Thesis
Study of concussion in umpires for softball and baseball via experimentation and numerical modelling
Washington State University
Master of Science (MS), Washington State University
2018
Handle:
https://hdl.handle.net/2376/103763
Abstract
Brain Injury in sports have gained a lot of attention in the past few decades and the research in understanding it, has vastly been improved. Concussive and sub-concussive impacts leading up to brain degeneration diseases has made the sports community hyper-vigilant of the preventive measures. The aim of this project was to study the injury scenarios encountered by umpires in softball & baseball game through ball impacts on head and find reasons for why they get concussed in these two sports, when the traditional linear acceleration-based injury criteria are well below the threshold values. The project studied the reasons of concussion by studying the effect of fit, design and ageing of facemask on the impact attenuation. Seven distinct types of facemasks outfitted on hybrid-III headform were tested in the experimental study. Numerical models for the ball impact on hybrid-III headform and bio-model of head outfitted with facemask, were developed. Injury parameters from experiments and numerical models were compared to understand injury mechanisms. The study showed that injury parameters which contain rotational parameters offer more contrast in performance of facemasks than the ones based on only linear acceleration. The study showed that, as compared to the softball impacts at 70mph, baseball impacts at 95mph had 127% higher probability of concussion for Wilson and 547% for Nike facemask. For baseball impacts, the probability of concussion ranges from 3.6% to 19.6%, while for softball impacts, it ranges from 1.36% to 4.76% based on Gambit. Aged facemasks had the probability of concussion 440% and 250% times higher than the best performing facemask in baseball and softball impact respectively. Fit of facemask on head was found to be important, with worst case of different fit on headform saw an increase of probability of concussion by 275%, for a hit at the same location. The numerical simulations of hybrid-III headform helped in selecting potential high concussion probability locations. THUMS model simulation quantitatively predicted 44.7% concussion probability based on maximum principal strain for a chin impact and qualitatively explained the symptoms of concussion from high strain levels in cerebellum region of brain due to ball impact.
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Details
- Title
- Study of concussion in umpires for softball and baseball via experimentation and numerical modelling
- Creators
- Nitish Dhawan
- Contributors
- Lloyd V. Smith (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Mechanical and Materials Engineering, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525195701842
- Language
- English
- Resource Type
- Thesis