Face Guards Research Articles

Environmental impacts of circularity strategies for social distancing plastic shields made of polymethyl methacrylate in the United States.

One application of plastics that grew during the COVID-19 pandemic is for social distancing plastic shields, or protective barriers, made from polymethyl methacrylate (PMMA) such as transparent face guards. Although available for other applications, end-of-life impacts for barriers are currently lacking in the literature, and there is a need to fill in this gap to guide decisions. This study evaluated the end-of-life environmental impacts of PMMA barriers in the United States by using life cycle assessment. We evaluated five strategies including landfilling, waste-to-energy, mechanical recycling, chemical recycling and reuse. Data were sourced from literature and various life cycle inventory databases. The Tool for Reduction and Assessment of Chemicals and Other Environmental Impacts (TRACI) was used as the life cycle impact assessment method. Landfilling exhibited the highest impact in all indicators and reuse demonstrated optimal results for global warming potential. A scenario analysis was conducted to explore a combination of strategies, revealing that the most promising approach involved a mix of 40% reuse, 20% mechanical recycling and 40% chemical recycling. Circular economy recommendations are proposed for managing these sources of plastic waste in the United States.

Shock absorption of 3D-printed ABS and fabric for sports faceguard

Sports faceguards (FG) to protect the maxillofacial area get sweaty due to bad air permeability. To solve this problem, a combination of 3D-printed perforated acrylonitrile butadiene styrene (ABS) and knitted fabric with honeycomb structure (AKE) is considered as one option but it was unclear whether the combination have enough shock absorption ability or not. The aim of this study was to test the shock absorption ability of the various combination of 3D-printed materials compared with conventional FG. 3D-printed ABS sheets (100 mm square, 3 mm thick) were prepared with 5 different perforated patterns; ABS0 without hole, ABS10S with 2.52 mm round holes/10 % open area, ABS10 with 3.60 mm RHs/10 % OA, ABS20S with 2.56 mm RHs/20 % OA and ABS20 with 3.57 mm RHs/20 % OA. The hole arrangement was unified in the 45-degree staggered formation. The impact test was performed on each specimen with AKE (n=5 for each). The combination of polycaprolactone sheet without hole and polychloroprene rubber cushioning material was used as a control. The maximum loads, maximum stress and stress impressed area were analyzed using 2-way ANOVA with Dunnett's Test or Tukey HSD test ( p <0.05). On the maximum loads, maximum stress and stress impressed area, there was statistical interaction between ABS and AKE. The combination of ABS10S and AKE showed good enough shock absorption properties compatible to control. The FG made with 10% perforated ABS and honeycomb knitted fabric may establish good air permeability and enough shock-absorbing properties.

Air Permeability, Shock Absorption Ability, and Flexural Strength of 3D-Printed Perforated ABS Polymer Sheets with 3D-Knitted Fabric Cushioning for Sports Face Guard Applications.

Sports face guards (FGs) are devices that protect athletes from maxillofacial injury or ensure rapid return to play following orofacial damage. Conventional FGs are uncomfortable to wear owing to stuffiness caused by poor ventilation and often slip off due to increase in weight due to absorption of moisture from perspiration, lowering players’ performance. Herein, combinations of 3D-printed perforated acrylonitrile butadiene styrene (ABS) polymer sheets and 3D-knitted fabrics with honeycomb structures as cushioning materials were investigated to balance better wearing feel and mechanical properties. The flexural strength, weight, and shock absorption ability of, and air flow rate through, the ABS sheets with five different perforation patterns were evaluated and compared with those of conventional FG materials comprising a combination of polycaprolactone sheets for the medical splint and polychloroprene rubber for the cushioning material. The ABS sheets having 10% open area and 2.52 mm round holes, combined with knitted fabric cushioning, exhibited the requisite shock absorbing, higher air permeability, and lower weight properties than the conventional materials. Our results suggest that FGs fabricated using combinations of 3D-printed perforated ABS polymer sheets and 3D-knitted fabrics with honeycomb structures may impart enhanced wearing comfort for athletes.

Analysis of the Protection Performance of Face Guard for Large Mining Height Hydraulic Support

With the increase of mining height, the problem of coal wall spalling in the working face gradually worsens. Hydraulic support and its face guard structure are the key pieces of equipment to restrain the coal wall spalling. However, at present, the hydraulic jack is mostly considered as rigid in the analysis of protection mechanism. This simplification cannot effectively reflect the true bearing state of the face guard. In order to improve the accuracy of analysis, this study considers the face guard jack as a flexible spring and establishes a rigid-flexible coupling analysis model of the face guard mechanism. First, based upon the multibody dynamics software ADAMS®, the multibody numerical model of the face guard of the hydraulic support was established. The influence of the two kinds of structures on the coal wall disturbance was analyzed and compared. Then, the rigid model was meshed. The hydraulic jacks were equivalent to the spring system, and the rigid-flexible coupling model was established. Based upon the application load on different positions of the rigid-flexible model, the load-bearing characteristics and hinge point force transfer characteristics of the two face guards were analyzed. The results show that the support efficiency of the integral type was higher than that of the split type. In the vertical support attitude, the dynamic disturbance of the coal wall, produced by the two kinds of face guards, was small. The four-bar linkage effectively improved the ultimate bearing capacity of the integral face guard. The results provide theoretical support for the design and optimization of the face guard.

Application of Glass Fiber and Carbon Fiber-Reinforced Thermoplastics in Face Guards.

Face guards (FGs) are protectors that allow for the rapid and safe return of athletes who are to play after sustaining traumatic facial injuries and orbital fractures. Current FGs require significant thickness to achieve sufficient shock absorption abilities. However, their weight and thickness render the FGs uncomfortable and reduce the field of vision of the athlete, thus hindering their performance. Therefore, thin and lightweight FGs are required. We fabricated FGs using commercial glass fiber-reinforced thermoplastic (GFRTP) and carbon fiber-reinforced thermoplastic (CFRTP) resins to achieve these requirements and investigated their shock absorption abilities through impact testing. The results showed that an FG composed of CFRTP is thinner and lighter than a conventional FG and has sufficient shock absorption ability. The fabrication method of an FG comprising CFRTP is similar to the conventional method. FGs composed of commercial FRTPs exhibit adequate shock absorption abilities and are thinner and lower in weight as compared to conventional FGs.

Walking the line between benefit and harm from tracheostomy in COVID-19

Walking the line between benefit and harm from tracheostomy in COVID-19

Evaluation of Impact Absorbing Properties of Thermoplastic Elastomers

The thermoplastic elastomers (TPEs) are physical mixtures of polymers. Impact absorbing materials in sports equipment are one of the expected applications of TPEs due to good process ability and less-smell. For examples, face guards, head-gears and protectors are expected to be applied. In this paper, static and dynamic mechanical properties of TPEs were investigated to expand the applicability of TPEs to the impact absorbing material for the sports equipment. In this study, TPEs developed by the Kuraray Plastics Co., Ltd. were applied for static and dynamic tests. To investigate the static mechanical properties of TPEs, the uniaxial tensile loading tests were conducted. The nonlinear viscoelasticity considering damage were applied to representation of the experimental results. The FEM analysis showed good applicability to static mechanical properties including damage which was excited by the maximum deformation. TPE. To investigate the dynamic mechanical properties of TPEs, a drop weight impact testing machine was developed. Impact absorbing properties of TPEs were evaluated by the impact force and impact time with baseball weight.

Improvement of the Shock Absorption Ability of a Face Guard by Incorporating a Glass-Fiber-Reinforced Thermoplastic and Buffering Space.

This study aimed to evaluate the shock absorption ability of trial face guards (FGs) incorporating a glass-fiber-reinforced thermoplastic (GF) and buffering space. The mechanical properties of 3.2 mm and 1.6 mm thick commercial medical splint materials (Aquaplast, AP) and experimental GF prepared from 1.6 mm thick AP and fiberglass cloth were determined by a three-point bending test. Shock absorption tests were conducted on APs with two different thicknesses and two types of experimental materials, both with a bottom material of 1.6 mm thick AP and a buffering space of 30 mm in diameter (APS) and with either (i) 1.6 mm thick AP (AP-APS) or (ii) 1.6 mm thick GF (GF-APS) covering the APS. The GF exhibited significantly higher flexural strength (64.4 MPa) and flexural modulus (7.53 GPa) than the commercial specimens. The maximum load of GF-APS was 75% that of 3.2 mm AP, which is widely used clinically. The maximum stress of the GF-APS only could not be determined as its maximum stress is below the limits of the analysis materials used (<0.5 MPa). Incorporating a GF and buffering space would enhance the shock absorption ability; thus, the shock absorption ability increased while the total thickness and weight decreased.

Traumatic Dental Injuries In Sports

Sports dentistry is a developing field of dentistry and includes the prevention and management of sports-related dental traumas. Dental injuries are the most frequent type of orofacial injuries that may occur during participation in sports activities. When considering the esthetic, functional, psychological, and economic consequences of traumatic injuries, prevention becomes more of an issue. Decreasing the incidence of sports-related dental trauma is possibly due to the education of athletes, coaches and sports organizations about sports-related orofacial injuries. Athletes, whether in amateur or professional level, should have a knowledge of the prevention strategies including the wearing of mouth-guards, face guards and helmets. Sports related dental injuries together with the prevention and treatment of such injuries will be the focus of this review.

Face masks and basketball: NCAA division I consumer trends and a review of over-the-counter face masks.

This study aims to: 1) determine the current consumer trends of over-the-counter (OTC) and custom-made face mask usage among National Collegiate Athletic Association (NCAA) Division I athletic programs; and 2) provide a literature review of OTC face guards and a classified database. Literature review and survey. Consumer trends were obtained by contacting all 352 NCAA Division I programs. Athletic trainers present in the office when called answered the following questions: 1) "When an athlete breaks his or her nose, is a custom or generic face guard used?" and 2) "What brand is the generic face guard that is used?" Data was analyzed to determine trends among athletic programs. Also, a database of OTC devices available was generated using PubMed, Google, and manufacturer Web sites. Among the 352 NCAA Division I athletic programs, 254 programs participated in the survey (72% response rate). The majority preferred custom-made guards (46%). Disadvantages included high cost and slow manufacture turnaround time. Only 20% of the programs strictly used generic brands. For the face mask database, 10 OTC products were identified and classified into four categories based on design, with pricing ranging between $35.99 and $69.95. Only a handful of face masks exist for U.S. consumers, but none of them have been reviewed or classified by product design, sport application, price, and collegiate consumer use. This project details usage trends among NCAA Division I athletic programs and provides a list of available devices that can be purchased to protect the nose and face during sports. NA. Laryngoscope, 126:1054-1060, 2016.

Reprint of: Face-guarding polyhedra

We study the Art Gallery Problem for face guards in polyhedral environments. The problem can be informally stated as: how many (not necessarily convex) windows should we place on the external walls of a dark building, in order to completely illuminate its interior?We consider both closed and open face guards (i.e., faces with or without their boundary), and we study several classes of polyhedra, including orthogonal polyhedra, 4-oriented polyhedra, and 2-reflex orthostacks.We give upper and lower bounds on the minimum number of faces required to guard the interior of a given polyhedron in each of these classes, in terms of the total number of its faces, f. In several cases our bounds are tight: ⌊f/6⌋open face guards for orthogonal polyhedra and 2-reflex orthostacks, and ⌊f/4⌋open face guards for 4-oriented polyhedra. Additionally, for closed face guards in 2-reflex orthostacks, we give a lower bound of ⌊(f+3)/9⌋ and an upper bound of ⌊(f+1)/7⌋.Then we show that it is NP-hard to approximate the minimum number of (closed or open) face guards within a factor of Ω(log⁡f), even for polyhedra that are orthogonal and simply connected. We also obtain the same hardness results for polyhedral terrains.Along the way we discuss some applications, arguing that face guards are not a reasonable model for guards patrolling on the surface of a polyhedron.

Face-guarding polyhedra

We study the Art Gallery Problem for face guards in polyhedral environments. The problem can be informally stated as: how many (not necessarily convex) windows should we place on the external walls of a dark building, in order to completely illuminate its interior?We consider both closed and open face guards (i.e., faces with or without their boundary), and we study several classes of polyhedra, including orthogonal polyhedra, 4-oriented polyhedra, and 2-reflex orthostacks.We give upper and lower bounds on the minimum number of faces required to guard the interior of a given polyhedron in each of these classes, in terms of the total number of its faces, f. In several cases our bounds are tight: ⌊f/6⌋open face guards for orthogonal polyhedra and 2-reflex orthostacks, and ⌊f/4⌋open face guards for 4-oriented polyhedra. Additionally, for closed face guards in 2-reflex orthostacks, we give a lower bound of ⌊(f+3)/9⌋ and an upper bound of ⌊(f+1)/7⌋.Then we show that it is NP-hard to approximate the minimum number of (closed or open) face guards within a factor of Ω(logf), even for polyhedra that are orthogonal and simply connected. We also obtain the same hardness results for polyhedral terrains.Along the way we discuss some applications, arguing that face guards are not a reasonable model for guards patrolling on the surface of a polyhedron.

Softball injuries treated in US EDs, 1994 to 2010

BackgroundSoftball is a popular participant sport in the United States. This study investigated the epidemiology of softball injuries with comparisons between children and adults. MethodsData from the National Electronic Injury Surveillance System for patients 7 years and older treated in an emergency department (ED) for a softball injury from 1994 through 2010 were analyzed. ResultsAn estimated 2107823 (95% confidence interval [CI], 1736417-2479229) patients were treated in US EDs for a softball injury during the 17-year study period. The annual number of injuries decreased by 23.0% from 1994 to 2010 (P < .001); however, during the last 6 years of the study, injuries increased by 11.7% (P = .008). The annual rate of softball injuries increased significantly during the study period (P = .035). The most commonly injured body regions were the hand/wrist (22.2%) and face (19.3%). Being hit by a ball was the most common mechanism of injury (52.4%) and accounted for most of face (89.6%) and head (75.7%) injuries. Injuries associated with running (relative risk, 2.36; 95% CI, 1.97-2.82) and diving for a ball (relative risk, 4.61; 95% CI, 3.50-6.09) were more likely to occur among adult than pediatric patients. ConclusionsTo our knowledge, this is the first study to investigate softball injuries using a nationally representative sample. Softball is a common source of injury among children and adults. Increased efforts are needed to promote safety measures, such as face guards, mouth guards, safety softballs, and break-away bases, to decrease these injuries.

Attitudes towards the use of mouth and face guards in Swedish ice hockey: part I. Materials and method

The most common method to study the use and attitudes of mouth and face guards is a limited number of preprepared questions. This approach, however, risks information restriction and lowers the general value of the study. The aim of this study was therefore to present a phenomenographic approach to capture the use and attitudes towards mouth and face guards in two Swedish ice hockey clubs. The phenomenographic study was set up as 12 focus group interviews: six interviews with one elite and six interviews with one division 3 ice hockey club in Sweden. A number of categories were identified, which became the basis for how the results are presented. The participants inspired each other to speak freely, which allowed for much wider and deeper discussions than was expected. In comparison with the use of a preprepared questionnaire with a limited number of questions sent home by post, this method included comments from the participants and revealed new angles of approach in 12 identified categories. Using a phenomenographic research method, more variations and different apprehensions could be revealed than what would be possible with a set of preprepared questions sent by post or used in individual interviews.

Attitudes towards the use of mouth and face guards in Swedish ice hockey: part 2. Results

The yearly cost of sports injuries, which affects Swedish society, is estimated to 3billion SEK (460 million USD). Injuries in ice hockey represent at least 270 million SEK (42 million USD). Despite the high number of injuries, mouth and face guards are rarely used in Swedish ice hockey. The major aim of this study was to examine the attitudes of mouth and face guards in two ice hockey clubs in Sweden (one elite and one division 3 club). A second purpose was to determine why some players use mouth and face guards, while others do not. A third goal was to present a material that ice hockey clubs could use for further discussions. A phenomenographic analysis of focus groups interviews. The phenomenographic analysis of the data resulted in 12 categories. Within each category, issues, activities and engagement of the participants were described. Further, similarities and differences in the discussions between the elite club and the division 3 club were described. The following categories were found to engage the participants the most: 'Ice hockey is a high-velocity collision sport in which injuries are expected', 'Attitudes towards personal protection guards' and 'Suggested measures'. The participants were aware of the risk of playing ice hockey, but they know little about the consequences of a dental injury. Although ice hockey players wish to protect themselves, they refuse to accept just any mouth or face guard. Through the discussions about reducing dental and jaw injuries by routine use of protection devices, many reform proposals were presented that could be useful in future discussions.

Lower Bound of Face Guards of Polyhedral Terrains

We study the problem of determining the minimum number of face guards which cover the surface of a polyhedral terrain. We show that ⌊(2n-5)/7⌋ face guards are sometimes necessary to guard the surface of an n-vertex triangulated polyhedral terrain.

Finding the Minimum Number of Face Guards is NP-Hard

Finding the Minimum Number of Face Guards is NP-Hard

Lower Bound of Face Guards of Polyhedral Terrains

Lower Bound of Face Guards of Polyhedral Terrains

Modelling and analysis of alternative face guard designs for cricket using finite element modelling

In professional cricket, where bowlers can bowl balls that reach speeds of up to 160 km h-1, effective head protection is vital. Current head protection equipment typically consists of a helmet with a high impact grade polypropylene shell, a high density EPS liner, and a metal face guard. Most of the weight in existing helmets is attributed to the steel grill used as the face guard. We present a virtual design approach to the development and evaluation of new face guards made from alternative materials. In particular, we investigate a face guard design for cricket made from polycarbonate rather than steel using an explicit dynamic finite element analysis (FEA) approach. The FEA model developed for this purpose incorporates the headform, helmet, polycarbonate face guard and the impacting ball. ABAQUS CAE was used for FEA. HyperMesh and SolidWorks were used to develop the geometric model. This work identifies appropriate modelling and simulation strategies, and key design attributes for the development of new face guards using alternative materials. A preliminary study shows that by using polycarbonates it is possible to reduce the mass of the face guard by 20%, thus contributing to greater comfort of the players without compromising their safety. The key criteria for reduction of ball deceleration by at least 25% at each test site were satisfied, with deceleration reduction values ranging from 44% to 87% from those due to ball impact with the bare head.

Survey of the injury rate for children in community sports.

To determine the baseline injury rate for children ages 7 to 13 participating in community organized baseball, softball, soccer, and football. In this observational cohort study, 1659 children were observed during 2 seasons of sports participation in an urban area. Data were collected by coaches using an injury survey tool designed for the study. A reportable injury was defined as one requiring on-field evaluation by coaching staff, or causing a player to stop participation for any period of time, or requiring first aid during an event. Logistic regression analyses were done within and across sports for injury rates, game versus practice injury frequencies, and gender differences where appropriate. The injury rates, calculated per 100 athlete exposures during total events (games plus practices), were: baseball, 1.7; softball, 1.0; soccer, 2.1; and football, 1.5. The injury rates for baseball and football were not significantly different. Across sports, contusions were the most frequent type of injury. Contact with equipment was the most frequent method of injury, except in football where contact with another player was the most frequent method. In baseball, 3% of all injuries reported were considered serious (fracture, dislocation, concussion); in soccer, 1% were considered serious; and in football, 14% were considered serious. The frequency of injury per team per season (FITS), an estimation of injury risk, was 3 for baseball and soccer, 2 for softball, and 14 for football for total events. For all sports, there were more game than practice injuries; this difference was significant except for softball. There were no significant gender differences in soccer for injury rates during total events. Given the classification of football as a collision sport, the high number of exposures per player, the FITS score, and the percentage of injuries considered serious, youth football should be a priority for injury studies. Health professionals should establish uniform medical coverage policies for football even at this age level. RECOMMENDATIONS FOR MODIFICATIONS: Injury surveillance for youth sports is gaining momentum as an important step toward formulating injury prevention methods. However, establishing patterns of injuries, taking preventive measures, and evaluating equipment and coaching modifications may take years. In addition to the objective findings of this study, our direct observations of community sports through 2 seasons showed areas where immediate modifications could reduce injury risk. The first recommendation is that youth sports leagues provide and require first aid training for coaches. Training could be done by sports medicine professionals and include recognition and immediate response to head, neck, and spine injuries, as well as heat-related illnesses. The second recommendation is that youth sports leagues have clear, enforceable return to play guidelines for concussions, neck and back injuries, fractures, and dislocations. The third recommendation is that baseball and softball leagues consider the injury prevention potential of face guards on batting helmets.