scholarly journals Quantifying the effect of the facemask on helmet performance

2017 ◽  
Vol 232 (2) ◽  
pp. 94-101 ◽  
Author(s):  
Bethany Rowson ◽  
Evan J Terrell ◽  
Steven Rowson
Keyword(s):  
Severity Index ◽  
Head Acceleration ◽  
Factor Analyses ◽  
Impact Performance ◽  
Impact Location ◽  
Hockey Players ◽  
Football Helmets ◽  
Athletic Equipment ◽  
Helmet Type ◽  
Standard Development

Evaluating and improving helmet design play a crucial role in reducing sports-related concussions. Despite widespread use of facemasks by football and hockey players, no helmet standards currently exist to test helmets equipped with facemasks. The purpose of this study was to determine the effect that attached facial protection has on the head kinematics resulting from impacts to the helmet shell. Helmets were fit to a modified NOCSAE (National Operating Committee on Standards for Athletic Equipment) headform and subjected to blows from a pneumatic impactor. A total of 240 impact tests were performed to evaluate the effect of the facemask on four helmet models (two for football, two for hockey). For each helmet model, one sample was tested with a facemask and another without a facemask. Tests were conducted at two impact velocities (6, 9 m/s) and three impact locations (front, side, and rear boss) for a total of six impact conditions. Five trials were performed for each helmet sample at each condition. Two-factor analyses of variance were used to quantify effects on linear and rotational head acceleration and Severity Index due to impact location and facemask presence. Significant effects varied by helmet model and impact location and were more commonly associated with football helmets. Differences in facemask effects between sports are likely attributed to differences in facemask-shell attachment mechanisms, and differences in the structure of the facemask itself. The effects of the facemask on linear and rotational acceleration were small, approximately 5% for both football and hockey helmets. On average, peak accelerations were decreased with the addition of a facemask, but individual differences were mixed and varied by helmet type and impact location. These small differences would not greatly affect impact performance tests in the lab. The results of this study have direct applications toward helmet standard development.

Validation of a Noninvasive System for Measuring Head Acceleration for Use during Boxing Competition

2007 ◽  
Vol 23 (3) ◽  
pp. 238-244 ◽  
Author(s):  
Jonathan G. Beckwith ◽  
Jeffrey J. Chu ◽  
Richard M. Greenwald
Keyword(s):  
Severity Index ◽  
Rotational Acceleration ◽  
Head Acceleration ◽  
Measuring Head ◽  
Head Injury Criterion ◽  
Impact Location ◽  
Hybrid Iii ◽  
Biomechanical Factors ◽  
Accuracy And Repeatability ◽  
Impact Events

Although the epidemiology and mechanics of concussion in sports have been investigated for many years, the biomechanical factors that contribute to mild traumatic brain injury remain unclear because of the difficulties in measuring impact events in the field. The purpose of this study was to validate an instrumented boxing headgear (IBH) that can be used to measure impact severity and location during play. The instrumented boxing headgear data were processed to determine linear and rotational acceleration at the head center of gravity, impact location, and impact severity metrics, such as the Head Injury Criterion (HIC) and Gadd Severity Index (GSI). The instrumented boxing headgear was fitted to a Hybrid III (HIII) head form and impacted with a weighted pendulum to characterize accuracy and repeatability. Fifty-six impacts over 3 speeds and 5 locations were used to simulate blows most commonly observed in boxing. A high correlation between the HIII and instrumented boxing headgear was established for peak linear and rotational acceleration (r2= 0.91), HIC (r2= 0.88), and GSI (r2= 0.89). Mean location error was 9.7 ± 5.2°. Based on this study, the IBH is a valid system for measuring head acceleration and impact location that can be integrated into training and competition.

scholarly journals Relating on-field youth football head impacts to pneumatic ram laboratory testing procedures

2020 ◽  
pp. 175433712094906
Author(s):  
Eamon T Campolettano ◽  
Steven Rowson
Keyword(s):  
Severity Index ◽  
Football Players ◽  
Head Acceleration ◽  
Head Impacts ◽  
Testing Procedures ◽  
Youth Athletes ◽  
Football Helmet ◽  
Youth Football ◽  
Impact Data ◽  
Athletic Equipment

A youth-specific football helmet testing standard has been proposed to address the physical and biomechanical differences between adult and youth football players. This study sought to relate the proposed youth standard-defined laboratory impacts to on-field head impacts collected from youth football players. Head impact data from 112 youth football players (ages 9–14) were collected through the use of helmet-mounted accelerometer arrays. These head impacts were filtered to only include those that resided in corridors near prescribed National Operating Committee on Standards for Athletic Equipment (NOCSAE) impact locations. Peak linear head acceleration and peak rotational head acceleration magnitudes collected from pneumatic ram impactor tests as specified by the proposed NOCSAE youth standard were compared to the distribution of on-field head impacts. All laboratory impact tests were among the top 10% in terms of magnitude for Severity Index and peak rotational acceleration of matched location head impacts experienced by youth football players. As concussive head impacts are among the most severe impacts experienced on the field, a safety standard geared toward mitigating concussion should assess the most severe on-field head impacts. This proposed testing standard may be refined as more becomes known regarding the biomechanics of concussion among youth athletes.

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 Ability of an Aftermarket Helmet Add-On Device to Reduce Impact-Force Accelerations During Drop Tests

2017 ◽  
Vol 52 (9) ◽  
pp. 802-808 ◽  
Author(s):  
Katherine M. Breedlove ◽  
Evan Breedlove ◽  
Eric Nauman ◽  
Thomas G. Bowman ◽  
Monica R. Lininger
Keyword(s):  
High Velocity ◽  
Significant Interaction ◽  
Skull Fracture ◽  
Linear Acceleration ◽  
Severity Index ◽  
Impact Forces ◽  
Football Helmets ◽  
Drop Tests ◽  
Athletic Equipment ◽  
The Guardian

Context:  The Guardian Cap provides a soft covering intended to mitigate energy transfer to the head during football contact. Yet how well it attenuates impacts remains unknown. Objective:  To evaluate the changes in the Gadd Severity Index (GSI) and linear acceleration during drop tests on helmeted headforms with or without Guardian Caps. Design:  Crossover study. Setting:  Laboratory. Patients or Other Participants:  Nine new football helmets sent directly from the manufacturer. Intervention(s):  We dropped the helmets at 3 velocities on 6 helmet locations (front, side, right front boss, top, rear right boss, and rear) as prescribed by the National Operating Committee on Standards for Athletic Equipment. Helmets were tested with facemasks in place but no Guardian Cap and then retested with the facemasks in place and the Guardian Cap affixed. Main Outcome Measure(s):  The GSI scores and linear accelerations measured in g forces. Results:  For the GSI, we found a significant interaction among drop location, Guardian Cap presence, and helmet brand at the high velocity (F10,50 = 3.01, P = .005) but not at the low (F3.23,16.15 = 0.84, P = .50) or medium (F10,50 = 1.29, P = .26) velocities. Similarly for linear accelerations, we found a significant interaction among drop location, Guardian Cap presence, and helmet brand at the high velocity (F10,50 = 3.01, P = .002, ω2 = 0.05) but not at the low (F10,50 = 0.49, P = .89, ω2 < 0.01, 1–β = 0.16) or medium (F5.20,26.01 = 2.43, P = .06, ω2 < 0.01, 1–β = 0.68) velocities. Conclusions:  The Guardian Cap failed to significantly improve the helmets' ability to mitigate impact forces at most locations. Limited evidence indicates how a reduction in GSI would provide clinically relevant benefits beyond reducing the risk of skull fracture or a similar catastrophic event.

An examination of the current National Operating Committee on Standards for Athletic Equipment system and a new pneumatic ram method for evaluating American football helmet performance to reduce risk of concussion

2016 ◽  
Vol 231 (2) ◽  
pp. 83-90 ◽  
Author(s):  
Thomas Blaine Hoshizaki ◽  
Clara Karton ◽  
R. Anna Oeur ◽  
Marshall Kendall ◽  
Lauren Dawson ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Significant Risk ◽  
Standard Test ◽  
American Football ◽  
New Method ◽  
Rotational Acceleration ◽  
Football Helmets ◽  
Athletic Equipment ◽  
New System

Brain injuries are prevalent in the sport of American football. Helmets have been used which effectively have reduced the incidence of traumatic brain injury, but have had a limited effect on concussion rates. In an effort to improve the protective capacity of American football helmets, a standard has been proposed by National Operating Committee on Standards for Athletic Equipment that may better represent helmet-to-helmet impacts common to football concussions. The purpose of this research was to examine the National Operating Committee on Standards for Athletic Equipment standard and a new impact method similar to the proposed National Operating Committee on Standards for Athletic Equipment standard to examine the information these methods provide on helmet performance. Five National Operating Committee on Standards for Athletic Equipment–certified American football helmets were impacted according to the National Operating Committee on Standards for Athletic Equipment standard test and a new method based on the proposed standard test. The results demonstrated that the National Operating Committee on Standards for Athletic Equipment test produced larger linear accelerations than the new method, which were a reflection of the stiffer compliance of the standard meant to replicate traumatic brain injury mechanisms of injury. When the helmets were impacted using a new helmet-to-helmet method, the results reflected significant risk of concussive injury but showed differences in rotational acceleration responses between different helmet models. This suggests that the new system is sensitive enough to detect the effect of different design changes on rotational acceleration, a metric more closely associated with risk of concussion. As only one helmet produced magnitudes of response lower than the National Operating Committee on Standards for Athletic Equipment pass/fail using the new system, and all helmets passed the National Operating Committee on Standards for Athletic Equipment standard, these results suggest that further development of helmet technologies must be undertaken to reduce this risk in the future. Finally, these results show that it would be prudent to use both standards together to address risk of injury from traumatic brain injury and concussion.

Evaluation of Impulse Attenuation by Football Helmets in the Frequency Domain

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Nicolas Leiva-Molano ◽  
Robert J. Rolley ◽  
Taylor Lee ◽  
Kevin G. McIver ◽  
Goutham Sankaran ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Head Injuries ◽  
Mechanical Impedance ◽  
Design Parameters ◽  
Impact Loads ◽  
Design Standards ◽  
Impact Location ◽  
Dynamic Impedance ◽  
Grading Systems ◽  
Football Helmets

Abstract Design of helmets used in contact sports has been driven by the necessity of preventing severe head injuries. Manufacturing standards and pass or fail grading systems ensure protective headgear built to withstand large impacts, but design standards do no account for impacts resulting in subconcussive episodes and the effects of cumulative impacts on its user. Thus, it is important to explore new design parameters, such as the frequency-domain measures of transmissibility and mechanical impedance that are based on energy absorption from a range of impact loads. Within the experimentally determined frequency range of interest (FROI), transmissibilities above unity were found in the 0–40 Hz range with the magnitude characteristics varying considerably with impact location. A similar variability with location was observed for the mechanical impedance, which ranged from 9 N/m to 50 N/m. Additional research is required to further understand how changes in the components or materials of the components will affect the performance of helmets, and how they may be used to reduce both transmissibility and dynamic impedance.

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.

scholarly journals Protective Equipment

Concussion ◽  
2019 ◽  
pp. 173-176
Author(s):  
Brian Hainline ◽  
Lindsey J. Gurin ◽  
Daniel M. Torres
Keyword(s):  
Brain Injury ◽  
Intracranial Hemorrhage ◽  
National Football League ◽  
Head Impact ◽  
Protective Equipment ◽  
Skull Fractures ◽  
Football Helmets ◽  
Athletic Equipment ◽  
Concussive Injury

Helmets are designed to prevent catastrophic brain injury such as skull fractures and intracranial hemorrhage. Helmets do not prevent concussion, and are sometimes used as a weapon that may actually lead to a concussive injury. Football helmets are certified by the National Operating Committee on Standards for Athletic Equipment (NOCSAE), and the National Football League has also developed criteria for evaluating football helmets independent of NOCSAE. To mitigate concussion and repetitive head impact exposure, the head needs to be taken out of the game, irrespective of the use of helmets.

scholarly journals Negative self-appraisal mediates the relationship between mindfulness and confidence among adolescent female provincial hockey players in South Africa

10.17159/4371 ◽  
2019 ◽  
Vol 31 (1) ◽  
pp. 1-5
Author(s):  
Stephen Walker
Keyword(s):  
Indirect Effect ◽  
Correlation Coefficients ◽  
Ordinary Least Squares ◽  
Mental Toughness ◽  
Adolescent Female ◽  
Least Squares Regression ◽  
Impact Performance ◽  
Hockey Players ◽  
The Impact ◽  
The Relationship

Introduction: Mounting evidence suggests that mindfulness is positively related to athletic performance and athlete wellbeing. However, few attempts have been made to uncover the psychological processes by which mindfulness might impact performance. Objective: To determine whether negative self-appraisal mediates the relationship between mindfulness and the confidence component of mental toughness among provincial adolescent female hockey players. Methods: Provincial adolescent female hockey players (N=486) completed measures of mindfulness, mental toughness-related confidence and negative self-appraisal. Correlation coefficients were calculated between all variables included in the study. An ordinary least-squares regression analysis was performed to test the indirect effect of negative self-appraisal on the relationship between mindfulness and confidence. Results: Negative self-appraisal exhibited an indirect effect on the relationship between mindfulness and the confidence component of mental toughness (b = .06, SE = .0, CI95 = .04, .09). A subsequent Soble test confirmed that negative self-appraisal served as a statistically significant mediator (b = .06, SE = .01, Z = 5.76, p = .001) in the model. Furthermore 78.3% of the variance in the effect of mindfulness on the confidence component of mental toughness was accounted for by negative self-appraisal. Conclusion: The effect of mindfulness on the confidence component of mental toughness among adolescent athletes is mediated by negative self-appraisal. Based on the current findings, mindfulness seems to foster confidence by lessening the impact of rigid negative appraisals of one’s performance and worth as an athlete. Keywords: mindfulness, confidence, negative self-appraisal, mediation, adolescent female athlete

scholarly journals Efficacy of Softball Face Masks at Reducing Linear and Rotational Head Acceleration

2021 ◽  
Vol 10 (4) ◽  
Author(s):  
Kacie Burroughs ◽  
Robert Hodgson
Keyword(s):  
Research Study ◽  
Face Mask ◽  
Head Acceleration ◽  
Ball Speed ◽  
Impact Location ◽  
Study Results

This research study looked at the efficacy of infield softball face masks at reducing concussion risk. The primary goal of this research was to contrast head accelerations experienced during softball impacts for different brands of softball face masks. In order to achieve this goal, a surrogate headform equipped with different brands of face masks was impacted at a constant impact location and ball speed. The resulting headform accelerations (linear and rotational) were collected with a Vernier accelerometer upon each impact and analyzed. The results of the study showed that all tested brands of face masks were successful at reducing head acceleration severity. Moreover, significant differences in performance were observed between the different brands of face masks. One can conclude from this research that particular brands of face masks can more effectively reduce concussion risk because they better reduce head acceleration values. Due to the study results, softball players may have a better understanding of face mask performance, which could lead to higher mask implementation in the sport and an overall reduction in softball-related concussion occurrence.

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