Repeated Impacts Diminish the Impact Performance of Equestrian Helmets

2019 ◽  
Vol 28 (4) ◽  
pp. 368-372
Author(s):  
Carl G. Mattacola ◽  
Carolina Quintana ◽  
Jed Crots ◽  
Kimberly I. Tumlin ◽  
Stephanie Bonin
Keyword(s):  
Injury Risk ◽  
Head Injuries ◽  
The United States ◽  
Expanded Polystyrene ◽  
Head Acceleration ◽  
Safety Equipment ◽  
Impact Performance ◽  
Computed Tomography Scans ◽  
Impact Attenuation ◽  
The Impact

Context: During thoroughbred races, jockeys are placed in potentially injurious situations, often with inadequate safety equipment. Jockeys frequently sustain head injuries; therefore, it is important that they wear appropriately certified helmets. Objective: The goals of this study are (1) to perform impact attenuation testing according to ASTM F1163-15 on a sample of equestrian helmets commonly used by jockeys in the United States and (2) to quantify headform acceleration and residual crush after repeat impacts at the same location. Participants and Design: Seven helmet models underwent impact attenuation testing according to ASTM F1163-15. A second sample of each helmet model underwent repeat impacts at the crown location for a total of 4 impacts. Setting: Laboratory. Intervention: Each helmet was impacted against a flat and equestrian hazard anvil. Main Outcome Measures: Headform acceleration was recorded during all impact and computed tomography scans were performed preimpact and after impacts 1 and 4 on the crown to quantify liner thickness. Results: Four helmets had 1 impact that exceeded the limit of 300g. During the repeated crown impacts, acceleration remained below 300g for the first and second impacts for all helmets, while only one helmet remained below 300g for all impacts. Foam liner thickness was reduced between 5% and 39% after the first crown impact and between 33% and 70% after the fourth crown impact. Conclusions: All riders should wear a certified helmet and replace it after sustaining a head impact. Following an impact, expanded polystyrene liners compress, and their ability to attenuate head acceleration during subsequent impacts to the same location is reduced. Replacing an impacted helmet may reduce a rider’s head injury risk.

Impact performance of innovative corrugated polystyrene foam for bicycle helmets

2020 ◽  
pp. 0021955X2096521
Author(s):  
Somen K Bhudolia ◽  
Goram Gohel ◽  
Kah Fai Leong
Keyword(s):  
Energy Absorption ◽  
High Speed ◽  
Head Injuries ◽  
Expanded Polystyrene ◽  
The Novel ◽  
Comparison Study ◽  
Impact Performance ◽  
Bicycle Helmets ◽  
Weight Property ◽  
The Impact

Expanded Polystyrene (EPS) is a common material used to manufacture the inner foam liner of a bicycle helmet due to its outstanding energy absorption characteristics and light-weight property. The current research presents a novel corrugated expanded polystyrene (EPS) foam design concept which is used to enhance the impact dissipation of bicycle helmets from the safety standpoint to reduce head injuries and make them lighter. The baseline comparison study under impact for different foam configurations is compared with a conventional EPS foam sample without corrugation. Corrugated foam designs under current investigation are 12.5–20% lighter and provide up to 10% higher energy absorption. The details of the novel manufacturing concept, CPSC 1203 helmet impact tests, high-speed camera study to understand the differences in the failure mechanisms are deliberated in this paper.

A Base Study to Investigate MASH Conservativeness of Occupant Risk Evaluation

2016 ◽  
Author(s):  
Chiara Silvestri Dobrovolny ◽  
Harika Reddy Prodduturu ◽  
Dusty R. Arrington ◽  
Nathan Schulz ◽  
Stefan Hurlebaus ◽  
...  
Keyword(s):  
Risk Evaluation ◽  
Injury Risk ◽  
Evaluation Criteria ◽  
Oblique Impact ◽  
Full Scale ◽  
Crash Test ◽  
Vehicle Interior ◽  
Impact Performance ◽  
Space Model ◽  
The Impact

The Manual for Assessing Safety Hardware (MASH) defines crash tests to assess the impact performance of highway safety features in frontal and oblique impact events. Within MASH, the risk of injury to the occupant is assessed based on a “flail-space” model that estimates the average deceleration that an unrestrained occupant would experience when contacting the vehicle interior in a MASH crash test and uses the parameter as a surrogate for injury risk. MASH occupant risk criteria, however, are considered conservative in their nature, due to the fact that they are based on unrestrained occupant accelerations. Therefore, there is potential for increasing the maximum limits dictated in MASH for occupant risk evaluation. A frontal full-scale vehicle impact was performed with inclusion of an instrumented anthropomorphic test device (ATD). The scope of this study was to investigate the performance of the Flail Space Model in a full scale crash test compared to the instrumented ATD recorded forces which can more accurately predict the occupant response during a collision event. Results obtained through this research will be considered for better correlation between vehicle accelerations and occupant injury. This becomes extremely important for designing and evaluating barrier systems that must fit within geometrical site constraints, which do not provide adequate length to redirect test vehicles according to MASH conservative evaluation criteria.

Impact Performance of the G4(1W) and G4(2W) Guardrail Systems: Comparison Under NCHRP Report 350 Test 3-11 Conditions

2000 ◽  
Vol 1720 (1) ◽  
pp. 7-18 ◽  
Author(s):  
Chuck A. Plaxico ◽  
Malcolm H. Ray ◽  
Kamarajugadda Hiranmayee
Keyword(s):  
The United States ◽  
Full Scale ◽  
Nonlinear Finite Element ◽  
Crash Test ◽  
Test Vehicle ◽  
Element Analysis ◽  
Impact Performance ◽  
Performance Requirements ◽  
The Impact ◽  
Standard Techniques

Several types of strong-post W-beam guardrails are used in the United States. Usually the only difference between one type of strong-post W-beam guardrail and another is the choice of post and block-out types. The impact performance of two very similar strong-post W-beam guardrails are compared—the G4(2W), which uses a 150×200 mm wood post and the G4(1W), which uses a 200×200 mm wood post. Although G4(2W) is used in numerous states, G4(1W) is now common only in the state of Iowa. The performance of the two guardrails has been presumed equal, but only one full-scale crash test has been performed on G4(1W) and that was over 30 years ago, using a now-obsolete test vehicle. The nonlinear finite element analysis program LS-DYNA was used to evaluate the crashworthiness of the two guardrails. The G4(2W) guardrail model was validated with the results of a full-scale crash test. A model of the G4(1W) guardrail system was developed, and the deflection, vehicle redirection, and occupant risk factors of the two guardrails were compared. The impact performance of the two guardrails was quantitatively compared using standard techniques. The analysis results indicate similar collision performance for G4(1W) and G4(2W) and show that both satisfy NCHRP Report 350 Test 3-11 safety performance requirements.

scholarly journals Epidemiology of Cheerleading Fall-Related Injuries in the United States

2009 ◽  
Vol 44 (6) ◽  
pp. 578-585 ◽  
Author(s):  
Brenda J. Shields ◽  
Gary A. Smith
Keyword(s):  
Cruciate Ligament ◽  
Head Injuries ◽  
The United States ◽  
Severe Injuries ◽  
Closed Head Injuries ◽  
Wood Floor ◽  
Closed Head ◽  
Serious Injury ◽  
The Impact ◽  
Fall Height

Abstract Context: Over the past several decades, cheerleaders have been performing fewer basic maneuvers and more gymnastic tumbling runs and stunts. As the difficulty of these maneuvers has increased, cheerleading injuries have also increased. Objective: To describe the epidemiology of cheerleading fall-related injuries by type of cheerleading team and event. Design: Prospective injury surveillance study. Setting: Participant exposure and injury data were collected from US cheerleading teams via the Cheerleading RIO (Reporting Information Online) surveillance tool. Patients or Other Participants: Athletes from 412 enrolled cheerleading teams who participated in official, organized cheerleading practices, pep rallies, athletic events, or cheerleading competitions. Main Outcome Measure(s): The numbers and rates of cheerleading fall-related injuries during a 1-year period (2006–2007) are reported. Results: A total of 79 fall-related injuries were reported during the 1-year period. Most occurred during practice (85%, 67/79) and were sustained by high school cheerleaders (51%, 40/79). A stunt or pyramid was being attempted in 89% (70/79) of cases. Fall heights ranged from 1 to 11 ft (0.30–3.35 m) (mean  =  4.7 ± 2.0 ft [1.43 ± 0.61 m]). Strains and sprains were the most common injuries (54%, 43/79), and 6% (5/79) of the injuries were concussions or closed head injuries. Of the 15 most serious injuries (concussions or closed head injuries, dislocations, fractures, and anterior cruciate ligament tears), 87% (13/15) were sustained while the cheerleader was performing on artificial turf, grass, a traditional foam floor, or a wood floor. The fall height ranged from 4 to 11 ft (1.22–1.52 m) for 87% of these cases (13/15). Conclusions: Cheerleading-related falls may result in severe injuries and even death, although we report no deaths in the present study. The risk for serious injury increases as fall height increases or as the impact-absorbing capacity of the surfacing material decreases (or both).

Aircraft Impact Considerations for NuScale SMR Plant Design

2011 ◽  
Author(s):  
Randy J. James ◽  
Josh Parker ◽  
Rick Hill ◽  
Jeremy Wiesner ◽  
John Groome
Keyword(s):  
Power Plants ◽  
The United States ◽  
Plant Design ◽  
Spent Fuel ◽  
Safety Equipment ◽  
Internal Damage ◽  
Advantages And Disadvantages ◽  
Small Modular Reactors ◽  
Spent Fuel Pool ◽  
The Impact

All new nuclear power plants to be constructed and operated in the United States must meet regulatory requirements for aircraft impact from a large commercial aircraft under 10CFR50.150. Under the regulation, the applicant, using realistic analyses, must identify and incorporate into the design those design features and functional capabilities to show that, with reduced use of operator actions, 1) either the primary containment system remains intact or the reactor core remains cooled, and 2) either spent fuel cooling or spent fuel pool integrity is maintained. Small modular reactors have both advantages and disadvantages over conventional large plant designs in this regard. Small modular reactors generally have smaller footprints and can be configured where the reactor vessels and containment systems are entirely below grade. This minimizes the exposed structure that houses the reactors and spent fuel pool, which generally means that the structural configuration can be more efficiently hardened to resist the impact forces without excessive costs. However, the smaller footprint also means that transmission of shock through the structure can affect more safety equipment than in the larger conventional plant where the safety related equipment for the divisions are physically farther apart. Modular designs by nature tend to have all associated safety equipment together for each reactor module. Larger plants may be more tolerant for allowing internal damage and controlling ensuing fire due to perforation of aircraft wreckage at some strike locations, whereas the smaller footprints for small modular reactors could mean more systems are at risk if the reactor building is not hardened to prevent perforation. This paper presents design considerations employed for the NuScale 12 Module Power Plant in regards to aircraft impact requirements.

scholarly journals Impact attenuation provided by older adult protective headwear products during simulated fall-related head impacts

2021 ◽  
Vol 8 ◽  
pp. 205566832110503
Author(s):  
Daniel R Martel ◽  
Michelle R Tanel ◽  
Andrew C Laing
Keyword(s):  
Head Injuries ◽  
Linear Acceleration ◽  
Positive Association ◽  
Protective Capacity ◽  
Low Velocity ◽  
Head Impacts ◽  
Frontal Impacts ◽  
Wide Range ◽  
Impact Attenuation ◽  
The Impact

Introduction While protective headwear products (PHP) are designed to protect older adults from fall-related head injuries, there are limited data on their protective capacity. This study’s goal was to assess the impact attenuation provided by commercially available PHP during simulated head impacts. Methods A drop tower and Hybrid III headform measured the decrease in peak linear acceleration ( g atten) provided by 12 PHP for front- and back-of-head impacts at low (clinically relevant: 3.5 m/s) and high (5.7 m/s) impact velocities. Results The range of g atten across PHP was larger at the low velocity (56% and 41% for back and frontal impacts, respectively) vs. high velocity condition (27% and 38% for back and frontal impacts, respectively). A significant interaction between impact location and velocity was observed ( p < .05), with significantly greater g atten for back-of-head compared to front-of-head impacts at the low impact velocity (19% mean difference). While not significant, there was a modest positive association between g atten and product padding thickness for back-of-head impacts ( p = .095; r = 0.349). Conclusion This study demonstrates the wide range in impact attenuation across commercially available PHP, and suggests that existing products provide greater impact attenuation during back-of-head impacts. These data may inform evidence-based decisions for clinicians and consumers and help drive industry innovation.

scholarly journals Analysis on the Effect of Ball Pressure on Head Acceleration to Ensure Safety in Soccer

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 3
Author(s):  
Andrew J. Christenson ◽  
Douglas J. Casa
Keyword(s):  
United States ◽  
Dynamic Model ◽  
National Football League ◽  
Head Injuries ◽  
The United States ◽  
Comprehensive Analysis ◽  
Head Acceleration ◽  
Soccer Ball ◽  
The World ◽  
Rule Changes

Soccer/football is one of the most popular sports in the world. Any sport requires continuous adjustments to rules to keep the game safe and engaging. Increased awareness of concussions in the American National Football League (NFL) has consequently raised attention to concussion-related injuries in other sports. One of the first steps the United States Soccer Federation (USSF) has taken to reduce head injuries is to implement age restrictions on heading. This encourages safer play but discourages an important skill until players are a certain age which is not good for player development. An alternative is to ensure mean head acceleration from a header is reduced with minimal rule changes. This paper presents a dynamic model of a player heading a soccer ball to examine the general relationship between ball pressure and mean head acceleration toward the purpose of motivating a more complex and comprehensive analysis of heading in soccer.

Horseback Riding and Head Injuries

PEDIATRICS ◽  
1992 ◽  
Vol 89 (3) ◽  
pp. 512-512
Author(s):  
Keyword(s):  
United States ◽  
Head Injuries ◽  
The United States ◽  
Horseback Riding ◽  
Safety Equipment ◽  
Combined Training ◽  
American Academy Of Pediatrics ◽  
The Central Nervous System ◽  
American Society ◽  
Athletic Equipment

Horseback riding accidents can cause head injuries resulting in death or permanent residual defects. These riding injuries occur most frequently in riders younger than 21 years of age.1 Approximately 20% of injuries in young riders are to the central nervous system.2,3 The majority of these injuries are cerebral contusions, concussions, or skull fractures.3 Use of approved helmets has been associated with a decline in the occurrence of severe head injuries.4 In the early 1980s, numerous organizations (American Horse Shows Association, United States Pony Club, United States Combined Training Association, and the United States Equestrian team) began requiring all competitors to use helmets meeting the United States Pony Club Standard. This standard was developed by the National Operating Committee on Standards for Athletic Equipment.5 In 1988, the American Society for Testing and Materials (ASTM) passed new standards (ASTM F-1163) for equestrian helmets that required helmets to provide a higher level of protection than previous models.6 This is an industry-wide standard that replaces previous standards. As of March 1990, the United States Pony Club required use of these new helmets for all activities.7 New helmets that meet the ASTM standard will be certified by the Safety Equipment Institute (SEI), a compliance organization responsible for certifying industrial products. The SEI seal, containing the date and manufacturer's lot number, must be permanently applied to the inside of the helmet so the buyer will know it is an approved equestrian helmet.7 The American Academy of Pediatrics (AAP) recommends the following steps for preventing and/or lessening the severity of horseback riding-related injuries:

scholarly journals Biomechanical performance of leather and modern football helmets

2013 ◽  
Vol 119 (3) ◽  
pp. 805-809 ◽  
Author(s):  
Steven Rowson ◽  
Ray W. Daniel ◽  
Stefan M. Duma
Keyword(s):  
Technical Note ◽  
Drop Test ◽  
Biomechanical Analysis ◽  
Head Acceleration ◽  
Impact Performance ◽  
Performance Differences ◽  
Football Helmets ◽  
Drop Tests ◽  
The Impact

With the increased national concern about concussions in football, recent research has focused on evaluating the impact performance of modern football helmets. Specifically, this technical note offers a biomechanical analysis of classic leather helmets compared with modern helmets. Furthermore, modern helmets were examined to illustrate the performance differences between the better- and worse-performing ones. A total of 1224 drop tests were performed from a range of drop heights and impact locations on 11 different helmet types (10 modern and 1 leather helmet model). The resulting head acceleration was used to assess the risk of concussion for each drop test. The results of this analysis demonstrate that modern helmets are significantly and substantially superior to leather helmets in all impact scenarios, and that notable differences exist among modern helmets.

scholarly journals The Impact of the Helmet-Lowering Rule on Regular Season NFL Injuries

2020 ◽  
Vol 8 (7_suppl6) ◽  
pp. 2325967120S0040
Author(s):  
Erik Stapleton ◽  
Randy Cohn ◽  
Colin Burgess
Keyword(s):  
Relative Risk ◽  
Lower Extremity ◽  
Risk Reduction ◽  
Injury Risk ◽  
National Football League ◽  
Head Injuries ◽  
Lower Extremity Injuries ◽  
Extremity Injuries ◽  
The Impact ◽  
Rule Implementation

Objectives: The National Football League (NFL) has been under growing scrutiny from the public due to the apparent rise in concussions and head injuries and the subsequent deleterious effects. In efforts to address these concerns, the NFL implemented a new “Helmet-lowering” rule prior to the 2018-2019 season. This rule is defined as “a foul if a player lowers his head to initiate and make contact with his helmet against an opponent.” The purpose of this paper was to compare incidence of injuries in NFL players prior to and after implementation of this new rule. Methods: NFL injury data was retrospectively reviewed from public league records for all players in regular season games played from the 2017 and 2018 NFL seasons. An injury was defined as any player listed on a team’s injury report that was not previously documented on the team’s report one week preceding the index injury. Injury rates were reported as the number of injuries per 1000 athletic exposures (AE’s). Athletic exposures were defined as equal to the sum of the total number of NFL regular-season games played. Relative risk (with 95% CI) was calculated by using the number of injuries per 1000 athletic exposures for the season before and after the new rule implementation. Risk reduction was then calculated for the overall injuries, upper/lower extremity and head injuries. Results: Over the 2 seasons there were a total of 2,774 injuries identified. After rule implementation at the beginning of the 2018 season, there was an overall relative risk (RR) of 0.91 for injury (95% CI 0.88 to 0.95, p<0.0001), with an injury risk reduction of 8.73%. Upper extremity injuries had a RR of 0.76 (95% CI 0.65 to 0.87, p=0.0005) and a risk reduction of 24.10%. Lower extremity injuries had a RR of 0.91 (95% CI 0.87 to 0.96, p=0.0005) with a risk reduction of 8.63%. In concussions and head injuries there was an overall RR of 0.55 for injury (95% CI 0.44 to 0.69, p<0.0001), with an injury risk reduction of 45.10%. Wide receivers and linebackers were most commonly injured players on offense and defense, respectively. Conclusion: Implementation of the new Helmet-Lowering rule seems to have played a role in significantly decreasing the NFL athlete’s risk of injury across all measures, most notably in concussion and head injuries.

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