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4. Development of a Concussion Risk Function for a Youth Population Using Head Linear and Rotational Acceleration

Author

Campolettano, Eamon T., Gellner, Ryan A., Smith, Eric P., Bellamkonda, Srinidhi, Tierney, Casey T., Crisco, Joseph J., Jones, Derek A., Kelley, Mireille E., Urban, Jillian E., Stitzel, Joel D., Genemaras, Amaris, Beckwith, Jonathan G., Greenwald, Richard M., Maerlender, Arthur C., Brolinson, Per Gunnar, Duma, Stefan M., and Rowson, Steven

Published
2020
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7. Proceedings From the Ice Hockey Summit III: Action on Concussion

Author

Smith, Aynsley M., Alford, Patrick A., Aubry, Mark, Benson, Brian, Black, Amanda, Brooks, Alison, Burke, Charles, DʼArcy, Ryan, Dodick, David, Eaves, Michael, Eickhoff, Chad, Erredge, Kristen, Farrell, Kyle, Finnoff, Jonathan, Fraser, Douglas D., Giza, Christopher, Greenwald, Richard M., Hoshizaki, Blaine, Huston, John, Jorgensen, Janelle, Joyner, Michael, Krause, David, LaVoi, Nicole, Leaf, Matthew, Leddy, John, Margarucci, Kevin, Margulies, Susan, Mihalik, Jason, Munce, Thayne, Oeur, Anna, Prideaux, Cara, Roberts, William O., Shen, Francis, Soma, David, Tabrum, Mark, Stuart, Michael B., Wethe, Jennifer, Whitehead, James, Wiese-Bjornstal, Diane, and Stuart, Michael J.

Published
2019
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9. Mechanical metamaterials for sports helmets: structural mechanics, design optimisation, and performance

Author

Haid, Daniel, Foster, Leon, Hart, John, Greenwald, Richard, Allen, Tom, Sareh, Pooya, Duncan, Olly, Haid, Daniel, Foster, Leon, Hart, John, Greenwald, Richard, Allen, Tom, Sareh, Pooya, and Duncan, Olly

Abstract

Sports concussions are a public health concern. Improving helmet performance to reduce concussion risk is a key part of the research and development community response. Direct and oblique head impacts with compliant surfaces that cause long-duration moderate or high linear and rotational accelerations are associated with a high rate of clinical diagnoses of concussion. As engineered structures with unusual combinations of properties, mechanical metamaterials are being applied to sports helmets, with the goal of improving impact performance and reducing brain injury risk. Replacing established helmet material (i.e. foam) selection with a metamaterial design approach (structuring material to obtain desired properties) allows the development of near-optimal properties. Objective functions based on an up-to-date understanding of concussion, and helmet testing that is representative of actual sporting collisions and falls, could be applied to topology optimisation regimes, when designing mechanical metamaterials for helmets. Such regimes balance computational efficiency with predictive accuracy, both of which could be improved under high strains and strain rates to allow helmet modifications as knowledge of concussion develops. Researchers could also share mechanical metamaterial data, topologies, and computational models in open, homogenised repositories, to improve the efficiency of their development.

Published
2023

10. Snow Sports Trauma and Safety : Conference Proceedings of the International Society for Skiing Safety: 21st Volume

Author

Greenwald, Richard M., Petrone, Nicola, and Scher, Irving S.

Subjects
Technology & Engineering / Biomedical
Abstract

This book covers the latest in snow sport epidemiology, snow sport injuries and treatment, and biomechanical/mechanical engineering related to snow sports injuries (mechanisms of injury, injury prevention by equipment design, injury prevention by design of resort features, and more). It brings together a collection of papers from the International Congress on Ski Trauma and Safety (the biennal meeting of the International Society for Skiing Safety) and presents the latest research on the effectiveness of winter sports equipment, the behavior of winter sports participants, and the epidemiology and biomechanics of winter sports injuries. This is an ideal book for researchers and professionals working in the field of sports medicine and safety. This book also: Covers the latest body of literature dealing with safety in winter sports as well as the prevention and treatment of injuries sustained by participants in these activities Broadens readers’ understanding of snow sport injury prevention research Illustrates ways safety standards for snow sports can be improved based on evidence-based research.

Published
2017

24. Head Impact Exposure in Practices Correlates With Exposure in Games for Youth Football Players.

Author

Bellamkonda, Srinidhi, Woodward, Samantha J., Campolettano, Eamon, Gellner, Ryan, Kelley, Mireille E., Jones, Derek A., Genemaras, Amaris, Beckwith, Jonathan G., Greenwald, Richard M., Maerlender, Arthur C., Rowson, Steven, Duma, Stefan M., Urban, Jillian E., Stitzel, Joel D., and Crisco, Joseph J.

Subjects
FOOTBALL injuries, HEAD injury prevention, FOOTBALL, PHYSIOLOGICAL effects of acceleration, GAMES, ROTATIONAL motion, PHYSICAL training & conditioning, ADOLESCENCE, PREVENTION
Abstract

This study aimed to compare head impact exposures between practices and games in football players ages 9 to 14 years, who account for approximately 70% of all football players in the United States. Over a period of 2 seasons, 136 players were enrolled from 3 youth programs, and 49,847 head impacts were recorded from 345 practices and 137 games. During the study, individual players sustained a median of 211 impacts per season, with a maximum of 1226 impacts. Players sustained 50th (95th) percentile peak linear acceleration of 18.3 (46.9) g, peak rotational acceleration of 1305.4 (3316.6) rad·s−2, and Head Impact Technology Severity Profile of 13.7 (24.3), respectively. Overall, players with a higher frequency of head impacts at practices recorded a higher frequency of head impacts at games (P <.001, r2 =.52), and players who sustained a greater average magnitude of head impacts during practice also recorded a greater average magnitude of head impacts during games (P <.001). The youth football head impact data quantified in this study provide valuable insight into the player exposure profile, which should serve as a key baseline in efforts to reduce injury. [ABSTRACT FROM AUTHOR]

Published
2018
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32. An investigation of the NOCSAE linear impactor test method based on in vivo measures of head impact acceleration in American football

Author

Gwin, Joseph T., Chu, Jeffery J., Diamond, Solomon G., Halstead, P. David, Crisco, Joseph J., and Greenwald, Richard M.

Subjects
Helmets -- Standards, Helmets -- Safety and security measures, Biomechanics -- Research, Engineering and manufacturing industries, Science and technology
Abstract

The performance characteristics of football helmets are currently evaluated by simulating head impacts in the laboratory using a linear drop test method. To encourage development of helmets designed to protect against concussion, the National Operating Committee for Standards in Athletic Equipment recently proposed a new headgear testing methodology with the goal of more closely simulating in vivo head impacts. This proposed test methodology involves an impactor striking a helmeted headform, which is attached to a nonrigid neck. The purpose of the present study was to compare headform accelerations recorded according to the current (n = 30) and proposed (n = 54) laboratory test methodologies to head accelerations recorded in the field during play. In-helmet systems of six single-axis accelerometers were worn by the Dartmouth College men's football team during the 2005 and 2006 seasons (n = 20,733 impacts; 40 players). The impulse response characteristics of a subset of laboratory test impacts (n = 27) were compared with the impulse response characteristics of a matched sample of in vivo head accelerations (n =24). Second-and third-order underdamped, conventional, continuous-time process models were developed for each impact. These models were used to characterize the linear head/headform accelerations for each impact based on frequency domain parameters. Headform linear accelerations generated according to the proposed test method were less similar to in vivo head accelerations than headform accelerations generated by the current linear drop test method. The nonrigid neck currently utilized was not developed to simulate sport-related direct head impacts and appears to be a source of the discrepancy between frequency characteristics of in vivo and laboratory head/headform accelerations. In vivo impacts occurred 37% more frequently on helmet regions, which are tested in the proposed standard than on helmet regions tested currently. This increase was largely due to the addition of the facemask test location. For the proposed standard, impactor velocities as high as 10.5 m/s were needed to simulate the highest energy impacts recorded in vivo. The knowledge gained from this study may provide the basis for improving sports headgear test apparatuses with regard to mimicking in vivo linear head accelerations. Specifically, increasing the stiffness of the neck is recommended. In addition, this study may provide a basis for selecting appropriate test impact energies for the standard performance specification to accompany the proposed standard linear impactor test method. [DOI: 10.1115/1.4000249]

Published
2010

34. Abstracts from the 6th International Conference on the Engineering of Sport, 10–14 July 2006, Olympic Hall, Munich, Germany: Volume 3 — Developments for innovation

Author

Gerrits, Anton, Jones, Chris Lewis, Valero, Rafael, Müller, Maximilian, Senner, Veit, Krohn, Michael, Krueger, Andreas, Witte, Kerstin, Edelmann-Nusser, Juergen, Giannakis, Alexandros, Stricker, Claude, Kotrotsios, Giorgos, Shah, Sonali K., Podgaets, Alexander, Ockels, Wubbo, Seo, Kazuya, Stolbov, Valeriy, Belyaev, Alexey, Shumihin, Anton, Vasilenko, Sergey, Subic, Aleksandar, Paterson, Niall, Hanna, R. Keith, Moritz, Eckehard Fozzy, Justham, Laura, West, Andrew, Cubitt, Aimee C., Bramley, Alan N., Hodgkins, Philip, Rothberg, Steve, Caine, Mike, Fischer, Peter R., Nolte, Christian, McHutchon, Mark, Manson, Graeme, Carré, Matt, Sabo, Anton, Reichel, Martin, Eckelt, Markus, Kogler, Hannes, Anderson, Lauren, Fleming, Paul, Ansarifar, Ali, Dumm, Melanie, Hainzlmaier, Christian, Boerboom, Stephan, Wintermantel, Erich, Ewart, Paul D., Verbeek, C. J. R., Irander, Carl Johan, Berglund, Göran, Zaeh, Michael E., Gebhard, Paul, Kaiser, Michael, Himmel, Norbert, Hamilton, Nick, Senior, Terry, Franklin, Kathryn, Williams, Simon, Gordon, Rae, Miyazaki, Yusuke, Ujihashi, Sadayuki, Jin, Tomohiko, Akiyama, Shinichirou, CheolWoong, Ko, Schwiewagner C., Böhm H., Senner V., Greenwald, Richard M., Chu, Jeffrey J., Jessiman, Alexander W., Shealy, Jasper E., Johnson, Robert J., Ettlinger, Carl F., Justham, Laura, West, Andrew, Cork, Alex, Miyaji, Chikara, Ito, Koji, Shimizu, Jun, Baca, Arnold, Stevens, Gunnar, Wulf, Volker, Rohde, Markus, Zimmermann, Andreas, Ganter, Nico, Witte, Kerstin, Edelmann-Nusser, Jürgen, Wiemeyer, Josef, Henneke, Christian, Hoisl, Frank, Schönberger, Stefan, Moritz, Eckehard F., Sierksma, Gerard, Vernadakis, Nicholas, Zetou, Eleni, Avgerinos, Andreas, Giannousi, Maria, Kioumourtzoglou, Efthimis, Meyer, Imke K., McHutchon, Mark, Okubo, Hiroki, Hubbard, Mont, Marmo, Brett A., Buckingham, Mark-Paul, Blackford, Jane R., Stiles, Victoria H., Dixon, Sharon J., James, Iain T., Memmert, Daniel, Perl, Jürgen, Kawamura, S., Takihara, H., Minamoto, H., Zahid, Hossain Md., James, David M., Haake, Stephen J., Strehler, Martin, Hasenknopf, Andreas, Moritz, Eckehard Fozzy, James, Daniel A., Knoll, Klaus, Wagner, Klaus, Blair, Kim B., Culligan, Kieran F., Walfisch, David, Maw, Sean, Johnston, Clifton R., Yuen, Allen, Lee, Manryung, Kim, Cheol, Adelman, Simon, Otto, Steve, Strangwood, Martin, Kim, Moo Sun, Kim, Sun Jin, Han, Dong Chul, Lee, Woo Il, Cornish, James, Monk, Stuart, Mase, Tom, Timms, Mark, West, Cory, Iwatsubo, Takuzo, Nakajima, Daiki, McCloy, Alex J., Wallace, Eric S., Chen, Chaochao, Inoue, Yoshio, Shibata, Kyoko, Gillet, Christophe, Foissac, Matthieu, Leteneur, Sébastien, Freychat, Philippe, Barbier, Franck, Rosa, David, Alcántara, Enrique, González, Juan Carlos, Martínez, Natividad, Comín, Mario, José Such, María, Vera, Pedro, Prat, Jaime, Millet, Guillaume, Perrey, Stéphane, Foissac, Matthieu, Waller, Tom, Morris, Rhys, Roberts, Bryan C., Kirk, Bob, Haake, Stephen, Manson, Graeme, Gibbs, Paul J., Mitchell, Sean R., Harland, Andy R., Toon, Daniel, Kamperman, Nico, Ajoku, Uzoma, Hopkinson, Neil, Roux, Maxime, Puyaubreau, Céline, Gorce, Philippe, Petrone, Nicola, Faggiano, Emanuela, and Meneghello, Roberto

Published
2006
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36. An algorithm for estimating acceleration magnitude and impact location using multiple nonorthogonal single-axis accelerometers

Author

Crisco, Joseph J., Chu, Jeffrey J., and Greenwald, Richard M.

Subjects
Biomechanics -- Research, Brain -- Concussion, Brain -- Research, Brain -- Causes of, Engineering and manufacturing industries, Science and technology
Abstract

Accelerations of the head are the likely cause of concussion injury, but identifying the specific etiology of concussion has been difficult due to the lack of a valid animal or computer model. Contact sports, in which concussions are a rising health care concern, offer a unique research laboratory environment. However, measuring head acceleration in the field has many challenges including the need for large population sampling because of the relatively low incidence of concussions. We report a novel approach for calculating linear acceleration that can be incorporated into a head-mounted system for on-field use during contact sports. The advantages of this approach include the use of single-axis linear accelerometers, which reduce costs, and a nonorthogonal arrangement of the accelerometers, which simplifies the design criteria for a head-mounted and helmet compatible system. The purpose of this study was to describe the algorithm and evaluate its accuracy for measuring linear acceleration magnitude and impact location using computer simulation and experimental tests with various accelerometer configurations. A 10% error in magnitude and a 10 deg error in impact location were achieved using as few as six single-axis accelerometers mounted on a hemispherical headform.

Published
2004

43. Neuropsychological Change After a Single Season of Head Impact Exposure in Youth Football

Author

Maerlender, Arthur, primary, Smith, Eric, additional, Brolinson, P. Gunnar, additional, Crisco, Joseph, additional, Urban, Jillian, additional, Ajamil, Amaris, additional, Rowson, Steven, additional, Campolettano, Eamon T., additional, Gellner, Ryan A., additional, Bellamkonda, Srinidhi, additional, Kieffer, Emily, additional, Kelley, Mireille E., additional, Jones, Derek, additional, Powers, Alex, additional, Beckwith, Jonathan, additional, Stitzel, Joel, additional, Greenwald, Richard M., additional, and Duma, Stefan, additional

Published
2020
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44. Psychometric properties of the standardized assessment of concussion in youth football: Validity, reliability, and demographic factors

Author

Maerlender, Arthur, primary, Smith, Eric, additional, Brolinson, P. Gunnar, additional, Urban, Jillian, additional, Rowson, Steven, additional, Ajamil, Amaris, additional, Campolettano, Eamon T., additional, Gellner, Ryan A., additional, Bellamkonda, Srinidhi, additional, Kelley, Mireille E., additional, Jones, Derek, additional, Powers, Alex, additional, Beckwith, Jonathan, additional, Crisco, Joseph, additional, Stitzel, Joel, additional, Duma, Stefan, additional, and Greenwald, Richard M., additional

Published
2020
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45. Synthesis of thio-linked disaccharides by 1--> 2 intramolecular thioglycosyl migration: oxacarbenium versus episulfonium ion intermediates

Author

Johnston, Blair D., Pinto, B. Mario, Boro, Michelle, Guan, Shuiyun, Greenwald, Richard B., and Pendri, Annapurna

Subjects
Esters -- Chemical properties, Ions -- Research, Ions -- Chemical properties, Organic compounds -- Synthesis, Organic compounds -- Research, Organic compounds -- Chemical properties, Biological sciences, Chemistry
Abstract

The1.1' -thio-linked glucopyranosyl alpha-D-mannopyranosides conversion to 1,2-thio-linked methyl sophorosides is described. The methyl glycoside is formed as a mixture of alpha and bet-isomers due to an oxacarbenium-ion intermediate rather than an episulfonium-ion intermediate.

Published
2000

46. 20-micron-acylcamptothecin derivatives: evidence for lactone stabilization

Author

Hong Zhao, Prakash, Boro, Michelle, Guan, Shuiyun, Greenwald, Richard B., Pendri, Annapurna, Sai, Yun H. Choe, and Chyi Lee

Subjects
Acylation -- Chemical properties, Lactones -- Research, Lactones -- Chemical properties, Biological sciences, Chemistry
Abstract

It was shown that the acylation of the 20-OH group of camptothecin (CPT) with PEG yielded water soluble derivatives in which the lactone structure (E-ring) remained stable under physiological conditions (PH7.4, 37 degrees C). UV and NMR spectrophotometry and HPCL analysis were used for the experiment.

Published
2000

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