study was to examine the difference in plantar loading between two different running shoe types. We hypothesized that a higher maximum force, peak pressure, and contact area would exist beneath the entire foot while running in a racing flat when compared to a training shoe. 37 at

  4. DEVELOPMENT AND REPRODUCIBILITY OF A SHORT QUESTIONNAIRE TO MEASURE USE AND USABILITY OF CUSTOM-MADE ORTHOPAEDIC SHOES

    NARCIS (Netherlands)

    van Netten, Jaap J.; Hijmans, Juha M.; Jannink, Michiel J. A.; Geertzen, Jan H. B.; Postema, Klaas

    2009-01-01

    Objective:To develop it short and easy to use questionnaire to measure use and usability of custom-made orthopaedic shoes, and to investigate its reproducibility. Design: Development of the questionnaire (Monitor Orthopaedic Shoes) was based on a literature search. expert interviews. 2 expert meetin

  5. Development and reproducibility of a short questionnaire to measure use and usability of custom-made orthopaedic shoes

    NARCIS (Netherlands)

    Netten, van Jaap J.; Hijmans, Juha M.; Jannink, Michiel J.A.; Geertzen, Jan H.B.; Postema, Klaas

    2009-01-01

    Objective: To develop a short and easy to use questionnaire to measure use and usability of custom-made orthopaedic shoes, and to investigate its reproducibility. Design: Development of the questionnaire (Monitor Orthopaedic Shoes) was based on a literature search, expert interviews, 2 expert meetin

  6. [Measuring plantar pressure in conventional shoes with the TEKSCAN sensory system].

    Science.gov (United States)

    Koch, M

    1993-10-01

    This article describes the assessment of the TEKSCAN pressure monitoring system used in association with normal footwear. After allowing a warm-up period of 5-10 minutes inside the shoe the stability of the sensor output improved as compared with the falsely higher pressures recorded when the warm-up period was not observed. The intra-person coefficient of variation of a single sensor was < 23%, and the intersensor variation was < 31%. However, intrasensor variation was reduced to 15% by appropriate prior preparation. Neither repeated use (< 6 times) of a sensor in a single shoe, nor the use of a single sensor in several different shoes had any effect on sensor function. Active deformation of the sensor resulted in so significant signal.

  7. Exploiting Fashion Features for Floor Storage Systems in the Shoe Industry

    Directory of Open Access Journals (Sweden)

    Antonella Meneghetti

    2013-08-01

    Full Text Available Floor storage systems are used in the shoe industry to store fashion products of seasonal collections of low quantity and high variety. Since space is valuable and order picking must be sped up, stacking of shoeboxes should be optimized. The problem is modelled based on shoe features (model, type, colour, and size and with the goal of forcing similar boxes into locations close to each other in order to improve workers’ ability to retrieve orders fast. The model is encoded in Constraint Logic Programming and solved comparing different strategies, also using Large Neighbourhood Search. Simulation experiments are run to evaluate how the stacking model affects picking performance.

  8. Effect of children's shoes on gait: a systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Burns Joshua

    2011-01-01

    Full Text Available Abstract Background The effect of footwear on the gait of children is poorly understood. This systematic review synthesises the evidence of the biomechanical effects of shoes on children during walking and running. Methods Study inclusion criteria were: barefoot and shod conditions; healthy children aged ≤ 16 years; sample size of n > 1. Novelty footwear was excluded. Studies were located by online database-searching, hand-searching and contact with experts. Two authors selected studies and assessed study methodology using the Quality Index. Meta-analysis of continuous variables for homogeneous studies was undertaken using the inverse variance approach. Significance level was set at P 2. Where I2 > 25%, a random-effects model analysis was used and where I2 Results Eleven studies were included. Sample size ranged from 4-898. Median Quality Index was 20/32 (range 11-27. Five studies randomised shoe order, six studies standardised footwear. Shod walking increased: velocity, step length, step time, base of support, double-support time, stance time, time to toe-off, sagittal tibia-rearfoot range of motion (ROM, sagittal tibia-foot ROM, ankle max-plantarflexion, Ankle ROM, foot lift to max-plantarflexion, 'subtalar' rotation ROM, knee sagittal ROM and tibialis anterior activity. Shod walking decreased: cadence, single-support time, ankle max-dorsiflexion, ankle at foot-lift, hallux ROM, arch length change, foot torsion, forefoot supination, forefoot width and midfoot ROM in all planes. Shod running decreased: long axis maximum tibial-acceleration, shock-wave transmission as a ratio of maximum tibial-acceleration, ankle plantarflexion at foot strike, knee angular velocity and tibial swing velocity. No variables increased during shod running. Conclusions Shoes affect the gait of children. With shoes, children walk faster by taking longer steps with greater ankle and knee motion and increased tibialis anterior activity. Shoes reduce foot motion and

  9. Effects of aluminum hinged shoes on the structure of contracted feet in Thoroughbred yearlings.

    Science.gov (United States)

    Tanaka, Kousuke; Hiraga, Atsushi; Takahashi, Toshiyuki; Kuwano, Atsutoshi; Morrison, Scott Edward

    2015-01-01

    We applied aluminum hinged shoes (AHSs) to the club foot-associated contracted feet of 11 Thoroughbred yearlings to examine the effects of the shoes on the shape of the hoof and third phalanx (P III). After 3 months of AHS use, the size of the affected hooves increased significantly, reaching the approximate size of the healthy contralateral hooves with respect to the maximum lateral width of the foot, the mean ratio of the bearing border width to the coronary band width, and the mean ratio of the solar surface width to the articular surface width. These results suggest that the AHSs corrected the contracted feet in these yearling horses.

  10. Enhancing indoor inertial pedestrian navigation using a shoe-worn marker.

    Science.gov (United States)

    Placer, Mitja; Kovačič, Stanislav

    2013-08-02

    We propose a novel hybrid inertial sensors-based indoor pedestrian dead reckoning system, aided by computer vision-derived position measurements. In contrast to prior vision-based or vision-aided solutions, where environmental markers were used-either deployed in known positions or extracted directly from it-we use a shoe-fixed marker, which serves as positional reference to an opposite shoe-mounted camera during foot swing, making our system self-contained. Position measurements can be therefore more reliably fed to a complementary unscented Kalman filter, enhancing the accuracy of the estimated travelled path for 78%, compared to using solely zero velocities as pseudo-measurements.

  11. Wear mechanism and wear prevention in coal-fueled diesel engines. Task 3, Traditional approaches to wear prevention

    Energy Technology Data Exchange (ETDEWEB)

    Schwalb, J.A.

    1991-06-01

    Contamination of the lube-oil with hard abrasive particles leads to a three-body abrasive wear mechanism that highly accelerates piston ring/cylinder liner wear in coal-fueled diesel engines. One approach to reducing that wear is to modify the size and orientation of surface asperities on the cylinder to enhance the formation of a hydrodynamic film, and to provide avenues of escape for particles that would otherwise be trapped in the wear zone. Another approach is to introduce additives into the contaminated lube-oil that further enhance hydrodynamic film formation, form chemical films on the wearing surfaces, or form films on the contaminant particles. This work focuses on defining the effects of cylinder liner surface finish, various configurations of slots in the cylinder liner surface, and various additives in the contaminated lube-oil on the wear process. Wear tests were initiated in a bench apparatus using coal-ash contaminated lube-oil to test the various wear configurations. The results of these tests indicate that the formation of a hydrodynamic film between the ring and cylinder specimens is enhanced by increasing surface roughness, and by orienting the surface asperities normal to the direction of ring travel but modifications to the cylinder liner surface did not greatly reduce the wear rate. Additives to the lubricant seemed to have a much more significant effect on wear, with a dispersant additive highly accelerating the wear, while a detergent additive was able to reduce the wear almost to the rate achieved where there was no contaminant.

  12. A new methodology for predictive tool wear

    Science.gov (United States)

    Kim, Won-Sik

    An empirical approach to tool wear, which requires a series of machining tests for each combination of insert and work material, has been a standard practice for industries since early part of the twentieth century. With many varieties of inserts and work materials available for machining, the empirical approach is too experiment-intensive that the demand for the development of a model-based approach is increasing. With a model-based approach, the developed wear equation can be extended without additional machining experiments. The main idea is that the temperatures on the primary wear areas are increasing such that the physical properties of the tool material degrade substantially and consequently tool wear increases. Dissolution and abrasion are identified to be the main mechanisms for tool wear. Flank wear is predominantly a phenomenon of abrasion as evident by the presence of a scoring mark on the flank surface. Based on this statement, it is reasonable to expect that the flank-wear rate would increase with the content of hard inclusions. However, experimental flank wear results did not necessary correspond to the content of cementite phase present in the steels. Hence, other phenomena are believed to significantly affect wear behavior under certain conditions. When the cutting temperature in the flank interface is subjected to high enough temperatures, pearlitic structure austenizes. During the formation of a new austenitic phase, the existing carbon is dissolved into the ferrite matrix, which will reduce the abrasive action. To verify the austenitic transformation, turning tests were conducted with plain carbon steels. The machined surface areas are imaged using X-ray diffraction the Scanning Electron Microscope (SEM) and the Transmission Electron Microscope (TEM). On the other hand, crater wear occurs as a result of dissolution wear and abrasive wear. To verify the wear mechanisms of crater wear, various coating inserts as well as uncoated inserts were

  13. Laterally wedged insoles in knee osteoarthritis: do biomechanical effects decline after one month of wear?

    Directory of Open Access Journals (Sweden)

    Bennell Kim L

    2009-11-01

    Full Text Available Abstract Objective This study aimed to determine whether the effect of laterally wedged insoles on the adduction moment in knee osteoarthritis (OA declined after one month of wear, and whether higher reported use of insoles was associated with a reduced effect on the adduction moment at one month. Methods Twenty people with medial compartment OA underwent gait analysis in their own shoes wearing i no insoles and; ii insoles wedged laterally 5° in random order. Testing occurred at baseline and after one month of use of the insoles. Participants recorded daily use of insoles in a log-book. Outcomes were the first and second peak external knee adduction moment and the adduction angular impulse, compared across conditions and time with repeated measures general linear models. Correlations were obtained between total insole use and change in gait parameters with used insoles at one month, and change scores were compared between high and low users of insoles using general linear models. Results There was a significant main effect for condition, whereby insoles significantly reduced the adduction moment (all p Conclusion Effects of laterally wedged insoles on the adduction moment do not appear to decline after one month of continuous use, suggesting that significant wedge degradation does not occur over the short-term.

  14. Surface Wear Measurement Using Optical Correlation Technique

    Science.gov (United States)

    Acinger, Kresimir

    1983-12-01

    The coherent optical correlation technique was applied for measuring the surface wear of a tappet (part of car engine), worn by friction with the camshaft. It was found that maximum correlation intensity decays exponentially with the number of wear cycles (i.e. camshaft revolutions). Tappets of the same make have an identical rate of correlation decay. Tappets of different makes have different rates of correlation decay which are in agreement with observed long term wear.

  15. The Effectiveness Evaluation among Different Player-Matching Mechanisms in a Multi-Player Quiz Game

    Science.gov (United States)

    Tsai, Fu-Hsing

    2016-01-01

    This study aims to investigate whether different player-matching mechanisms in educational multi-player online games (MOGs) can affect students' learning performance, enjoyment perception and gaming behaviors. Based on the multi-player quiz game, TRIS-Q, developed by Tsai, Tsai and Lin (2015) using a free player-matching (FPM) mechanism, the same…

  16. Wear of hard materials by hard particles

    Energy Technology Data Exchange (ETDEWEB)

    Hawk, Jeffrey A.

    2003-10-01

    Hard materials, such as WC-Co, boron carbide, titanium diboride and composite carbide made up of Mo2C and WC, have been tested in abrasion and erosion conditions. These hard materials showed negligible wear in abrasion against SiC particles and erosion using Al2O3 particles. The WC-Co materials have the highest wear rate of these hard materials and a very different material removal mechanism. Wear mechanisms for these materials were different for each material with the overall wear rate controlled by binder composition and content and material grain size.

  17. The NBA’s Maximum Player Salary and the Distribution of Player Rents

    Directory of Open Access Journals (Sweden)

    Kelly M. Hastings

    2015-03-01

    Full Text Available The NBA’s 1999 Collective Bargaining Agreement (CBA included provisions capping individual player pay in addition to team payrolls. This study examines the effect the NBA’s maximum player salary on player rents by comparing player pay from the 1997–1998 and 2003–2004 seasons while controlling for player productivity and other factors related to player pay. The results indicate a large increase in the pay received by teams’ second highest and, to a lesser extent, third highest paid players. We interpret this result as evidence that the adoption of the maximum player salary shifted rents from stars to complementary players. We also show that the 1999 CBA’s rookie contract provisions reduced salaries of early career players.

  18. Abrasive Wear Map of Polymer Tapes in Sand Dust Environment

    Institute of Scientific and Technical Information of China (English)

    WU Tong-hai; DIAO Dong-feng

    2006-01-01

    To make clear the wear conditions of ATM (Automatic Teller Machine) tribosystem when servicing in Chinese sand dust environment, abrasive wear of two kinds of polymer tapes specified for ATM, PI (Polyimide) and PEN (Polyethylene-2, 6-naphthalenedicarboxylate), was investigated in simulated sand dust environment with ATM tape-scraper tribosystem under various conditions of loads and sliding distances. The surface profiles of worn tape were measured with a surface profiler in order to calculating the wear cross-section areas and the wear volumes. The specific wear rates of polymer tapes were calculated under load conditions of 0.6, 1 and 1.5 N, and wear mechanisms were investigated with optical topography photos. As main results, the specific wear rates show stage variations in the wear process and the wear resistance of polymer tape shows good relationship with the mechanical deformation factors. In consideration of the service life, four wear models are generalized according to the magnitude of specific wear rates,which include no wear, mild wear, normal wear and severe wear model and the corresponding wear mechanisms for the four wear models are discussed with typical worn topographies. Based on the wear models and corresponding wear mechanisms, the abrasive wear maps of two polymer tapes servicing in sand dust environments are concluded for its industrial applications.

  19. Kinematics and Electromyogram of Healthy Women Walking with Negative-Heeled Shoe and Normal Sports Shoe%健康成年女性穿倒跟鞋和普通运动鞋行走时的运动学参数及下肢肌电比较

    Institute of Scientific and Technical Information of China (English)

    洪友廉; 王琳; 李静先

    2011-01-01

    Objective The aim of this study was to investigate the kinematics and muscle activities of the trunk and lower extremities in normal subjects during treadmill walking with negative-heeled sports shoes and normal sports shoes. Methods Thirteen healthy female college students wearing negative-heeled sports shoes and normal sports shoes walked on a treadmill at the speed of 1.33 m/s. Their kinematics of sagittal movement and electromyogram (EMG) of the erector spinae, rectus abdominal, rectus femoris, biceps femoris, tibialis anterior, and lateral gastrocnemius of the dominant side during walking were recorded and analyzed. Results The results showed that the negative-heeled gait is characterized by faster cadence, shorter stride length, increased maximal extension in the trunk and the hip, increased flexion of the knee, larger dorsiflexion in stance phase, and a larger range of motion of the ankle joint. The negative-heeled gait results in a significantly larger integrative EMG, longer duration of EMG, and higher mean amplitude of EMG in the tibialis anteriror, lateral gastrocnemius, and biceps femoris. Conclusion The findings in this study indicate that walking with negative-heeled shoes alters trunk and lower extremity kinematics and results in higher muscle activities of the tibialis anterior, lateral gastrocnemius, and biceps femoris.%目的:比较受试者穿着倒跟运动鞋和普通运动鞋在跑台上行走时,躯干和下肢的运动学特征,以及躯干和下肢肌肉活动特征.方法:13名健康女大学生志愿受试者,分别穿着倒跟和普通两种运动鞋在测试跑台上以1.33 m/s的速度行走.采用摄像机和Ariel运动解析系统记录和分析矢状面的行走的运动学参数.采用BTS表面肌电系统采集和分析优势侧竖脊肌、腹直肌、股直肌、股二头肌、胫骨前肌和腓肠肌外侧头表面肌电.结果:与普通运动鞋相比,穿着倒跟鞋行走时,步频加快、步幅缩短;躯干和髋关节最

  20. Assessment of asymmetric leg loading before and after total hip arthroplasty using instrumented shoes

    NARCIS (Netherlands)

    Martínez-Ramírez, Alicia; Weenk, Dirk; Lecumberri, Pablo; Verdonschot, Nico; Pakvis, Dean; Veltink, Peter H.

    2013-01-01

    The stance time and the average vertical ground reaction force measured with the instrumented shoes during walking, and their symmetry index, showed significant differences before and after total hip arthroplasty. However, the data obtained with the sit to stand test did not reveal this improvement

  1. Local outcomes of globalization: manufacturing decline and labor response in the Philippine garment and shoe industries

    NARCIS (Netherlands)

    Beerepoot, N.

    2008-01-01

    In the past few decades, globalisation has led to major international shifts in labour intensive manufacturing generating ‘winners’ and ‘losers’ among countries, industries and workers. This paper uses case studies of the shoe industry in Marikina City and the garments sector in Metro Manila in orde

  2. The strategic capability of a shoe company from Brazil: the Olympikus case

    Directory of Open Access Journals (Sweden)

    Juliana Suzin

    2007-01-01

    Full Text Available The main objective in this article is to analyze how the opportunities and resources are identified and mobilized to assure conditions to a traditional industry to compete through innovation. In this study decisions and actions associated to enterprising and innovations are analyzed in the context of the traditional Brazilian Industry. In this context, the global production chains are evaluated, in particular, the behavior and performance of the Brazilian Shoe Industry. The study of one case of the shoe industry provides the empiric base to discuss the questions proposed. The analysis of one line from articles produced by Calçados Azaléia, one of the biggest shoe factories in Brazil, is made. The evidences are based on interviews proposed to the executives of the company in the years of 2005 and 2006 where secondary data helps to analyze the subject, shoe business sector and the company. The conclusion is that the case takes a ‘revolutionary’ perspective of competitiveness, through the launching of one product that allies technology, quality and design, assuming a new level on administrative innovation and a new strategic position at the dynamic value chain.

  3. Modified distal shoe appliance for premature loss of multiple deciduous molars: a case report.

    Science.gov (United States)

    Bhat, Prasanna Kumar; K, Navin H; Idris, Mohammed; Christopher, Pradeep; Rai, Niharika

    2014-08-01

    Preservation of the primary dentition until the normal time of exfoliation is one of the most important factor involved in preventive and interceptive dentistry. The premature loss of second primary molar before the eruption of permanent first molar can create a significant arch space/tooth size discrepancy. Distal shoe space maintainer is a valuable part of the Paediatric Dentist's armamentarium in those cases where the second primary molar is prematurely lost and it helps to guide the first permanent molar into place. Conventional design poses various limitations in cases of premature loss of multiple deciduous molars. Thus, it is required to modify the conventional designs according to the needs of the patient. This case report describes an innovative modification of distal shoe appliance in cases of premature loss of multiple deciduous molars. In the present case, modification of distal shoe space maintainer was advocated because of inadequate abutments caused due to multiple loss of deciduous molars. Bilateral design of distal shoe was planned for unilateral loss of deciduous molars.

  4. "Thank Goodness the Goose Is Here": Creativity and Women's Writing in Eudora Welty's "The Shoe Bird."

    Science.gov (United States)

    Cohoon, Lorinda B.

    2002-01-01

    Suggests that "The Shoe Bird" uses animal characters to explore women's authorship. Locates in Gloria, one of the main characters, evidence of the creativity and fortitude required to write as a woman in cultures where written language has conventionally been seen as the domain of men. (SG)

  5. The knee adduction moment measured with an instrumented force shoe in patients with knee osteoarthritis

    NARCIS (Netherlands)

    Noort, van den Josien C.; Esch, van der Martin; Steultjens, Martijn P.M.; Dekker, Joost; Schepers, H. Martin; Veltink, Peter H.; Harlaar, Jaap

    2012-01-01

    The external knee adduction moment (KAdM) during gait is an important parameter in patients with knee osteoarthritis (OA). KAdM measurement is currently restricted to instruments only available in gait laboratories. However, ambulatory movement analysis technology, including instrumented force shoes

  6. Quantitative self-assessment of exposure to solvents among shoe repair men

    NARCIS (Netherlands)

    Hertsenberg, S.; Brouwer, D.; Lurvink, M.; Rubingh, C.; Rijnders, E.; Tielemans, E.

    2007-01-01

    Self-assessment of exposure (SAE) refers to any exposure assessment methodology wherein the worker takes an active role in establishing his or her exposure status. The objective of this study was to investigate the reliability and feasibility of SAE approaches among shoe repair workers collecting

  7. The Oblique Art of Shoes: Popular Culture, Aesthetic Pleasure, and the Humanities

    NARCIS (Netherlands)

    C. Lindner

    2015-01-01

    This article addresses popular culture and the humanities. It uses shoes as an object of analysis to interrogate the place and function of aesthetic pleasure in critical thinking and cultural practice in the age of globalization and the neoliberal university. Tracking contemporary articulations of t

  8. "Thank Goodness the Goose Is Here": Creativity and Women's Writing in Eudora Welty's "The Shoe Bird."

    Science.gov (United States)

    Cohoon, Lorinda B.

    2002-01-01

    Suggests that "The Shoe Bird" uses animal characters to explore women's authorship. Locates in Gloria, one of the main characters, evidence of the creativity and fortitude required to write as a woman in cultures where written language has conventionally been seen as the domain of men. (SG)

  9. Rocker shoes reduce Achilles tendon load in running and walking in patients with chronic Achilles tendinopathy

    NARCIS (Netherlands)

    Sobhani, Sobhan; Zwerver, Johannes; van den Heuvel, Edwin; Postema, Klaas; Dekker, Rienk; Hijmans, Juha M.

    2015-01-01

    OBJECTIVES: Relative rest and pain relief play an important role in the management of Achilles tendinopathy, and might be achieved by reducing the load on the Achilles tendon. Previous studies have provided evidence that rocker shoes are able to decrease the ankle internal plantar flexion moment in

  10. Quantitative self-assessment of exposure to solvents among shoe repair men

    NARCIS (Netherlands)

    Hertsenberg, S.; Brouwer, D.; Lurvink, M.; Rubingh, C.; Rijnders, E.; Tielemans, E.

    2007-01-01

    Self-assessment of exposure (SAE) refers to any exposure assessment methodology wherein the worker takes an active role in establishing his or her exposure status. The objective of this study was to investigate the reliability and feasibility of SAE approaches among shoe repair workers collecting ex

  11. Effects of shoe type on lower extremity muscle activity during treadmill walking.

    Science.gov (United States)

    Kim, Mi-Kyoung; Kim, Young-Hwan; Yoo, Kyung-Tae

    2015-12-01

    [Purpose] The purpose of this study was to analyze the effects of different shoe types on lower extremity muscle activity in healthy young women by using electromyography. [Subjects and Methods] Fifteen healthy young women in their 20s were included in this single-group repeated measures study. The subjects were divided into three groups: Converse sneakers, rain boots, and combat boots. The subjects walked on a treadmill at 4 km/h for 30 min, during which six muscles were examined using electromyography: the rectus femoris, vastus medialis, semimembranosus, tibialis anterior, peroneus longus, and medial head of the gastrocnemius. Between switching shoe types, a 24-h rest period was instated to prevent the fatigue effect from treadmill walking. [Results] One-way analysis of variance used to compare electromyography results among the three groups showed that the main effect of group differed significantly for the vastus medialis. Vastus medialis activity was higher in the rain boots group than the Converse sneakers group, and it was higher in the combat boots group than rain boots group. [Conclusion] Shoe type affects lower extremity muscle activity. Our findings may help individuals choose the ideal shoes for daily walking.

  12. Customization of consumer goods: First steps to fully customizable fashionable ladies′ shoes

    NARCIS (Netherlands)

    Zande, M. van der; Bergmans, S.; Kamperman, N.; Vorst, B. van de

    2009-01-01

    The production of fashionable footwear has basically been the same for almost a century. It consists of combining elements of various materials together formed around a physical shape - the last - thereby making a product that fits around the foot - the shoe. This process requires different stages

  13. Customization of consumer goods: First steps to fully customizable fashionable ladies′ shoes

    NARCIS (Netherlands)

    Zande, M. van der; Bergmans, S.; Kamperman, N.; Vorst, B. van de

    2009-01-01

    The production of fashionable footwear has basically been the same for almost a century. It consists of combining elements of various materials together around a physical shape – the last – and thereby making a product around the foot – the shoe. This process requires different stages in production,

  14. Measurement of oil film thickness and friction force on a guide shoe bearing

    DEFF Research Database (Denmark)

    Vølund, Anders

    2002-01-01

    An experimental program was carried out in order to reveal oil film thickness, and friction force of the guide shoe bearing of a large two stroke marine diesel engine. The experiment was conducted on a full size engine located at the research facility at MAN B&W Diesel A/S. The experiment was con...

  15. Fecundity of the Indian Horse-shoe crab, Carcinoscorpius rotundicauda (Latreille)

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A.; Parulekar, A.H.

    Fecundity in the horse-shoe crab Carcinoscorpius rotundicauda ranges from 4217 to 10,982 with an average of 7438. The ova diameter varies between 1.5-2.3 mm with a model value of 1.7 mm. Number of ova per mm carapace length, per g body weight...

  16. Identification of virtual grounds using virtual reality haptic shoes and sound synthesis

    DEFF Research Database (Denmark)

    Serafin, Stefania; Turchet, Luca; Nordahl, Rolf

    2010-01-01

    We describe a system which simulates in real-time the auditory and haptic sensation of walking on different surfaces. The system is based on physical models, that drive both the haptic and audio synthesizers, and a pair of shoes enhanced with sensors and actuators. In a discrimination experiment,...

  17. A Novel Method for Measuring In-Shoe Navicular Drop during Gait

    Directory of Open Access Journals (Sweden)

    Henrik Karstoft

    2012-08-01

    Full Text Available Analysis of foot movement is essential in the treatment and prevention of foot-related disorders. Measuring the in-shoe foot movement during everyday activities, such as sports, has the potential to become an important diagnostic tool in clinical practice. The current paper describes the development of a thin, flexible and robust capacitive strain sensor for the in-shoe measurement of the navicular drop. The navicular drop is a well-recognized measure of foot movement. The position of the strain sensor on the foot was analyzed to determine the optimal points of attachment. The sensor was evaluated against a state-of-the-art video-based system that tracks reflective markers on the bare foot. Preliminary experimental results show that the developed strain sensor is able to measure navicular drop on the bare foot with an accuracy on par with the video-based system and with a high reproducibility. Temporal comparison of video-based, barefoot and in-shoe measurements indicate that the developed sensor measures the navicular drop accurately in shoes and can be used without any discomfort for the user.

  18. Post-warmup strategies to maintain body temperature and physical performance in professional rugby union players.

    Science.gov (United States)

    West, Daniel J; Russell, Mark; Bracken, Richard M; Cook, Christian J; Giroud, Tibault; Kilduff, Liam P

    2016-01-01

    We compared the effects of using passive-heat maintenance, explosive activity or a combination of both strategies during the post-warmup recovery time on physical performance. After a standardised warmup, 16 professional rugby union players, in a randomised design, completed a counter-movement jump (peak power output) before resting for 20 min and wearing normal-training attire (CON), wearing a passive heat maintenance (PHM) jacket, wearing normal attire and performing 3 × 5 CMJ (with a 20% body mass load) after 12 min of recovery (neuromuscular function, NMF), or combining PHM and NMF (COMB). After 20 min, participants completed further counter-movement jump and a repeated sprint protocol. Core temperature (Tcore) was measured at baseline, post-warmup and post-20 min. After 20 min of recovery, Tcore was significantly lower under CON and NMF, when compared with both PHM and COMB (P union players.

  19. Acute effect of different minimalist shoes on foot strike pattern and kinematics in rearfoot strikers during running.

    Science.gov (United States)

    Squadrone, Roberto; Rodano, Renato; Hamill, Joseph; Preatoni, Ezio

    2015-01-01

    Despite the growing interest in minimalist shoes, no studies have compared the efficacy of different types of minimalist shoe models in reproducing barefoot running patterns and in eliciting biomechanical changes that make them differ from standard cushioned running shoes. The aim of this study was to investigate the acute effects of different footwear models, marketed as "minimalist" by their manufacturer, on running biomechanics. Six running shoes marketed as barefoot/minimalist models, a standard cushioned shoe and the barefoot condition were tested. Foot-/shoe-ground pressure and three-dimensional lower limb kinematics were measured in experienced rearfoot strike runners while they were running at 3.33 m · s⁻¹ on an instrumented treadmill. Physical and mechanical characteristics of shoes (mass, heel and forefoot sole thickness, shock absorption and flexibility) were measured with laboratory tests. There were significant changes in foot strike pattern (described by the strike index and foot contact angle) and spatio-temporal stride characteristics, whereas only some among the other selected kinematic parameters (i.e. knee angles and hip vertical displacement) changed accordingly. Different types of minimalist footwear models induced different changes. It appears that minimalist footwear with lower heel heights and minimal shock absorption is more effective in replicating barefoot running.

  20. Influence of footwear designed to boost energy return on running economy in comparison to a conventional running shoe.

    Science.gov (United States)

    Sinclair, J; Mcgrath, R; Brook, O; Taylor, P J; Dillon, S

    2016-01-01

    Running economy is a reflection of the amount of inspired oxygen required to maintain a given velocity and is considered a determining factor for running performance. Athletic footwear has been advocated as a mechanism by which running economy can be enhanced. New commercially available footwear has been developed in order to increase energy return, although their efficacy has not been investigated. This study aimed to examine the effects of energy return footwear on running economy in relation to conventional running shoes. Twelve male runners completed 6-min steady-state runs in conventional and energy return footwear. Overall, oxygen consumption (VO2), heart rate, respiratory exchange ratio, shoe comfort and rating of perceived exertion were assessed. Moreover, participants subjectively indicated which shoe condition they preferred for running. Differences in shoe comfort and physiological parameters were examined using Wilcoxon signed-rank tests, whilst shoe preferences were tested using a chi-square analysis. The results showed that VO2 and respiratory exchange ratio were significantly lower, and shoe comfort was significantly greater, in the energy return footwear. Given the relationship between running economy and running performance, these observations indicate that the energy return footwear may be associated with enhanced running performance in comparison to conventional shoes.

  1. Enamel wear opposing polished and aged zirconia.

    Science.gov (United States)

    Burgess, J O; Janyavula, S; Lawson, N C; Lucas, T J; Cakir, D

    2014-01-01

    Aging of dental zirconia roughens its surface through low temperature degradation. We hypothesized that age-related roughening of zirconia crowns may cause detrimental wear to the enamel of an opposing tooth. To test our hypothesis, we subjected artificially aged zirconia and reference specimens to simulated mastication in a wear device and measured the wear of an opposing enamel cusp. Additionally, the roughness of the pretest surfaces was measured. The zirconia specimens, artificially aged by autoclave, showed no significant increase in roughness compared to the nonaged specimens. Furthermore, no significant difference in material or opposing enamel wear between the aged and nonaged zirconia was seen. All zirconia specimens showed less material and opposing enamel wear than the enamel to enamel control or veneering porcelain specimens. Scanning electron micrographs showed relatively smooth surfaces of aged and nonaged zirconia following wear testing. The micrographs of the veneering ceramic showed sharp fractured edges and fragments of wear debris. Zirconia may be considered a wear-friendly material for restorations opposing enamel, even after simulated aging.

  2. Numerical prediction of car tire wear

    NARCIS (Netherlands)

    Lupker, H.A.; Cheli, F.; Braghin, F.; Gelosa, E.; Keckman, A.

    2004-01-01

    Due to their many economic and ecological implications, the possibility to predict tire wear is of major importance to tire manufacturers, fleet owners and governments. Based on these observations, in 2000, a three-year project named TROWS (Tire and Road Wear and Slip assessment was started. One of

  3. Concrete ice abrasion rig and wear measurements

    NARCIS (Netherlands)

    Shamsutdinova, G.; Rike, P.B.; Hendriks, M.A.N.; Jacobsen, S.

    2015-01-01

    The wear of concrete material due to ice movement is a challenge for offshore and coastal structures. Concrete surfaces exposed to moving ice are subjected to wear at various rates depending on concrete and ice properties. At NTNU, Department of Structural Engineering, concrete ice abrasion phenomen

  4. Wear and microstructure in fine ceramic coatings

    Energy Technology Data Exchange (ETDEWEB)

    Vijande-Diaz, R.; Belzunce, J.; Fernandez, E. (ETS de Ingenieros Industriales, Area de Ingeneria Mecanica, Gijon (Spain)); Rincon, A.; Perez, M.C. (Inst. de Fisica-Quimica ' Roco Solano' , CSIC, Madrid (Spain))

    1991-08-15

    This paper presents a study of the wear resistance of two ceramic, plasma sprayed coatings of Al{sub 2}O{sub 3} and Cr{sub 2}O{sub 3}. Tests were carried out using an LWF-1 standard machine, with lineal contact, under dry friction, abrasion and lubricant conditions. The purpose of the tests were to study how load and speed affect material wear. Results show the lower wear rate of the ceramic coating compared with the steel one, as well as how remarkably load affects wear. On the other hand, however, considering the speed ranges used, wear resistance does not depend significantly on speed. The paper proves that the wear process follows Czichos' law. At the same time, reformulation of Archard's equation allows us to quantify wear using easily measurable factors such as pressure, speed, hardness, and those factors typically featuring this type of coatings, e.g. porosity. Also, a micrographic study of the coatings carried out by means of a scanning electron microscope has evidenced three stages in the wear mechanism: (a) plastic deformation of particles; (b) crack nucleation and propagation; and (c) loosening of ceramic particles. (orig.).

  5. Contact lens wear is intrinsically inflammatory.

    Science.gov (United States)

    Efron, Nathan

    2017-01-01

    Eye-care practitioners typically associate ocular inflammation during contact lens wear with serious complications such as microbial keratitis; however, more subtle mechanisms may be at play. This paper tests the notion that contact lens wear is intrinsically inflammatory by exploring whether uncomplicated contact lens wear meets the classical, clinical definition of inflammation - rubor (redness), calor (heat), tumor (swelling), dolor (pain) and functio laesa (loss of function) - as well as the contemporary, sub-clinical definition of inflammation (cellular and biochemical reactions). It is demonstrated that all of these clinical and sub-clinical criteria are met with hydrogel lens wear and most are met with silicone hydrogel lens wear, indicating that uncomplicated contact lens wear is intrinsically inflammatory. Consideration of both traditional and contemporary thinking about the role of inflammation in the human body leads to the perhaps surprising conclusion that the chronic, low grade, sub-clinical inflammatory status of the anterior eye during contact lens wear, which may be termed 'para-inflammation', is a positive, protective phenomenon, whereby up-regulation of the immune system, in a non-damaging way, maintains the eye in a state of 'heightened alert', ready to ward off any extrinsic noxious challenge. Characterisation of this inflammatory status may lead to the development of lens engineering or pharmacological strategies to modulate contact lens-induced inflammation, so as to render lens wear more safe and comfortable. © 2016 Optometry Australia.

  6. Inhibition of erosive wear by fluoride varnish

    NARCIS (Netherlands)

    Vieira, A.; Jager, D. H. J.; Ruben, J. L.; Huysmans, M. C. D. N. J. M.

    2007-01-01

    It has been suggested that fluoride products with a protective mechanical component are advantageous in the prevention of erosive wear. The aim of this study was to evaluate in situ the effect of fluoride varnish (FV) in the prevention of wear due to erosion and combined erosion and toothbrush abras

  7. Concrete ice abrasion rig and wear measurements

    NARCIS (Netherlands)

    Shamsutdinova, G.; Rike, P.B.; Hendriks, M.A.N.; Jacobsen, S.

    2015-01-01

    The wear of concrete material due to ice movement is a challenge for offshore and coastal structures. Concrete surfaces exposed to moving ice are subjected to wear at various rates depending on concrete and ice properties. At NTNU, Department of Structural Engineering, concrete ice abrasion phenomen

  8. Friction and Wear Behaviors of Nanostructured Metals

    Institute of Scientific and Technical Information of China (English)

    Zhong HAN; Yusheng ZHANG; Ke LU

    2008-01-01

    Nanostructured (ns) materials, i.e., polycrystalline materials with grain sizes in the nanometer regime (typically below 100 nm), have drawn considerable attention in the past decades due to their unique properties such as high strength and hardness. Wear resistance of ns materials, one of the most important properties for engineering materials, has been extensively investigated in the past decades. Obvious differences have been identified in friction and wear behaviors Between the ns materials and their corresponding coarse-grained (cg) counterparts, consistently correlating with their unique structure characteristics and mechanical properties. On the other hand, the superior tribological properties of ns materials illustrate their potential applications under contact loads. The present overview will summarize the important progresses achieved on friction and wear behaviors of ns metallic materials, including ultrafine-grained (ufg) materials in recent years. Tribological properties and effects on friction and wear behaviors of ns materials will be discussed under different wear conditions including abrasive wear, sliding wear, and fretting wear. Their correlations with mechanical properties will be analyzed. Perspectives on development of this field will be highlighted as well.

  9. Inhibition of erosive wear by fluoride varnish

    NARCIS (Netherlands)

    Vieira, A.; Jager, D. H. J.; Ruben, J. L.; Huysmans, M. C. D. N. J. M.

    2007-01-01

    It has been suggested that fluoride products with a protective mechanical component are advantageous in the prevention of erosive wear. The aim of this study was to evaluate in situ the effect of fluoride varnish (FV) in the prevention of wear due to erosion and combined erosion and toothbrush

  10. Influência da altura do salto de sapatos na função venosa da mulher jovem Influence of shoe heel height on venous function in young women

    Directory of Open Access Journals (Sweden)

    Wagner Tedeschi Filho

    2007-12-01

    Full Text Available CONTEXTO: A influência da altura do salto de sapatos na função venosa é ainda assunto controverso na literatura mundial. A importância da ergonomia na qualidade de vida é um fator consagrado e situações que a prejudiquem como permanência prolongada na posição supina, qualidade dos calçados e condições do local de trabalho podem interferir na saúde do indivíduo. OBJETIVO: Estudar a influência da altura do salto do sapato na drenagem venosa dos membros inferiores, utilizando-se a pletismografia a ar (PGA. MÉTODO: Quinze mulheres, com idade média de 24,6 anos, assintomáticas, utilizando calçados de tamanhos apropriados, foram examinadas em três momentos: descalças (0 cm, salto médio (3,5 cm e alto (7 cm. Apresentavam índice de massa corporal BACKGROUND: The influence of shoe heel height on venous function is still a controversial subject in the international literature. The importance of ergonomics for quality of life is a universally accepted factor, and situations that impair it, such as prolonged permanence in the supine position, shoe quality and workplace conditions may interfere with the individual"s health. OBJECTIVE: To analyze the influence of shoe heel height on lower limb venous drainage using air plethysmography. METHOD: Fifteen asymptomatic women with mean age of 24.6 years, wearing shoes of appropriate size were examined in three different situations: barefoot (0 cm, medium heels (3.5 cm and high heels (7 cm. Body mass index was < 25 and the subjects were classified according to the CEAP International Classification based on clinical (C0 or C1, etiologic (Ep, anatomic (As and physiopathological (Pr criteria. The values of venous filling index (VFI, ejection fraction (EF and residual volume fraction (RVF were divided into three categories according to heel height and compared to one another by repeated means analysis of variance (ANOVA. RESULTS: EF was decreased and RVF was increased in the high heel group

  11. Fault Wear and Friction Evolution: Experimental Analysis

    Science.gov (United States)

    Boneh, Y.; Chang, J. C.; Lockner, D. A.; Reches, Z.

    2011-12-01

    Wear is an inevitable product of frictional sliding of brittle rocks as evidenced by the ubiquitous occurrence of fault gouge and slickenside striations. We present here experimental observations designed to demonstrate the relationship between wear and friction and their governing mechanisms. The experiments were conducted with a rotary shear apparatus on solid, ring-shaped rock samples that slipped for displacements up to tens of meters. Stresses, wear and temperature were continuously monitored. We analyzed 86 experiments of Kasota dolomite, Sierra White granite, Pennsylvania quartzite, Karoo gabbro, and Tennessee sandstone at slip velocities ranging from 0.002 to 0.97 m/s, and normal stress from 0.25 to 6.9 MPa. We conducted two types of runs: short slip experiments (slip distance mechanisms; and long slip experiments (slip distance > 3 m) designed to achieve mature wear conditions and to observe the evolution of wear and friction as the fault surfaces evolved. The experiments reveal three wear stages: initial, running-in, and steady-state. The initial stage is characterized by (1) discrete damage striations, the length of which is comparable to total slip , and local pits or plow features; (2) timing and magnitude of fault-normal dilation corresponds to transient changes of normal and shear stresses; and (3) surface roughness increasing with the applied normal stress. We interpret these observations as wear mechanisms of (a) plowing into the fresh rock surfaces; (b) asperity breakage; and (c) asperity climb. The running-in stage is characterized by (1) intense wear-rate over a critical wear distance of Rd = 0.3-2 m; (2) drop of friction coefficient over a weakening distance of Dc = 0.2-4 m; (3) Rd and Dc display positive, quasi-linear relation with each other. We interpret these observations as indicating the organizing of newly-created wear particles into a 'three-body' structure that acts to lubricate the fault (Reches & Lockner, 2010). The steady

  12. Biologically Based Restorative Management of Tooth Wear

    Directory of Open Access Journals (Sweden)

    Martin G. D. Kelleher

    2012-01-01

    Full Text Available The prevalence and severity of tooth wear is increasing in industrialised nations. Yet, there is no high-level evidence to support or refute any therapeutic intervention. In the absence of such evidence, many currently prevailing management strategies for tooth wear may be failing in their duty of care to first and foremost improve the oral health of patients with this disease. This paper promotes biologically sound approaches to the management of tooth wear on the basis of current best evidence of the aetiology and clinical features of this disease. The relative risks and benefits of the varying approaches to managing tooth wear are discussed with reference to long-term follow-up studies. Using reference to ethical standards such as “The Daughter Test”, this paper presents case reports of patients with moderate-to-severe levels of tooth wear managed in line with these biologically sound principles.

  13. Wear simulation effects on overdenture stud attachments.

    Science.gov (United States)

    Rutkunas, Vygandas; Mizutani, Hiroshi; Takahashi, Hidekazu; Iwasaki, Naohiko

    2011-01-01

    The aim of this study was to evaluate wear effects on overdenture resilient attachments. Six commercially available attachments were investigated: ERA orange and white (EO and EW), Locator pink, white and blue (LRP, LRW and LRB) and OP anchor (OP). Five specimens were used for wear simulation while other two specimens served as controls. Fifteen thousands insertion-removal cycles were simulated. Dimensional changes and surface characteristics were evaluated using light microscopy and SEM, respectively. Sudden decrease of retentive force was characteristic for EO and EW attachments. Retentive force of Locator attachments fluctuated throughout the wear simulation period. Dimensional changes and surface wear was more expressed on plastic cores than on plastic rings of attachment males. Based on SEM analysis, some of the specimens obtained smoother surface after wear simulation. Mechanism of retention loss of resilient overdenture attachments can be only partially explained by dimensional changes and surface alterations.

  14. Modeling wear of cast Ti alloys.

    Science.gov (United States)

    Chan, Kwai S; Koike, Marie; Okabe, Toru

    2007-05-01

    The wear behavior of Ti-based alloys was analyzed by considering the elastic-plastic fracture of individual alloys in response to the relevant contact stress field. Using the contact stresses as the process driving force, wear was computed as the wear rate or volume loss as a function of hardness and tensile ductility for Ti-based cast alloys containing an alpha, alpha+beta or beta microstructure with or without the intermetallic precipitates. Model predictions indicated that wear of Ti alloys increases with increasing hardness but with decreasing fracture toughness or tensile ductility. The theoretical results are compared with experimental data to elucidate the roles of microstructure in wear and contrasted against those in grindability.

  15. Assessment of variations in wear test methodology.

    Science.gov (United States)

    Gouvêa, Cresus V D; Weig, Karin; Filho, Thales R M; Barros, Renata N

    2010-01-01

    The properties of composite resin for dental fillings were improved by development, but its weakness continues to be its wear strength. Several tests have been proposed to evaluate wear in composite resin materials. The aim of this study was to verify how polishing and the type of abrasive can influence the wear rate of composite resin. The test was carried out on two groups. In one group we employed an ormocer and a hybrid composite that was polished group the composite was polished with the same abrasive paper plus a 1 microm and 0.25 microm grit diamond paste. A three-body wear test was performed using the metal sphere of the wear test machine, the composite and an abrasive. A diamond paste and aluminum oxide dispersion were used as abrasive. Analysis of the results showed that there was no difference between polishing techniques, but revealed a difference between abrasives.

  16. Dynamic SEM wear studies of tungsten carbide cermets. [friction and wear experiments

    Science.gov (United States)

    Brainard, W. A.; Buckley, D. H.

    1975-01-01

    Dynamic friction and wear experiments were conducted in a scanning electron microscope. The wear behavior of pure tungsten carbide and composite with 6 and 15 weight percent cobalt binder was examined, and etching of the binder was done to selectively determine the role of the binder in the wear process. Dynamic experiments were conducted as the tungsten carbide (WC) and bonded WC cermet surfaces were transversed by a 50 micron radiused diamond stylus. These studies show that the predominant wear process in WC is fracture initiated by plastic deformation, and the wear of the etched cermets is similar to pure WC. The presence of the cobalt binder reduces both friction and wear. The cementing action of the cobalt reduces granular separation, and promotes a dense polished layer because of its low shear strength film-forming properties. The wear debris generated from unetched surface is approximately the same composition as the bulk.

  17. Neuro-mechanical and metabolic adjustments to the repeated anaerobic sprint test in professional football players.

    Science.gov (United States)

    Brocherie, Franck; Millet, Gregoire P; Girard, Olivier

    2015-05-01

    This study aimed to determine the neuro-mechanical and metabolic adjustments in the lower limbs induced by the running anaerobic sprint test (the so-called RAST). Eight professional football players performed 6 × 35 m sprints interspersed with 10 s of active recovery on artificial turf with their football shoes. Sprinting mechanics (plantar pressure insoles), root mean square activity of the vastus lateralis (VL), rectus femoris (RF), and biceps femoris (BF) muscles (surface electromyography, EMG) and VL muscle oxygenation (near-infrared spectroscopy) were monitored continuously. Sprint time, contact time and total stride duration increased from the first to the last repetition (+17.4, +20.0 and +16.6 %; all P 0.05), decreased over sprint repetitions and were correlated with the increase in running time (r = -0.82 and -0.90; both P sprint repetitions, players with a better repeated-sprint performance (lower cumulated times) also displayed faster muscle de- (during sprints) and re-oxygenation (during recovery) rates (r = -0.74 and -0.84; P repeated anaerobic sprint test leads to substantial alterations in stride mechanics and leg-spring behaviour. Our results also strengthen the link between repeated-sprint ability and the change in neuromuscular activation as well as in muscle de- and re-oxygenation rates.

  18. Asphalt wear and pollution transport

    Energy Technology Data Exchange (ETDEWEB)

    Lindgren, Asa [Division of Traffic Engineering, Lulea University of Technology Lulea (Sweden)

    1996-09-06

    Studded tires cause extensive wear of road surfaces during winter producing small particles. Besides transporting different adsorbed pollutants these particles also discharge metal ions by their own natural content. The major part (95%) of the asphalt is composed of stone fractions. The rest consists mainly of bitumen, which contains trace quantities of metals. Laboratory studies in this study have demonstrated different adsorbing properties of metal ions, as well as differences in adsorption when comparing stone materials. Two stone materials, a gabbro and a porphyry, have been tested for their adsorption properties concerning Pb, Cu, Zn and Cd. The gabbro showed better adsorption capacity than the porphyry. Gabbro has coarser grains, it is softer, and also has a higher content of most metals compared to the porphyry. In all tests lead and copper are more adsorbed than zinc and cadmium. All metal ions are released at about the same pH ({approx}4)

  19. Energetic aspects of boring tools wear

    Directory of Open Access Journals (Sweden)

    Lazarová Edita

    2002-03-01

    Full Text Available In the process of rock desintegration a boring tool is subjected to the wear. From a viewpoint of the bit wear, changes on the contact of operating tool with rock at its one-shot and rerun load or overload by external forces are technically significant. Theis change results in the degradation of bit working properties and the output of desintegration also decreases. In the major part of cases, together with the bit wear, the contact area of a tool with a rock massifs enhanced and this fact causes an increase of fines (dust creation during the desintegration. The wear is always connected with a friction, forces action, deformation, damage, and the increased mechanical work consumption. As to energetic aspects of bit wear, the wear was observed as a function of bore length and in the most of cases as a dependence of the operating time. A linear dependence between the wear intensity (bit wear per unit of bore length and the specific energy of desintegration (energy consumed per volume unit of desintegrated rock was experimentally verified. Thus, the changes of bit wear can be implicitly observed by monitoring the specific energy. At the same time, the specific energy is a function of input parameters of the desintegration process and in the field of applicable external forces it shows an extreme (minimum. Therefore, the specific energy is useful for the extreme optimisation of the rock desintegration process from the viewpoint of the bit wear. It was mathematically proven that the tool output at the desintegration exponentially decreases with the amount of work consumed in the rock desintegration. The derivation of this knowledge comes out from the Krendelev equation.

  20. Adhesive Wear of Rollers in Vacuum

    Science.gov (United States)

    Shaeef, Iqbal; Krantz, Timothy L.

    2012-01-01

    This work was done to support NASA's James Webb Space Telescope that is equipped with a Near Infrared Camera and Spectrograph and Micro Shutter Assembly (MSA). A MSA mechanism's qualification test in cryogenic vacuum at 30deg K for 96K cycles resulted in roller wear and formation of some debris. Lab tests in vacuum were conducted at NASA Glenn Research Center (GRC) to understand the wear of Ti6Al4V mated with 440F steel rollers. Misalignment angle was found to have the most significant effect on debris formation. At misalignment angle of 1.4deg, significant amount of wear debris were formed within 50,000 cycles. Very few wear particles were found for a zero misalignment angle, and the total wear was small even after 367,000 cycles. The mode of wear in all the tests was attributed to adhesion, which was clearly evident from video records as well as the plate-like amalgamated debris material from both rollers. The adhesive wear rate was found to be approximately proportional to the misalignment angle. The wear is a two-way phenomenon, and the mixing of both roller materials in wear debris was confirmed by x-ray fluorescence (XRF) and EDX spectra. While there was a net loss of mass from the steel rollers, XRF and energy dispersive x-ray (EDX) spectra showed peaks of Ti on steel rollers, and peaks of Fe on Ti rollers. These results are useful for designers in terms of maintaining appropriate tolerances to avoid misalignment of rolling elements and the resulting severe wear

  1. Equilíbrio e retração muscular em jovens estudantes usuárias de calçado de salto alto Equilibrium and muscle retraction in young female students users of high-heeled shoes

    Directory of Open Access Journals (Sweden)

    Dernival Bertoncello

    2009-06-01

    Full Text Available Verifica-se precocidade na utilização de calçado de salto alto, mas não há muitos estudos identificando suas conseqüências. O objetivo deste trabalho foi verificar alterações de equilíbrio e eventual retração muscular em estudantes universitárias habituadas a utilizar salto alto diariamente. Foram avaliadas 30 jovens (média de 20 anos de idade que anotaram, durante duas semanas, o tempo diário em que permaneciam com o calçado. Foram avaliadas quanto a desvios posturais, quanto às retrações musculares da cadeia posterior, pelo teste de alcance horizontal, e quanto ao equilíbrio, pelo teste de Romberg. Os resultados foram analisados estatisticamente. A média de estatura foi 1,63 m e a de massa corporal, 58,5 kg. O tempo médio de uso dos sapatos de salto alto foi de 34 h por semana. Ao relacionar o alcance horizontal com o tempo semanal de uso do salto alto, verificou-se forte correlação negativa (r=-0,8692; pPrecocity has been noticed in the use of high-heeled shoes. However, there are not many studies on its consequences. The aim of this work was to search for equilibrium alterations in young women used to daily wearing high-heeled shoes. Thirty female undergraduates (mean aged 20 years old were asked to write down, for two weeks, the number of hours per day they remained with the shoes on. They were then assessed as to posture deviations, as to muscle retractions of the posterior chain by means of the sit and reach test, and as to equilibrium by the Romberg test. Results were statistically analysed. Mean volunteers' height was 1.63 m and mean body mass, 58.5 kg. A negative, strong correlation (r=-0.8692; p<0.0001 was noticed between reach range and weekly time (in hours of high-heeled shoe wearing. No correlation was found between reach range and time of high-heel use in years. Seventeen out of the 30 volunteers presented positive test for loss of equilibrium when barefoot with closed eyes. A weak, negative correlation (r

  2. Adapting playware to multiple players

    DEFF Research Database (Denmark)

    Þorsteinsson, Arnar Tumi; Lund, Henrik Hautop; Mastorakis, Nikos

    2011-01-01

    With the creation of playware as intelligent hardware and software that creates play, it is possible to adapt the play tool to the individual user, and even to multiple users playing at the same time with the play tool. In this paper, we show how it is possible to implement adaptivity in modular...... to such differences, and argues that adaptivity is needed to make games fit to the individual users in both single-player games and multi-player games. As a case study, we implemented such adaptivity on modular interactive tiles for the single-user game ColorTimer, and for the multiple-user games PingPong, in which...

  3. Psychological games of entangled players

    CERN Document Server

    Zak, Michail

    2012-01-01

    The paper introduces a new approach to theory of differential games in which entangled players try to predict and influence actions of their adversaries. The entanglement is generated be a joint probability density known by the players. Incase of complex density, its imaginary part represents a measure of uncertainty of the density distribution. The novelty of the approach is in non-Newtonian mathematical formalism thatis based upon a behavioral model of Livings. The model is quantum-inspired: it represented by a modified Madelung equation which the quantum potential is replaced by different, specially chosen "computational" potential. It consists of motor dynamics simulating actual behavior of the object, and mental dynamics representing evolution of the corresponding knowledge-based and incorporating this knowledge in the for m of information flows into the motor dynamics. Due to feedback from mental dynamics, motor dynamics attains quantum-like properties: its trajectory splits into a family of different t...

  4. Two-Player Graph Pebbling

    Science.gov (United States)

    Prudente, Matthew James

    Given a graph G with pebbles on the vertices, we define a pebbling move as removing two pebbles from a vertex u, placing one pebble on a neighbor v, and discarding the other pebble, like a toll. The pebbling number pi( G) is the least number of pebbles needed so that every arrangement of pi(G) pebbles can place a pebble on any vertex through a sequence of pebbling moves. We introduce a new variation on graph pebbling called two-player pebbling. In this, players called the mover and the defender alternate moves, with the stipulation that the defender cannot reverse the previous move. The mover wins only if they can place a pebble on a specified vertex and the defender wins if the mover cannot. We define η(G), analogously, as the minimum number of pebbles such that given every configuration of the η( G) pebbles and every specified vertex r, the mover has a winning strategy. First, we will investigate upper bounds for η( G) on various classes of graphs and find a certain structure for which the defender has a winning strategy, no matter how many pebbles are in a configuration. Then, we characterize winning configurations for both players on a special class of diameter 2 graphs. Finally, we show winning configurations for the mover on paths using a recursive argument.

  5. Motivational profile quality players handball

    Directory of Open Access Journals (Sweden)

    Alfonso Martínez Moreno

    2017-06-01

    Full Text Available In the sport context, elite category, it is necessary to know all the factors, which in one way or another, affect the athletes throughout the different competitions. The object of study is to know the motivational profile of elite handball players. The sample consisted of 495 players, of whom 47.8% were boys and 52.2% girls, their ages ranged from 12 to 16 years, with an average of 13.8 years (dt = 1.0. Descriptive statistical analyzes of the sample, absolute and relative frequencies were performed for the qualitative variables and for the quantitative values minimum, maximum, mean, standard deviation, Cronbach's alpha. Correlation between variables, with the Pearson correlation coefficient. The MANCOVA test was performed to determine if there were differences between the dimensions of the questionnaire, according to age and years of practice. The results reveal that handball players elite category of the sample object of study have mainly intrinsic motivation, achieving high scores on general motivation, motivation achievement and motivation stimulation. In addition to moderately high values in introjected regulation and very low values in demotivation.

  6. [Dietary behaviours of volleyball and basketball players].

    Science.gov (United States)

    Szczepańska, Elzbieta; Spałkowska, Agnieszka

    2012-01-01

    In sports, such as basketball and volleyball, players must demonstrate the speed, strength, stamina and concentration. Correct nutrition affects the strength of the muscles and the extension of capacity. It is also necessary for the proper functioning of the nervous system and determines the rate of regeneration after physical effort. The aim of this study was to assess dietary behaviours of professional volleyball and basketball players and compare the prevalence of correct behaviours in both groups. 209 professional volleyball and basketball players from sports clubs localized in six Silesian cities were survived with the mean of author questionnaire. The chi-square test was used to examine differences in the prevalence of the correct behaviours among players. Analysis of the results obtained showed that 52% of the players had 4-5 meals a day. 35% of respondents had wholemeal bread and/or groats daily. Milk and dairy products daily ate 71% of surveyed players, meat and sausages 70% respectively. 41% of respondents had cottage cheese and 28% had fish several times a week. Vegetables and fruit were eaten by 21% and respectively 23% of respondents. Sweets were eaten daily by 40% of surveyed, while fast-food were eaten several times a week by 17% of players. Nutrients for athletes were used by 32%, and vitamin supplementation by 48% of respondents. Prevalence of correct dietary behaviour in the group of professional volleyball and basketball players differed. Basketball players statistically more frequently than volleyball players had 4-5 meals a day, had wholemeal bread and/or thick groats, milk and dairy products, meat and sausages, especially poultry. They had raw vegetables and fruit several times a day. They drank more than 2.5 liters of fluids per day. They also significantly more frequently than volleyball players consumed the fast-food occasionally or never. Dietary behaviours of surveyed players were incorrect. Comparison of prevalence of proper behaviours

  7. Low handicap golfers generate more torque at the shoe-natural grass interface when using a driver.

    Science.gov (United States)

    Worsfold, Paul; Smith, Neal A; Dyson, Rosemary J

    2008-01-01

    The aim was to determine the rotational torque occurring at the shoe-natural grass interface during golf swing performance with different clubs, and to determine the influence of handicap and golf shoe design. Twenty-four golfers (8 low 0-7; 8 medium 8-14; and 8 high 15+) performed 5 shots with a driver, 3-iron and 7-iron when 3 shoes were worn: a modern 8 mm metal 7-spike shoe, an alternative 7-spike shoe and a flat soled shoe. Torque was measured at the front and back foot by grass covered force platforms in an outdoor field. Torque at the shoe- natural turf interface was similar at the front foot when using a driver, 3-iron and 7-iron with maximum mean torque (Tzmax 17-19 Nm) and torque generation in the entire backswing and downswing approximately 40 Nm. At the back foot, torque was less than at the front foot when using the driver, 3-iron and 7-iron. At the back foot Tzmax was 6-7 Nm, and torque generation was 10-16 Nm, with a trend for greater torque generation when using the driver rather than the irons. The metal spike shoe allowed significantly more back foot torque generation when using a driver than a flat- soled shoe (p 0.05), although back foot mean torques generated tended to be greater for the metal spike shoe. The golf shot outcomes were similar for low, medium and high handicappers in both metal and alternative spike shoes (metal: 87%; 76%; 54%; alternative: 85%; 74%; 54% respectively). The better, low handicap golfers generated significantly more back foot torque (metal spike: 18.2 Nm; alternative: 15.8 Nm; p low handicap and lighter body-weight golfers. Key pointsShoe to natural turf torque generation is an important component in performing a golf swing with a driver club.Torque at the shoe to natural turf interface was similar at the front foot when using a driver, 3-iron and 7-iron with Tzmax (17-19 Nm approx) and torque generation in the entire backswing and downswing of 40 Nm.Torque at the back foot was less than at the front foot when using

  8. Wear Characteristics of Metallic Biomaterials: A Review

    Directory of Open Access Journals (Sweden)

    Mohamed A. Hussein

    2015-05-01

    Full Text Available Metals are extensively used in a variety of applications in the medical field for internal support and biological tissue replacements, such as joint replacements, dental roots, orthopedic fixation, and stents. The metals and alloys that are primarily used in biomedical applications are stainless steels, Co alloys, and Ti alloys. The service period of a metallic biomaterial is determined by its abrasion and wear resistance. A reduction in the wear resistance of the implant results in the release of incompatible metal ions into the body that loosen the implant. In addition, several reactions may occur because of the deposition of wear debris in tissue. Therefore, developing biomaterials with high wear resistance is critical to ensuring a long life for the biomaterial. The aim of this work is to review the current state of knowledge of the wear of metallic biomaterials and how wear is affected by the material properties and conditions in terms of the type of alloys developed and fabrication processes. We also present a brief evaluation of various experimental test techniques and wear characterization techniques that are used to determine the tribological performance of metallic biomaterials.

  9. Wear mechanism and wear prevention in coal-fueled diesel engines. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schwalb, J.A.; Ryan, T.W.

    1991-10-01

    Coal fueled diesel engines present unique wear problems in the piston ring/cylinder liner area because of their tendency to contaminate the lube-oil with high concentrations of highly abrasive particles. This program involved a series of bench-scale wear tests and engine tests designed to investigate various aspects of the ring/liner wear problem and to make specific recommendations to engine manufacturers as to how to alleviate these problems. The program was organized into tasks, designed to accomplish the following objectives: (1) define the predominant wear mechanisms causing accelerated wear in the ring/liner area; (2) investigate the effectiveness of traditional approaches to wear prevention to prevent wear in coal-fueled engines; (3) further refine information on the most promising approaches to wear prevention; (4) present detailed information and recommendations to engine manufacturers on the most promising approach to wear prevention; (5) present a final report covering the entire program; (6)complete engine tests with a coal-derived liquid fuel, and investigate the effects of the fuel on engine wear and emissions.

  10. Wear mechanism and wear prevention in coal-fueled diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Schwalb, J.A.; Ryan, T.W.

    1991-10-01

    Coal fueled diesel engines present unique wear problems in the piston ring/cylinder liner area because of their tendency to contaminate the lube-oil with high concentrations of highly abrasive particles. This program involved a series of bench-scale wear tests and engine tests designed to investigate various aspects of the ring/liner wear problem and to make specific recommendations to engine manufacturers as to how to alleviate these problems. The program was organized into tasks, designed to accomplish the following objectives: (1) define the predominant wear mechanisms causing accelerated wear in the ring/liner area; (2) investigate the effectiveness of traditional approaches to wear prevention to prevent wear in coal-fueled engines; (3) further refine information on the most promising approaches to wear prevention; (4) present detailed information and recommendations to engine manufacturers on the most promising approach to wear prevention; (5) present a final report covering the entire program; (6)complete engine tests with a coal-derived liquid fuel, and investigate the effects of the fuel on engine wear and emissions.

  11. Dimensional Description of On-line Wear Debris Images for Wear Characterization

    Institute of Scientific and Technical Information of China (English)

    WU Tonghai; PENG Yeping; DU Ying; WANG Junqun

    2014-01-01

    As one of the most wear monitoring indicator, dimensional feature of individual particles has been studied mostly focusing on off-line analytical ferrograph. Recent development in on-line wear monitoring with wear debris images shows that merely wear debris concentration has been extracted from on-line ferrograph images. It remains a bottleneck of obtaining the dimension of on-line particles due to the low resolution, high contamination and particle’s chain pattern of an on-line image sample. In this work, statistical dimension of wear debris in on-line ferrograph images is investigated. A two-step procedure is proposed as follows. First, an on-line ferrograph image is decomposed into four component images with different frequencies. By doing this, the size of each component image is reduced by one fourth, which will increase the efficiency of subsequent processing. The low-frequency image is used for extracting the area of wear debris, and the high-frequency image is adopted for extracting contour. Second, a statistical equivalent circle dimension is constructed by equaling the overall wear debris in the image into equivalent circles referring to the extracted total area and premeter of overall wear debris. The equivalent circle dimension, reflecting the statistical dimension of larger wear debris in an on-line image, is verified by manual measurement. Consequently, two preliminary applications are carried out in gasoline engine bench tests of durability and running-in. Evidently, the equivalent circle dimension, together with the previously developed concentration index, index of particle coverage area (IPCA), show good performances in characterizing engine wear conditions. The proposed dimensional indicator provides a new statistical feature of on-line wear particles for on-line wear monitoring. The new dimensional feature conveys profound information about wear severity.

  12. Prediction of Wear in Crosslinked Polyethylene Unicompartmental Knee Arthroplasty

    Directory of Open Access Journals (Sweden)

    Jonathan Netter

    2015-05-01

    Full Text Available Wear-related complications remain a major issue after unicompartmental arthroplasty. We used a computational model to predict knee wear generated in vitro under diverse conditions. Inverse finite element analysis of 2 different total knee arthroplasty designs was used to determine wear factors of standard and highly crosslinked polyethylene by matching predicted wear rates to measured wear rates. The computed wear factor was used to predict wear in unicompartmental components. The articular surface design and kinematic conditions of the unicompartmental and tricompartmental designs were different. Predicted wear rate (1.77 mg/million cycles was very close to experimental wear rate (1.84 mg/million cycles after testing in an AMTI knee wear simulator. Finite element analysis can predict experimental wear and may reduce the cost and time of preclinical testing.

  13. Vitamin D Deficiency Among Professional Basketball Players.

    Science.gov (United States)

    Fishman, Matthew P; Lombardo, Stephen J; Kharrazi, F Daniel

    2016-07-01

    Vitamin D plays an important role in several systems of the human body. Various studies have linked vitamin D deficiency to stress and insufficiency fractures, muscle recovery and function, and athletic performance. The prevalence of vitamin D deficiency in the elite athletic population has not been extensively studied, and very few reports exist among professional athletes. There is a high prevalence of vitamin D deficiency or insufficiency among players attending the National Basketball Association (NBA) Combine. Cross-sectional study; Level of evidence, 3. This is a retrospective review of data previously collected as part of the routine medical evaluation of players in the NBA Combines from 2009 through 2013. Player parameters evaluated were height, weight, body mass index (BMI), and vitamin D level. Statistical analysis using t tests and analysis of variance was used to detect any correlation between the player parameters and vitamin D level. Vitamin D levels were categorized as deficient (32 ng/mL). After institutional review board approval was submitted to the NBA, the NBA released deidentified data on 279 players who participated in the combines from 2009 through 2013. There were 90 players (32.3%) who were deficient, 131 players (47.0%) who were insufficient, and 58 players (20.8%) who were sufficient. A total of 221 players (79.3%) were either vitamin D deficient or insufficient. Among all players included, the average vitamin D level was 25.6 ± 10.2 ng/mL. Among the players who were deficient, insufficient, and sufficient, the average vitamin D levels were 16.1 ± 2.1 ng/mL, 25.0 ± 3.4 ng/mL, and 41.6 ± 8.6 ng/mL, respectively. Player height and weight were significantly increased in vitamin D-sufficient players compared with players who were not sufficient (P = .0008 and .009, respectively). Player age and BMI did not significantly differ depending on vitamin D status (P = .15 and .77, respectively). There is a high prevalence of vitamin D deficiency

  14. Prediction of wear rates in comminution equipment

    DEFF Research Database (Denmark)

    Jensen, Lucas Roald Dörig; Fundal, Erling; Møller, Per

    2010-01-01

    Raw material comminution equipment may be exposed to excessive wear, which makes it difficult to operate minerals processing plants continuously because lengthy and unplanned shut-downs interrupt the overall process. In general, most comminution equipment is fine-tuned to operate at low vibrations......-resistant high chromium white cast iron (21988/JN/HBW555XCr21), a heat-treated wear resistant steel (Hardox 400) and a plain carbon construction steel (S235). Quartz, which accounts for the largest wear loss in the cement industry, was chosen as abrasive. Other process parameters such as velocity (1–7 m...

  15. Player-character dynamics in multi-player Role Playing Games

    DEFF Research Database (Denmark)

    Tychsen, Anders; McIlwain, Doris; Brolund, Thea

    2007-01-01

    This paper presents the results of a comprehensive empirical study of the impact of integrating complex game characters in multi-player Role Playing Games across tabletop and digital formats. Players were provided with characters that had detailed background history, personality and goals. Player...... and player engagement with their character and no correlation between enjoyment and similarity between player and character personality. © 2007 Authors & Digital Games Research Association (DiGRA)....... and character personality were assessed using the Extended Personal Attributes Questionnaire (EPAQ) and further questionnaires administered to measure player enjoyment and the player-character relationship. Results include a high level of player enjoyment across all formats, a high correlation between enjoyment...

  16. An investigation of player to player character identification via personal pronouns

    DEFF Research Database (Denmark)

    Hichens, Michael; Drachen, Anders; Richards, Deborah

    2012-01-01

    The player character is an important feature of many games, where it is through the character that the player interacts with game world. There has been considerable interest in the relationship between the player and the player character. Much of this work has examined the identification of players...... in playing video games, did have a statistically significant affect, indicating that different levels of identification are more dependent on the player than on the game. This indicates that players are not a homogeneous group with respect to player character identification and is an important consideration...... with their characters, generally taking either a textual analysis approach, or has been empirical work that has explicitly identified the idea of identification through survey instruments, etc. The work presented here takes a different empirical approach, focusing on the use of various pronoun forms (first, second...

  17. The Prevalence of Injuries in Professional Turkish Soccer Players

    Science.gov (United States)

    Yamaner, Faruk; Gumusdag, Hayrettin; Kartal, Alparslan; Gumus, M.; Gullu, A.; Imamoglu, O.

    2011-01-01

    Study aim: To assess the prevalence and anatomical sites of injuries in professional soccer players in one game season. Material and methods: A cohort of 510 professional male soccer players consisting of 48 goalkeepers, 194 defence players, 189 mid-field players and 79 forward players of the 1st and 2nd Turkish Professional Soccer Leagues in…

  18. Engineering specification and system design for CAD/CAM of custom shoes: UMC project effort

    Science.gov (United States)

    Bao, Han P.

    1991-01-01

    The goal of this project is to supplement the footwear design system of North Carolina State University (NCSU) with a software module to design and manufacture a combination sole. The four areas of concentration were: customization of NASCAD (NASA Computer Aided Design) to the footwear project; use of CENCIT data; computer aided manufacturing activities; and beginning work for the bottom elements of shoes. The task of generating a software module for producing a sole was completed with a demonstrated product realization. The software written in C was delivered to NCSU for inclusion in their design system for custom footwear known as LASTMOD. The machining process of the shoe last was improved using a spiral tool path approach.

  19. Shoe-mounted vibration energy harvester of PZT piezoelectric thin films on metal foils

    Science.gov (United States)

    Nishi, T.; Ito, T.; Hida, H.; Kanno, I.

    2016-11-01

    This paper describes shoe-mounted piezoelectric vibration energy harvesters (PVEHs). The PVEHs were fabricated from Pb(ZrTi)O3 (PZT) thin films which were directly deposited onto Pt/Ti-coated stainless steel foil by rf-magnetron sputtering. We experimentally and theoretically evaluated impulse responses of the PVEHs by applying a simple impulse input on the energy harvesters, typical damped free vibration behaviour was clearly observed, and the output signal was in good agreement with the theoretical value. We measured the output power by applying the impulse input with an optimal load resistance of 33.9 kΩ. The maximum output power was approximately 20 μW, which correspond with the calculated value based on theoretical equation. From these results, the theoretical equation we derived might be helpful for design purposes of the shoe-mounted PVEHs.

  20. Enhancing Indoor Inertial Pedestrian Navigation Using a Shoe-Worn Marker

    Directory of Open Access Journals (Sweden)

    Mitja Placer

    2013-08-01

    Full Text Available We propose a novel hybrid inertial sensors-based indoor pedestrian dead reckoning system, aided by computer vision-derived position measurements. In contrast to prior vision-based or vision-aided solutions, where environmental markers were used—either deployed in known positions or extracted directly from it—we use a shoe-fixed marker, which serves as positional reference to an opposite shoe-mounted camera during foot swing, making our system self-contained. Position measurements can be therefore more reliably fed to a complementary unscented Kalman filter, enhancing the accuracy of the estimated travelled path for 78%, compared to using solely zero velocities as pseudo-measurements.

  1. Study on Walking Training System using High-Performance Shoes constructed with Rubber Elements

    Science.gov (United States)

    Hayakawa, Y.; Kawanaka, S.; Kanezaki, K.; Doi, S.

    2016-09-01

    The number of accidental falls has been increasing among the elderly as society has aged. The main factor is a deteriorating center of balance due to declining physical performance. Another major factor is that the elderly tend to have bowlegged walking and their center of gravity position of the body tend to swing from side to side during walking. To find ways to counteract falls among the elderly, we developed walking training system to treat the gap in the center of balance. We also designed High-Performance Shoes that showed the status of a person's balance while walking. We also produced walk assistance from the insole in which insole stiffness corresponded to human sole distribution could be changed to correct the person's walking status. We constructed our High- Performances Shoes to detect pressure distribution during walking. Comparing normal sole distribution patterns and corrected ones, we confirmed that our assistance system helped change the user's posture, thereby reducing falls among the elderly.

  2. On the interaction between structure and oil film of a guide shoe bearing

    DEFF Research Database (Denmark)

    Vølund, Anders

    2001-01-01

    A solution procedure for the determination of the oil film thickness of a guide shoe bearing for a large two stroke marine diesel engine is presented. Based on a previous study considering oil film thickness of a guide shoe bearing with rigid structural parts a model for the interaction between s...... of the structure is a 3D finite element model and the oil film description is made using a 2D finite difference mesh....... structure and oil film is implemented. The model takes into account the elastic deformation of the bearing parts. An iterative procedure for determining pressure, deformation and squeeze velocity is applied. The results are compared to a traditional calculation of rigid components. The model...

  3. The predictive analysis of wear work-rates in wear test rigs

    Energy Technology Data Exchange (ETDEWEB)

    Phalippou, C.; Delaune, X.

    1996-12-31

    Impact and sliding wear in components is classically studied, as far as the wear laws are concerned, in specific wear test rigs that simulate the vibratory motion induced by the flow. In this paper, an experimental and numerical study on the impact forces and wear work-rates of a typical AECL rig is presented. The mode shapes and frequencies are measured and compared with finite element computations. Impact and sliding motions between the wear specimens are calculated and compared to the experimental results. Impact forces, mean values of wear work-rates as well as the specimen relative motions are found to be close to the experimental data. (authors). 14 refs., 9 figs., 5 tabs.

  4. Chess players' fame versus their merit

    CERN Document Server

    Simkin, M V

    2015-01-01

    We investigate a pool of international chess title holders born between 1901 and 1943. Using Elo ratings we compute for every player his expected score in a game with a randomly selected player from the pool. We use this figure as player's merit. We measure players' fame as the number of Google hits. The correlation between fame and merit is 0.38. At the same time the correlation between the logarithm of fame and merit is 0.61. This suggests that fame grows exponentially with merit.

  5. Physiological characteristics of international female soccer players.

    Science.gov (United States)

    Manson, Sarah A; Brughelli, Matt; Harris, Nigel K

    2014-02-01

    The purpose of this study was to investigate the physiological characteristics of Fédération Internationale de Football Association (FIFA) eligible international female soccer players aged 14-36 years and to determine if measures were significantly different for players selected (i.e., starters) to the starting line up for an FIFA tournament as compared with those not selected (i.e., nonstarters). Fifty-one (N = 18 Under 17; N = 18 Under 20; N = 15 Senior) international female soccer players participated in this study. The subjects underwent measurements of anthropometry (height and body mass), lower body strength (isokinetic testing), sprint kinetics and kinematics (nonmotorized treadmill), leg power (unilateral jumping), and maximal aerobic velocity (30:15 intermittent fitness test) during the final preparatory stage for an FIFA event. Outcomes of the age group data indicate that differences in physiological capacities are evident for the Under 17 players as compared with those for the Under 20 and Senior capped international players, suggesting a plateau in the acquisition of physical qualities as players mature. Starters tended to be faster (effect size [ES] = 0.55-1.0, p velocity (ES = 0.78-2.45, p velocity (ES = 0.87, p players, where maximal aerobic velocity was the primary difference between starters and nonstarters (ES = 0.83-2.45, p players. Coaches should emphasize the development of speed, maximal aerobic velocity, and leg strength in developing female soccer players.

  6. Study on friction behaviour of brake shoe materials for mining hoist

    Science.gov (United States)

    Ungureanu, M.; Ungureanu, N. S.; Crăciun, I.

    2017-02-01

    The friction coefficient in the brake linkages has an important influence on the braking efficiency and safety of machines. The paper presents a method for the study of the friction coefficient of the friction couple brake shoe-drum for mining hoist. In this context, it is interesting to define the friction coefficient, not just according to the materials in contact, but according to the entire ensemble of tribological factors of the friction couple.

  7. EFFECT OF SHOE RAISE ALONG WITH MOTOR RELEARNING PROGRAMME (MRP ON AMBULATION IN CHRONIC STROKE

    Directory of Open Access Journals (Sweden)

    Gajanan Bhalerao

    2016-06-01

    Full Text Available Background: Stroke subjects face reduced tolerance to activity and sedentary lifestyle due to various impairments, such as muscle weakness, pain, spasticity, and poor balance. Thus, loss of independent ambulation especially outdoors is generally observed in them. Methods: Chronic stroke patients (> 6 months with Functional Ambulation Category score > 2 and able to walk at least 10 meters of distance with and without assistance from a tertiary healthcare centre were selected and treated. Subjects were randomly divided into 2 groups control group (n=14 and experimental group (n=13. Each group received Motor Relearning Programme for 60 minutes, 6 times a week for 4 weeks. The experimental group received an additional shoe-raise of 1 cm on the unaffected side along with while ambulating during therapy as well as at home. Pre and post treatment the patients were assessed for spatio-temporal parameters using foot print analysis method and Rivermead Visual Gait Assessment (RVGA Score using RVGA scale. Results: There was significant improvement seen in almost all the spatio-temporal gait parameters and RVGA score in within group analysis. Whereas on between group the results from between group comparison suggests that subjects in MRP with shoe-raise group showed better results in spatio-temporal parameters of gait than subjects receiving MRPalone. But there was no additional benefit of shoe-raise seen on RGVA score and angle of toe-out parameter. Conclusion: Additional use of shoe-raise helps to improve spatio-temporal gait parameters. However, there was no additional change seen in RVGA score.

  8. Wear mechanism and wear prevention in coal-fueled diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Schwalb, J.A.

    1991-06-01

    Contamination of the lube-oil with hard abrasive particles leads to a three-body abrasive wear mechanism that highly accelerates piston ring/cylinder liner wear in coal-fueled diesel engines. One approach to reducing that wear is to modify the size and orientation of surface asperities on the cylinder to enhance the formation of a hydrodynamic film, and to provide avenues of escape for particles that would otherwise be trapped in the wear zone. Another approach is to introduce additives into the contaminated lube-oil that further enhance hydrodynamic film formation, form chemical films on the wearing surfaces, or form films on the contaminant particles. This work focuses on defining the effects of cylinder liner surface finish, various configurations of slots in the cylinder liner surface, and various additives in the contaminated lube-oil on the wear process. Wear tests were initiated in a bench apparatus using coal-ash contaminated lube-oil to test the various wear configurations. The results of these tests indicate that the formation of a hydrodynamic film between the ring and cylinder specimens is enhanced by increasing surface roughness, and by orienting the surface asperities normal to the direction of ring travel but modifications to the cylinder liner surface did not greatly reduce the wear rate. Additives to the lubricant seemed to have a much more significant effect on wear, with a dispersant additive highly accelerating the wear, while a detergent additive was able to reduce the wear almost to the rate achieved where there was no contaminant.

  9. STUDIES ON TOOL WEAR CONDITION MONITORING

    Directory of Open Access Journals (Sweden)

    Hüseyin Metin ERTUNÇ

    2001-01-01

    Full Text Available In this study, wear mechanisms on cutting tools, especially for the drill bits, during the cutting operation have been investigated. As the importance of full automation in industry has gained substantial importance, tool wear condition monitoring during the cutting operation has been the subject of many investigators. Tool condition monitoring is very crucial in order to change the tool before breakage. Because tool breakage can cause considerable economical damage to both the machine tool and workpiece. In this paper, the studies on the monitoring of drill bit wear in literature have been introduced; the direct/indirect techniques used and sensor fusion techniques have been summarized. The methods which were proposed to determine tool wear evolution as processing the sensor signals collected have been provided and their references have been given for detailed information.

  10. Wear behavior of austenite containing plate steels

    Science.gov (United States)

    Hensley, Christina E.

    As a follow up to Wolfram's Master of Science thesis, samples from the prior work were further investigated. Samples from four steel alloys were selected for investigation, namely AR400F, 9260, Hadfield, and 301 Stainless steels. AR400F is martensitic while the Hadfield and 301 stainless steels are austenitic. The 9260 exhibited a variety of hardness levels and retained austenite contents, achieved by heat treatments, including quench and tempering (Q&T) and quench and partitioning (Q&P). Samples worn by three wear tests, namely Dry Sand/Rubber Wheel (DSRW), impeller tumbler impact abrasion, and Bond abrasion, were examined by optical profilometry. The wear behaviors observed in topography maps were compared to the same in scanning electron microscopy micrographs and both were used to characterize the wear surfaces. Optical profilometry showed that the scratching abrasion present on the wear surface transitioned to gouging abrasion as impact conditions increased (i.e. from DSRW to impeller to Bond abrasion). Optical profilometry roughness measurements were also compared to sample hardness as well as normalized volume loss (NVL) results for each of the three wear tests. The steels displayed a relationship between roughness measurements and observed wear rates for all three categories of wear testing. Nanoindentation was used to investigate local hardness changes adjacent to the wear surface. DSRW samples generally did not exhibit significant work hardening. The austenitic materials exhibited significant hardening under the high impact conditions of the Bond abrasion wear test. Hardening in the Q&P materials was less pronounced. The Q&T microstructures also demonstrated some hardening. Scratch testing was performed on samples at three different loads, as a more systematic approach to determining the scratching abrasion behavior. Wear rates and scratch hardness were calculated from scratch testing results. Certain similarities between wear behavior in scratch testing

  11. A Study of Slipper and Rail Wear Interaction at Low Speed

    Science.gov (United States)

    2014-06-19

    taking care of the boys, a house and a dog and for not getting discouraged. I pray that they will learn as I have how important it is to ensure Yahovah...wear, delamination wear, seizure wear, melt wear, severe oxidational wear and adhesive wear. Adhesive wear comprised of three zones: low speed...model is experiencing seizure or melt wear, then something is wrong with the model. Lim and Ashby also published on their wear map the normalized wear

  12. [Use of tempered, particle-reinforced aluminum horse shoes in sport horses under field conditions].

    Science.gov (United States)

    Brandstetter, J; Stanek, C; Hinterhofer, C

    1999-02-01

    The use of handmade particulate reinforced alloy horseshoes (MMC metal matrix composites) was tested in a field study on 15 riding and draught horses. All horseshoes have been tempered after having been manually forged and tested concerning their surface imperfection. Forging temperature ranged between 350 degrees and 420 degrees C. Horseshoes in series A consisted of particulate reinforced wrought alloy (22% Al2O3 in alloy matrix). 11 shoeing periods with a duration of mean = 49.7 days (sd = 13.6) were evaluated. Horseshoes in series B consisted of particulate reinforced foundry alloy (20% SiC in alloy matrix), 5 shoeing periods were evaluated with a duration of mean = 45.4 days (sd = 7.9). Series C tested horseshoes made of particulated reinforced coextruded wrought alloy evaluating 6 shoeing periods with a duration of mean = 49.2 days (sd = 18.7). Service of the tempered particulate reinforced alloy horseshoes was significantly higher compared to untempered alloy horseshoes. Mechanical and forging properties of tempered particulate reinforced alloy are satisfactory. Service is only suitable for riding horses but not for draught horses.

  13. Effect of midsole thickness of dance shoes on dynamic postural stability.

    Science.gov (United States)

    Wyon, Matthew A; Cloak, Ross; Lucas, Josephine; Clarke, Frances

    2013-12-01

    Landing from jumps is one of the main causes of injury within dance. A number of studies have reported a negative effect of shoe midsole thickness on lower limb kinematics during running due to the reduction in afferent sensory outputs from the foot's epithelium. The purpose of this study was to examine the influence of varying midsole thicknesses in dance shoes on dynamic postural stability during a single-leg landing. Twenty-eight female undergraduate dance participants volunteered for the study. They carried out three trials under four conditions: barefoot and in ballet flats (2 mm midsole thickness), jazz shoes (7 mm), and dance sneakers (30 mm). The task consisted of a single-leg forward jump over a hurdle at 50% of their maximal vertical jump height, landing on a force platform, and balancing for 3 seconds. The stability indices for vertical stability (VSI), anterior-posterior stability (APSI), medial-lateral stability (MLSI), and dynamic postural stability (DPSI) were calculated using Wikstrom's revised method. Significant differences were reported between the midsole thicknesses for both DPSI and VSI (p<0.01). No statistical differences were noted for the indices SPSI or MLSI. The present data agree with the running studies in that increased midsole thickness has a negative influence on landing stability.

  14. Foot dimensions of elderly people with and without diabetes mellitus - a data basis for shoe design.

    Science.gov (United States)

    Chantelau, E; Gede, A

    2002-01-01

    Injuries from footwear are common in elderly people, particularly in those with diabetes mellitus and polyneuropathy. A common cause is a mismatch between foot and shoe. To assess the length and the breadth of the feet by an automatic measuring device in 568 patients with diabetic polyneuropathy and in 100 nondiabetic control subjects of the same mean age of 64 years. While the foot length in all cases matched well with the size of the normal footwear available on the market, more than two thirds of the feet were considerably broader than the normal footwear available. The foot breadth correlated variably with the foot length. Tables of foot dimensions for men and women are provided over the complete range of shoe sizes. This anthropometric data set on feet, which is the first conducted in elderly people, proves that most feet of elderly people with or without diabetic neuropathy do not fit ordinary casual footwear. Therefore, the construction of shoes according to the anthropometric data of elderly people is required in order to prevent foot injuries in this particular population. Copyright 2002 S. Karger AG, Basel

  15. Design and characterization of an aerodynamic shoe sampling system for screening trace explosive materials

    Science.gov (United States)

    Staymates, Matthew; Gillen, Greg; Grandner, Jessica; Lukow, Stefan

    2011-11-01

    As part of an ongoing effort with the Transportation Security Laboratory, the National Institute of Standards and Technology has been developing a prototype shoe sampling system that relies on aerodynamic sampling as the primary mechanism for liberating, transporting, and collecting explosive contamination. This presentation will focus on the fluid dynamics associated with the current prototype design. This design includes several air jets and air blades that are used to dislodge particles from target areas of a shoe. A large blower then draws air and liberated particles into a collection device at several hundred liters per second. Experiments that utilize optical particle counting techniques have shown that the applied shear forces from these jets are capable of liberating particles efficiently from shoe surfaces. Results from real-world contamination testing also support the effectiveness of air jet impingement in this prototype. Many examples of flow visualization will be shown. The issues associated with air spillage, particle release efficiency, and particle transport will also be discussed.

  16. Wireless patient monitoring on shoe for the assessment of foot dysfunction: an overview

    Science.gov (United States)

    Abraham, Jose K.; Whitchurch, Ashwin K.; Varadan, Vijay K.; Sarukesi, Karunakaran

    2003-04-01

    This paper presents an overview of the wireless monitoring and quantitative assessment of joint dynamics of ankle which has suffered from soft tissue injury, immobilization or any dysfunction with special focus on the treatment and rehabilitation applications. The inadequacy of a reliable and easy method for continuous measurement and recording of ankle movement while doing physical therapy makes the monitoring of its progress difficult. Development of a wireless ankle motion monitoring system inside the shoe provides information on several aspects of activities associated with a dysfunctional foot. The system is based on continuous wireless monitoring of signals from accelerometers and gyroscopes fixed inside the shoe. From these signals, the duration, rate, and moment of occurrence of activities associated with mobility (e.g., lying, sitting, standing, walking up and down, running, cycling, wheelchair use and general movement) and transitions (changes in angle) can be detected. Information about the movement can be obtained by the acceleration sensors, which is related to the intensity of body-segment movement. Apart from monitoring accelerations, other signals due to turning and angular movements can be obtained using the miniature gyroscope attached to the shoe.

  17. Measurement of Lubricating Condition between Swashplate and Shoe in Swashplate Compressors under Practical Operating Conditions

    Science.gov (United States)

    Suzuki, Hisashi; Fukuta, Mitsuhiro; Yanagisawa, Tadashi

    In this paper, lubricating conditions between a swashplate and a shoe in a swashplate compressor for automotive air conditioners is investigated experimentally. The conditions are measured with an electric resistance method that utilizes the swash plate and the shoe as electrodes respectively. The instrumented compressor is connected to an experimental cycle with R134a and operated under various operating conditions of pressure and rotational speed. An improved measurement technique and applying a solid contact ratio to the measurement results permit to measure the lubricating condition at high rotational speed (more than 8000 rpm) and to predic an occurrence of scuffing between the swashplate and the shoe, and therefore enables a detailed study of lubricating characteristics. It is shown by the measurement that the voltage of the contact signal decreases, which means better lubricating condition, with the decrease of the compression pressure and with the increase of the rotational speed from 1000 rpm through 5000 rpm. The lubricating condition tends to worsen at more than 5000 rpm. Furthermore, it is confirmed that the lubricating condition under transient operation is worse obviously as compared with that under steady-state operation.

  18. Third abrasive wear mode: is it possible?

    Directory of Open Access Journals (Sweden)

    Ronaldo Câmara Cozza

    2014-04-01

    Full Text Available The objective of this paper is to propose an initial discussion on the characterization of a third abrasive wear mode. The results obtained in a previous work [1] under different test conditions revealed the occurrence of the superposition of the “rolling” and “grooving” abrasive wear modes. This phenomenon was denoted “micro-rolling abrasion” due to the observation that “rolling abrasion” was found to act on “grooving abrasion”.

  19. Biotribology :articular cartilage friction, wear, and lubrication

    OpenAIRE

    Schroeder, Matthew O

    1995-01-01

    This study developed, explored, and refined techniques for the in vitro study of cartilage-on-cartilage friction, deformation, and wear. Preliminary results of in vitro cartilage-on- cartilage experiments with emphasis on wear and biochemistry are presented. Cartilage-bone specimens were obtained from the stifle joints of steers from a separate controlled study. The load, sliding speed, and traverse of the lower specimens were held constant as lubricant and test length were varied. Lubric...

  20. Sex differences in head acceleration during heading while wearing soccer headgear.

    Science.gov (United States)

    Tierney, Ryan T; Higgins, Michael; Caswell, Shane V; Brady, Jessica; McHardy, Krista; Driban, Jeffrey B; Darvish, Kurosh

    2008-01-01

    Researchers have indicated that female soccer players may be at greater risk of concussion compared with their male counterparts. Soccer headgear is marketed for reducing head acceleration and risk of concussion. To determine the effect of sex and soccer headgear on head impact kinematics and dynamic stabilization during soccer heading. Cross-sectional design. Research laboratory. Forty-four college-aged soccer players (29 women, 15 men). Using a head impact model, participants performed 4 soccer headers under 3 headgear conditions (control, Head Blast Soccer Band, and Full90 Select Performance Headguard). Dependent variables assessed before soccer heading were head-neck anthropometrics and isometric neck muscle strength, and those assessed during soccer headers were resultant linear head acceleration, Head Injury Criteria (HIC(36)), and superficial neck muscle electromyography. Statistical analyses included multivariate and univariate analyses of variance with repeated measures, independent-samples t tests, appropriate follow-up analyses of variance and post hoc t tests, and Pearson product moment correlations (alpha = .05). Head acceleration in women was 32% and 44% greater than in men when wearing the Head Blast (21.5 g versus 16.3 g) and Full90 Select (21.8 g versus 15.2 g), respectively (P head accelerations (20.2 g versus 18.2 g) during the control condition (P = .164). Female soccer players exhibited greater head accelerations than their male counterparts when wearing headgear. Our results are important clinically because they indicate that soccer headgear may not be an appropriate head injury prevention tool for all athletes.

  1. Pseudomembranous candidiasis in patient wearing full denture

    Directory of Open Access Journals (Sweden)

    Nurdiana Nurdiana

    2009-06-01

    Full Text Available Background: Oral candidiasis is a common opportunistic infection of the oral cavity caused by an overgrowth of Candida species, the commonest being Candida albicans. Candida albicans is a harmless commensal organism inhabiting the mouths but it can change into pathogen and invade tissue and cause acute and chronic disease. Dentures predispose to infection with Candida in as many as 65% of elderly people wearing full upper dentures. Purpose: The purpose of this case report is to discuss thrush in patient wearing full denture which rapidly developed. Case: This paper report a case of 57 year-old man who came to the Oral Medicine Clinic Faculty of Dentistry Airlangga University with clinical appearance of pseudomembranous candidiasis (thrush. Case Management: Diagnosis of this case is confirmed with microbiology examination. Patient was wearing full upper dentures, and from anamnesis known that patient wearing denture for 24 hours and he had poor oral hygiene. Patient was treated with topical (nystatin oral suspension and miconazole oral gel and systemic (ketoconazole antifungal. Patient also instructed not to wear his denture and cleaned white pseudomembrane on his mouth with soft toothbrush. Conclusion: Denture, habit of wearing denture for 24 hours, and poor oral hygiene are predisposing factors of thrush and it can healed completely after treated with topical and systemic antifungal.

  2. Effects of wearing compression garments on thermoregulation during simulated team sport activity in temperate environmental conditions.

    Science.gov (United States)

    Houghton, Laurence A; Dawson, Brian; Maloney, Shane K

    2009-03-01

    Anecdotal evidence suggests compression garments (CGs) are being worn underneath normal playing attire during team sports. Wearing CGs as a baselayer could possibly increase heat storage, and so this field study investigated the effects of wearing CGs, comprising knee-length shorts and short-sleeved top underneath normal match-day attire (COMP), versus normal match-day attire alone (NORM) on thermoregulation during simulated team sport activity. Ten match-fit field hockey players twice performed 4x15min exercise bouts consisting of repeated cycles of intermittent, varied-intensity 20m shuttle running (Loughborough intermittent shuttle test), once in COMP and once in NORM. Testing was conducted in an indoor gymnasium (ambient conditions: approximately 17 degrees C, approximately 60% relative humidity). Participants acted as their own controls. Heart rate (HR), 15m sprint time, ratings of perceived exertion (RPE), blood lactate concentration, sweat rate and body core temperature (T(core)) were similar between trials (p>0.05). Mean skin temperature (T(skin)) was significantly higher in COMP than NORM (p<0.05). Overall, CGs worn as a baselayer during simulated team sport exercise in temperate ambient conditions had no thermoregulatory benefits nor any detrimental effects on T(core), physiological performance or dehydration. However, the higher T(skin) may affect individual preference for wearing CGs as an undergarment during team sports.

  3. Effect of Five-Finger Shoes on Vertical Ground Reaction Force Loading Rates and Perceived Comfort during the Stance Phase of the Running

    Directory of Open Access Journals (Sweden)

    Seyede Zeynab Hoseini

    2016-06-01

    Full Text Available Objective:  Increased vertical ground reaction force loading rates and lack of comfort footwear in the early stance phase can increase the risk of overuse injuries. The purpose of this study was to investigate the effect of Five-finger shoes on vertical ground reaction force loading rate and perceived comfort during the stance phase of running. Methods: 15 male students (aged 24 ± 5/24 years, weight 75/8 ± 4/61 kg, height 178/6 ± 6/64 cm were selected. Subjects were asked to run over a force plate, in control shoe, five finger shoe and barefoot conditions. Loading rate using the slope of the vertical reaction force and perceived comfort were determined using a visual analogue scale. One factor repeated measures ANOVA was used to test the loading rate hypothesis and Paired t-tests was used to test the meaningfulness of perceived comfort (P<0/05. Results: The effect of shoes on loading rate was found to be not significant (P=0.1. However, comfort of control shoes increased by 10. 92% as compared to that of five-finger shoes (P=0.001.  Conclusion: The loading rate of five-finger shoes is the same as that of barefoot during running; however, as subjects did not perceive them as comfortable as regular shoes are five-finger shoes cannot be advised as a desirable choice in exercises.

  4. Wear Property of Cast Steel Wheel Material in Rail Truck

    Institute of Scientific and Technical Information of China (English)

    MI Guo-fa; LIU Yan-lei; ZHANG Bin; FU Xiu-qin; ZHANG Hong; SONG Guo-xiang

    2009-01-01

    Wear property of material plays a key role in the service time of workpiece.A major objective in the development of new wheel materials is to improve the wear performance.The wear property of B and B+ grade cast steel materials was reported.The results showed that B+ grade cast steel material exhibited better wear property than the B grade material.Carbon content related to the hardness match was the principal factor affecting the wear properties.

  5. Wear-resistance of Aluminum Matrix Microcomposite Materials

    Directory of Open Access Journals (Sweden)

    M. Kandeva

    2011-03-01

    Full Text Available A procedure is developed for the study of wear of aluminum alloys AlSi7 obtained by casting, reinforced by TiC microparticles, before and after heat treatment. Tribological study is realized under conditions of friction on counterbody with fixed abrasive. Experimental results were obtained for mass wear, wear rate, wear intensity and wear-resistance of the alloys with different wt% of microparticles.

  6. Cooperation: New Players in Africa

    Directory of Open Access Journals (Sweden)

    Philippe Hugon

    2010-03-01

    Full Text Available In the context of globalisation and the current global financial crisis, new players are emerging in cooperation in Africa. These partners loosen financial constraints and conditionalities, increase the room for manoeuvre and stimulate commodity markets. On the other hand, they also increase the risks of renewed indebtedness and potentially weaken the coordination of aid policies. Do these partnerships call the new cooperation practices of OECD countries into question? Do they justify the return to a realpolitik or are they repeating the earlier mistakes of industrial powers? Can these mistakes be corrected? The question also arises as to whether the global crisis, which has a profound effect on Africa, will lead to a withdrawal or to a passing of the baton on to new, emerging powers. This article highlights the new geopolitical issues concerning Africa in a multipolar world, then discusses the new players involved in cooperation in Africa, before going on to explore the horizons that are opening up for cooperation in Africa, in particular with regard to the global crisis.

  7. The potential risk of personal stereo players

    DEFF Research Database (Denmark)

    Hammershøi, Dorte; Ordoñez, Rodrigo Pizarro; Reuter, Karen

    2010-01-01

    The technological development within personal stereo systems, such as MP3 players, e. g. iPods, has changed music listening habits from home entertainment to everyday and everywhere use. The technology has developed considerably, since the introduction of cassette players and CD walkmen. High...

  8. The potential risk of personal stereo players

    DEFF Research Database (Denmark)

    Hammershøi, Dorte; Ordoñez, Rodrigo Pizarro; Reuter, Karen

    2010-01-01

    The technological development within personal stereo systems,such as MP3 players, e. g. iPods, has changed music listening habits from home entertainment to everyday and everywhere use. The technology has developed considerably, since the introduction of cassette players and CD walkmen. High...

  9. Who Are the Players in Canadian Curriculum?

    Science.gov (United States)

    Milburn, Geoffrey

    1987-01-01

    Labels range of persons advocating different theoretical positions of Canadian curriculum as "players." Describes players as "managers,""predictors,""transformers,""sleuths,""analysts." Values varied viewpoints for attention to language regarding curriculum, critical review of ideas/concepts, examination of current policies, awareness of history…

  10. QuizUp Single Player Web

    OpenAIRE

    Gunnar Marteinsson 1983; Kristinn Júlíusson 1993; Sonja Jónsdóttir 1992; Steinar Þór Árnason 1993

    2016-01-01

    In this report we discuss the B.Sc. project named QuizUp Single Player Web. The project was developed at Reykjavik University in the spring of 2016 in collaboration with Plain Vanilla Games, the makers of the world famous QuizUp app. We developed a Single Player Web application based on the original multiplayer game.

  11. Inferring Player Experiences Using Facial Expressions Analysis

    NARCIS (Netherlands)

    Tan, C.T.; Bakkes, S.; Pisan, Y.; Blackmore, K.; Nesbitt, K.; Smith, S.P.

    2014-01-01

    Understanding player experiences is central to game design. Video captures of players is a common practice for obtaining rich reviewable data for analysing these experiences. However, not enough has been done in investigating ways of preprocessing the video for a more efficient analysis process. Thi

  12. Finite stage asymmetric repeated games: Both players' viewpoints

    KAUST Repository

    Li, Lichun

    2017-01-05

    In asymmetric zero-sum games, one player has superior information about the game over the other. It is known that the informed players (maximizer) face the tradeoff of exploiting its superior information at the cost of revealing its superior information, but the basic point of the uninformed player (minimizer)\\'s decision making remains unknown. This paper studies the finite stage asymmetric repeated games from both players\\' viewpoints, and derives that not only security strategies but also the opponents\\' corresponding best responses depends only on the informed player\\'s history action sequences. Moreover, efficient LP formulations to compute both player\\'s security strategies are provided.

  13. Injuries in racket sports among Slovenian players.

    Science.gov (United States)

    Kondric, Miran; Matković, Branka R; Furjan-Mandić, Gordana; Hadzić, Vedran; Dervisević, Edvin

    2011-06-01

    On the sample of 83 top Slovenian athletes we have studied the frequency of injuries among table tennis, tennis and badminton players, types of injuries and severity of injuries--the latter based on data of players absences from training and/or competition processes. The most liable parts to injuries are shoulder girdle (17.27%), spine (16.55%) and ankle (15.83%), while foot (10.07%) and wrist (12.23%) are slightly less liable to injuries. The most frequent injuries in racket sports pertain to muscle tissues. According to this data, the majority of injuries occur halfway through a training session or a competition event, mostly during a competition season. The injuries primarily pertain to muscle tissues; these are followed by joint and tendon injuries. There are no differences between male and female players. Compared to other racket sports players, table tennis players suffer from fewer injuries.

  14. Decreased Nerve Conduction Velocity in Football Players

    Directory of Open Access Journals (Sweden)

    Daryoush Didehdar

    2014-06-01

    Full Text Available Background: Lower limbs nerves are exposed to mechanical injuries in the football players and the purpose of this study is to evaluate the influence of football on the lower leg nerves. Materials and Methods: Nerve conduction studies were done on 35 male college students (20 football players, 15 non active during 2006 to 2007 in the Shiraz rehabilitation faculty. Standard nerve conduction techniques using to evaluate dominant and non dominant lower limb nerves. Results: The motor latency of deep peroneal and tibial nerves of dominant leg of football players and sensory latency of superficial peroneal, tibial and compound nerve action potential of tibial nerve of both leg in football players were significantly prolonged (p<0.05. Motor and sensory nerve conduction velocity of tibial and common peroneal in football players were significant delayed (p<0.05. Conclusion: It is concluded that football is sport with high contact and it causes sub-clinical neuropathies due to nerve entrapment.

  15. Outcomes of microfracture in professional basketball players.

    Science.gov (United States)

    Cerynik, Douglas L; Lewullis, Gabriel E; Joves, Brian C; Palmer, Michael P; Tom, James A

    2009-09-01

    Surgical treatment for chondral defects of the knee in competitive running and jumping athletes remains controversial. This study evaluated the performance outcomes of professional basketball players in the National Basketball Association (NBA) who underwent microfracture. Data from 24 professional basketball players from 1997 to 2006 was obtained and analyzed. NBA player efficiency ratings (PER) were calculated for two seasons before and after injury. A control group of 24 players was used for comparison. Study group and control group demographics including age, NBA experience, and minutes per game demonstrated no statistical difference. Mean time to return to an NBA game was 30.0 weeks from the time of surgery. The first season after returning to competition PER and minutes per game decreased by 3.5 (P 0.05) and 3.0 min (P NBA game. On return to competition player performance and minutes per game are diminished.

  16. Microstructure-Wear Resistance Correlation and Wear Mechanisms of Spark Plasma Sintered Cu-Pb Nanocomposites

    Science.gov (United States)

    Sharma, Amit Siddharth; Biswas, Krishanu; Basu, Bikramjit

    2014-01-01

    The dispersion of a softer phase in a metallic matrix reduces the coefficient of friction (COF), often at the expense of an increased wear rate at the tribological contact. To address this issue, unlubricated fretting wear tests were performed on spark plasma sintered Cu-Pb nanocomposites against bearing steel. The sintering temperature and the Pb content as well as the fretting parameters were judiciously selected and varied to investigate the role of microstructure (grain size, second-phase content) on the wear resistance properties of Cu-Pb nanocomposites. A combination of the lowest wear rate (~1.5 × 10-6 mm3/Nm) and a modest COF (~0.4) was achieved for Cu-15 wt pct Pb nanocomposites. The lower wear rate of Cu-Pb nanocomposites with respect to unreinforced Cu is attributed to high hardness (~2 to 3.5 GPa) of the matrix, Cu2O/Fe2O3-rich oxide layer formation at tribological interface, and exuding of softer Pb particles. The wear properties are discussed in reference to the characteristics of transfer layer on worn surface as well as subsurface damage probed using focused ion beam microscopy. Interestingly, the flash temperature has been found to have insignificant effect on the observed oxidative wear, and alternative mechanisms are proposed. Importantly, the wear resistance properties of the nanocomposites reveal a weak Hall-Petch-like relationship with grain size of nanocrystalline Cu.

  17. Executive functioning in highly talented soccer players.

    Science.gov (United States)

    Verburgh, Lot; Scherder, Erik J A; van Lange, Paul A M; Oosterlaan, Jaap

    2014-01-01

    Executive functions might be important for successful performance in sports, particularly in team sports requiring quick anticipation and adaptation to continuously changing situations in the field. The executive functions motor inhibition, attention and visuospatial working memory were examined in highly talented soccer players. Eighty-four highly talented youth soccer players (mean age 11.9), and forty-two age-matched amateur soccer players (mean age 11.8) in the age range 8 to 16 years performed a Stop Signal task (motor inhibition), the Attention Network Test (alerting, orienting, and executive attention) and a visuospatial working memory task. The highly talented soccer players followed the talent development program of the youth academy of a professional soccer club and played at the highest national soccer competition for their age. The amateur soccer players played at a regular soccer club in the same geographical region as the highly talented soccer players and play in a regular regional soccer competition. Group differences were tested using analyses of variance. The highly talented group showed superior motor inhibition as measured by stop signal reaction time (SSRT) on the Stop Signal task and a larger alerting effect on the Attention Network Test, indicating an enhanced ability to attain and maintain an alert state. No group differences were found for orienting and executive attention and visuospatial working memory. A logistic regression model with group (highly talented or amateur) as dependent variable and executive function measures that significantly distinguished between groups as predictors showed that these measures differentiated highly talented soccer players from amateur soccer players with 89% accuracy. Highly talented youth soccer players outperform youth amateur players on suppressing ongoing motor responses and on the ability to attain and maintain an alert state; both may be essential for success in soccer.

  18. REDUCED ENGINE FRICTION AND WEAR

    Energy Technology Data Exchange (ETDEWEB)

    Ron Matthews

    2005-05-01

    This Final Technical Report discusses the progress was made on the experimental and numerical tasks over the duration of this project regarding a new technique for decreasing engine friction and wear via liner rotation. The experimental subtasks involved quantifying the reduction in engine friction for a prototype rotating liner engine relative to a comparable baseline engine. Both engine were single cylinder conversions of nominally identical production four-cylinder engines. Hot motoring tests were conducted initially and revealed that liner rotation decreased engine friction by 20% under motoring conditions. A well-established model was used to estimate that liner rotation should decrease the friction of a four-cylinder engine by 40% under hot motoring conditions. Hot motoring tear-down tests revealed that the crankshaft and valve train frictional losses were essentially the same for the two engines, as expected. However, the rotating liner engine had much lower (>70%) piston assembly friction compared to the conventional engine. Finally, we used the Instantaneous IMEP method to compare the crank-angle resolved piston assembly friction for the two engines. Under hot motoring conditions, these measurements revealed a significant reduction in piston assembly friction, especially in the vicinity of compression TDC when the lubrication regime transitions from hydrodynamic through mixed and into boundary friction. We have some remaining problems with these measurements that we expect to solve during the next few weeks. We will then perform these measurements under firing conditions. We also proposed to improve the state-of-the-art of numerical modeling of piston assembly friction for conventional engines and then to extend this model to rotating liner engines. Our research team first modeled a single ring in the Purdue ring-liner test rig. Our model showed good agreement with the test rig data for a range of speeds and loads. We then modeled a complete piston

  19. Structural transformations in wear resistance of iron- and cobalt-based amorphous alloys during abrasive wear

    Science.gov (United States)

    Korshunov, L. G.; Shabashov, V. A.; Chernenko, N. L.

    2010-04-01

    The wear resistance and structural changes in a number of amorphous alloys based on iron and cobalt and in high-carbon tool steels are studied during wear by a fixed abrasive (crondum, Carborundum) at room temperature and -196°C. The abrasive wear resistance of the amorphous alloys is shown to be 1.6-3.1 lower than that of the high-carbon tool steels having a similar hardness. The relatively low level of the abrasive wear resistance of the amorphous alloys is assumed to be caused by strain softening of their surface during wear. A nanocrystalline structure is found to form in local microvolumes in a thin deformed surface layer of the alloys.

  20. Incisor wear and age in Yellowstone bison

    Science.gov (United States)

    Christianson, D.A.; Gogan, P.J.P.; Podruzny, K.M.; Olexa, E.M.

    2005-01-01

    Biologists commonly use tooth eruption and wear patterns or cementum annuli techniques to estimate age of ungulates. However, in some situations the accuracy or sampling procedures of either approach are undesirable. We investigated the progression of several quantitative measures of wear with age, using permanent first incisors from Yellowstone bison (Bison bison), and tested for differences between sexes and herds. We further investigated the relationship of wear and age to explore an age-estimation method. Labial-lingual width (LLW) correlated best with assigned age (r2=0.66, males; r2=0.76 females). Labial-lingual width differed between sexes, with females showing ∼0.2 mm more wear than males. Additionally, differences in rate of wear existed between bison of the northern and central Yellowstone herds (1.2 and 0.9 mm/year, respectively). We developed a regression formula to test the power of LLW as an estimator of Yellowstone bison age. Our method provided estimated ages within 1 year of the assigned age 73% and 82% of the time for female and male bison, respectively.

  1. Dental Wear: A Scanning Electron Microscope Study

    Directory of Open Access Journals (Sweden)

    Luca Levrini

    2014-01-01

    Full Text Available Dental wear can be differentiated into different types on the basis of morphological and etiological factors. The present research was carried out on twelve extracted human teeth with dental wear (three teeth showing each type of wear: erosion, attrition, abrasion, and abfraction studied by scanning electron microscopy (SEM. The study aimed, through analysis of the macro- and micromorphological features of the lesions (considering the enamel, dentin, enamel prisms, dentinal tubules, and pulp, to clarify the different clinical and diagnostic presentations of dental wear and their possible significance. Our results, which confirm current knowledge, provide a complete overview of the distinctive morphology of each lesion type. It is important to identify the type of dental wear lesion in order to recognize the contributing etiological factors and, consequently, identify other more complex, nondental disorders (such as gastroesophageal reflux, eating disorders. It is clear that each type of lesion has a specific morphology and mechanism, and further clinical studies are needed to clarify the etiological processes, particularly those underlying the onset of abfraction.

  2. Brush seal shaft wear resistant coatings

    Science.gov (United States)

    Howe, Harold

    1995-03-01

    Brush seals suffer from high wear, which reduces their effectiveness. This work sought to reduce brush seal wear by identifying and testing several industry standard coatings. One of the coatings was developed for this work. It was a co-sprayed PSZ with boron-nitride added for a high temperature dry lubricant. Other coatings tested were a PSZ, chrome carbide and a bare rotor. Testing of these coatings included thermal shocking, tensile testing and wear/coefficient of friction testing. Wear testing consisted of applying a coating to a rotor and then running a sample tuft of SiC ceramic fiber against the coating. Surface speeds at point of contact were slightly over 1000 ft/sec. Rotor wear was noted, as well as coefficient of friction data. Results from the testing indicates that the oxide ceramic coatings cannot withstand the given set of conditions. Carbide coatings will not work because of the need for a metallic binder, which oxidizes in the high heat produced by friction. All work indicated a need for a coating that has a lubricant contained within itself and the coating must be resistant to an oxidizing environment.

  3. Impact wear behaviors of Hadfield manganese steel

    Institute of Scientific and Technical Information of China (English)

    FANG Liang; XU Yun-hua; CEN Qi-hong; ZHU Jin-hua

    2005-01-01

    Impact wear behaviors of Hadfield manganese steel at different impact angles were investigated. The results of impact wear tests show that there exists a critical impact load for Hadfield steel. The wear rate suddenly turns down after some impact cycles when the impact load is greater than the critical load. The critical impact load is smaller than 8.2 J in this research because the nano-sized austenitic grains embedded in amorphous delay the crack propagation in subsurface. From high resolution transmission electron microscope (HRTEM) examination of subsurface microstructure, it is found that a large amount of nano-sized grains embedded in bulk amorphous matrix are fully developed and no martensitic transformation occurs during the impact wear process. The analytical results of worn surface morphology and debris indicate that the initiation of crack, propagation and spalling are restricted in the amorphous phase, resulting in the size distribution of debris in nano-sizes, which is the reason why the wear rate of Hadfield steel is greatly decreased at high impact load.

  4. [Wear and different restorative materials--a review].

    Science.gov (United States)

    Beyth, N; Sharon, E; Lipovetsky, M; Smidt, A

    2006-07-01

    Wear of materials is a complex and unpredictable phenomenon. The variables affecting the mechanism of wear include the properties of the two contacting materials and the surrounding and interfacial media. This paper reviews the dental wear of different restorative materials and their counter effect on the tooth structure. It presents the updated classifications for tooth surface lesions termed dental wear, and discusses the wear behavior of various restorative materials. Some guidelines for restorative material selection are given. Clinical wear bears a multifactorial etiology, understanding the mechanism of action is an important step in an appropriate restoration material selection. Each material selected should meet the individual wear behavior and needs. Individual factors may enhance the wear rates: aggressive tooth brushing, parafunctions, diet, acidic/aqueous environment, surface geometry, and diminished tooth support. Supportive treatment following restoration is important to monitor wear rates.

  5. A kind of high-efficiency milling shoe research%一种高效铣鞋的研制

    Institute of Scientific and Technical Information of China (English)

    刘志鹏; 曾恒; 周学军; 张玉清; 杨沁彤; 田岿

    2012-01-01

    on the basis of summarizing the experience of using conventional milling shoes, comprehensive optimization of traditional milling shoe has been made with respect to material choosing of matrix and cutter teeth, teeth distribution, size of milling shoes and scraps groove and number etc. And a kind of high-efficiency milling shoes was designed. The field application in Well Longgang 001-3 shows that the drilling speed, drilling depth and safety of optimized milling shoes have been greatly enhanced, which realize high-efficiency milling.%在总结常规铣鞋使用经验的基础上,从本体材料和切削齿材料的选择、布齿方式、铣鞋尺寸、排屑槽的尺寸和数量等方面入手对常规铣鞋做了全面的优化,设计出了一种高效铣鞋.龙岗001-3井的现场使用情况表明,优化后的铣鞋套铣速度、进尺、安全性均有大幅度的提高,实现了高效套铣.

  6. In-shoe multi-segment foot kinematics of children during the propulsive phase of walking and running.

    Science.gov (United States)

    Wegener, Caleb; Greene, Andrew; Burns, Joshua; Hunt, Adrienne E; Vanwanseele, Benedicte; Smith, Richard M

    2015-02-01

    Certain styles of children's shoes reduce 1st metatarsophalangeal joint (MTPJ) and midfoot motion during propulsion of walking. However, no studies have investigated if the splinting effect of shoes on children's 1st MTPJ and midfoot motion occurs during running. This study investigated the effect of sports shoes on multi-segment foot kinematics of children during propulsion of walking and running. Twenty children walked and ran at a self-selected velocity while barefoot and shod in a random order. Reflective markers were used to quantify sagittal plane motion of the 1st MTPJ and three-dimensional motion of the midfoot and ankle. Gait velocity increased during shod walking and running and was considered a covariate in the statistical analysis. Shoes reduced 1st MTPJ motion during propulsion of walking from 36.0° to 10.7° and during running from 31.5° to 12.6°. Midfoot sagittal plane motion during propulsion reduced from 22.5° to 6.2° during walking and from 27.4° to 9.6° during running. Sagittal plane ankle motion during propulsion increased during shod running from 26.7° to 34.1°. During propulsion of walking and running, children's sports shoes have a splinting effect on 1st MTPJ and midfoot motion which is partially compensated by an increase in ankle plantarflexion during running.

  7. Incidence of Stingers in Young Rugby Players.

    Science.gov (United States)

    Kawasaki, Takayuki; Ota, Chihiro; Yoneda, Takeshi; Maki, Nobukazu; Urayama, Shingo; Nagao, Masashi; Nagayama, Masataka; Kaketa, Takefumi; Takazawa, Yuji; Kaneko, Kazuo

    2015-11-01

    A stinger is a type of neurapraxia of the cervical roots or brachial plexus and represents a reversible peripheral nerve injury. The incidence of and major risk factors for stingers among young rugby players remain uninvestigated. To investigate the incidence, symptoms, and intrinsic risk factors for stingers in elite rugby union teams of young players. Descriptive epidemiology study. A total of 569 male rugby players, including 358 players from 7 high school teams and 211 players from 2 university teams, were investigated using self-administered preseason and postseason questionnaires. The prevalence of a history of stingers was 33.9% (95% CI, 30.3-37.9), and 20.9% (119/569) of players experienced at least 1 episode of a stinger during the season (34.2 [95% CI, 26.2-42.1] events per 1000 player-hours of match exposure). The reinjury rate for stingers per season was 37.3% (95% CI, 30.4-44.2). Using the multivariate Poisson regression method, a history of stingers in the previous season and the grade and position of the player were found to be risk factors for stingers during the current season. The mean severity of injury was 2.9 days, with 79.3% (191/241) of the players not losing any time from playing after sustaining a stinger injury and 5.8% (14/241) of the players recovering within more than 14 days. The most frequent symptom was numbness in the unilateral upper extremity, and the most severe symptom was weakness of grasping (mean severity, 6 days). A logistic regression analysis indicated that a history of stingers in the previous season and an injury with more than 3 symptoms, especially motor weakness, were correlated with the severity of injury. Young rugby players with a history of stingers have a significantly high rate of repeat injuries. Although nearly 80% of the players experienced only minimal (0-1 day) time loss injuries, neurological deficits sometimes last beyond 1 month. A history of stingers was identified to be the strongest risk factor for

  8. Wear Resistant Amorphous and Nanocomposite Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Racek, O

    2008-03-26

    Glass forming materials (critical cooling rate <10{sup 4}K.s{sup -1}) are promising for their high corrosion and wear resistance. During rapid cooling, the materials form an amorphous structure that transforms to nanocrystalline during a process of devitrification. High hardness (HV 1690) can be achieved through a controlled crystallization. Thermal spray process has been used to apply coatings, which preserves the amorphous/nanocomposite structure due to a high cooling rate of the feedstock particles during the impact on a substrate. Wear properties have been studied with respect to process conditions and feedstock material properties. Application specific properties such as sliding wear resistance have been correlated with laboratory tests based on instrumented indentation and scratch tests.

  9. Examining Player Anger in World of Warcraft

    Science.gov (United States)

    Barnett, Jane; Coulson, Mark; Foreman, Nigel

    This questionnaire study of the sources of anger in World of Warcraft applies classical quantitative measurement scale construction to a new problem, generating a host of questionnaire items that could find use in future studies, and identifying four major categories of events that cause negative effect among players. First, 33 players provided examples of in-game scenarios that had made them angry, and their responses were culled to create a 93-item battery rated by hundreds of player respondents in terms of anger intensity and anger frequency. An iterative process of factor analysis and scale reliability assessment led to a 28-item instrument measuring four anger-provoking factors: Raids/Instances, Griefers, Perceived Time Wasting, and Anti-social Players. These anger-causing scenarios were then illustrated by concrete examples from player and researcher experiences in World of Warcraft. One striking finding is that players become angry at other players' negative behavior, regardless of whether that behavior was intended to harm.

  10. Applied physiology of female soccer players.

    Science.gov (United States)

    Davis, J A; Brewer, J

    1993-09-01

    Women's soccer is in its infancy as a sport and research into its physiological demands and the physical characteristics of players is somewhat limited. There is now an increasing demand for scientific investigation of the female game and of the players, match analysis and role variations requiring particular attention. Current research suggests that the demands of the game for women are similar to those placed on male players. Women are reported to cover a similar distance (mean 8471m) to their male counterparts during a game and much the same proportions of the game appear to be devoted to exercise of varying intensities. Furthermore, female and male players appear to tax the aerobic and anaerobic energy systems to a similar level. The physical and physiological characteristics of female soccer players are comparable with those of other female games players and are more favourable than average for the population. Mean body fat percentages of between 19.7 and 22.0% and VO2max values of between 47.1 and 57.6 ml/kg/min have been reported for elite female players, while faster than average sprint times are also characteristic of them.

  11. A View on Wear Mechanism of Metallic Card Clothing

    Institute of Scientific and Technical Information of China (English)

    WU Liang; WANG Wen-qiang; NI Huai-sheng

    2008-01-01

    The wear mechanism of metallic card clothing,used in textile industry, was analyzed. A fast wear test for metallic card clothing racks was developed, which was used as collecting the wear metal particles. The failure type of card clothing was analyzed by the mean of scanning electron microscopy (SEM) and ferro-spectrum technology. The results show that the main wear mechanism of metallic card clothing is low load and high repetition interval fatigue wear caused by friction force between fiber and metal wire teeth.The appropriate quenching microstmcture, which improves the wear resistance of the metallic card clothing rack is also discussed.

  12. The Delamination Theory of Wear - III

    Science.gov (United States)

    1977-12-01

    117. 18 A. P. Orson , J. Mach. Phys. Solids, 2 (1954) 197 - 211, 19 D. R. Wheeler and D, H. Buckley, Wear, 83 (1975) 65. 20 V. C, Scott end H. Wilman...papers were also published In Volume 44 no. I of the Journal Wear, edited by1). Scott . "ELSEVIER SEQUOIA S.A., LAUSANNE, 1977 APproved for public ioleoee...possible without the enthusiasm and support of Messrs. Douglas Scott and VOrnon C, Westoott. This kind of research cannot reodily be undertaken at a

  13. Consideration of wear rates at high velocity

    Science.gov (United States)

    Hale, Chad S.

    The development of the research presented here is one in which high velocity relative sliding motion between two bodies in contact has been considered. Overall, the wear environment is truly three-dimensional. The attempt to characterize three-dimensional wear was not economically feasible because it must be analyzed at the micro-mechanical level to get results. Thus, an engineering approximation was carried out. This approximation was based on a metallographic study identifying the need to include viscoplasticity constitutive material models, coefficient of friction, relationships between the normal load and velocity, and the need to understand wave propagation. A sled test run at the Holloman High Speed Test Track (HHSTT) was considered for the determination of high velocity wear rates. In order to adequately characterize high velocity wear, it was necessary to formulate a numerical model that contained all of the physical events present. The experimental results of a VascoMax 300 maraging steel slipper sliding on an AISI 1080 steel rail during a January 2008 sled test mission were analyzed. During this rocket sled test, the slipper traveled 5,816 meters in 8.14 seconds and reached a maximum velocity of 1,530 m/s. This type of environment was never considered previously in terms of wear evaluation. Each of the features of the metallography were obtained through micro-mechanical experimental techniques. The byproduct of this analysis is that it is now possible to formulate a model that contains viscoplasticity, asperity collisions, temperature and frictional features. Based on the observations of the metallographic analysis, these necessary features have been included in the numerical model, which makes use of a time-dynamic program which follows the movement of a slipper during its experimental test run. The resulting velocity and pressure functions of time have been implemented in the explicit finite element code, ABAQUS. Two-dimensional, plane strain models

  14. Wear Analysis of Wind Turbine Gearbox Bearings

    Energy Technology Data Exchange (ETDEWEB)

    Blau, Peter Julian [ORNL; Walker, Larry R [ORNL; Xu, Hanbing [ORNL; Parten, Randy J [ORNL; Qu, Jun [ORNL; Geer, Tom [ORNL

    2010-04-01

    The objective of this effort was to investigate and characterize the nature of surface damage and wear to wind turbine gearbox bearings returned from service in the field. Bearings were supplied for examination by S. Butterfield and J. Johnson of the National Wind Technology Center (NREL), Boulder, Colorado. Studies consisted of visual examination, optical and electron microscopy, dimensional measurements of wear-induced macro-scale and micro-scale features, measurements of macro- and micro-scale hardness, 3D imaging of surface damage, studies of elemental distributions on fracture surfaces, and examinations of polished cross-sections of surfaces under various etched and non-etched conditions.

  15. Gradient Index in Wear Debris Image Collection

    Institute of Scientific and Technical Information of China (English)

    LVZhi-yong; GAOHui-liang; YANXin-ping

    2004-01-01

    In order to solve a problem of oil on-line monitoring, this instrument adopts a prinripium of self-focus lens of Gradieat index fiber( GRIN Len) to design optics system and magnetic circuit. For the magnetic circuit, the monitor can catch particle wear debris in oil. And for the optics circuit. GRIN Len can transfer image of debris to apparatus of gather image, e . g, CCD and camera. And the image of debris is transferred to computer for analyzing seize and physiognomy of debris. The character of the monitor is of micro weight, micro volume andcurve imaging And it is directly pluged into oil to catch image of wear particles.

  16. Surface engineering for enhanced performance against wear

    CERN Document Server

    2013-01-01

    Surface Engineering constitutes a variety of processes and sub processes. Each chapter of this work covers specific processes by experts working in the area. Included for each topic are tribological performances for each process as well as results of recent research. The reader also will benefit from in-depth studies of diffusion coatings, nanocomposite films for wear resistance, surfaces for biotribological applications, thin-film wear, tribology of thermal sprayed coatings, hardfacing, plating for tribology and high energy beam surface modifications. Material scientists as well as engineers working with surface engineering for tribology will be particularly interested in this work.

  17. A sample-freezing drive shoe for a wire line piston core sampler

    Science.gov (United States)

    Murphy, F.; Herkelrath, W.N.

    1996-01-01

    Loss of fluids and samples during retrieval of cores of saturated, noncohesive sediments results in incorrect measures of fluid distributions and an inaccurate measure of the stratigraphic position of the sample. To reduce these errors, we developed a hollow drive shoe that freezes in place the lowest 3 inches (75 mm) of a 1.88-inch-diameter (48 mm), 5-foot-long (1.5 m) sediment sample taken using a commercial wire line piston core sampler. The end of the core is frozen by piping liquid carbon dioxide at ambient temperature through a steel tube from a bottle at the land surface to the drive shoe where it evaporates and expands, cooling the interior surface of the shoe to about -109??F (-78??C). Freezing a core end takes about 10 minutes. The device was used to collect samples for a study of oil-water-air distributions, and for studies of water chemistry and microbial activity in unconsolidated sediments at the site of an oil spill near Bemidji, Minnesota. Before freezing was employed, samples of sandy sediments from near the water table sometimes flowed out of the core barrel as the sampler was withdrawn. Freezing the bottom of the core allowed for the retention of all material that entered the core barrel and lessened the redistribution of fluids within the core. The device is useful in the unsaturated and shallow saturated zones, but does not freeze cores well at depths greater than about 20 feet (6 m) below water, possibly because the feed tube plugs with dry ice with increased exhaust back-pressure, or because sediment enters the annulus between the core barrel and the core barrel liner and blocks the exhaust.

  18. Biomechanical factors associated with shoe/pedal interfaces. Implications for injury.

    Science.gov (United States)

    Gregor, R J; Wheeler, J B

    1994-02-01

    The principal demand on the body during cycling is on the lower extremities as they are responsible for producing a majority of the energy imparted to the bike. As a result the legs, due to high reactive forces between the foot and pedal, experience high loads on the joints. These loads may adversely affect joint tissues and contribute to overuse injuries, e.g. knee pain. The mechanical link between the leg and the bike is the shoe/pedal interface. This transmission site, by design, can either create smooth transfer of energy or abnormally high repetitive loads which are potentially injurious to the body. Incidence of lower extremity injury in cycling is high, and historically biomechanical analyses of this activity have focused their attention on either the rider or the bike, but not the link between the two. Recently, pedal designs have changed in response to complaints of sore knees with the development of pedals allowing varying degrees of float. This form of transmission is intended to enhance power transfer from rider to bike as well as minimise trauma to the legs by permitting the foot to rotate during the pedalling cycle in a toe-in/heel-out or heel-in/toe-out movement pattern. Recent evidence suggests this type of pedal design does reduce trauma and maintains power output. This article reviews common lower extremity overuse injuries and biomechanical factors during the pedalling cycle with the primary focus on the shoe/pedal interface. We will summarise information available on lower extremity kinematics and kinetics as well as recent data specifically related to shoe/pedal interface kinetics, evaluation of different pedal types-specifically comparison between clipless 'fixed' and clipless 'float' systems-and discuss their resultant effect on lower extremity dynamics and their implications for injury.

  19. Audience Intoxicated by Acrobatic Fairy Story——Large Acrobatic Play of Fairy Story Red Dancing Shoes of Chongqing Acrobatic Artistic Troupe

    Institute of Scientific and Technical Information of China (English)

    马洁

    2007-01-01

    In order to celebrate Chongqing as a directly governed city region for ten years and also the First China Chongqing Cultural Artistic Festival, Chongqing Acrobatic Artistic Troupe gave a large acrobatic play of fairy story Red Dancing Shoes. From June 1st to June 3rd, the performance in public of Red Dancing Shoes got a complete success. The media including Chongqing TV Station,

  20. Computing Decoupled Residuals for Compact Disc Players

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob; Andersen, Palle

    2006-01-01

    In order to improve Compact Disc Players playability regarding playing Compact Discs with surface faults, like scratches and fingerprints etc, the attention has been put on fault tolerant control schemes. Almost every of those methods are based on fault detection. The standard approach is to use...... a pair of residuals generated by Compact Disc Player. However, these residuals depend on the performance of position servos in the Compact Disc Player. In other publications of the same authors a pair of decoupled residuals is derived. However, the computation of these alternative residuals has been...

  1. Towards Player-Driven Procedural Content Generation

    DEFF Research Database (Denmark)

    Shaker, Noor; Yannakakis, Georgios N.; Togelius, Julian

    2012-01-01

    Generating immersive game content is one of the ultimate goals for a game designer. This goal can be achieved by realizing the fact that players’ perception of the same game differ according to a number of factors including: players’ personality, playing styles, expertise and culture background....... While one player might find the game immersive, others may quit playing as a result of encountering a seemingly insoluble problem. One promising avenue towards optimizing the gameplay experience for individual game players is to tailor player experience in real-time via automatic game content generation......-driven content generation....

  2. Complications of surgical extraction of ankylosed primary teeth and distal shoe space maintainers.

    Science.gov (United States)

    Kirshenblatt, S; Kulkarni, G V

    2011-01-01

    The purpose of this report was to present the iatrogenic complications that may result from the management of ankylosed primary teeth as well as describe the case of a patient with an ankylosed primary mandibular left second molar which was surgically extracted and an adjacent primary first molar that was cemented with a distal shoe space maintainer. Aggressive surgical removal of the ankylosed tooth caused damage to the developing crown of the successor. Improper placement of the appliance caused perforation of the developing tooth follicle. Orthodontic therapy and a polycarbonate temporary crown were used to restore occlusion. Nonsurgical extractions and alternative appliances should be considered when treating patients with ankylosed primary second molars.

  3. The shoelace book a mathematical guide to the best (and worst) ways to lace your shoes

    CERN Document Server

    Polster, Burkard

    2006-01-01

    Crisscross, zigzag, bowtie, devil, angel, or star: which are the longest, the shortest, the strongest, and the weakest lacings? Pondering the mathematics of shoelaces, the author paints a vivid picture of the simple, beautiful, and surprising characterizations of the most common shoelace patterns. The mathematics involved is an attractive mix of combinatorics and elementary calculus. This book will be enjoyed by mathematically minded people for as long as there are shoes to lace. Burkard Polster is a well-known mathematical juggler, magician, origami expert, bubble-master, shoelace charmer, an

  4. Prevention of recurrent foot ulcers with plantar pressure-based in-shoe orthoses: the CareFUL prevention multicenter randomized controlled trial.

    Science.gov (United States)

    Ulbrecht, Jan S; Hurley, Timothy; Mauger, David T; Cavanagh, Peter R

    2014-07-01

    To assess the efficacy of in-shoe orthoses that were designed based on shape and barefoot plantar pressure in reducing the incidence of submetatarsal head plantar ulcers in people with diabetes, peripheral neuropathy, and a history of similar prior ulceration. Single-blinded multicenter randomized controlled trial with subjects randomized to wear shape- and pressure-based orthoses (experimental, n = 66) or standard-of-care A5513 orthoses (control, n = 64). Patients were followed for 15 months, until a study end point (forefoot plantar ulcer or nonulcerative plantar forefoot lesion) or to study termination. Proportional hazards regression was used for analysis. There was a trend in the composite primary end point (both ulcers and nonulcerative lesions) across the full follow-up period (P = 0.13) in favor of the experimental orthoses. This trend was due to a marked difference in ulcer occurrence (P = 0.007) but no difference in the rate of nonulcerative lesions (P = 0.76). At 180 days, the ulcer prevention effect of the experimental orthoses was already significant (P = 0.003) when compared with control, and the benefit of the experimental orthoses with respect to the composite end point was also significant (P = 0.042). The hazard ratio was 3.4 (95% CI 1.3-8.7) for the occurrence of a submetatarsal head plantar ulcer in the control compared with experimental arm over the duration of the study. We conclude that shape- and barefoot plantar pressure-based orthoses were more effective in reducing submetatarsal head plantar ulcer recurrence than current standard-of-care orthoses, but they did not significantly reduce nonulcerative lesions. © 2014 by the American Diabetes Association.

  5. Innovative approach in the management of horse-shoe fistula-in-ano with Kṣārasūtra

    OpenAIRE

    Amruta A Wali; Dongargaon, Tajahmed N.; Shilpa, M P; Toshikhane, Hemant D.

    2015-01-01

    Fistula-in-ano is a common surgical problem. Horse-shoe fistulas usually have an internal opening in the posterior midline and extend anteriorly and laterally to one or both ischiorectal spaces by way of the deep potential space. The "Śambukāvarta Bhagandara" described by Suśruta can be correlated with the horse-shoe type of fistula. In this condition, neither fistulotomy nor "Kṣārasūtra" treatment alone, are useful hence there is a need for newer innovative surgical techniques to tackle this...

  6. High School Football Players Use Their Helmets to Tackle Other Players Despite Knowing the Risks

    Science.gov (United States)

    Kuriyama, Andrew M; Nakatsuka, Austin S

    2017-01-01

    There is greater attention to head-related injuries and concussions in American football. The helmet's structural safety and the way that football players use their helmets are important in preventing head injuries. Current strategies include penalizing players for high-risk behavior such as leading with their helmet or hitting an opposing player above the shoulder. Passive strategies include helmet modification to better protect the head of the players or to change the playing style of the players. Hawai‘i high school varsity football players were surveyed to determine how they use their helmets and how a new helmet design would affect their style of play. One hundred seventy-seven surveys were completed; 79% said that they used their helmet to hit an opposing player during a tackle and 46% said they made this contact intentionally. When asked about modifying helmets with a soft material on the outside, 48% said they thought putting a soft cover over a regular helmet would protect their head better. However, many participants said that putting a soft cover over their regular helmet was a bad idea for various reasons. Most young football players use their helmets to block or tackle despite being taught they would be penalized or potentially injured if they did so. By gaining a better understanding of why and how players use their helmets and how they would respond to new helmet designs, steps can be taken to reduce head injuries for all levels of play.

  7. Technical player profiles related to the physical fitness of young female volleyball players predict team performance.

    Science.gov (United States)

    Dávila-Romero, C; Hernández-Mocholí, M A; García-Hermoso, A

    2015-03-01

    This study is divided into three sequential stages: identification of fitness and game performance profiles (individual player performance), an assessment of the relationship between these profiles, and an assessment of the relationship between individual player profiles and team performance during play (in championship performance). The overall study sample comprised 525 (19 teams) female volleyball players aged 12-16 years and a subsample (N.=43) used to examine study aims one and two was selected from overall sample. Anthropometric, fitness and individual player performance (actual game) data were collected in the subsample. These data were analyzed through clustering methods, ANOVA and independence chi-square test. Then, we investigated whether the proportion of players with the highest individual player performance profile might predict a team's results in the championship. Cluster analysis identified three volleyball fitness profiles (high, medium, and low) and two individual player performance profiles (high and low). The results showed a relationship between both types of profile (fitness and individual player performance). Then, linear regression revealed a moderate relationship between the number of players with a high volleyball fitness profile and a team's results in the championship (R2=0.23). The current study findings may enable coaches and trainers to manage training programs more efficiently in order to obtain tailor-made training, identify volleyball-specific physical fitness training requirements and reach better results during competitions.

  8. The Cheerleader and the Football Player.

    Science.gov (United States)

    Patil, Malati

    2001-01-01

    Describes an activity in physics using a narrative about a bet between a cheerleader who claims she can lift a 300-pound football player off the ground. Includes questions, teaching notes, and solutions. (MM)

  9. Menstrual cycle disorders in female volleyball players.

    Science.gov (United States)

    Wodarska, M; Witkoś, J; Drosdzol-Cop, A; Dąbrowska, J; Dąbrowska-Galas, M; Hartman, M; Plinta, R; Skrzypulec-Plinta, V

    2013-07-01

    The aim of this study was to examine the relation between increased physical activity and menstrual disorders in adolescent female volleyball players. The study was conducted on 210 Polish female volleyball players, aged 13-17 years, the authorship questionnaire was used. The results of the study showed that irregular menstruation occurred in 19% of girls, spotting between menstrual periods in 27% and heavy menstruation was reported in 33% of girls. Out of all volleyball female players participating in the study, 94 girls (45%) declared absence of menstrual periods after regular cycles. Statistical analysis showed that the more training hours per week, the bigger probability of the occurrence of irregular menstruation. It was concluded that the number of hours of volleyball training per week affects regularity of menstrual cycles in female volleyball players. The absence of menstruation might be caused by the duration of training per week or years of training.

  10. Towards Generic Models of Player Experience

    DEFF Research Database (Denmark)

    Shaker, Noor; Shaker, Mohammad; Abou-Zleikha, Mohamed

    2015-01-01

    further examine whether generic features of player be- haviour can be defined and used to boost the modelling per- formance. The accuracies obtained in both experiments in- dicate a promise for the proposed approach and suggest that game-independent player experience models can be built.......-dependent and their applicability is usually limited to the system and the data used for model construction. Establishing models of user experience that are highly scalable while maintaing the performance constitutes an important research direction. In this paper, we propose generic models of user experience in the computer games...... domain. We employ two datasets collected from players in- teractions with two games from different genres where accu- rate models of players experience were previously built. We take the approach one step further by investigating the mod- elling mechanism ability to generalise over the two datasets. We...

  11. Video Player Keyboard Shortcuts: MedlinePlus

    Science.gov (United States)

    ... page: https://medlineplus.gov/hotkeys.html Video Player Keyboard Shortcuts To use the sharing features on this ... enable JavaScript. MedlinePlus offers a set of accessible keyboard shortcuts for our latest Health videos on the ...

  12. Scouting the Elite, Unbreakable Football Player.

    Science.gov (United States)

    Moore, M

    1981-02-01

    Some NFL football teams see physiological profiling as a means to protect and enhance their competitive and business success. Whether football players will benefit by increased performance and fewer injuries remains to be seen.

  13. An Explanation of the Influence on Deciding which Type of Foot Strike to Use when Running Barefoot or in Minimalistic Shoes.

    Science.gov (United States)

    Dolenec, Aleš; Radi, Petra; Strojnik, Vojko

    2015-07-01

    Buying minimalistic shoes does not mean that you know how to use them. Salespersons are rarely competent to give adequate advice how to transition to new shoes. The same happens when someone chooses to run barefoot. So, the aim of the present experiment was to find out whether giving or not giving an explanation of the correct technique of foot placement in barefoot running and running in a minimalistic shoe influences the frequency of rear-foot strikes in natural, rear foot strikers when running barefoot or in minimalistic shoes. Thirty-nine subjects (age =34.9 ± 6.9 years, height = 174 ± 9 cm, mass = 73.1 ± 13.8 kg), randomly divided into four groups participated in this experiment. Subjects in groups 1 and 3 did not receive an explanation, while groups 2 and 4 did. Besides the difference in explanation, there was also a difference in the shoes worn during the intervention. Subjects in the groups 1 and 2 ran barefoot, while subjects in groups 3 and 4 ran in minimalistic shoes. The initial state of the foot strike patterns was measured in classic running shoes. During the intervention subjects ran according to the group they were in. 80% of the subjects in groups 1 and 3 took the most steps in a rear-foot strike pattern (Median =100) while only 21% of the subjects in groups 2 and 4 took the most steps in a rear-foot strike pattern (Median = 15.7), U = 64, z = 3.619, p (0.00) barefoot running and running in a minimalistic shoe is important when someone decides to switch from classic running shoes to minimalistic shoes or to go barefoot.

  14. Wear behaviour of laser melted an ion implanted materials.

    NARCIS (Netherlands)

    Beurs, Hans de

    1988-01-01

    The emphasis in this thesis is on the development of wear resistant materials by laser melting. Furthermore, the principle aim is to search for the dislocation characteristics common to the wear process in heterogeneous materials. ... Zie: Summary

  15. Comparison of two measurement techniques for clinical wear

    DEFF Research Database (Denmark)

    Peters, M C; Delong, R; Pintado, M R

    1999-01-01

    Clinical wear of restorations is generally evaluated by marginal integrity over time. In this study, both a subjective and an objective method for wear assessment are compared, and the relative advantages and disadvantages of each are considered....

  16. Interactions between nonlinear spur gear dynamics and surface wear

    Science.gov (United States)

    Ding, Huali; Kahraman, Ahmet

    2007-11-01

    In this study, two different dynamic models, a finite elements-based deformable-body model and a simplified discrete model, and a surface wear model are combined to study the interaction between gear surface wear and gear dynamic response. The proposed dynamic gear wear model includes the influence of worn surface profiles on dynamic tooth forces and transmission error as well as the influence of dynamic tooth forces on wear profiles. This paper first introduces the nonlinear dynamic models that include gear backlash and time-varying gear mesh stiffness, and a wear model separately. It presents a comparison to experiments for validation of the dynamic models. The dynamic models are combined with the wear model to study the interaction of surface wear and dynamic behavior in both linear and nonlinear response regimes. At the end, several sets of simulation results are used to demonstrate the two-way relationship between nonlinear gear dynamics and surface wear.

  17. ERRATUM: Work smart, wear your hard hat

    CERN Multimedia

    2003-01-01

    An error appeared in the article «Work smart, wear your hard hat» published in Weekly Bulletin 27/2003, page 5. The impact which pierced a hole in the hard hat worn by Gerd Fetchenhauer was the equivalent of a box weighing 5 kg and not 50 kg.

  18. Reciprocating wear in a steam environment

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.J.; Gee, M.G. [National Physical Laboratory, Teddington, Middlesex (United Kingdom)

    2010-07-01

    Tests to simulate the wear between sliding components in steam power plant have been performed using a low frequency wear apparatus at elevated temperatures under static load, at ambient pressure, in a steam environment. The apparatus was modified to accept a novel method of steam delivery. The materials tested were pre-exposed in a flowing steam furnace at temperature for either 500 or 3000 hours to provide some simulation of long term ageing. The duration of each wear test was 50 hours and tests were also performed on as-received material for comparison purposes. Data has been compared with results of tests performed on non-oxidised material for longer durations and also on tests without steam to examine the effect of different environments. Data collected from each test consists of mass change, stub height measurement and friction coefficient as well as visual inspection of the wear track. Within this paper, it is reported that both pre-ageing and the addition of steam during testing clearly influence the friction between material surfaces. (orig.)

  19. Saliva parameters and erosive wear in adolescents

    NARCIS (Netherlands)

    Zwier, N.; Huysmans, M.C.D.N.J.M.; Jager, D.H.J.; Ruben, J.; Bronkhorst, E.M.; Truin, G.J.

    2013-01-01

    The aim of this study was to investigate the relationship between several parameters of saliva and erosive wear in adolescents. (Un-)stimulated saliva was collected from 88 adolescents with erosion and 49 controls (age 16 ± 1 years). Flow rate, pH and buffer capacity were determined immediately.

  20. Saliva Parameters and Erosive Wear in Adolescents

    NARCIS (Netherlands)

    Zwier, N.; Huysmans, M. C. D. N. J. M.; Jager, D. H. J.; Ruben, J.; Bronkhorst, E. M.; Truin, G. J.

    2013-01-01

    The aim of this study was to investigate the relationship between several parameters of saliva and erosive wear in adolescents. (Un-)stimulated saliva was collected from 88 adolescents with erosion and 49 controls (age 16 +/- 1 years). Flow rate, pH and buffer capacity were determined immediately.

  1. Healthy Contact Lens Wear and Care

    Centers for Disease Control (CDC) Podcasts

    2014-02-04

    In this podcast, CDC’s Dr. Jennifer Cope explains some basic steps for proper wear and care of soft contact lenses.  Created: 2/4/2014 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 2/4/2014.

  2. Friction and wear of human hair fibres

    Science.gov (United States)

    Bowen, James; Johnson, Simon A.; Avery, Andrew R.; Adams, Michael J.

    2016-06-01

    An experimental study of the tribological properties of hair fibres is reported, and the effect of surface treatment on the evolution of friction and wear during sliding. Specifically, orthogonally crossed fibre/fibre contacts under a compressive normal load over a series of 10 000 cycle studies are investigated. Reciprocating sliding at a velocity of 0.4 mm s-1, over a track length of 0.8 mm, was performed at 18 °C and 40%-50% relative humidity. Hair fibres retaining their natural sebum were studied, as well as those stripped of their sebum via hexane cleaning, and hair fibres conditioned using a commercially available product. Surface topography modifications resulting from wear were imaged using scanning electron microscopy and quantified using white light interferometry. Hair fibres that presented sebum or conditioned product at the fibre/fibre junction exhibited initial coefficients of friction at least 25% lower than those that were cleaned with hexane. Coefficients of friction were observed to depend on the directionality of sliding for hexane cleaned hair fibres after sufficient wear cycles that cuticle lifting was present, typically on the order 1000 cycles. Cuticle flattening was observed for fibre/fibre junctions exposed to 10 mN compressive normal loads, whereas loads of 100 mN introduced substantial cuticle wear and fibre damage.

  3. Tribology: Friction, lubrication, and wear technology

    Science.gov (United States)

    Blau, Peter J.

    1993-01-01

    The topics are presented in viewgraph form and include the following: introduction and definitions of terms; friction concepts; lubrication technology concepts; wear technology concepts; and tribological transitions. This document is designed for educators who seek to teach these concepts to their students.

  4. Powdered Hexagonal Boron Nitride Reducing Nanoscale Wear

    Science.gov (United States)

    Chkhartishvili, L.; Matcharashvili, T.; Esiava, R.; Tsagareishvili, O.; Gabunia, D.; Margiev, B.; Gachechiladze, A.

    2013-05-01

    A morphology model is suggested for nano-powdered hexagonal boron nitride that can serve as an effective solid additive to liquid lubricants. It allows to estimate the specific surface, that is a hard-to-measure parameter, based on average size of powder particles. The model can be used also to control nanoscale wear processes.

  5. Does the Quantum Player Always Win the Classical One?

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hai-Jun; FANG Xi-Ming

    2004-01-01

    @@ We study quantum games in which the players have different strategic spaces. We find that the player who can use a quantum strategic space does not always possess more payoffs than the player who is restricted to apply only classical strategies. We find the condition of the classical player getting more payoffs than the quantum player. We also find that the game exhibits intriguing structures.

  6. Corrosive wear. Evaluation of wear and corrosive resistant materials; Noetningskorrosion. Utvaerdering av noetnings- och korrosionsbestaendiga material

    Energy Technology Data Exchange (ETDEWEB)

    Persson, H.; Hjertsen, D.; Waara, P.; Prakash, B.; Hardell, J.

    2007-12-15

    With a new purchase of a waste conveyer screw at hand, for the 'A-warehouse' at the combined power and heating plant at E.ON Norrkoeping, the request for improved construction materials was raised. The previous screw required maintenance with very short intervals due to the difficult operation conditions. With the new screw the expectation is to manage 6 months of operation without interruption. The environment for the screw has two main components that sets the demand on the materials, on one hand the corrosive products that comes along and which forms at digestion of the waste and on the other hand the abrasive content in the waste. The term of the mechanism is wear-corrosion and can give considerably higher material loss than the two mechanisms wear and corrosion separately. Combination of a strong corrosive environment together with extensive wear is something that we today have limited knowledge about. The overall objective of the project has been to establish better wear and corrosive resistant construction materials for a waste conveyer screw that will lead to reduced operational disturbance costs. The evaluation has been performed in both controlled laboratory environments and in field tests, which has given us a better understanding of what materials are more suitable in this tough environment and has given us a tool for future predictions of the wear rate of the different material. The new conveyer screw, installed in February 2007 and with which the field test have been performed, has considerably reduced the wear of the construction and the target of 6 month maintenance-free operation is met with this screw for all the evaluated materials. The wear along the screw varies very much and with a clear trend for all the materials to increase towards the feeding direction of the screw. As an example, the wear plate SS2377 (stainless duplex steel) has a useful life at the most affected areas that is calculated to be 1077 days of operation with the

  7. Structurally Integrated Coatings for Wear and Corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Beardsley, M. Brad; Sebright, Jason L.

    2008-11-18

    Wear and corrosion of structures cuts across industries and continues to challenge materials scientists and engineers to develop cost effective solutions. Industries typically seek mature technologies that can be implemented for production with rapid or minimal development and have little appetite for the longer-term materials research and development required to solve complex problems. The collaborative work performed in this project addressed the complexity of this problem in a multi-year program that industries would be reluctant to undertake without government partnership. This effort built upon the prior development of Advanced Abrasion Resistant Materials conduct by Caterpillar Inc. under DOE Cooperative Agreement No. DE-FC26-01NT41054. In this referenced work, coatings were developed that exhibited significant wear life improvements over standard carburized heat treated steel in abrasive wear applications. The technology used in this referenced work, arc lamp fusing of thermal spray coatings, was one of the primary technical paths in this work effort. In addition to extending the capability of the coating technology to address corrosion issues, additional competitive coating technologies were evaluated to insure that the best technology was developed to meet the goals of the program. From this, plasma transferred arc (PTA) welding was selected as the second primary technology that was investigated. Specifically, this project developed improved, cost effective surfacing materials and processes for wear and corrosion resistance in both sliding and abrasive wear applications. Materials with wear and corrosion performance improvements that are 4 to 5 times greater than heat treated steels were developed. The materials developed were based on low cost material systems utilizing ferrous substrates and stainless steel type matrix with hard particulates formed from borides and carbides. Affordability was assessed against other competing hard surfacing or coating

  8. STUDY ON WEAR AND DESTRUCTION OF HOB IN GEAR HOBBING

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The wear and destruction appearances of hobs are researched. The reasons of the wear and destruction of hobare analyzed. And the influence of the change of the hobbing force and the hobbing temperature on the wear and destruc-tion of hob in gear hobbing is also analyzed. In gear hobbing, the main wear mechanisms are adhesion and ploughingwhen cutting the 20CrMnTi gear using W 18Cr4V high-speed steel hob.

  9. New synthesizing feature parameter of wear particles image

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper outlines the application of wavelet analysis method to computering wear par-ticles image processing and introduces the concept of grain parameter for wear particle imagebased on statistical feature parameters. The feature of wear particles image can be obtained fromthe wavelet decomposition and the statistics analysis. Test results showed that grain parametercan be used as a synthesizing feature parameter for wear particle image.

  10. A panorama of tooth wear during the medieval period.

    Science.gov (United States)

    Esclassan, Rémi; Hadjouis, Djillali; Donat, Richard; Passarrius, Olivier; Maret, Delphine; Vaysse, Frédéric; Crubézy, Eric

    2015-01-01

    Tooth wear is a natural phenomenon and a universal occurrence that has existed from the origin of humankind and depends on the way of life, especially diet. Tooth wear was very serious in ancient populations up to the medieval period. The aim of this paper is to present a global view of tooth wear in medieval times in Europe through different parameters: scoring systems, quantity and direction of wear, gender, differences between maxilla and mandible, relations with diet, caries, tooth malpositions and age.

  11. An On-line Ferrograph for Monitoring Machine Wear

    Institute of Scientific and Technical Information of China (English)

    L(U) Xiao-jun; JING Min-qing; XIE You-bai

    2005-01-01

    In order to improve an on-line ferrograph, this paper simulates a three dimensional magnetic field distribution of an electromagnet, builds a sinking motion model of a wear particle, and investigates the motion law of wear particles under two different conditions. Both numeric results and experimental results show that the on-line ferrograph is capable of monitoring machine wear conditions by measuring the concentration and size distribution of wear particles in lubricating oil.

  12. Wear numbers for ball cup and journal bearings

    OpenAIRE

    Ligterink, D.J.; Moes, H.

    1980-01-01

    A wear number is defined for ball cup bearings and for journal bearings where the cup and the cylindrical bearing are made of soft material. This dimensionless wear number provides a relation between the following five quantities: the radius of the ball or the length of the journal bearing in millimetres, the wear modulus in newtons per square millimetre, the maximum wear depth rate of the cup or the cylindrical bearing in millimetres per second, the force between the mating surfaces in newto...

  13. RETIRED MATCHES AMONG MALE PROFESSIONAL TENNIS PLAYERS

    Directory of Open Access Journals (Sweden)

    Kristijan Breznik

    2012-06-01

    Full Text Available The aim of this study was to explore the effect of characteristics of various games and players on the proportion of retired tennis matches in the Open Era of tennis. The data included over 420,000 matches played among 17,553 tennis players in the period from 1968 to the end of 2010. The influence of the surface type was clearly confirmed, with the proportion of retired matches being higher on hard and clay courts compared to grass and carpet surfaces. Similarly, more retired matches were observed in outdoor venues than in indoor ones. The impact of other variables, tournament types, rounds at which the game was played and both players' ranks, is more ambiguous. Our interpretation of the obtained results is presented in the paper. Network analytic methods were applied to extract players with the most retired matches in their careers. Eventually, we defined a group of top tennis players and gave a more precise insight into retired matches in that group. Correspondence analysis was used to visually display the two-mode network of top players and the proportion of retired matches by surface type

  14. Cortical thinning in former professional soccer players.

    Science.gov (United States)

    Koerte, Inga K; Mayinger, Michael; Muehlmann, Marc; Kaufmann, David; Lin, Alexander P; Steffinger, Denise; Fisch, Barbara; Rauchmann, Boris-Stephan; Immler, Stefanie; Karch, Susanne; Heinen, Florian R; Ertl-Wagner, Birgit; Reiser, Maximilian; Stern, Robert A; Zafonte, Ross; Shenton, Martha E

    2016-09-01

    Soccer is the most popular sport in the world. Soccer players are at high risk for repetitive subconcussive head impact when heading the ball. Whether this leads to long-term alterations of the brain's structure associated with cognitive decline remains unknown. The aim of this study was to evaluate cortical thickness in former professional soccer players using high-resolution structural MR imaging. Fifteen former male professional soccer players (mean age 49.3 [SD 5.1] years) underwent high-resolution structural 3 T MR imaging, as well as cognitive testing. Fifteen male, age-matched former professional non-contact sport athletes (mean age 49.6 [SD 6.4] years) served as controls. Group analyses of cortical thickness were performed using voxel-based statistics. Soccer players demonstrated greater cortical thinning with increasing age compared to controls in the right inferolateral-parietal, temporal, and occipital cortex. Cortical thinning was associated with lower cognitive performance as well as with estimated exposure to repetitive subconcussive head impact. Neurocognitive evaluation revealed decreased memory performance in the soccer players compared to controls. The association of cortical thinning and decreased cognitive performance, as well as exposure to repetitive subconcussive head impact, further supports the hypothesis that repetitive subconcussive head impact may play a role in early cognitive decline in soccer players. Future studies are needed to elucidate the time course of changes in cortical thickness as well as their association with impaired cognitive function and possible underlying neurodegenerative process.

  15. Sliding Wear and Fretting Wear of DLC-Based, Functionally Graded Nanocomposite Coatings

    Science.gov (United States)

    Miyoshi, K.; Pohlchuck, B.; Street, Kenneth W.; Zabinski, J. S.; Sanders, J. H.; Voevodin, A. a.; Wu, R. L. C.

    1999-01-01

    Improving the tribological functionality of diamondlike carbon (DLC) films--developing, good wear resistance, low friction, and high load-carrying capacity-was the aim of this investigation. Nanocomposite coatings consisting of an amorphous DLC (a-DLC) top layer and a functionally graded titanium-titanium carbon-diamondlike carbon (Ti-Ti(sub x) C(sub y)-DLC) underlayer were produced on AISI 440C stainless steel substrates by the hybrid technique of magnetron sputtering and pulsed-laser deposition. The resultant DLC films were characterized by Raman spectroscopy, scanning electron microscopy, and surface profilometry. Two types of wear experiment were conducted in this investioation: sliding friction experiments and fretting wear experiments. Unidirectional ball-on-disk sliding friction experiments were conducted to examine the wear behavior of an a-DLC/Ti-Ti(sub x) C(sub y)-DLC-coated AISI 440C stainless steel disk in sliding contact with a 6-mm-diameter AISI 440C stainless steel ball in ultrahigh vacuum, dry nitrogen, and humid air. Although the wear rates for both the coating and ball were low in all three environments, the humid air and dry nitrogen caused mild wear with burnishing, in the a-DLC top layer, and the ultrahigh vacuum caused relatively severe wear with brittle fracture in both the a-DLC top layer and the Ti-Ti(sub x) C(sub y)-DLC underlayer. For reference, amorphous hydrogenated carbon (H-DLC) films produced on a-DLC/Ti-Ti(sub x) C(sub y)-DLC nanocomposite coatings by using an ion beam were also examined in the same manner. The H-DLC films markedly reduced friction even in ultrahigh vacuum without sacrificing wear resistance. The H-DLC films behaved much like the a-DLC/Ti-Ti(sub x) C(sub y)-DLC nanocomposite coating in dry nitrogen and humid air, presenting low friction and low wear. Fretting wear experiments were conducted in humid air (approximately 50% relative humidity) at a frequency of 80 Hz and an amplitude of 75 micron on an a

  16. Redistribution and magnitude of stresses around horse shoe and circular excavations opened in anisotropic rock

    Institute of Scientific and Technical Information of China (English)

    Mambou Ngueyep Luc Leroy; Ndop Joseph; Ndjaka Jean-Marie Bienvenu

    2015-01-01

    In this paper numerical analysis of underground structures, taking account the transverse isotropy system of rocks, was done using CAST 3M code by varying the shape of excavation and the coefficient of earth pressure k. Numerical results reveal that the anisotropy behavior, the shape of hole and the coefficient of earth pressure k have significant influence to the mining induced stress field and rock deformations which directly control the stability of underground excavation design. The magnitude of horizontal stress obtained for the horse shoe shape excavation (25.2 MPa for k=1; 52.7 MPa for k=2) is lower than the magnitude obtained for circular hole (26.4 MPa for k=1; 59.5 MPa for k=2). Therefore, we have concluded that the horse shoe shape offers the best stability and the best design for engineer. The anisotropy system presented by rock mass can also influence the redistribution of stresses around hole opened. Numerical results have revealed that the magnitude of redistribution of horizontal stresses obtained for transverse isotropic rock (12.1 MPa for k=0.5; 25.2 MPa for k=1 and 52.7 MPa for k=2) is less than those obtained in the case of isotropic rock (27.6 MPa for k=1;48.6 MPa for k=2 and 90.81 MPa for k=2). The more the rock has the anisotropic behavior, the more the mass of rock around the tunnel is stable.

  17. An Acute Bout of Barefoot Running Alters Lower-limb Muscle Activation for Minimalist Shoe Users.

    Science.gov (United States)

    Snow, N J; Basset, F A; Byrne, J

    2016-05-01

    Despite the abundance of barefoot running-related research, there have been no electromyography studies evaluating the effects of this mode of exercise on habitual users of minimalist footwear. The present study investigated differences in muscle activation during acute bouts of barefoot and shod running, in minimalist shoe users. 8 male participants ran on a motorized treadmill for 10 min under both conditions, at 70% maximal aerobic speed. Electromyographic data were sampled from the biceps femoris, gluteus maximus, gastrocnemius medialis, tibialis anterior, and vastus lateralis during both swing and stance. Root-mean-square analysis of electromyographic data was conducted to compare muscle activation between conditions. During stance, barefoot running resulted in greater muscle activity in gastrocnemius medialis and gluteus maximus, and lower muscle activity in tibialis anterior. During swing, barefoot running resulted in increased muscle activity in vastus lateralis and gastrocnemius medialus. These results indicate that, for minimalist shoe users, an acute bout of barefoot running results in significantly different lower-limb muscle activity. Increased activation in the above muscles presents a possible mechanism for injury, which should be considered during exercise prescription.

  18. Physical Behavior in Older Persons during Daily Life: Insights from Instrumented Shoes

    Directory of Open Access Journals (Sweden)

    Christopher Moufawad el Achkar

    2016-08-01

    Full Text Available Activity level and gait parameters during daily life are important indicators for clinicians because they can provide critical insights into modifications of mobility and function over time. Wearable activity monitoring has been gaining momentum in daily life health assessment. Consequently, this study seeks to validate an algorithm for the classification of daily life activities and to provide a detailed gait analysis in older adults. A system consisting of an inertial sensor combined with a pressure sensing insole has been developed. Using an algorithm that we previously validated during a semi structured protocol, activities in 10 healthy elderly participants were recorded and compared to a wearable reference system over a 4 h recording period at home. Detailed gait parameters were calculated from inertial sensors. Dynamics of physical behavior were characterized using barcodes that express the measure of behavioral complexity. Activity classification based on the algorithm led to a 93% accuracy in classifying basic activities of daily life, i.e., sitting, standing, and walking. Gait analysis emphasizes the importance of metrics such as foot clearance in daily life assessment. Results also underline that measures of physical behavior and gait performance are complementary, especially since gait parameters were not correlated to complexity. Participants gave positive feedback regarding the use of the instrumented shoes. These results extend previous observations in showing the concurrent validity of the instrumented shoes compared to a body-worn reference system for daily-life physical behavior monitoring in older adults.

  19. Single leg balancing in ballet: effects of shoe conditions and poses.

    Science.gov (United States)

    Lobo da Costa, Paula H; Azevedo Nora, Fernanda G S; Vieira, Marcus Fraga; Bosch, Kerstin; Rosenbaum, Dieter

    2013-03-01

    The purpose of this study was to describe the effects of lower limb positioning and shoe conditions on stability levels of selected single leg ballet poses performed in demi-pointe position. Fourteen female non-professional ballet dancers (mean age of 18.4±2.8 years and mean body mass index of 21.5±2.8kg/m(2)) who had practiced ballet for at least seven years, without any musculoskeletal impairment volunteered to participate in this study. A capacitive pressure platform allowed for the assessment of center of pressure variables related to the execution of three single leg ballet poses in demi pointé position: attitude devant, attitude derriére, and attitude a la second. Peak pressures, contact areas, COP oscillation areas, anterior-posterior and medio-lateral COP oscillations and velocities were compared between two shoe conditions (barefoot versus slippers) and among the different poses. Barefoot performances produced more stable poses with significantly higher plantar contact areas, smaller COP oscillation areas and smaller anterior-posterior COP oscillations. COP oscillation areas, anterior-posterior COP oscillations and medio-lateral COP velocities indicated that attitude a la second is the least challenging and attitude derriére the most challenging pose.

  20. Physical Behavior in Older Persons during Daily Life: Insights from Instrumented Shoes

    Science.gov (United States)

    Moufawad el Achkar, Christopher; Lenoble-Hoskovec, Constanze; Paraschiv-Ionescu, Anisoara; Major, Kristof; Büla, Christophe; Aminian, Kamiar

    2016-01-01

    Activity level and gait parameters during daily life are important indicators for clinicians because they can provide critical insights into modifications of mobility and function over time. Wearable activity monitoring has been gaining momentum in daily life health assessment. Consequently, this study seeks to validate an algorithm for the classification of daily life activities and to provide a detailed gait analysis in older adults. A system consisting of an inertial sensor combined with a pressure sensing insole has been developed. Using an algorithm that we previously validated during a semi structured protocol, activities in 10 healthy elderly participants were recorded and compared to a wearable reference system over a 4 h recording period at home. Detailed gait parameters were calculated from inertial sensors. Dynamics of physical behavior were characterized using barcodes that express the measure of behavioral complexity. Activity classification based on the algorithm led to a 93% accuracy in classifying basic activities of daily life, i.e., sitting, standing, and walking. Gait analysis emphasizes the importance of metrics such as foot clearance in daily life assessment. Results also underline that measures of physical behavior and gait performance are complementary, especially since gait parameters were not correlated to complexity. Participants gave positive feedback regarding the use of the instrumented shoes. These results extend previous observations in showing the concurrent validity of the instrumented shoes compared to a body-worn reference system for daily-life physical behavior monitoring in older adults. PMID:27527172

  1. Novel In-Shoe Exoskeleton for Offloading of Forefoot Pressure for Individuals With Diabetic Foot Pathology.

    Science.gov (United States)

    Roser, Mark C; Canavan, Paul K; Najafi, Bijan; Cooper Watchman, Marcy; Vaishnav, Kairavi; Armstrong, David G

    2017-09-01

    Infected diabetic foot ulcers are the leading cause of lower limb amputation. This study evaluated the ability of in-shoe exoskeletons to redirect forces outside of body and through an exoskeleton as an effective means of offloading plantar pressure, the major contributing factor of ulceration. We compared pressure in the forefoot and hind-foot of participants (n = 5) shod with novel exoskeleton footwear. Plantar pressure readings were taken during a 6-m walk at participant's self-selected speed, and five strides were averaged. Results were taken with Achilles exotendon springs disengaged as a baseline, followed by measurements taken with the springs engaged. When springs were engaged, all participants demonstrated a decrease in forefoot pressure, averaging a 22% reduction ( P exoskeleton solution. Results suggest that when the novel exoskeletons were deployed in footwear and exotendon springs engaged, force was successfully transferred from the lower leg through the exoskeleton-enabled shoe to ground, reducing load on the forefoot. The results need to be confirmed in a larger sample. Another study is warranted to examine the effectiveness of this offloading to prevent diabetic foot ulcer, while minimizing gait alteration in daily physical activities.

  2. Evaluation of a New Method of Heading Estimation for Pedestrian Dead Reckoning Using Shoe Mounted Sensors

    Science.gov (United States)

    Stirling, Ross; Fyfe, Ken; Lachapelle, Gérard

    2005-01-01

    In this paper, a novel method of sensor based pedestrian dead reckoning is presented using sensors mounted on a shoe. Sensor based systems are a practical alternative to global navigation satellite systems when positioning accuracy is degraded such as in thick forest, urban areas with tall buildings and indoors. Using miniature, inexpensive sensors it is possible to create self-contained systems using sensor-only navigation techniques optimised for pedestrian motion. The systems developed extend existing foot based stride measurement technology by adding the capability to sense direction, making it possible to determine the path and displacement of the user. The proposed dead-reckoning navigation system applies an array of accelerometers and magneto-resistive sensors worn on the subject's shoe. Measurement of the foot's acceleration allows the precise identification of separate stride segments, thus providing improved stride length estimation. The system relies on identifying the stance phase to resolve the sensor attitude and determine the step heading. Field trials were carried out in forested conditions. Performance metrics include position, stride length estimation and heading with respect to a high accuracy reference trajectory.

  3. Work-related depression and associated factors in a shoe manufacturing factory in Haiphong City, Vietnam

    Directory of Open Access Journals (Sweden)

    Khue Pham Minh

    2014-12-01

    Full Text Available Objectives: To determine the prevalence and associated factors of work-related depression among the employees of a shoe manufacturing factory in Haiphong City, Vietnam. Material and Methods: We carried out this cross-sectional study among 420 workers in 2012 in Le Lai II Shoe Manufacturing Factory in Haiphong City, Vietnam using Karasek’s Job Content Questionnaire (JCQ and the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM IV tool for measuring depression. Results: The study results show that a relatively high proportion of workers (20.7% belongs to the high-strain group based on Karasek’s model. The prevalence of work-related depression among workers was relatively high (18.8%. The factors associated with depression at work were high psychological demand (adjusted OR = 3.0, 95% CI: 1.1–8.3, low social support (adjusted OR = 4.7, 95% CI: 1.2–12.8, inadequate work protection materials (OR = 4.1, 95% CI: 2.2–10.1 and work absenteeism (OR = 6.2, 95% CI: 2.5–18.9. Conclusions: Strengthening the social support network (involving supervisors and co‑workers, reducing psychological job demand and assuring work protection materials at the workplace may highly facilitate reducing work-related depression.

  4. Shoe cleat position during cycling and its effect on subsequent running performance in triathletes.

    Science.gov (United States)

    Viker, Tomas; Richardson, Matt X

    2013-01-01

    Research with cyclists suggests a decreased load on the lower limbs by placing the shoe cleat more posteriorly, which may benefit subsequent running in a triathlon. This study investigated the effect of shoe cleat position during cycling on subsequent running. Following bike-run training sessions with both aft and traditional cleat positions, 13 well-trained triathletes completed a 30 min simulated draft-legal triathlon cycling leg, followed by a maximal 5 km run on two occasions, once with aft-placed and once with traditionally placed cleats. Oxygen consumption, breath frequency, heart rate, cadence and power output were measured during cycling, while heart rate, contact time, 200 m lap time and total time were measured during running. Cardiovascular measures did not differ between aft and traditional cleat placement during the cycling protocol. The 5 km run time was similar for aft and traditional cleat placement, at 1084 ± 80 s and 1072 ± 64 s, respectively, as was contact time during km 1 and 5, and heart rate and running speed for km 5 for the two cleat positions. Running speed during km 1 was 2.1% ± 1.8 faster (P < 0.05) for the traditional cleat placement. There are no beneficial effects of an aft cleat position on subsequent running in a short distance triathlon.

  5. Monitoring of posture allocations and activities by a shoe-based wearable sensor.

    Science.gov (United States)

    Sazonov, Edward S; Fulk, George; Hill, James; Schutz, Yves; Browning, Raymond

    2011-04-01

    Monitoring of posture allocations and activities enables accurate estimation of energy expenditure and may aid in obesity prevention and treatment. At present, accurate devices rely on multiple sensors distributed on the body and thus may be too obtrusive for everyday use. This paper presents a novel wearable sensor, which is capable of very accurate recognition of common postures and activities. The patterns of heel acceleration and plantar pressure uniquely characterize postures and typical activities while requiring minimal preprocessing and no feature extraction. The shoe sensor was tested in nine adults performing sitting and standing postures and while walking, running, stair ascent/descent and cycling. Support vector machines (SVMs) were used for classification. A fourfold validation of a six-class subject-independent group model showed 95.2% average accuracy of posture/activity classification on full sensor set and over 98% on optimized sensor set. Using a combination of acceleration/pressure also enabled a pronounced reduction of the sampling frequency (25 to 1 Hz) without significant loss of accuracy (98% versus 93%). Subjects had shoe sizes (US) M9.5-11 and W7-9 and body mass index from 18.1 to 39.4 kg/m2 and thus suggesting that the device can be used by individuals with varying anthropometric characteristics.

  6. The Final SHOE; Completing a Rich Cepheid Field in NGC 1309

    Science.gov (United States)

    Riess, Adam

    2007-07-01

    The Cycle 15 SHOES program {GO 10802} is a large HST program allocated 186 orbits to rebuild the distance ladder using NGC 4258 as a new anchor, a set of 6 recent, ideal type Ia supernovae and Cepheids in their hosts, and NICMOS as a single, homogeneous photometer of long period Cepheids. These tools provide the means to achieve a 4% measurement of the Hubble constant, an invaluable constraint for cosmic concordance fits to dark energy models. Unfortunately, the SHOES NICMOS integrations of long period Cepheids in the last and most recent nearby type Ia supernova host, NGC 1309, are too short because the preliminary estimate of its distance, 30 Mpc, was too low. Our refined estimate now based on the full reduction of both our Cycle 14 and 15 ACS data is 36 Mpc, or 0.4 mag farther. Fortunately, Nature was extremely kind providing a single rich NIC2 field in which we can fully make up for the shortfall due to its abundance of Cepheids. We are expensing our final 4 orbits on this field of a dozen P>30 day Cepheids and seek an additional 5 orbits to reach the depth for measuring the mean F160W magnitudes of the long-period Cepheids with the necessary signal-to-noise ratios of better than 10.

  7. Severe tooth wear: European consensus statement on management guidelines

    DEFF Research Database (Denmark)

    Loomans, Bas AC; Opdam, Niek JM; Attin, Thomas

    2017-01-01

    This paper reports a European expert consensus statement on guidelines for the management of severe tooth wear. It focuses on the definition of physiological versus pathological tooth wear and recommends diagnosis, monitoring and counseling to define the activity of the wear. Restorative...

  8. 16 CFR 423.6 - Textile wearing apparel.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Textile wearing apparel. 423.6 Section 423.6 Commercial Practices FEDERAL TRADE COMMISSION TRADE REGULATION RULES CARE LABELING OF TEXTILE WEARING APPAREL AND CERTAIN PIECE GOODS AS AMENDED § 423.6 Textile wearing apparel. This section applies to...

  9. Comparative study of plantar pressure distribution on unstable shoes and running shoes%摇摆鞋和慢跑鞋对足底压力分布影响的对比研究

    Institute of Scientific and Technical Information of China (English)

    汤运启; 秦蕾; 徐娇萍; 王幽幽

    2016-01-01

    采用Novel pedar‐X鞋垫式足底压力测试系统,对10名女大学生穿着摇摆鞋和普通慢跑鞋两种状态下分别进行足底压力测试。对比分析峰值压强、峰值压力/体重、足底接触面积、压强‐时间积分等测试指标的差异。通过对比分析得出以下结论:(1)摇摆鞋和普通慢跑鞋的足底压力的各个测量指标分析表明,在脚趾区摇摆鞋的各项指标占整足的比重均大于普通慢跑鞋。(2)摇摆鞋和普通慢跑鞋足底分区的研究结果表明各项测试指标分别在 T1、T2‐5、M2‐3、M F等区域存在显著差异。%In this paper ,10 female college students were participated in this study ,planter pressure w ere tested under the condition of w earing unstable shoes and running shoes by u‐sing Novel pedar‐X insole system .The parameters of peak pressure ,ratio of max force and body weight ,contact area and pressure time integral were analyzed with similarities and differences .Conclusions were the followings :(1)Each index of plantar pressure was analyzed and showed that every index accounts for the whole foot of unstable shoes were more than ordinary running shoes in the toe area .(2)Compared with the ordinary running shoes ,each biomechanical parameter of unstable shoes with running shoes had significant difference only on the zone of T1 ,T2‐5 ,M2‐3 and M F .

  10. An Investigation into the Behavior of Disc Blake Wear

    Directory of Open Access Journals (Sweden)

    Muneer A. H.Jassim

    2007-01-01

    Full Text Available A real method of predication brake pad wear ,could lead to substantiol economies of time and money. This paper describes how such a procedure has been used and gives the results to establish is reliability by comparing the predicted wear with that which actually occurs in an existing service. The experimental work was carried out on three different commercial samples ,tested under different operation conditions (speed,load,time...etcusing a test ring especially modified for this purpose. Abrasive wear is mainly studied , since it is the type of wear that takes place in such arrangements. Samples wear tested in presences of sand or mud between the mating surfaces under different operational conditions of speed, load and braking time .Mechanical properties of the pad material samples (hardness, young,s modulus and collapse load under pure bending condition wear established . The thermal conductivity and surface roughness of the pad material wear also found in order to enable comparison between the surface condition before and after testing. Sliding velocity had a small effect on the wear rate but it had great effect on friction coefficient. Wear rate was affected mainly by the surface temperature which causing a reduction friction coefficient and increasing the wear rate. Surface roughness had almost no effect on the wear rate since it was proved experimentally ,that the surface becomes softer during operation .mechanical properties of the pad material had fluctuating effect on wear rate. The existence of solid particles between pad and disc increasing wear rate and friction coefficient while the mud caused a reduction in wear rate of the pad surface since it acts as a lubricant absorbing the surface heat generated during sliding the area of contact between pad and disc. wear rate obtained experimentally agreed fairly well that found from empirically obtained equations.

  11. Is tooth wear in the primary dentition predictive of tooth wear in the permanent dentition? Report from a longitudinal study.

    LENUS (Irish Health Repository)

    Harding, M A

    2010-03-01

    To determine the prevalence of tooth wear in the permanent dentition of a sample of 12-year-old school children and establish whether an association exists between tooth wear recorded now and tooth wear recorded in their primary dentition at age five.

  12. Morphology of young handball players

    Directory of Open Access Journals (Sweden)

    Adair da Silva Lopes

    2007-06-01

    Full Text Available The purpose of this study was to compare anthropometric and body composition variables from the best male handball athletes competing in the Santa Catarina state youth competition to variables from the other athletes in the same competition, by game position. Seven of the twelve coaches participating in the Santa Catarina Open Youth Games 2004 (up to 18 years freely consented to select the seven best athletes in the competition (one goalkeeper, one pivot, two wingers and three backcourt players. In addition to these seven players, there were a further 79 team members taking part, bringing the total sample size to 86 athletes. The following variables were analyzed: body weight (MC, height (ES, arm span (ENV, hand breadth (DPA, wrist breadth (DRU, forearm circumference (PA, percentage fat (%G, fat mass (MG and lean body mass (MCM. Descriptive statistics (means and standard deviations were employed to classify the athletes according to court position. The chosen athletes were compared with the others using the single-sample t test (p RESUMO Este estudo objetivou comparar variáveis antropométricas e da composição corporal dos melhores atletas de uma competição juvenil (até 18 anos de handebol masculino de Santa Catarina, em relação aos demais atletas da competição por posição de jogo. Sete dentre os doze técnicos participantes dos Joguinhos Abertos de Santa Catarina 2004 aceitaram, voluntariamente, realizar a escolha da seleção dos sete melhores atletas da competição (um goleiro, um pivô, dois extremas e três armadores. Contabilizou-se, além dos sete atletas da seleção, mais 79 atletas titulares de suas equipes, totalizando na amostra, 86 atletas. Foram analisadas as variáveis: massa corporal (MC, estatura (ES, percentual de gordura (%G, massa de gordura (MG, massa corporal magra (MCM, envergadura (ENV, diâmetro palmar (DPA, diâmetro biestilóide rádio-ulnar (DRU e perímetro do antebraço (PA. Utilizou-se a estat

  13. Evaluation and optimization of therapeutic footwear for neuropathic diabetic foot patients using in-shoe plantar pressure analysis

    NARCIS (Netherlands)

    S.A. Bus; R. Haspels; T.E. Busch-Westbroek

    2011-01-01

    Therapeutic footwear for diabetic foot patients aims to reduce the risk of ulceration by relieving mechanical pressure on the foot. However, footwear efficacy is generally not assessed in clinical practice. The purpose of this study was to assess the value of in-shoe plantar pressure analysis to eva

  14. Questionnaire for usability evaluation of orthopaedic shoes : Construction and reliability in patients with degenerative disorders of the foot

    NARCIS (Netherlands)

    Jannink, MJA; de Vries, J; Stewart, RE; Groothoff, JW; Lankhorst, GJ

    2004-01-01

    Objective: To develop a self-report questionnaire for patients with degenerative disorders of the foot to evaluate the usability of their orthopaedic shoes, and to assess the reproducibility and responsiveness of the instrument. Design: Development of the Questionnaire for Usability Evaluation of or

  15. Orthopaedic shoes along with physical therapy was effective in Charcot-Marie-Tooth patient over 10 years.

    Science.gov (United States)

    Bensoussan, Laurent; Jouvion, Arnaud; Kerzoncuf, Marjorie; Delarque, Alain; Theodoridou, Efy; Milhe de Bovis, Virginie; Thefenne, Laurent; Attarian, Sharam; Viton, Jean-Michel

    2016-10-01

    The aim was to investigate the effectiveness of custom-made orthopaedic shoes (derby shoes) along with physiotherapy (twice a week) on a person with Charcot-Marie-Tooth over a period of 10 years. A 66-year-old woman with Charcot-Marie-Tooth disease, who did not have other health conditions, complained of pain and frequent falls. Physical examination, including ankle, knee and hip muscle strength; sensory evaluation of foot and joint range of motion; self-reported assessment of pain, frequency of falls and sprains; and gait analyses, including spatial and temporal parameters and motion analyses, were performed in 2001, 2007 and 2011. During the 10 years of follow-up, the physical examination parameters had stabilized since 2001; falls, sprains and walking distance had improved as compared to 2000; pain had alleviated since 2001 and gait parameters had improved up to 2007 and stabilized between 2007 and 2011. Bracing with orthopaedic shoes along with physical therapy was effective in treating pain, improving the gait and enhancing the walking distance (>500 m) without assistive device in a person with Charcot-Marie-Tooth disease. Orthopaedic shoes along with physical therapy can be a good option for treating Charcot-Marie-Tooth associated pain, foot drop, falls and sprains, improving the gait abnormalities and also increasing the walking distance. © The International Society for Prosthetics and Orthotics 2015.

  16. Questionnaire for usability evaluation of orthopaedic shoes: construction and reliability in patients with degenerative disorders of the foot

    NARCIS (Netherlands)

    Jannink, Michiel J.A.; Vries, de Jaap; Stewart, Roy E.; Groothoff, Johan W.; Lankhorst, Gustaaf J.

    2004-01-01

    Objective: To develop a self-report questionnaire for patients with degenerative disorders of the foot to evaluate the usability of their orthopaedic shoes, and to assess the reproducibility and responsiveness of the instrument. Design: Development of the Questionnaire for Usability Evaluation of or

  17. The effect of gait training with shoe inserts on the improvement of pain and gait in sacroiliac joint patients.

    Science.gov (United States)

    Cho, Byung-Yun; Yoon, Jung-Gyu

    2015-08-01

    [Purpose] The purpose of the current research was to identify how gait training with shoe inserts affects the pain and gait of sacroiliac joint dysfunction patients. [Subjects and Methods] Thirty subjects were randomly selected and assigned to be either the experimental group (gait training with shoe insert group) or control group. Each group consisted of 15 patients. Pain was measured by Visual Analogue Scale, and foot pressure in a standing position and during gait was measured with a Gateview AFA-50 system (Alpus, Seoul, Republic of Korea). A paired sample t-test was used to compare the pain and gait of the sacroiliac joint before and after the intervention. Correlation between pain and walking after gait training with shoe inserts was examined by Pearson test. The level of significance was set at α=0.05. [Results] It was found that application of the intervention to the experimental group resulted in a significant decrease in sacroiliac joint pain. It was also found that there was a significant correlation between Visual Analogue Scale score and dynamic asymmetric index (r= 0.796) and that there was a negative correlation between Visual Analogue Scale score and forefoot/rear foot peak pressure ratio (r=-0.728). [Conclusion] The results of our analysis lead us to conclude that the intervention with shoe inserts had a significant influence on the pain and gait of sacroiliac joint patients.

  18. Effects of Shoe Heel Height on Loading and Muscle Activity for Trans-Tibial Amputees During Standing

    Institute of Scientific and Technical Information of China (English)

    JIA Xiaohong; WANG Rencheng; Winson Lee

    2009-01-01

    This study accesses the effects of shoe heel heights on loading, muscle activity, and plantar foot pressure of trans-tibial amputees during standing. Five male subjects with unilateral trans-tibial amputation volunteered to participate in this study. Three pairs of shoes with zero, 20 mm, and 40 mm heel heights were used. The loading line of the prosthetic side, the plantar foot pressure, and the surface electromyography (EMG) of 10 muscles were simultaneously recorded. With increasing shoe heel heights during standing, the loading line of the prosthetic side shifted from the anterior to the posterior side of the knee center, the peak pressure was increased in the medial forefoot region, and the peak pressure was reduced in the heel region. The EMG of the medial and lateral gastrocnemius of the sound leg almost doubled and that of the rectus fomris, vastus lateralis, and vastus medialis of the prosthetic side increased to different extents with in-creasing heel heights from zero to 40 mm. These results show a high correlation with human physical be-havior. Changing of the heel heights for trans-tibial amputees during standing actually had similar effects to altering the prosthetic sagittal alignment. The results suggest that an alignment change is necessary to ac-commodate heel height changes and that prosthesis users should be cautious when choosing shoes.

  19. Influence of high-heeled shoes on the sagittal balance of the spine and the whole body

    National Research Council Canada - National Science Library

    Weitkunat, Tim; Buck, Florian M; Jentzsch, Thorsten; Simmen, Hans-Peter; Werner, Clément M. L; Osterhoff, Georg

    2016-01-01

    .... The mechanisms behind this have not been fully understood. The purpose of this study was to investigate the influence of high-heeled shoes on the sagittal balance of the spine and the whole body in non-habitual wearers of high...

  20. Sports injuries in Plus League volleyball players.

    Science.gov (United States)

    Cieśla, E; Dutkiewicz, R; Mgłosiek, M; Nowak-Starz, G; Markowska, M; Jasiński, P; Dudek, J

    2015-06-01

    Although physical activity brings a range of lifelong health benefits, it may also lead to injuries that pose a significant threat to health. It is particularly noticeable in people involved in professional sports where sport-related injuries commonly occur and are associated with intense exercise which aims to improve physical fitness. The article attempts to determine incidence of sports injuries reported by Plus League volleyball players, as well as to identify their most common types and causes. The research project involved 90 Plus League volleyball players aged 18-37 with the average age of 25.11 (SD±5.378). A method of diagnostic survey was applied to collect empirical data by means of questionnaire developed by the authors (researchers). The results were statistically analysed and verified with the analysis of variance (ANOVA) and χ2 test at the significance level (or critical P-value) of P≤0.05. Over 87% of the respondents suffered from at least one sport-related injury. In total, 362 injuries occurred, on average 4.02 injuries per one volleyball player. The most common sports injuries involved ankle or talocrural joint (46 injuries), knee and lower leg muscles (30), interphalangeal articulations of fingers (30) as well as shoulder joint. More than half of the injuries (57%) occurred twice or three times. Volleyball players commonly sustain injuries through contact with an opposing player in competition. Sport-specific injuries may also occur due to exhaustion, lack of rest and undertreated injuries. The most common volleyball-related injuries are primarily talocrural joint, hand and shoulder injuries. Common types of injuries that can affect volleyball players include muscles, joints and ligaments injuries, sprains and strains as well as bruises. Most of these injuries are caused by exhaustion, contact with an opposing player during competition and fatigue. The incidence of sport-related injuries seems to be influenced by such factors as somatic

  1. Wear Studies on Metal Matrix Composites: a Taguchi Approach

    Institute of Scientific and Technical Information of China (English)

    S. Basavarajappa; G. Chandramohan

    2005-01-01

    An attempt has been made to study the influence of wear parameters like applied load, sliding speed, sliding distance and percentage of reinforcement on the dry sliding wear of the metal matrix composites. A plan of experiments,based on techniques of Taguchi, was pedormed to acquire data in controlled way. An orthogonal array and the analysis of variance were employed to investigate the influence of process parameters on the wear of composites. The objective is to establish a correlation between dry sliding wear of composites and wear parameters. These correlations were obtained by multiple regressions. Finally, confirmation tests were conducted to verify the experimental results foreseen from the mentioned correlations.

  2. The effect of different types of insoles or shoe modifications on medial loading of the knee in persons with medial knee osteoarthritis: a randomised trial.

    Science.gov (United States)

    Jones, Richard K; Chapman, Graham J; Parkes, Matthew J; Forsythe, Laura; Felson, David T

    2015-11-01

    Many conservative treatments exist for medial knee osteoarthritis (OA) which aims to reduce the external knee adduction moment (EKAM). The objective of this study was to determine the difference between different shoes and lateral wedge insoles on EKAM, knee adduction angular impulse (KAAI), external knee flexion moment, pain, and comfort when walking in individuals with medial knee OA. Seventy individuals with medial knee OA underwent three-dimensional walking gait analysis in five conditions (barefoot, control shoe, typical wedge, supported wedge, and mobility shoe) with pain and comfort recorded concurrently. The change in EKAM, KAAI, external knee flexion moment, pain, and comfort were assessed using multiple linear regressions and pairwise comparisons. Compared with the control shoe, lateral wedge insoles and barefoot walking significantly reduced early stance EKAM and KAAI. The mobility shoe showed no effect. A significant reduction in latter stance EKAM was seen in the lateral wedge insoles compared to the other conditions, with only the barefoot condition reducing the external knee flexion moment. However, the mobility shoe showed significant immediate knee pain reduction and improved comfort scores. Different lateral wedge insoles show comparable reductions in medial knee loading and in our study, the mobility shoe did not affect medial loading.

  3. Immediate effects of EVA midsole resilience and upper shoe structure on running biomechanics: a machine learning approach

    Directory of Open Access Journals (Sweden)

    Andrea N. Onodera

    2017-02-01

    Full Text Available Background Resilience of midsole material and the upper structure of the shoe are conceptual characteristics that can interfere in running biomechanics patterns. Artificial intelligence techniques can capture features from the entire waveform, adding new perspective for biomechanical analysis. This study tested the influence of shoe midsole resilience and upper structure on running kinematics and kinetics of non-professional runners by using feature selection, information gain, and artificial neural network analysis. Methods Twenty-seven experienced male runners (63 ± 44 km/week run ran in four-shoe design that combined two resilience-cushioning materials (low and high and two uppers (minimalist and structured. Kinematic data was acquired by six infrared cameras at 300 Hz, and ground reaction forces were acquired by two force plates at 1,200 Hz. We conducted a Machine Learning analysis to identify features from the complete kinematic and kinetic time series and from 42 discrete variables that had better discriminate the four shoes studied. For that analysis, we built an input data matrix of dimensions 1,080 (10 trials × 4 shoes × 27 subjects × 1,254 (3 joints × 3 planes of movement × 101 data points + 3 vectors forces × 101 data points + 42 discrete calculated kinetic and kinematic features. Results The applied feature selection by information gain and artificial neural networks successfully differentiated the two resilience materials using 200(16% biomechanical variables with an accuracy of 84.8% by detecting alterations of running biomechanics, and the two upper structures with an accuracy of 93.9%. Discussion The discrimination of midsole resilience resulted in lower accuracy levels than did the discrimination of the shoe uppers. In both cases, the ground reaction forces were among the 25 most relevant features. The resilience of the cushioning material caused significant effects on initial heel impact, while the effects

  4. Immediate effects of EVA midsole resilience and upper shoe structure on running biomechanics: a machine learning approach

    Science.gov (United States)

    Gavião Neto, Wilson P.; Roveri, Maria Isabel; Oliveira, Wagner R.

    2017-01-01

    Background Resilience of midsole material and the upper structure of the shoe are conceptual characteristics that can interfere in running biomechanics patterns. Artificial intelligence techniques can capture features from the entire waveform, adding new perspective for biomechanical analysis. This study tested the influence of shoe midsole resilience and upper structure on running kinematics and kinetics of non-professional runners by using feature selection, information gain, and artificial neural network analysis. Methods Twenty-seven experienced male runners (63 ± 44 km/week run) ran in four-shoe design that combined two resilience-cushioning materials (low and high) and two uppers (minimalist and structured). Kinematic data was acquired by six infrared cameras at 300 Hz, and ground reaction forces were acquired by two force plates at 1,200 Hz. We conducted a Machine Learning analysis to identify features from the complete kinematic and kinetic time series and from 42 discrete variables that had better discriminate the four shoes studied. For that analysis, we built an input data matrix of dimensions 1,080 (10 trials × 4 shoes × 27 subjects) × 1,254 (3 joints × 3 planes of movement × 101 data points + 3 vectors forces × 101 data points + 42 discrete calculated kinetic and kinematic features). Results The applied feature selection by information gain and artificial neural networks successfully differentiated the two resilience materials using 200(16%) biomechanical variables with an accuracy of 84.8% by detecting alterations of running biomechanics, and the two upper structures with an accuracy of 93.9%. Discussion The discrimination of midsole resilience resulted in lower accuracy levels than did the discrimination of the shoe uppers. In both cases, the ground reaction forces were among the 25 most relevant features. The resilience of the cushioning material caused significant effects on initial heel impact, while the effects of different

  5. Footloose Shoes?

    DEFF Research Database (Denmark)

    Lorentzen, Jochen

    2003-01-01

    the (partial) geographic fragmentation of local supply chains, dislocating select local parts manufacturers in its wake. The findings suggest that when international competition threatens the viability of local production, firms with the requisite organisational capabilities delocalise parts of the value chain....... This helps them to retain competitive advantages but it also reduces agglomeration. This insight should inform regional development policy.Keywords: Industrial districts, footwear industry, international competition, delocalisation...

  6. Shoe Giant

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    ShoeGiantByYANGDALITHEcityofWenzhouinZhejiangProvinceisChi-na'sshoecapital.AmongthemillionsofshoesproduceddailybyWenzhou'smor...

  7. Car Shoe

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    历史悠久的意大利制鞋商Car Shoe为日本爱知世界博览会意大利展团迎宾小姐设计的两款皮鞋,轻松休闲又不失高雅,完美再现Car Shoe的设计理念,其中一款舒适大方“Driving”软底鞋,白1963年上市至今,始终风靡全球,成为一代经典。布满黑色胶皮钉的鞋底,是Car Shoe鞋子的标志性特点,另有一款3.5厘米的矮跟 鞋,尽显女性独特魅力。

  8. Contact Thermal Analysis and Wear Simulation of a Brake Block

    Directory of Open Access Journals (Sweden)

    Nándor Békési

    2013-01-01

    Full Text Available The present paper describes an experimental test and a coupled contact-thermal-wear analysis of a railway wheel/brake block system through the braking process. During the test, the friction, the generated heat, and the wear were evaluated. It was found that the contact between the brake block and the wheel occurs in relatively small and slowly moving hot spots, caused by the wear and the thermal effects. A coupled simulation method was developed including numerical frictional contact, transient thermal and incremental wear calculations. In the 3D simulation, the effects of the friction, the thermal expansion, the wear, and the temperature-dependent material properties were also considered. A good agreement was found between the results of the test and the calculations, both for the thermal and wear results. The proposed method is suitable for modelling the slowly oscillating wear caused by the thermal expansions in the contact area.

  9. 7-Be Implantation in Plastics for Prosthesis Wear Studies

    Science.gov (United States)

    Greife, Uwe; Erikson, L.; Patel, N.; Wimmer, M.; Dwiwedi, Y.; Laurent, M.; Chipps, K.; Blackmon, J.; Kozub, R.; Bardayan, D.; Gross, C.; Stracener, D.; Smith, M.; Nesaraya, C.; Rehm, E.; Ahmed, I.; Greene, J.

    2010-11-01

    The current generation of highly cross linked ultrahigh molecular weight polyethylenes (PE) for hip and knee joint replacement have achieved such low in vitro wear rates that efforts have been underway to develop more sensitive methods to measure polyethylene wear. The most widely used technique, the gravimetric method, suffers from the notable disadvantage that mass gain by fluid absorption can considerably exceed mass loss by wear, making the wear measurement inaccurate, sometimes even leading to negative ``wear'' values. The purpose of this experiment was to investigate the use of a radioactive tracer, beryllium-7 (7-Be), to circumvent the problem of fluid absorption and thereby achieve a much more sensitive and accurate wear measurement. This proof of principle study demonstrated the general feasibility of 7-Be implantation (performed at the Holifield Radioactive Ion Beam Facility of Oak Ridge National Laboratory) for PE wear analysis.

  10. Dynamic SEM wear studies of tungsten carbide cermets

    Science.gov (United States)

    Brainard, W. A.; Buckley, D. H.

    1975-01-01

    Dynamic friction and wear experiments were conducted in a scanning electron microscope. The wear behavior of pure tungsten carbide and composite with 6 and 15 weight percent cobalt binder was examined. Etching of the binder was done to selectively determine the role of the binder in the wear process. Dynamic experiments were conducted as the WC and bonded WC cermet surfaces were transversed by a 50 micron radiused diamond stylus. These studies show that the predominant wear process in WC is fracture initiated by plastic deformation. The wear of the etched cermets is similar to pure WC. The presence of the cobalt binder reduces both friction and wear. The cementing action of the cobalt reduces granular separation and promotes a dense polished layer because of its low shear strength film-forming properties. The wear debris generated from unetched surface is approximately the same composition as the bulk.

  11. Wear aspects of internal combustion engine valves

    Science.gov (United States)

    Panţuru, M.; Chicet, D.; Paulin, C.; Alexandru, A.; Munteanu, C.

    2016-08-01

    Because the surface engineering is becoming an increasingly viable alternative to the constructive changes made to improve the efficiency of internal combustion engines, have been proposed and tested various types of coatings of some organs of internal combustion engines. One vital organ is the engine valves, which is subjected during operation to combined thermal, mechanical, corrosion and wear solicitations, which are leading to severe corrosion and complete breakdown. In this paper were analyzed aspects of valves wear and the active surfaces were coated using the atmospheric plasma spraying method (APS) with two commercial powders: Ni-Al and YSZ. Microstructural analyzes were made on these layers and also observations regarding the possibility of using them as thermal barrier and anti-oxidant coatings.

  12. Exposure and risks from wearing asbestos mitts

    Directory of Open Access Journals (Sweden)

    Tindall Matthew

    2005-10-01

    Full Text Available Abstract Background Very high fibre inhalation exposure has been measured while people were wearing personal protective equipment manufactured from chrysotile asbestos. However, there is little data that relates specifically to wearing asbestos gloves or mitts, particularly when used in hot environments such as those found in glass manufacturing. The aim of this study was to assess the likely personal exposure to asbestos fibres when asbestos mitts were used. Results Three types of work activity were simulated in a small test room with unused mitts and artificially aged mitts. Neither pair of mitts were treated to suppress the dust emission. The measured respirable fibre exposure levels ranged from Conclusion People who wore asbestos mitts were likely to have been exposed to relatively low levels of airborne chrysotile asbestos fibres, certainly much lower than the standards that were accepted in the 1960's and 70's. The cancer risks from this type of use are likely to be very low.

  13. Do media players cause interference with pacemakers?

    Science.gov (United States)

    Thaker, Jay P; Patel, Mehul B; Shah, Ashok J; Liepa, Valdis V; Brunett, Joseph D; Jongnarangsin, Krit; Gardiner, Joseph C; Thakur, Ranjan

    2009-11-01

    Electrical devices generate electromagnetic fields that may interfere with pacemakers. Media players cause telemetry interference with pacemakers, but it is not known whether they cause direct interference with pacemakers. The purpose of this study was to examine the interaction between pacemakers and 3 different media players. In this prospective, randomized study, 54 patients with dual chamber pacemakers who were in sinus rhythm underwent baseline observation, followed by observation under telemetry communication. These patients were then randomly evaluated with 3 media players (iPod 3G, iPod Photo, and iPod Touch Apple, Cupertino, CA) with and without telemetry communication for 1 minute each. Patients were monitored for pacemaker malfunction using a single-channel ECG during exposure to media players. The pacemaker was interrogated after each exposure and an interrogation report was printed for evaluation. Pacemaker interference was categorized as type I, II, or III. Types I and II interference described telemetry interference and type III interference was defined as any direct interference with pacemaker function or programmed parameters. A total of 54 patients (29 men and 25 women; mean age 77.2 +/- 9.3 y) were evaluated. In total, of the 162 tests (for telemetry interference) 36.4% were positive (Type I and II). Type III interference was also evaluated in 162 tests and none showed any evidence of direct interference. Media players cause telemetry interference with pacemakers, but they do not directly interfere with pacemaker function.

  14. Game Performance Evaluation in Male Goalball Players

    Directory of Open Access Journals (Sweden)

    Molik Bartosz

    2015-12-01

    Full Text Available Goalball is a Paralympic sport exclusively for athletes who are visually impaired and blind. The aims of this study were twofold: to describe game performance of elite male goalball players based upon the degree of visual impairment, and to determine if game performance was related to anthropometric characteristics of elite male goalball players. The study sample consisted of 44 male goalball athletes. A total of 38 games were recorded during the Summer Paralympic Games in London 2012. Observations were reported using the Game Efficiency Sheet for Goalball. Additional anthropometric measurements included body mass (kg, body height (cm, the arm span (cm and length of the body in the defensive position (cm. The results differentiating both groups showed that the players with total blindness obtained higher means than the players with visual impairment for game indicators such as the sum of defense (p = 0.03 and the sum of good defense (p = 0.04. The players with visual impairment obtained higher results than those with total blindness for attack efficiency (p = 0.04, the sum of penalty defenses (p = 0.01, and fouls (p = 0.01. The study showed that athletes with blindness demonstrated higher game performance in defence. However, athletes with visual impairment presented higher efficiency in offensive actions. The analyses confirmed that body mass, body height, the arm span and length of the body in the defensive position did not differentiate players’ performance at the elite level.

  15. Low-Wear Ball-Bearing Separator

    Science.gov (United States)

    Hawkinson, Elden L.

    1991-01-01

    Proposed ball-bearing separator for use in cryogenic pump stronger and more resistant to wear. Consists of molded plastic-and-metal composite ring imbued with solid lubricant and containing embedded metal ring. Obtains combination of strength and lubricity. Before molding and machining, ring includes tooling portion for handling and indexing. Molded composite blend of PTFE and fluorinated ethylene/propylene (FEP) filled with brass and bronze powder and molybdenum disulfide powder.

  16. Wear debris in cemented total hip arthroplasty.

    Science.gov (United States)

    Huo, M H; Salvati, E A; Buly, R L

    1991-03-01

    One of the most prevalent clinical problems in long-term follow up of total hip arthroplasty patients is loosening of prosthetic fixation. Factors contributing to mechanical failure of total hip reconstruction are complex and multiple. It has become increasingly apparent that wear debris from the prosthetic components may contribute significantly to this process. The authors summarize some of the current concepts concerning the detrimental effects of metallic debris in total hip arthroplasty.

  17. Wear Resistant Rubber Tank Track Pads

    Science.gov (United States)

    1975-10-01

    stereospecific SBR (Stereon 750), SBR/polybutadiene blends (Fhilprene 1609/Cis-4 1350 (or Cis-4 1351), Ameripoi 1834/Ameripol CB 1352) and alfin ...polybutadiene blends has confirmed this improvement in tread wear. The uncertainty regarding the future commercial availibility of the alfin catalyzed...polybutadiene blend) (S212-2), and HYTRANS 1227-2S9-1 ( alfin catalyzed copolymer of butadiene/ styrene) (S223-4) to determine their effect on the resistance to

  18. A Predictive Multiscale Model of Wear

    Science.gov (United States)

    2011-03-09

    of Robust Protective Coatings for Metal Components Subjected to Extreme Conditions,” at the Computer Aided Molecular Design Conference, St. Johns...2006 to July 31, 2010 on developing and applying first principles quantum mechanics methods to describe mechanical wear of chrome -plated steel gun...than the corresponding value for Fe3+, which makes sense since Fe’s orbitals are more contracted than Cr’s due to Fe’s larger effective nuclear charge

  19. Wear measurement by surface layer activation

    Energy Technology Data Exchange (ETDEWEB)

    Blatchley, C.

    1987-05-01

    The purpose of these projects was to demonstrate the capability for precisely but remotely measuring small increments of wear, erosion or corrosion in utility components using detectors mounted outside the system to monitor the presence of radionuclide surface markers. These gamma ray emitting markers are produced by surface layer activation (SLA) using a high energy particle beam from a Van de Graaff or cyclotron particle accelerator. The work was divided into three major projects: (1) determination of the feasibility of applying SLA based surface monitoring techniques to key power plant systems; (2) a field demonstration of SLA monitoring in steam turbine components subject to severe solid particle erosion; and (3) a field demonstration of SLA wear or corrosion monitoring of components in boiler auxiliaries. In the field tests, surface material removal was successfully measured from both selected systems, demonstrating the feasibility of the technique for long term diagnostic condition monitoring. Three bearing components in a boiler circulation pump were monitored almost continuously for a period of over 5 months until the pump was stopped due to electrical problems unrelated to the wear measurements. Solid particle erosion from two stop valve bypass valves was measured during a series of nine startup cycles. Both test demonstrations confirmed the earlier feasibility estimates and showed how SLA markers can be used to provide valuable diagnostic information to plant operators. 22 refs., 63 figs., 29 tabs.

  20. Study of Wear of Pitched Blade Impellers

    Directory of Open Access Journals (Sweden)

    I. Fořt

    2000-01-01

    Full Text Available A study was made of the erosion of blades of pitched blade impellers in a suspension of solid particles in a liquid under a turbulent regime of flow of an agitated charge. The wear of the impeller is described by an analytical approximation in exponential form, and the influence of the pitch angle on the impeller blade wear was studied experimentally. It follows from the results of the experiments made that the wear rate of the pitched blade impellers increases linearly with the decreasing pitch angle within the interval a Î á15°; 45° ń. The proposed form of radial profile of the leading edge of the impeller blade enables us to calculate the surface of the worn blade. This quantity significantly decreases with the length of the period when the blades are affected by the solid particles, and its values calculated according to the suggested profile of the worn blade fit fairly well with the experimentally determined values. The results of the experiments performed are valid for homogeneous distribution of solid particles in an agitated suspension.

  1. Corrosion and wear in plasma electrosurgical devices

    Science.gov (United States)

    Gaspredes, J.; Ryan, T. P.; Stalder, K. R.; Woloszko, J.

    2017-02-01

    Data were previously reported on studies of the effects of electrical discharges on the corrosion and wear of simple, single-wire test devices immersed in isotonic saline 1 . This work showed that there are a wide variety of mechanisms that can explain various aspects of electrode mass loss, even with very simple electrode geometries and operating conditions. It was found that the electrode material composition played an important role. Subsequently, our studies were expanded to include more realistic device geometries and operating conditions. This paper shows the results of studies on wear characteristics of electrodes made from a variety of highly corrosion resistant metals and alloys, including Waspaloy, Hastelloy, Inconel, Havar, Monel, and other pure metals such as Hafnium. All of these metals underwent wear testing under clinically relevant conditions. Depending on the operating conditions, multiple discrete physical and chemical effects were observed at different locations on the surface of an individual millimeter-scale device electrode. Scanning electron microscope (SEM) micrographs, Energy-dispersive X-ray spectroscopy (EDS) and area loss data will be presented for a variety of test conditions and electrode materials.

  2. 和谐型大功率内燃机车高摩合成闸瓦的研制%Development of Composite Brake Shoes with High Friction Coefficient for High Power Diesel Locomotive (HXN)

    Institute of Scientific and Technical Information of China (English)

    裴顶峰; 张国文; 党佳; 贺春江

    2012-01-01

    Nitrile butadiene rubber modified phenolic resin was used as adhesive. Graphite, bauxite, potash feldspar powder, reduced ferrous powder and precipitated barium sulfate were used as filler. Steel fiber and sepiolite fiber were used as reinforcing fibers. The friction material of composite brake shoe with high friction coefficient was constituted by the blend of the above materials. Composite brake shoe with high friction coefficient for high power diesel locomotive was developed through optimizing technology and formula by trial and error. Test results show that all the physical, mechanical, braking, friction and wear properties of the developed composite brake shoe with high friction coefficient meet the technical requirements of high power diesel locomotive (HXN). The impact strength and compression modulus reaches 3. 8 kJ ? M-2 and 460 Mpa respectively. Tests of 1 : 1 Train braking dynamic test stand also show that, at the speed of 120 km ? H-1, the braking distance of the loaded car, the maximum temperature of wheel tread and abrasion loss is 817 m, 215 °C and 0. 87 cm3 ? MJ-1 respectively, which can fully meet the operating requirements of emergency braking distance less than 1100 m, the maximum temperature of wheel tread less than 400 t and the braking abrasion loss of loaded car less than 1. 5 cm3 ? MJ-1 at the speed of 120 km ? H-1. The compressive properties of composite brake shoes with high friction coefficient have reached the level of the same type foreign products.%以丁腈橡胶改性酚醛树脂为黏合剂,石墨、铝矾土、钾长石粉、还原铁粉和沉淀硫酸钡等为填料,钢纤维和海泡石纤维为增强纤维,混合构成了高摩合成闸瓦的摩擦材料;通过反复实验,优化配方及工艺,研制出适合我国和谐型大功率内燃机车运用需求的高摩合成闸瓦.测试结果显示:研制的高摩合成闸瓦的各项物理力学性能及制动摩擦磨损性能符合和谐型大功率

  3. Motivation and Sport Injuries in Handball Players

    Directory of Open Access Journals (Sweden)

    Laguna, María

    2010-12-01

    Full Text Available The aim of the study was to test whether different levels of motivation are related to the injuries suffered by elite athletes. The sample consists of 80 professional handball players of ASOBAL League, with a mean age of 24.83 years (+ 5.21. Motivation was assessed through the CPRD scale (Gimeno, Buceta & Pérez-Llantada; 1999 and a self-report questionnaire was used to register sports injuries. The results indicate that there is a relationship between motivational levels and the risk for injury. Specifically, players with high motivated players had a greater number of moderate injuries. Although it may seem paradoxical, it is possible that an excessively high motivation leads to overachievement and risk behaviors, which in turn facilitate the appearance of lesions.

  4. Cricket club looking for new players

    CERN Multimedia

    Cricket Club

    2016-01-01

    The CERN Cricket Club, having lost several key players, has had a very difficult season so far and is desperately in need of new players. Having qualified for the Cricket Switzerland semi-finals for the last two years (unfortunately losing both), this year we are bottom of the Western Pool, having played the last two league matches with only 10 players. If you are interested in playing cricket please join us at net practice, which takes place on the Prevessin site each Thursday evening from 18:00 to around 20:00 (weather permitting) or send me an e-mail (see below). Please have a look at the Cricket Club web site for more information: http://cern.ch/Club-Cricket/ Chris Onions, President of the CERN Cricket Club   (christopher.onions@gmail.com)

  5. Big Data for Business Ecosystem Players

    Directory of Open Access Journals (Sweden)

    Perko Igor

    2016-06-01

    Full Text Available In the provided research, some of the Big Data most prospective usage domains connect with distinguished player groups found in the business ecosystem. Literature analysis is used to identify the state of the art of Big Data related research in the major domains of its use-namely, individual marketing, health treatment, work opportunities, financial services, and security enforcement. System theory was used to identify business ecosystem major player types disrupted by Big Data: individuals, small and mid-sized enterprises, large organizations, information providers, and regulators. Relationships between the domains and players were explained through new Big Data opportunities and threats and by players’ responsive strategies. System dynamics was used to visualize relationships in the provided model.

  6. Adapting virtual camera behaviour through player modelling

    DEFF Research Database (Denmark)

    Burelli, Paolo; Yannakakis, Georgios N.

    2015-01-01

    Research in virtual camera control has focused primarily on finding methods to allow designers to place cameras effectively and efficiently in dynamic and unpredictable environments, and to generate complex and dynamic plans for cinematography in virtual environments. In this article, we propose...... a novel approach to virtual camera control, which builds upon camera control and player modelling to provide the user with an adaptive point-of-view. To achieve this goal, we propose a methodology to model the player’s preferences on virtual camera movements and we employ the resulting models to tailor...... the viewpoint movements to the player type and her game-play style. Ultimately, the methodology is applied to a 3D platform game and is evaluated through a controlled experiment; the results suggest that the resulting adaptive cinematographic experience is favoured by some player types and it can generate...

  7. Mean Field Games with a Dominating Player

    Energy Technology Data Exchange (ETDEWEB)

    Bensoussan, A., E-mail: axb046100@utdallas.edu [The University of Texas at Dallas, International Center for Decision and Risk Analysis, Jindal School of Management (United States); Chau, M. H. M., E-mail: michaelchaumanho@gmail.com; Yam, S. C. P., E-mail: scpyam@sta.cuhk.edu.hk [The Chinese University of Hong Kong, Department of Statistics (Hong Kong, People’s Republic of China) (China)

    2016-08-15

    In this article, we consider mean field games between a dominating player and a group of representative agents, each of which acts similarly and also interacts with each other through a mean field term being substantially influenced by the dominating player. We first provide the general theory and discuss the necessary condition for the optimal controls and equilibrium condition by adopting adjoint equation approach. We then present a special case in the context of linear-quadratic framework, in which a necessary and sufficient condition can be asserted by stochastic maximum principle; we finally establish the sufficient condition that guarantees the unique existence of the equilibrium control. The proof of the convergence result of finite player game to mean field counterpart is provided in Appendix.

  8. There is no game without a player

    DEFF Research Database (Denmark)

    Larsen, Lasse Juel

    on the subject matter from the catalogue of game theory. All four suggestions exclude the player from the relationship. This paper introduces a phenomenological point of view and includes the player in order to understand the relationship between structure and dressing. It argues that players constitute a bridge......This paper is a search for meaning or to be more precise a study of how meaning is produced between ontology and fiction in computer games. It sets out to investigate the relationship between formal abstract game structures and game representation (dressing) by presenting four suggestions...... or the center which establishes, upholds and renegotiate the relationship between formal game structure and game dressing. It also argues that players’ interaction with both structure and dressing produce meaning and the production of meaning is the relationship between formal abstract game structures and game...

  9. Modelling Virtual Camera Behaviour Through Player Gaze

    DEFF Research Database (Denmark)

    Picardi, Andrea; Burelli, Paolo; Yannakakis, Georgios N.

    2012-01-01

    In a three-dimensional virtual environment, aspects such as narrative and interaction largely depend on the placement and animation of the virtual camera. Therefore, virtual camera control plays a critical role in player experience and, thereby, in the overall quality of a computer game. Both game...... industry and game AI research focus on the devel- opment of increasingly sophisticated systems to automate the control of the virtual camera integrating artificial intel- ligence algorithms within physical simulations. However, in both industry and academia little research has been carried out...... on the relationship between virtual camera, game-play and player behaviour. We run a game user experiment to shed some light on this relationship and identify relevant dif- ferences between camera behaviours through different game sessions, playing behaviours and player gaze patterns. Re- sults show that users can...

  10. Individual recovery profiles in basketball players.

    Science.gov (United States)

    Moreno, Jordi; Ramos-Castro, Juan; Rodas, Gil; Tarragó, Joan R; Capdevila, Lluís

    2015-01-01

    In the sport context, recovery has been characterized as a multifactor process (physiological, psychological, behavioral, social, etc.). This study takes a multidisciplinary approach to find psychophysiological markers of the stress-recovery process. It aims to determine how athletes' specific recovery actions relate to their perceptions of recovery, and Heart Rate Variability (HRV). A total of 196 assessments were analyzed from 6 players on a men's professional basketball team within the Liga LEB Oro basketball federation (2012/2013 season). Perceptions of recovery, recovery strategies, and HRV were recorded. The results show a pattern of individual differences in behavior related to athletes' recovery actions and HRV profiles throughout the season (p < .05). Moreover, we observed that each player had different recovery needs. In light of these results, we suggest an individualistic approach to evaluating and monitoring recovery to attend more accurately to each player's recovery needs.

  11. The influence of store image on customer satisfaction: a case study of a shoe store

    Directory of Open Access Journals (Sweden)

    Tarsis Souza Silva

    2010-01-01

    Full Text Available Knowledge of customers' image of a store is an essential factor in the management of retail outlets. This article presents a case study of the effect of the image customers have of a shoe store on their satisfaction, based on a descriptive and quantitative survey, with the application of a structured questionnaire. We then employed factor analysis to obtain seven store image factors: assortment, convenience, reputation, price, atmosphere, layout and service. The results show that the factor that most affects customer satisfaction in the store studied is service, and that atmosphere and layout have no effect in this respect. The results provide a better understanding of the role store image plays in customer satisfaction and loyalty.

  12. Patch Testing With Shoe Series In Suspected Cases Of Footwear Dermatitis

    Directory of Open Access Journals (Sweden)

    Eapen Bell Raj

    2001-01-01

    Full Text Available One hundred fifty nine patients with clinically suspected footwear dermatitis were patch tested to determine the frequency of positivity of common footwear antigens. Patch testing was done with 22 allergens of Shoe series (Chemotechnique Diagnostics AB Sweden extended with neomycin, gentamycin, soframycin, paraben, cresol and lanolin. Forty- two percent of patients was sensitive to footwear allergen(s whereas the overall positivity was 62%. Potassium dichromate. 2 mercapto- benzothiazole (MBT and nickel sulphate were the frequent sensitizers followed by gentamycin, neomycin, gluteraldehyde, formaldehyde, diphenyl guanidine, diphenyl thiourea, dibutyl thiourea, para-tertiary butyl phenol and 4 aminoazobenzene. Dorsa of feet was the commonest site. potassium dichromate sensitivity was higher in males and the history was not always helpful in incriminating the antigen.

  13. Value generation in the context of manufacturing strategy: an analysis in shoe manufactories

    Directory of Open Access Journals (Sweden)

    Sergio Evangelista Silva

    2015-02-01

    Full Text Available The manufacturing function has the role of provide to the customers products with generate value. However this task is not unique of this function, it has to work with the functions research and development (R&D and marketing and sales (M&S. This paper call these three functions as generating value functions, and discuss their mutual role in the process of generating value in the products of a firm. The validation of this model is performed by three comparative case studies, conducted in three shoe manufactories (SMs, with different value generation strategies. The empirical study shows that the mutual role of generating value functions in the value generating process, and that the configuration and the relative role of each function change according to the firm strategy followed.

  14. Research on Extraction of Bottom of Shoe Pattern Based on Binocular Stereo Vision

    Institute of Scientific and Technical Information of China (English)

    MA Xin-wu; GAN Yi; SUN Fu-jia

    2016-01-01

    In order to quickly and efficiently get the information of the bottom of the shoe pattern and spraying trajectory, the paper proposes a method based on binocular stereo vision .After acquiring target image , edge detection based on the canny algorithm , the paper begins stereo matching based on area and characteristics of algorithm.To eliminate false matching points , the paper uses the principle of polar geometry in computer vision . For the purpose of gaining the 3D point cloud of spraying curve , the paper adopts the principle of binocular stereo vision 3D measurement , and then carries on cubic spline curve fitting .By HALCON image processing software programming , it proves the feasibility and effectiveness of the method .

  15. Modified distal shoe appliance for the loss of a primary second molar: a case report.

    Science.gov (United States)

    Dhull, Kanika Singh; Bhojraj, Nandlal; Yadav, Shweta; Prabhakaran, Sheeja Devi

    2011-01-01

    Preservation of primary teeth until their normal exfoliation plays a crucial role in preventive and interceptive dentistry. Premature loss of the primary second molar prior to the eruption of the permanent first molar in the absence of the primary second molar can lead to mesial movement and migration of the permanent molar before and during its eruption. In such cases, an intra-alveolar type of space maintainer to guide the eruption of the permanent first molar is indicated. In certain cases, however, the conventional design is not practical. This paper describes a new design for distal shoe appliances in cases of primary second molar loss prior to the eruption of the permanent mandibular first molar.

  16. Harvested power and sensitivity analysis of vibrating shoe-mounted piezoelectric cantilevers

    Science.gov (United States)

    Moro, L.; Benasciutti, D.

    2010-11-01

    This paper presents a preliminary investigation on energy harvesting from human walking via piezoelectric vibrating cantilevers. Heel accelerations during human gait are established by correlating data gathered from the literature with direct experimental measurements. All the observed relevant features are synthesized in a typical (standard) acceleration signal, used in subsequent numerical simulations. The transient electromechanical response and the harvested power of a shoe-mounted bimorph cantilever excited by the standard acceleration signal is computed by numerical simulations and compared with measurements on a real prototype. A sensitivity analysis is finally developed to estimate the mean harvested power for a wide range of scavenger configurations. Acceptability criteria based on imposed geometrical constraints and resistance strength limits (e.g. fatigue limit) are also established. This analysis allows a quick preliminary screening of harvesting performance of different scavenger configurations.

  17. Cervical joint position sense in rugby players versus non-rugby players.

    Science.gov (United States)

    Pinsault, Nicolas; Anxionnaz, Marion; Vuillerme, Nicolas

    2010-05-01

    To determine whether cervical joint position sense is modified by intensive rugby practice. A group-comparison study. University Medical Bioengineering Laboratory. Twenty young elite rugby players (10 forwards and 10 backs) and 10 young non-rugby elite sports players. Participants were asked to perform the cervicocephalic relocation test (CRT) to the neutral head position (NHP) that is, to reposition their head on their trunk, as accurately as possible, after full active left and right cervical rotation. Rugby players were asked to perform the CRT to NHP before and after a training session. Absolute and variable errors were used to assess accuracy and consistency of the repositioning for the three groups of Forwards, Backs and Non-rugby players, respectively. The 2 groups of Forwards and Backs exhibited higher absolute and variable errors than the group of Non-rugby players. No difference was found between the two groups of Forwards and Backs and no difference was found between Before and After the training session. The cervical joint position sense of young elite rugby players is altered compared to that of non-rugby players. Furthermore, Forwards and Backs demonstrated comparable repositioning errors before and after a specific training session, suggesting that cervical proprioceptive alteration is mainly due to tackling and not the scrum.

  18. Structurally Integrated Coatings for Wear and Corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Beardsley, M. Brad; Sebright, Jason L.

    2008-11-18

    Wear and corrosion of structures cuts across industries and continues to challenge materials scientists and engineers to develop cost effective solutions. Industries typically seek mature technologies that can be implemented for production with rapid or minimal development and have little appetite for the longer-term materials research and development required to solve complex problems. The collaborative work performed in this project addressed the complexity of this problem in a multi-year program that industries would be reluctant to undertake without government partnership. This effort built upon the prior development of Advanced Abrasion Resistant Materials conduct by Caterpillar Inc. under DOE Cooperative Agreement No. DE-FC26-01NT41054. In this referenced work, coatings were developed that exhibited significant wear life improvements over standard carburized heat treated steel in abrasive wear applications. The technology used in this referenced work, arc lamp fusing of thermal spray coatings, was one of the primary technical paths in this work effort. In addition to extending the capability of the coating technology to address corrosion issues, additional competitive coating technologies were evaluated to insure that the best technology was developed to meet the goals of the program. From this, plasma transferred arc (PTA) welding was selected as the second primary technology that was investigated. Specifically, this project developed improved, cost effective surfacing materials and processes for wear and corrosion resistance in both sliding and abrasive wear applications. Materials with wear and corrosion performance improvements that are 4 to 5 times greater than heat treated steels were developed. The materials developed were based on low cost material systems utilizing ferrous substrates and stainless steel type matrix with hard particulates formed from borides and carbides. Affordability was assessed against other competing hard surfacing or coating

  19. Why forefoot striking in minimal shoes might positively change the course of running injuries

    Directory of Open Access Journals (Sweden)

    Irene S. Davis

    2017-06-01

    Full Text Available It is believed that human ancestors evolved the ability to run bipedally approximately 2 million years ago. This form of locomotion may have been important to our survival and likely has influenced the evolution of our body form. As our bodies have adapted to run, it seems unusual that up to 79% of modern day runners are injured annually. The etiology of these injuries is clearly multifactorial. However, 1 aspect of running that has significantly changed over the past 50 years is the footwear we use. Modern running shoes have become increasingly cushioned and supportive, and have changed the way we run. In particular, they have altered our footstrike pattern from a predominantly forefoot strike (FFS landing to a predominantly rearfoot strike (RFS landing. This change alters the way in which the body is loaded and may be contributing to the high rate of injuries runners experience while engaged in an activity for which they were adapted. In this paper, we will examine the benefits of barefoot running (typically an FFS pattern, and compare the lower extremity mechanics between FFS and RFS. The implications of these mechanical differences, in terms of injury, will be discussed. We will then provide evidence to support our contention that FFS provides an optimal mechanical environment for specific foot and ankle structures, such as the heel pad, the plantar fascia, and the Achilles tendon. The importance of footwear will then be addressed, highlighting its interaction with strike pattern on mechanics. This analysis will underscore why footwear matters when assessing mechanics. Finally, proper preparation and safe transition to an FFS pattern in minimal shoes will be emphasized. Through the discussion of the current literature, we will develop a justification for returning to running in the way for which we were adapted to reduce running-related injuries.

  20. Wear Behaviour of Pressible Lithium Disilicate Glass Ceramic

    Science.gov (United States)

    Peng, Zhongxiao; Rahman, Muhammad Izzat Abdul; Zhang, Yu; Yin, Ling

    2015-01-01

    This paper reports effects of surface preparation and contact loads on abrasive wear properties of highly aesthetic and high-strength pressible lithium disilicate glass-ceramics (LDGC). Abrasive wear testing was performed using a pin-on-disk device in which LDGC disks prepared with different surface finishes were against alumina pins at different contact loads. Coefficients of friction and wear volumes were measured as functions of initial surface finishes and contact loads. Wear-induced surface morphology changes in both LDGC disks and alumina pins were characterized using 3D laser scanning microscopy, scanning electron microscopy and energy dispersive x-ray spectroscopy. The results show that initial surface finishes of LDGC specimens and contact loads significantly affected the friction coefficients, wear volumes and wear-induced surface roughness changes of the material. Both wear volumes and friction coefficients of LDGC increased as the load increased while surface roughness effects were complicated. For rough LDGC surfaces, three-body wear was dominant while for fine LDGC surfaces, two-body abrasive wear played a key role. Delamination, plastic deformation and brittle fracture were observed on worn LDGC surfaces. The adhesion of LDGC matrix materials to alumina pins was also discovered. This research has advanced our understanding of the abrasive wear behaviour of LDGC and will provide guidelines for better utilisation and preparation of the material for long-term success in dental restorations. PMID:25980530

  1. Finite element based simulation of dry sliding wear

    Science.gov (United States)

    Hegadekatte, V.; Huber, N.; Kraft, O.

    2005-01-01

    In order to predict wear and eventually the life-span of complex mechanical systems, several hundred thousand operating cycles have to be simulated. Therefore, a finite element (FE) post-processor is the optimum choice, considering the computational expense. A wear simulation approach based on Archard's wear law is implemented in an FE post-processor that works in association with a commercial FE package, ABAQUS, for solving the general deformable-deformable contact problem. Local wear is computed and then integrated over the sliding distance using the Euler integration scheme. The wear simulation tool works in a loop and performs a series of static FE-simulations with updated surface geometries to get a realistic contact pressure distribution on the contacting surfaces. It will be demonstrated that this efficient approach can simulate wear on both two-dimensional and three-dimensional surface topologies. The wear on both the interacting surfaces is computed using the contact pressure distribution from a two-dimensional or three-dimensional simulation, depending on the case. After every wear step the geometry is re-meshed to correct the deformed mesh due to wear, thus ensuring a fairly uniform mesh for further processing. The importance and suitability of such a wear simulation tool will be enunciated in this paper.

  2. Association between Severity of Tooth Wear and Dentinal Hypersensitivity

    Directory of Open Access Journals (Sweden)

    Ashok Ayer

    2016-11-01

    Full Text Available Background & Objectives: Tooth wear (attrition, abrasion, erosion, and abfraction is perceived globally as ever increasing problem. Several outcome of the tooth wear are hypersensitivity, esthetic problems, functional impairment, annoyance to the patient, and fracture of the tooth. Among these, the measurable and more commonly reported outcome is hypersensitivity to stimuli. Although dentin hypersensitivity is a common clinical condition and is generally reported by the patient after experiencing a sharp, short pain caused by one of the several different external stimuli, it is often inadequately understood. None of the scientific literature available till date attempted to establish the relationship between tooth wear and dentin hypersensitivity which could be a key factor in monitoring those patients.  The aim of the study was to estimate the association between severity of teeth wear and sensitivity in the patients with reported dentinal hypersensitivity.Materials & Methods: Fifty patients with dentin hypersensitivity were investigated for tooth wear. Tooth wear measured using exact tooth wear index and level of sensitivity to stimuli was recorded using a numerical rating scale. Results: Enamel wear at cervical region of teeth showed a positive correlation (p=.010, similarly, dentin wear at cervical region of teeth showed positive correlation and significant association (p<.001 with dentinal hypersensitivity.Conclusion: The observation supports a significant association between severities of tooth surface wear and dentinal hypersensitivity.

  3. ON ASSESSMNENT OF PHYSICAL WEAR IN ELEMENTS OF TECHNICAL DEVICES

    Directory of Open Access Journals (Sweden)

    S. N. Osipov

    2015-01-01

    Full Text Available Real assessment of wear in technical devices, construction structures, minings, their elements and connections is of great importance for provision of operational security and efficiency. Natural properties of the overwhelming majority of materials follow to probabilistic (stochastic laws due to various reasons (external influence, processing technologies and others. An assessment of physical wear rate of buildings and structures and their elements is carried out in the former republics of the USSR mainly in accordance with external physical signs (deflections, cracks, layer separations, etc. but wear percentage is often calculated on the basis of replacement cost in comparison with the initial one even without taking into account inflation which did not officially exist in the USSR. In this case destruction or failure of structure or their elements are considered as 100 % wear.The paper proposes a new methodology for assessment of physical wear rate in accordance with probability ratio of nofailure operation (reliability, minimum ratio is assigned to admissible limit value in conformity with technical requirements for the technical devices, construction structures, minings in question, their elements and connections. In this context minimum permissible wear probability (reliability is taken as 100 % wear rate and its initial index is considered as 0 % wear rate. That is why wear intensity in time depends on type of value probability distribution while determining the rate of physical property. The proposed methodology is intended for probabilistic wear assessment in case of relatively simple changes in strength properties of materials (for example, within the elastic limit.

  4. Injury incidence and balance in rugby players.

    Science.gov (United States)

    M, Jaco Ras; Puckree, Threethambal

    2014-01-01

    Objective : This study determined and correlated injury incidence and balance in rugby players. A prospective survey with balance testing was conducted on first year rugby academy players (N= 114). Injury incidence, static and dynamic balance were tested pre and post-season using a Biosway portable balance system. The data was analysed using paired and independent samples t-tests at pscrum-half (14.80%) playing position, injuries in the 2nd half of the match (57%), and during contact (67%). Conclusion : Injury incidence was related to static and dynamic balance in forward right direction only.

  5. Fault Predictive Control of Compact Disk Players

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Wickerhauser, Mladen Victor

    2006-01-01

    Optical disc players such as CD-players have problems playing certain discs with surface faults like scratches and fingerprints. The problem is to be found in the servo controller which positions the optical pick-up, such that the laser beam is focused on the information track. A scheme handling ...... of the feature based control scheme, such that a prediction step is included. The proposed scheme is compared with the feature based control scheme, in the perspective of handling surface faults, by simulations. These simulations show the improvements given by the proposed algorithm....

  6. Wear characterization of abrasive waterjet nozzles and nozzle materials

    Science.gov (United States)

    Nanduri, Madhusarathi

    Parameters that influence nozzle wear in the abrasive water jet (AWJ) environment were identified and classified into nozzle geometric, AWJ system, and nozzle material categories. Regular and accelerated wear test procedures were developed to study nozzle wear under actual and simulated conditions, respectively. Long term tests, using garnet abrasive, were conducted to validate the accelerated test procedure. In addition to exit diameter growth, two new measures of wear, nozzle weight loss and nozzle bore profiles were shown to be invaluable in characterizing and explaining the phenomena of nozzle wear. By conducting nozzle wear tests, the effects of nozzle geometric, and AWJ system parameters on nozzle wear were systematically investigated. An empirical model was developed for nozzle weight loss rate. To understand the response of nozzle materials under varying AWJ system conditions, erosion tests were conducted on samples of typical nozzle materials. The effect of factors such as jet impingement angle, abrasive type, abrasive size, abrasive flow rate, water pressure, traverse speed, and target material was evaluated. Scanning electron microscopy was performed on eroded samples as well as worn nozzles to understand the wear mechanisms. The dominant wear mechanism observed was grain pullout. Erosion models were reviewed and along the lines of classical erosion theories a semi-empirical model, suitable for erosion of nozzle materials under AWJ impact, was developed. The erosion data correlated very well with the developed model. Finally, the cutting efficiency of AWJ nozzles was investigated in conjunction with nozzle wear. The cutting efficiency of a nozzle deteriorates as it wears. There is a direct correlation between nozzle wear and cutting efficiency. The operating conditions that produce the most efficient jets also cause the most wear in the nozzle.

  7. Sprint, agility, strength and endurance capacity in wheelchair basketball players

    National Research Council Canada - National Science Library

    Yanci, J; Granados, C; Otero, M; Badiola, A; Olasagasti, J; Bidaurrazaga-Letona, I; Iturricastillo, A; Gil, Sm

    ...; and secondly, to analyse the physical characteristics measured by sprint, agility, strength and endurance field tests in wheelchair basketball (WB) players. 16 WB players (33.06 ± 7.36 years, 71.89...

  8. Jet Lag a Drag on Pro Baseball Players

    Science.gov (United States)

    ... 163187.html Jet Lag a Drag on Pro Baseball Players Study found traveling across time zones linked ... might be more than just tiring for pro baseball players: The resulting jet lag may actually harm ...

  9. Assessment and Treatment of Foot-Shoe Fetish Displayed by a Man with Autism

    Science.gov (United States)

    Dozier, Claudia L.; Iwata, Brian A.; Worsdell, April S.

    2011-01-01

    Results of a functional analysis indicated that a man diagnosed with autism engaged in bizarre sexual behavior in the presence of women wearing sandals. Several treatments proved to be ineffective or impractical. By contrast, a response-interruption/time-out procedure quickly eliminated the problem behavior in multiple settings. (Contains 1…

  10. STUDY ON THE WEAR CHARACTERISTICS OF Ni-P BRUSH-PLATING COATING

    Institute of Scientific and Technical Information of China (English)

    WuWenyue; HuangJinruo; QuJinxin; ShaoHesheng

    1996-01-01

    This paper studied the wear characteristics as well as the wear mechanismof the Ni-P alloy brush-plating coating by means of sliding-wear tests, SEM and X-Ray analyses. The results show that Ni-Palloy coating has excellent wear-ability inhigh temperature, and the wear mechanism of the coating is that both the adhesivewear and abrasive wear exist in a boundary lubrication condition. The wear model wasbuilt up.

  11. The Effectiveness of Shin Guards Used by Football Players

    Directory of Open Access Journals (Sweden)

    Yasar Tatar

    2013-03-01

    Full Text Available In football, injuries from opponent contact occur commonly in the lower extremities. FIFA the world’s governing body for football requires players to wear shin guards. The aim of this study was to compare the protective effectiveness of polypropylene based shin guards with custom-made carbon fiber ones. Three commercial polypropylene shin guards (Adidas Predator™, Adidas UCL™, and Nike Mercurial™ and two custom-made carbon fiber shin guards were examined. The experimental setup had the following parts: 1 A pendulum attached a load cell at the tip (CAS Corp., Korea and a fixed prosthetic foot equipped with a cleat to simulate an attacker’s foot. 2 An artificial tibia prepared by condensed foam and reinforced by carbon fibers protected with soft clothing. 3 A multifunctional sensor system (Tekscan Corp., F-Socket System, Turkey to record the impact on the tibia. In the low impact force trials, only 2.79-9.63 % of the load was transmitted to the sensors. When comparing for mean force, peak force and impulse, both carbon fiber shin guards performed better than the commercial ones (Adidas Predator™, Adidas UCL™, and Nike Mercurial™ (p = 0.000. Based on these same parameters, the Nike Mercurial™ provided better protection than the Adidas Predator™ and the Adidas UCL™ (p = 0.000. In the high impact force trials, only 5.16-10.90 % of the load was transmitted to the sensors. For peak force and impulse, the carbon fiber shin guards provided better protection than all the others. Carbon fiber shin guards possess protective qualities superior to those of commercial polypropylene shin guards.

  12. The effectiveness of shin guards used by football players.

    Science.gov (United States)

    Tatar, Yasar; Ramazanoglu, Nusret; Camliguney, Asiye Filiz; Saygi, Evrim Karadag; Cotuk, Hasan Birol

    2014-01-01

    In football, injuries from opponent contact occur commonly in the lower extremities. FIFA the world's governing body for football requires players to wear shin guards. The aim of this study was to compare the protective effectiveness of polypropylene based shin guards with custom-made carbon fiber ones. Three commercial polypropylene shin guards (Adidas Predator™, Adidas UCL™, and Nike Mercurial™) and two custom-made carbon fiber shin guards were examined. The experimental setup had the following parts: 1) A pendulum attached a load cell at the tip (CAS Corp., Korea) and a fixed prosthetic foot equipped with a cleat to simulate an attacker's foot. 2) An artificial tibia prepared by condensed foam and reinforced by carbon fibers protected with soft clothing. 3) A multifunctional sensor system (Tekscan Corp., F-Socket System, Turkey) to record the impact on the tibia. In the low impact force trials, only 2.79-9.63 % of the load was transmitted to the sensors. When comparing for mean force, peak force and impulse, both carbon fiber shin guards performed better than the commercial ones (Adidas Predator™, Adidas UCL™, and Nike Mercurial™) (p = 0.000). Based on these same parameters, the Nike Mercurial™ provided better protection than the Adidas Predator™ and the Adidas UCL™ (p = 0.000). In the high impact force trials, only 5.16-10.90 % of the load was transmitted to the sensors. For peak force and impulse, the carbon fiber shin guards provided better protection than all the others. Carbon fiber shin guards possess protective qualities superior to those of commercial polypropylene shin guards. Key PointsShin guards decrease the risk of serious injuries.Carbon shin guards provide sufficient protection against high impact forces.Commercially available Polypropylene based shin guards do not provide sufficient protection against high impact forces.

  13. 基于Ansys workbench对某型后制动蹄疲劳分析%Fatigue analysis on a rear brake shoe based on Ansys workbench

    Institute of Scientific and Technical Information of China (English)

    雷健

    2014-01-01

    文章采用Ansys workbench对某型制动蹄建立动态接触分析模型,分析了领、从蹄在制动过程中的应力分布。基于应力结果计算出了领、从蹄的高周疲劳安全因数,结果表明制动蹄疲劳安全因数满足使用要求。%A dynamic contact analysis model of a brake shoe is established by Ansys workbench in this paper,stress distribution of front and rear brake shoe in braking process is analyzed.Based on the stress results,the high-cycle fatigue safety factor of front and rear brake shoe is calculated,from the hoofs of ,the result shows that the fatigue safety factor of brake shoe meets the requirement.

  14. The Green Shoe Option’s Effectiveness at Stabilizing the IPO’S Stock Price on the Indonesian Stock Exchange (2000-2013

    Directory of Open Access Journals (Sweden)

    Siti Saadah

    2016-02-01

    Full Text Available The increased of price volatility due to positive initial returns will reduce investor confidence and impact on the overall market. Market stabilization mechanism is needed to control the price volatility. This research is intended to explore the effectiveness of Green-Shoe Option in reducing stock price volatility after IPO. This study is done through GARCH model development intended to identify the volatility of IPO shares price. This research compares the volatility price of company shares that apply Green shoe option at IPO with companies that do not apply it. The result of this research on companies that conduct IPO on 2000-2013 periods showed that the green shoe option stabilization program which was used by the issuers was effective in muffing the stock prices’ volatility. Therefore, according to researchers Green Shoe Option stabilization program can be used to prevent or ease the drop of shares price under Public offering.

  15. Benefits Of Compression Garments Worn During Handball-Specific Circuit On Short-Term Fatigue In Professional Players.

    Science.gov (United States)

    Ravier, Gilles; Bouzigon, Romain; Beliard, Samuel; Tordi, Nicolas; Grappe, Frederic

    2016-01-29

    The purpose was to investigate the benefits of full-leg length compression garments (CGs) worn during a handball-specific circuit exercises on athletic performance and acute fatigue-induced changes in strength and muscle soreness in professional handball players. Eighteen males (mean ± SD: age 23.22 ± 4.97 years; body mass 82.06 ± 9.69 kg; height 184.61 ± 4.78 cm) completed two identical sessions either wearing regular gym short or CGs in a randomized crossover design. Exercise circuits of explosive activities included 3 periods of 12 minutes of sprints, jumps and agility drills every 25s. Before, immediately after and 24 h post-exercise, maximal voluntary knee extension (MVC), rate of force development (RFD) and muscle soreness were assessed. During the handball-specific circuit sprint and jump performances were unchanged in both conditions. Immediately after performing the circuit exercises MVC, RFD and PPT decreased significantly compared with preexercise with CGs and noncompression clothes. Decrement was similar in both conditions for RFD (ES = 0.40) and PPT for the soleus (ES = 0.86). However, wearing CGs attenuated decrement in MVC (P handball-specific circuit provides benefits on the impairment of the maximal muscle force characteristics and is likely to be worthwhile for handball players involved in activities such as tackles.

  16. Development and Validation of a Wear Model to Predict Polyethylene Wear in a Total Knee Arthroplasty: A Finite Element Analysis

    Directory of Open Access Journals (Sweden)

    Bernardo Innocenti

    2014-11-01

    Full Text Available Ultra-high molecular weight polyethylene (UHMWPE wear in total knee arthroplasty (TKA components is one of the main reasons of the failure of implants and the consequent necessity of a revision procedure. Experimental wear tests are commonly used to quantify polyethylene wear in an implant, but these procedures are quite expensive and time consuming. On the other hand, numerical models could be used to predict the results of a wear test in less time with less cost. This requires, however, that such a model is not only available, but also validated. Therefore, the aim of this study is to develop and validate a finite element methodology to be used for predicting polyethylene wear in TKAs. Initially, the wear model was calibrated using the results of an experimental roll-on-plane wear test. Afterwards, the developed wear model was applied to predict patello-femoral wear. Finally, the numerical model was validated by comparing the numerically-predicted wear, with experimental results achieving good agreement.

  17. 关于运动鞋几种性能的浅析%Analysis on some properties of sports shoes

    Institute of Scientific and Technical Information of China (English)

    巴洪冰

    2013-01-01

      随着社会的发展,人民对竞技体育和健身运动的热爱,高科技含量的运动鞋就显示出重要的意义,以性能指标作为反馈信息是实现高科技含量运动鞋的良好发展模式。通常科技含量较高,能满足更高运动要求的运动鞋应有几大特点:防滑性能及附着力强,运动员易于控制;减震功能极佳,保护运动员的下肢安全;吸湿性及透气性能好,能应对大运动量和长时间的体育运动,从而达到保持鞋内干爽透气。本文将就运动鞋性能的国内外研究现状和最新试验方法做一综述,为研究和制订我国运动鞋业提供绵薄之力。%With the development of society, people's love for sports and fitness, high-tech sports shoes will show great significance, with properties index as the feedback information is a good development mode of implementation of high-tech sports shoes. Usually, high technology content, can meet the higher requirements of sports shoes should have several characteristics:the antiskid properties and strong adhesion, excellent athletes is easy to control;damping function, protect lower limb safety of athletes;hygroscopicity and good air permeability, can deal with a large amount of exercise and a long time sports, so as to keep the shoes dry. The paper reviews the situation at home and abroad of sport shoes properties and new test method, contribute for the research and formulation of our country's sports shoes.

  18. Sliding wear and friction behaviour of zircaloy-4 in water

    Science.gov (United States)

    Sharma, Garima; Limaye, P. K.; Jadhav, D. T.

    2009-11-01

    In water cooled nuclear reactors, the sliding of fuel bundles in fuel channel handling system can lead to severe wear and it is an important topic to study. In the present study, sliding wear behaviour of zircaloy-4 was investigated in water (pH ˜ 10.5) using ball-on-plate sliding wear tester. Sliding wear resistance zircaloy-4 against SS 316 was examined at room temperature. Sliding wear tests were carried out at different load and sliding frequencies. The coefficient of friction of zircaloy-4 was also measured during each tests and it was found to decrease slightly with the increase in applied load. The micro-mechanisms responsible for wear in zircaloy-4 were identified to be microcutting, micropitting and microcracking of deformed subsurface zones in water.

  19. Ceramic-like wear behaviour of human dental enamel.

    Science.gov (United States)

    Arsecularatne, J A; Hoffman, M

    2012-04-01

    This paper reports a transmission electron microscopy (TEM) analysis of subsurfaces of enamel specimens following in vitro reciprocating wear tests with an enamel cusp sliding on a flat enamel specimen under hydrated conditions. The obtained results show that crack formation occurred in the wear scar subsurface. The path followed by these cracks seems to be dictated either by the histological structure of enamel or by the contact stress field. Moreover, the analysis of a set of enamel wear results obtained from the literature and application of fracture-based models, originally developed for ceramics, correlate well, confirming the similar wear processes taking place in these materials. This analysis also reveals a marked influence of coefficient of friction on the enamel wear rate: for a higher coefficient of friction value, enamel wear can be severe even under forces generated during normal operation of teeth. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. A physically-based abrasive wear model for composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Gun Y.; Dharan, C.K.H.; Ritchie, Robert O.

    2001-05-01

    A simple physically-based model for the abrasive wear of composite materials is presented based on the mechanics and mechanisms associated with sliding wear in soft (ductile) matrix composites containing hard (brittle) reinforcement particles. The model is based on the assumption that any portion of the reinforcement that is removed as wear debris cannot contribute to the wear resistance of the matrix material. The size of this non-contributing portion of the reinforcement is estimated by modeling the three primary wear mechanisms, specifically plowing, interfacial cracking and particle removal. Critical variables describing the role of the reinforcement, such as its relative size and the nature of the matrix/reinforcement interface, are characterized by a single contribution coefficient, C. Predictions are compared with the results of experimental two-body (pin-on drum) abrasive wear tests performed on a model aluminum particulate-reinforced epoxy matrix composite material.