Doctor of Philosophy, The Ohio State University, 2024, Nursing

Introduction: Walking is a healthy activity with numerous benefits, but pedestrian fatalities in the United States have risen alarmingly. From 2010 to 2020, pedestrian fatalities due to motor vehicle crashes increased by approximately 54%, reaching 6,607 deaths in 2020, accounting for nearly 18% of all road traffic fatalities. Concurrently, the U.S. population is aging, with one in five Americans projected to be aged 65 or older by 2030. These trends underscore the importance of understanding pedestrian fatalities across different age groups, particularly among older adults. However, few studies have explored age-related crash outcomes among pedestrian fatalities in both rural and urban contexts. Therefore, this research aims to identify the associations between age groups of fatally injured pedestrians and crash characteristics in rural and urban areas, examine factors influencing the place of death among fatally injured pedestrians, and analyze factors affecting the survival times of fatally injured pedestrians. Methods: This research used a cross-sectional design with data from the Fatality Analysis Reporting System (FARS) for the year 2021. Statistical analysis included descriptive statistics, chi-square tests, and log-rank tests. Multivariable logistic regression was performed to determine the predictors of binary outcomes, and Cox proportional hazards regression was used to determine the predictors of survival times. Results: Among fatally injured pedestrians, urban older adults had lower odds of being hit by a passenger car compared to urban younger adults. Urban middle-aged adults, urban older adults, and rural older adults, were less likely to be hit by vehicles traveling at 35 mph or over 35 mph, in the areas without crosswalks or sidewalks, in dark conditions, during weekends, and at non-intersections compared to their younger counterparts. Older adults had lower odds of dying at the scene/en-route compared to younger adults. The odds of dying at th (open full item for complete abstract)

Committee: Ethan Morgan (Advisor); Brittany Punches (Committee Member); John Bolte (Committee Member); Jodi McDaniel (Committee Member) Subjects: Nursing

Doctor of Philosophy, The Ohio State University, 2021, Public Health

Motor vehicle crash (MVC) related injuries remain the leading cause of death among children in the US. Age and size appropriate child restraint systems reduce the risk of MVC-related injuries. The American Academy of Pediatrics recommends that children who outgrow harness-based car seats should continue to use booster seats until they reach 57 inches tall. Many countries and US states have enacted legislation to promote the use of child restraint systems. However, the premature transition from using booster seats to seat belts is a public health hazard to children. The overarching goal of this dissertation was to examine the motor vehicle safety of child passengers by investigating the premature transition from booster seats to seat belts. The findings could be used to promote the appropriate use of child restraint systems and improve child passenger safety. The first aim of this dissertation (Chapter 3) was to compare the effectiveness of booster seats versus seat belts in protecting children aged 4 to 8 involved in MVCs. This chapter utilized data from Ohio Crash Outcome Data Evaluation System (CODES) from 2013 to 2016. By using propensity score methods with robust Poisson regression analysis, we found that children with booster seats had an 11% lower risk for overall MVC-related injuries, an 18% lower risk for moderate to severe injury, and a 59% lower risk for sustaining abdominal injury compared to those with seat belts alone. The second aim (Chapter 4) was to evaluate the impact of Ohio's booster seat law on child restraint use and MVC-related injuries. We included 18 years (2000-2017) of Ohio police accident report data and utilized an interrupted time series analysis with the generalized least-squares method. Our results indicated that Ohio's booster seat law was associated with an 18% increase in the proportion of age appropriate restraint use among children aged 4-7 years involved in MVCs, with this increase in usage occurring immediately after (open full item for complete abstract)

Committee: Motao Zhu Dr. (Committee Chair); William Miller Dr. (Committee Member); Rebecca Andridge Dr. (Committee Member); Jingzhen Yang Dr. (Committee Member); Dennis Durbin Dr. (Committee Member) Subjects: Public Health

Master of Science, The Ohio State University, 2021, Mechanical Engineering

Automotive crashes are a leading cause of death in the US, with side-impacts being the most fatal. Thoracic injuries are among the leading causes of such fatalities in small, elderly females. Thus, a series of six realistic side-impact post-mortem human surrogate (PMHS) sled tests were conducted. Results showed serious thoracic injuries in all PMHS, despite current side-impact anthropomorphic test devices (ATDs) predicting a <10% probability of such injuries. While this is partially due to the inaccuracy of injury risk scaling, it is hypothesized that combined thoracic loading, anteriorly-posteriorly (A/P) from the seatbelt pretensioner and laterally from the side airbag, increased rib fractures despite less-than-expected lateral chest deflection. The objectives of this study were to investigate the following in small, elderly female PMHS: 1) discrepancies between existing injury risk assessment tools and actual injury outcomes; 2) the effects of seatbelt pretensioners on thoracic injury; and 3) the effect of combined loading from the seatbelt pretensioner and side airbag on thoracic injury in side-impact. Prior to PMHS testing, SID-IIs ATD tests were run to match conditions to the previous study. A foam-padded pneumatic lateral impactor was used as a repeatable airbag surrogate. Three PMHS were tested, each under three different loading conditions: 1) A/P-only (seatbelt pretensioner), 2) lateral-only (airbag surrogate), and 3) combined loading (both). Anterior and posterior aspects of right and left ribs were instrumented with strain gages to detect potential fractures and fracture timing. Chest deflection was measured by axillary- and xiphoid process- level chestbands. Seatbelt load and spine motion were also measured. An anatomical dissection was completed after each test series to document all injuries. Each PMHS first underwent an A/P-only test, resulting in A/P chest compressions of 7-12% and no rib fractures. While the goal was to conduct one (open full item for complete abstract)

Committee: John H. Bolte IV Ph.D. (Advisor); Yun-Seok Kang Ph.D. (Committee Member); Sandra A. Metzler Ph.D. (Committee Member) Subjects: Biomechanics; Biomedical Engineering; Engineering; Mechanical Engineering

Doctor of Philosophy, The Ohio State University, 2017, Mechanical Engineering

Motor vehicle crashes claim thousands of lives each year in the US, and injure millions more. The thorax is the region of the body at greatest risk for serious injury, and thus is of interest for increased protection. In order to improve systems providing occupant protection, a better understanding of the thorax is required, particularly for vulnerable occupants. The work of this dissertation is focused on increasing understanding of the thorax, and does so by examining instrumentation commonly used on the thorax, by introducing a novel analysis technique for understanding thoracic characteristics, and finally by presenting response and injury data for side impact loading. The first study presented here provides an answer to the question, “Do chestbands alter thoracic response to impact?” This was accomplished by conducting a series of repeated impacts on two post-mortem human surrogates (PMHS), at the same impact velocity with 0, 1, and 2 chestbands. This was done for various impact speeds for a total of 22 impacts on the two subjects. `Response' was divided into global response, defined as chest deflection and thoracic stiffness, and local response, defined as the individual rib strain. Results showed no significant difference in global or local response, thus providing support for the commonly held assumption that chestbands do not alter thoracic response to impact. The second study introduces an analysis method, looking at rib strain as a function of chest deflection. An understanding of this relationship is intended to help bridge the gap between existing deflection-based injury criteria and strain-based injury prediction in finite element human body models. To this end, the strain-deflection (S-D) relationship was explored by rib level, fitting five different models to the data and constructing response corridors. It was additionally observed that the S-D relationship, or curve trajectory, tends to remain consistent across impacts on the same subject, (open full item for complete abstract)

Committee: John H., IV Bolte PhD (Advisor); Amanda M. Agnew PhD (Committee Member); Laura C. Boucher PhD (Committee Member); Rebecca B. Dupaix PhD (Committee Member); Yun-Seok Kang PhD (Committee Member) Subjects: Biomechanics; Engineering

Master of Science, University of Akron, 2009, Civil Engineering

Standard multinomial (MNL) and mixed multinomial logit (MMNL) models are used to estimate the degree of influence bicyclist, driver, motor vehicle, crash geometry, roadway geometry and environmental characteristics have on bicyclist injury-severity, classified as property damage only, possible, non-incapacitating or severe. This study is based on 10, 579 crash observations in the State of Ohio from 2002-2008. A log-likelihood ratio test is used to divide the bicycle/motor vehicle crashes into intersection and non-intersection location crashes. These models are used as base models for intersection and non-intersection MMNL models. Many variables are significant in both intersection and non-intersection location models. But six variables influenced bicyclist injury-severity at intersection locations but not non-intersection locations. Four variables influenced bicyclist injury-severity at non-intersection locations but not intersection locations. Some interesting finding are at intersection locations, the likelihood for a severe bicyclist injury increases by 31% if the bicyclist is not wearing a helmet, 99% if the motorist is under the influence of alcohol, 144% if the motor vehicle is a van, 59% if the motor vehicle front strikes the side of the bicycle, and 337% if the crash occurs on a horizontal curve with a grade. Non-intersection locations show the likelihood for a severe bicyclist injury increases by 608% if the bicyclist is under the influence of drugs, 194% if the motorist is under the influence of alcohol, 91% if the motor vehicle front strikes the side of the bicycle and 122% if motor vehicle is a heavy-duty truck.

Committee: William Schneider PhD (Advisor) Subjects: Transportation