Biomechanics of side impact: Injury criteria, aging occupants, and airbag technology

Abstract

This paper presents a survey of side impact trauma-related biomedical investigations with specific reference to certain aspects of epidemiology relating to the growing elderly population, improvements in technology such as side airbags geared toward occupant safety, and development of injury criteria. The first part is devoted to the involvement of the elderly by identifying variables contributing to injury including impact severity, human factors, and national and international field data. This is followed by a survey of various experimental models used in the development of injury criteria and tolerance limits. The effects of fragility of the elderly coupled with physiological changes (e.g., visual, musculoskeletal) that may lead to an abnormal seating position (termed out-of-position) especially for the driving population are discussed. Fundamental biomechanical parameters such as thoracic, abdominal and pelvic forces; upper and lower spinal and sacrum accelerations; and upper, middle and lower chest deflections under various initial impacting conditions are evaluated. Secondary variables such as the thoracic trauma index and pelvic acceleration (currently adopted in the United States Federal Motor Vehicle Safety Standards), peak chest deflection, and viscous criteria are also included in the survey. The importance of performing research studies with specific focus on out-of-position scenarios of the elderly and using the most commonly available torso side airbag as the initial contacting condition in lateral impacts for occupant injury assessment is emphasized.

A preliminary investigation of the dynamic viscoelastic relaxation of bovine cortical bone

“…Traditional approaches to quantify responses of the human body to impacts have typically included full scale experimental testing involving the use of a post mortem human subject (PMHS) [14]. However, such tests are expensive and time consuming which has lead to the increasing use of numerical modelling [6], for which detailed material models of bone are required.…”

Vertical accelerator device to apply loads simulating blast environments in the military to human surrogates

“…In automotive crashes, impact loading is generally horizontal, i.e., the vector lies along a clock direction: twelve, three or nine and six o'clock representing frontal, side and rear impacts (Backaitis and Mertz, 1994;Kuppa et al, 2003;Morgan et al, 1994;Yoganandan et al, 2014a;Yoganandan et al, 2015a;Yoganandan and Pintar, 2000). Devices such as acceleration and deceleration sleds have been used for over fifty years to simulate such loadings by positioning physical and biological models on their platforms to apply the intended load vector (Maltese et al, 2002;Philippens et al, 2000;Pintar et al, 1997;Yoganandan et al, 2007). The use of a pendulum is another example.…”

Lateral Impact Validation of a Geometrically Accurate Full Body Finite Element Model for Blunt Injury Prediction

“…Nearside occupants are at particular risk due to intrusion of the occupant compartment by the impacting vehicle. 56 It has also been found that pulmonary contusions are more likely to occur in lateral impact crashes. 13 While safety features such as side airbags are becoming more common in vehicles, the occupants of side impacts are still in need of better protection.…”