Nearly 27,000 vehicle occupants are killed annually in the United States, with passenger car and light truck occupants amassing 25,000 of these. Over 50% of passenger car and light truck occupant fatalities are due to frontal crashes. Although advancements in safety technology have reduced the number of fatalities and injuries, motor vehicle collisions are still a major issue in the United States. Continued development of computational models and biofidelic anthropomorphic test devices (ATDs) necessitates benchmarking of current surrogates and further analysis of an occupant's biomechanical response in automobile collisions. This thesis presents data from low-speed frontal sled tests performed with human volunteers, a Hybrid III 50th percentile male ATD, and post mortem human surrogates (PMHSs). The first study sought to investigate the effects of muscle bracing by human volunteers. The second study sought to compare the responses of the relaxed and braced volunteers in the first study to those of the Hybrid III and PMHS subjects. Overall, these two studies provide novel biomechanical data that can be used to refine and validate computational models and ATDs used to assess injury risk in automotive collisions. The third study was focused on quantifying the ability for children to swing a sword-like toy. Over 200,000 toy-related injuries occur every year in the United States. Currently, data is unavailable with regard to sword-like toys. Incorporating the knowledge gained by this study will allow manufacturers to reduce the inherent risks associated with their products as well as market them to the correct target age groups. / Master of Science

Unintentional injuries present a major threat to the health and welfare of humans. Over 120,000 deaths and over 30,000,000 non-fatal injuries are estimated annually in the United States. The leading causes of nonfatal injuries vary with age, but falls, motor vehicle collisions (occupants), and being struck by or against are among the top 4 leading causes of unintentional injury for all ages. The loading mechanism that cause forces to be transmitted to the body during these events can cause a wide assortment of injury types with a range of severities. Understanding the biomechanical response to loading in these environments can facilitate efforts in injury mitigation. Biomechanical responses can be quantified by performing controlled laboratory experiments with human volunteers and surrogates, such as anthropomorphic test devices (ATDs) and post mortem human surrogates (PMHSs). The overall objective of this dissertation is to quantify the biomechanical response to loading regimes present in motor vehicle collisions, falls, and when being struck by or against an object using human volunteers and surrogates. Specifically, the research will achieve the following: quantify the dynamic responses of human volunteers, Hybrid III ATD, and PMHSs in low-speed frontal sled tests; quantify the neck response of human volunteers and PMHSs in low-speed frontal sled tests; quantify the kinetic and kinematic responses of PMHSs and the Hybrid III ATD in high-speed frontal sled tests; characterize thoracic loading as a result of same level falls using a Hybrid III ATD; and quantify the ability of children to swing sword-like toys and the human kinematic response that could be anticipated as a result of forceful impact using a Hybrid III 6-year old head and neck. / Ph. D.