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Abstract Football helmet certification tests are performed without a facemask attached to the helmet; however, the facemask is expected to contribute substantially to the structure and dynamics of the helmet through the effects of added mass and added stiffness. Facemasks may increase the peak acceleration and severity index; therefore, as-used helmets may not mitigate head impacts as effectively as certification tests indicate. Furthermore, the effect is expected to depend on the helmet design as well as the orientation and speed of the impact. This study examined the influence of the facemask on impact behavior in a NOCSAE-style linear drop test and the interactions with location, velocity, and helmet model. Increases in peak acceleration and severity index of up to 36% were observed when helmets were tested with the facemask. [ABSTRACT FROM AUTHOR]

Background and objective The aim of this research is to study the behaviour of a human head during the event of an impact of a cricket ball. While many recent incidents were reported in relation to head injuries caused by the impact of cricket balls, there is no clear information available in the published literature about the possible threat levels and the protection level of the current protective equipment. This research investigates the effects of an impact of a cricket ball on a human head and the level of protection offered by the existing standard cricket helmet. Method An experimental program was carried out to measure the localised pressure caused by the impact of standard cricket balls. The balls were directed at a speed of 110 km/h on a 3D printed head model, with and without a standard cricket helmet. Numerical simulations were carried out using advanced finite element package LS-DYNA to validate the experimental results. Results The experimental and numerical results showed approximately a 60% reduction in the pressure on the head model when the helmet was used. Both frontal and side impact resulted in head acceleration values in the range of 225–250 g at a ball speed of 110 km/h. There was a 36% reduction observed in the peak acceleration of the brain when wearing a helmet. Furthermore, numerical simulations showed a 67% reduction in the force on the skull and a 95% reduction in the skull internal energy when introducing the helmet. Conclusions (1) Upon impact, high localised pressure could cause concussion for a player without helmet. (2) When a helmet was used, the acceleration of the brain observed in the numerical results was at non-critical levels according to existing standards. (3) A significant increase in the threat levels was observed for a player without helmet, based on force, pressure, acceleration and energy criteria, which resulted in recommending the compulsory use of the cricket helmet. (4) Numerical results showed a good correlation with experimental results and hence, the numerical technique used in this study can be recommended for future applications. [ABSTRACT FROM AUTHOR]

Introduction With more diversity in the workforce, companies are producing PPE such as hard hats, safety glasses, coveralls, foot protection, and safety harnesses for a larger range of body shapes and sizes. However, gray literature reports suggest that barriers exist to getting alternate sized PPE from the manufacturer to the workers who need it. The purpose of this study is to determine the extent to which alternative-sized PPE is marketed. Method A web-based review of seven major manufacturers of PPE was conducted to determine: (a) whether or not they offer alternative-sized products, (b) if these products are clearly labeled, and (c) if images used to display PPE are representative of a diverse workforce. Results Of the seven PPE manufacturers investigated, six had at least one product that was marketed as gender and/or size alternatives however, alternative sizes were more common for larger body types. Alternative-sized products rarely included size charts, and the models used to display PPE were overwhelmingly white males of average size. Conclusions Despite the growing availability of alternative-sized PPE, it can be difficult to find these products, which suggests that they are rarely promoted or labeled as alternative-sized. Our study indicates that companies should expand their product lines and more aggressively market and promote these items. Guidance on how to properly fit their products would also be extremely helpful to the end-user. Practical applications Manufacturers could improve the availability of alternative-sized PPE and increase their promotion of these products on their websites and in their catalogs. Individual companies and safety professionals may assist in this process by demonstrating demand for alternative-sized PPE. [ABSTRACT FROM AUTHOR]

The adequacy of the decision-making regarding the specification of Safety Instrumented Systems (SIS) deployed for hazardous processes, contributes to avoiding incidents and corresponding losses. This paper proposes an approach to mathematically and economically substantiated design of SIS. Markov analysis is used for the stochastic process of SIS failures and technological incidents occurrence. The model is used further for multi-objective optimization of SIS design. The research is relevant to engineering departments and contractors, who specialise in planning and designing the technological solution. [ABSTRACT FROM AUTHOR]

Objective: The objective of the present case series study was to analyze injury types and injured anatomic locations resulting from skiing in snow park (SP) features and to determine potential risk factors for ski injuries in an SP.Methods: The study was conducted during the 2013-2014 winter season in the SP of a major winter resort located in the Spanish Pyrenees. Cases involved skiers who experienced feature-related injuries in the SP. A total of 113 cases met the inclusion criteria. Logistic regression was used to calculate the odds of injury types and injury to anatomic locations on aerial versus nonaerial features.Results: The overall injury rate was 0.9 per 1000 skier runs. The proportion of injuries was higher for aerials (1.18% of uses) than for nonaerials (0.66% of uses). Results revealed that the upper extremities were the most commonly injured body region, and sprains/strains/dislocations and fractures were the most common injury type.Conclusions: The most commonly injured anatomic location on nonaerial features was the face, while on aerial features it was the head. A higher proportion of fractures was observed on aerial features, while a higher proportion of sprains/strains/dislocations was observed on nonaerial features. Prevention strategies to reduce injury risk include SP redesign, safety and communication policies, instruction on technical skills, and promotion of the use of protective equipment. [ABSTRACT FROM AUTHOR]

We report on friction properties between simulated tennis shoe treads created in house and a hard court tennis surface approved by the International Tennis Federation. To simulate tennis shoe tread, we use the compound N70 Nitrile Butadiene Rubber, which possesses similar physical characteristics as commercial tennis shoe treads, namely hardness, tensile strength, and elongation percentage. Into that compound we have created a series of tread patterns with various shapes, spacing, and heights. An in-house traction rig allows for the maintaining of a constant vertical load while a horizontal load is monotonically increased until our tread slips on the hard court tennis surface. Our experimental apparatus allows us to test a range of rubber compound areas and tread patterns. We performed experiments with different vertical loads and extracted both static and dynamic friction coefficients using force data supplied by load cells mounted vertically and horizontally. Variations in the compound's tread geometry lead to different friction coefficients. We also rotated our tread patterns over a range of angles and extracted associated friction coefficients. Our results have moved us closer to a better understanding of optimal tread patterns on a tennis shoe. Such results are especially of interest to us as sliding is becoming a more prominent feature of elite tennis play on hard courts. [ABSTRACT FROM AUTHOR]

This study compares fabrication methods for auxetic foam intended for use in sports safety equipment. Thermo-mechanical conversion methods were applied using: i) cubic moulds (150x150x150 mm), ii) cuboidal moulds (150x150x30 mm) & iii) cuboidal moulds (150x150x30 mm) with through-thickness pins. The cuboidal moulds having one reduced dimension relative to the cubic moulds enable faster heat transfer and more consistent through-thickness compression to the foam during conversion. The through-thickness pins allow greater control of in-plane compression throughout the bulk of the converted foam. Samples were compared using: i) density measurements and measurements of total surface folding (length multiplied by depth), ii) quasi-static compressive load/unload tests to obtain specific strain energy, stress/strain relationship and Poisson's ratio, iii) impact testing on a bespoke drop rig based on a standard for cricket pads (BS 6183-3: 2000, EN 2001) at 5, 10 and 15 J & iv) microscopic images of dissected samples to confirm their auxetic (re-entrant) structure. Samples fabricated in cuboidal moulds show less variation in final density, axial compressive stiffness and specific strain energy between samples than those cut from monoliths fabricated in cubic moulds. Samples created with through-thickness pins exhibited reduced surface folding. Greater control over final properties paves the way for further work designing auxetic foams for sport safety equipment. [ABSTRACT FROM AUTHOR]

Laceration injuries in rugby union account for approximately 6% of all injuries sustained during match play. Commentators often cite the design of studded footwear as a causal factor in laceration injuries. In order to assess the laceration injury risk of different stud designs, there is a need to develop a testing protocol that is able to replicate the laceration injury event. This study used a questionnaire to identify the play scenarios that result in laceration injuries. The questionnaire was answered by 191 rugby players, of which 72% had experienced one or more stud injuries during their career which hindered them playing rugby. Half of the laceration injuries described by the respondents came from the ruck, and 27% from a tackle. When analysing free-text responses, a deliberate stamp was described in 35% of the responses and a tackle from behind was described in 14% of responses. These injury scenarios are considered to be the dominant cause of laceration injuries. In future work the identified injury scenarios will be replicated in simulated play and kinetic and kinematic measurements will be recorded. This will inform test parameters for future assessment of laceration injury risk of stud designs. [ABSTRACT FROM AUTHOR]

The head is one of the most heat sensitive parts of the human body. In various sports head protection is obligatory resulting in a dilemma. In situations of high metabolism heat is accumulated due to insulation properties of the helmet, leading to enormous heat stress and discomfort. Today one way to improve heat dissipation from the head is via ventilation openings. But thermodynamically, further opportunities exist either active or passive. In this paper one material- and one technology-based concept are presented and evaluated with a physical thermal head model. The former uses evaporative cooling (convection). It consists of a water reservoir, a small pump to transport the water beneath the helmet, tubes and a textile for a homogeneous water distribution. The second uses materials with beneficial conductive properties (conduction) in direct contact to the head. This concept is realized by the use of heat pipes that are integrated in the structure of the helmet and a heat sink. Cooling effect of the concepts is evaluated in two controlled thermal environments (T 1 =15°C; T 2 =28°C; RH=70%). Thereby the head is heated up to a constant inner temperature of T hy =39°C that arises during high activity. The surface temperatures on the head are recorded by 61 evenly distributed temperature sensors, representing skin temperatures. Finally, cooling effect results from the heating energy that is needed to keep a constant core temperature. The analysed data relating to the required heating energy shows no differences between the HRSs and compared to the reference measurement. In contrast, a considerable effect of HRSs is determined, locally. Applying the HRS Heat pipe & Heat sink skin temperatures show decreases both at 15°C and at 28°C compared to the reference measurement. At sensor position 3 the maximum decrease can be seen by 25%. By using the HRS H 2 O at sensor position 3 skin temperature decreases by 13% at 15°C and by 8% at 28°C in comparison to the values of the reference measurement. Concerning the cooling effect, the comparison of both of the HRSs shows up to 17% better values at 15°C using the HRS Heat pipe & Heat sink . At 28°C no differences can be seen. Concerning the cooling effect and the disadvantages of the evaporative cooling principle, the HRS Heat Pipe & Heat sink is more suited for such an application in bicycle helmets. For applying this HRS to a bicycle helmet it has to be adapted to the entire helmet and to its shape. [ABSTRACT FROM AUTHOR]

Concussion awareness in sports-related injuries has increased over the past decade. This has resulted in improvement in protective equipment and in our understanding of head injury. While contact sports such as ice hockey or football are of interest, concussion also occurs in non- contact sports like softball and baseball. The aim of this project was to describe facemask response to ball impacts. The study involved one face mask design and two types of foam padding. A method is presented that allows foam characterization at deformation rates and magnitudes representative of impact conditions. The foam impacts were modelled numerically and shown to agree with experiment. The facemask/foam system was placed on a Hybrid III headform and impacted with softballs to measure its response experimentally. A numeric model of the facemask/foam system on a model of the Hybrid III headform showed good agreement with experiment. Facemask impacts with a stiffer foam showed superior attenuation at high speeds (above 31 m/s) while a softer foam attenuated impacts better at low speeds. [ABSTRACT FROM AUTHOR]

The design of ski and ski touring boots should consider three key elements: performance, safety and comfort. For all three aspects, the boot's (shaft) flexural behavior is one of the crucial characteristics. Knowing the importance of this design parameter it is surprising that up to now no generally accepted standardized method exists to test and quantify the stiffness of the boot. First test methods, developed in the late eighties, used a leg prosthesis loaded with a horizontal force at the top of the shank in order to apply a bending moment to the boot hinge. Since then the basic principle has not been changed and it is widely used to quantify the dorsal and plantar flexion under slope conditions as well as the effect of buckle closure, temperature and fit of the boot. This common approach however neglects some of the important boundary conditions such as the realistic plantar pressure distribution underneath the artificial foot or the correct location and shift of the point of force application during the flexion movement. The aim of this study was to design a new test bench which overcomes some of the previous limitations thus being able to improve validity of the load simulation. The major addition to the current state is that the new test bench simulates ground reaction forces by using a pneumatic driven active leg-prosthesis generating an internal extension moment in knee and ankle. Further a linear bearing allows simultaneous displacement of the foot in the sagittal plane, simulating forward or backward shift of the center of pressure, which is typical for skiing maneuvers. The presentation will illustrate the theory behind this new concept and describe the details of its design. [ABSTRACT FROM AUTHOR]

Foamed rubbers are widely used for the shoe-soles, shin-guards, protectors and so on. The complex microstructure of foamed rubber consists of rubber matrix and pores. Therefore, foamed rubbers show good shock-absorbing properties in addition to good formability and lightweight. The mechanical characteristics of foamed rubber are determined by the mechanical characteristics of rubber matrix and its microstructure. In this study, a homogenization numerical analysis of mechanical characteristics of foamed rubber considering the rubber matrix and microstructure was shown. In order to develop the evaluation method, the microstructure of the foamed rubber was assumed to have the periodical holes, and a homogenization FEM code for formed rubber was developed based on homogenization theory with hyperelasticity. To verify the applicability of our developed code, rectangular rubber specimens with periodically holes were prepared to observe stress distributions of periodical inner structure. Incompressible hyperelasticity was applied to the rubber matrix. The material parameters of hyperelasticity for rubber matrix were identified by the biaxial tensile test results. Compression test of the rubber specimen reproducing FEM model was conducted to verify the applicability of the analysis code. The analysis result showed good agreement with the compression test result in the low strain region. [ABSTRACT FROM AUTHOR]

The National Operating Committee on Standards for Athletic Equipment (NOCSAE) has developed impact attenuation thresholds that protective helmets worn in sport must meet to be commercially available in an attempt to prevent injury. It remains unknown how normal helmet use in athletic activity alters the force attenuation ability of lacrosse helmets. We tested 3 new and 3 randomly selected used helmets from 2 popular lacrosse models (Cascade Pro7, Cascade CPXR). All used helmets had been worn for 3 collegiate seasons prior to testing and had never been refurbished. Helmets were drop-tested using 3 prescribed impact velocities at 6 locations according to the NOCSAE lacrosse helmet standard, and we compared the Gadd Severity Index (GSI) scores between new and used helmets using a repeated measure ANOVA with location as the repeated variable and data separated by impact velocity. All 12 helmets passed the NOCSAE GSI threshold for all testing conditions; however 1 used helmet shell cracked resulting in a failed test. We found a significant main effect for helmet age at the low ( F 5,50 =2.98, P =.02), medium ( F 5,50 =3.71, P =.006), and high ( F 5,50 =2.70, P =.03) velocities. We suspect that helmet use can degrade materials under some conditions, but improve performance in others due to changes in helmet composition from use. The clinical implications of the differences in GSI scores noted remain unclear. Because one helmet shell cracked resulting in a failed test, used helmets should be regularly inspected for cracks or other signs of mechanical fatigue that may weaken helmet integrity. [ABSTRACT FROM AUTHOR]

The biomechanical experiment with eight male and four female firefighters demonstrates that the effect of adding essential equipment: turnout ensemble, self-contained breathing apparatus, and boots (leather and rubber boots), significantly restricts foot pronation. This finding is supported by a decrease in anterior-posterior and medial-lateral excursion of center of plantar pressure (COP) trajectory during walking. The accumulation of this equipment decreases COP velocity and increases foot-ground contact time and stride time, indicating increased gait instability. An increase in the flexing resistance of the boots is the major contributor to restricted foot pronation and gait instability as evidenced by the greater decrease in excursion of COP in leather boots (greater flexing resistance) than in rubber boots (lower resistance). The leather boots also shows the greatest increase in foot contact time and stride time. These negative impacts can increase musculoskeletal injuries in unfavorable fire ground environments. [ABSTRACT FROM AUTHOR]

Objective To survey young male athletes to determine the self-reported prevalence of sports-related testicular injuries and use of protective equipment among adolescents and young adults. Methods A self-administered questionnaire was distributed to male students at local high schools and colleges. Respondents were asked about personal and team member usage of athletic cups and history of testicular injuries. Returned surveys were analyzed for descriptive statistics and compared between high school and college respondents. Results Approximately 1700 surveys were distributed and 731 returned. The mean age of all respondents was 17.7 years. Across all sports, 18% of athletes experienced a testicular injury during sports and 36.4% observed injuries in team members, whereas only 12.9% of respondents reported wearing athletic cups. The prevalence of testicular injuries for lacrosse, wrestling, baseball, and football was 48.5%, 32.8%, 21%, and 17.8%, respectively. Of athletes reporting a prior injury, 20.1% reported that they wear a cup now. Rates of athletic cup usage were significantly less for college baseball, football, and all respondents compared with their high school counterparts. Conclusion Previously reported rates of testicular injury with sports participation may underestimate the prevalence of these injuries among adolescent and young adult athletes among whom testicular protective equipment is infrequently used. [ABSTRACT FROM AUTHOR]

Purpose To characterise the demographics, cycling habits and accident rates of adult cyclists in Tasmania. Methods Volunteers ≥18 years of age who had cycled at least once/week over the previous month provided information on demographics; cycling experience; bicycles owned; hours/km/trips cycled per week; cycling purpose; protective equipment used; and major (required third-party medical treatment or resulted ≥1 day off work) or minor (interfered with individuals’ regular daily activities and/or caused financial costs) accidents while cycling. Results Over 8-months, 136 cyclists (70.6% male) completed the telephone survey. Mean (standard deviation) age was 45.4 (12.1) years with 17.1 (11.4) years of cycling experience. In the week prior to interview, cyclists averaged 6.6 trips/week (totalling 105.7 km or 5.0 h). The most common reason for cycling was commuting/transport (34% of trips), followed by training/health/fitness (28%). The incidence of major and minor cycling accidents was 1.6 (95% CI 1.1–2.0) and 3.7 (2.3–5.0) per 100,000 km, respectively. Male sex was associated with a significantly lower minor accident risk (incidence rate ratio = 0.34, p = 0.01). Mountain biking was associated with a significantly higher risk of minor accident compared with road or racing, touring, and city or commuting biking ( p < 0.05). Conclusions Physical activity of regular cyclists’ exceeds the level recommended for maintenance of health and wellbeing; cyclists also contributed substantially to the local economy. Accident rates are higher in this sample than previously reported in Tasmania and internationally. Mountain biking was associated with higher risks of both major and minor accidents compared to road/racing bike riding. [ABSTRACT FROM AUTHOR]

Abstract: In competitive cycling, aero-helmets have been used around since 1980 to reduce aerodynamic resistance. Considerable design effort has been made to improve the aerodynamic efficiency of racing bicycle helmets over the years. However, the demand for further improvement has forced helmet manufacturers and designers to introduce new designs progressively. Recently several helmet manufacturers (e.g., LG, Lazer and Giro) have introduced dimples on the outer shell of helmet mimicking the so called ‘Golf-ball’ dimple effects with a view to further reduce aerodynamic drag of the helmet. However, no independently verifiable research so far has been reported in the public domain about the aerodynamic performance of ribbed bicycle helmets compared to smooth surfaced helmets. Hence, the primary objective of this work was to undertake an experimental study on four smooth aero-helmets including two latest model ribbed aero-helmets to understand their aerodynamic performance and the effect of dimples on helmets. The investigation was undertaken in an wind tunnel environment over a range of wind speeds, pitch and yaw angles. The experimental data indicate no measurable advantage between the smooth and ribbed helmets under varied pitch angles and at zero yaw angle. [Copyright &y& Elsevier]

Abstract: The thermo-mechanical and impact properties of materials used for hard-shell and soft-shell back protectors have been analysed in order to understand the mechanism of action of the foams used for protective equipment. Dynamical mechanical analysis has shown that materials used for soft-shell protectors present frequency-sensitive properties that permit to have a soft response when stressed at low speed and a hard response when subjected to a high-speed impact. Furthermore, by means of drop weight impact tests, the shock absorbing characteristics of the materials have been investigated at two temperatures pointing out the differences between soft and hard-shell protectors; in addition it has been demonstrated that the materials used for soft-shell protectors maintain their protective properties after multi-impacts on the same point. [Copyright &y& Elsevier]

Abstract: Objective: Standard protective athletic equipment used in collision sports such as American football poses a unique challenge to rescuers because they block access to both the airway and chest. The main objective of this investigation was to determine the effect of athletic equipment on the initiation of CPR. The feasibility of performing compressions over the chest protector as a potential time-saving step was also evaluated. Methods: Thirty-four certified athletic trainers performed CPR on a manikin wearing protective equipment during a simulated episode of cardiac arrest. For one trial the protective equipment was removed or unfastened prior to initiating CPR, and for another, chest compressions were initiated over the protective equipment. The following were recorded for comparison purposes: time until first breath and first compression; percentage of compressions delivered to the recommended depth; compression rate; accuracy of hand placement; percentage of compressions without full chest recoil. Results: Although chest compressions began sooner when compressions were delivered over the chest protector, this improvement was not statistically significant. A more notable positive outcome resulting from keeping the chest protector on was an increase in the number of compressions that were delivered to the recommended depth. Unfortunately, one of the significant negative outcomes of performing chest compression over the chest pad was the increased percentage of compressions that did not obtain full chest recoil. Conclusions: Although removal of the chest protector delays the initiation of chest compressions, keeping the chest protector on during CPR does not appear to be a feasible option. [Copyright &y& Elsevier]

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Abstract: Background: The traditional sport of polo has been played for centuries and has been deemed one of the most dangerous sports due to its high speed and the uncertainty of what might happen as directions change and contact occurs between horses and riders as well as with balls and mallets. Despite its longevity, there is very little in the medical literature about the sport of polo. Objectives: Two cases of thoracic trauma after falls from horses while playing polo are presented. Both falls resulted in similar injury patterns to the riders. A discussion follows that reviews the medical literature on equestrian injuries in general and polo injuries in particular. Discussion: Both cases show a similar injury pattern of clavicle fracture, multiple rib fractures, and lung injury (pulmonary contusion and pneumothorax). Literature review reveals severe injury including head and spinal trauma to be disproportionately represented in the equestrian sports. Conclusion: Emergency physicians should look for significant injuries when evaluating victims of polo accidents, as the forces generated can be quite high. Protective equipment, although potentially helpful, has not been studied and may not prevent these high-velocity injuries. [Copyright &y& Elsevier]

Abstract: Debate continues over bicycle helmet laws. Proponents argue that case-control studies of voluntary wearing show helmets reduce head injuries. Opponents argue, even when legislation substantially increased percent helmet wearing, there was no obvious response in percentages of cyclist hospital admissions with head injury—trends for cyclists were virtually identical to those of other road users. Moreover, enforced laws discourage cycling, increasing the costs to society of obesity and lack of exercise and reducing overall safety of cycling through reduced safety in numbers. Countries with low helmet wearing have more cyclists and lower fatality rates per kilometre. Cost-benefit analyses are a useful tool to determine if interventions are worthwhile. The two published cost-benefit analyses of helmet law data found that the cost of buying helmets to satisfy legislation probably exceeded any savings in reduced head injuries. Analyses of other road safety measures, e.g. reducing speeding and drink-driving or treating accident blackspots, often show that benefits are significantly greater than costs. Assuming all parties agree that helmet laws should not be implemented unless benefits exceed costs, agreement is needed on how to derive monetary values for the consequences of helmet laws, including changes in injury rates, cycle-use and enjoyment of cycling. Suggestions are made concerning the data and methodology needed to help clarify the issue, e.g. relating pre- and post-law surveys of cycle use to numbers with head and other injuries and ensuring that trends are not confused with effects of increased helmet wearing. [Copyright &y& Elsevier]

Despite female soldiers representing a growing user population, military body armour systems are currently better suited to the anthropometric dimensions of male soldiers. The aim of this study was to explore issues that female soldiers experience with current Australian Defence Force (ADF)-issue body armour. Following a sequential exploratory design, an initial questionnaire was completed by 97 Australian female soldiers. Subsequently, 33 Australian female soldiers participated in one of three focus groups. Descriptive statistics of questionnaire data considered alongside thematic analysis of focus group transcripts revealed problems with the design (fit, form and function) of current ADF-issue body armour, as well as problems with the issuance and education surrounding use of the system. It is recommended that anthropometric data of female soldiers be better incorporated into future body armour designs, that these data inform processes surrounding both acquisition and issuance of body armour and that training protocols for body armour use be reviewed. [ABSTRACT FROM AUTHOR]