Drivers Of Overweight Research Articles

Application of Inertial Measurement Units to Assess Vehicle Ingress and Egress Characteristics

The increasing number of elderly and overweight drivers in the United States has necessitated that vehicle manufacturers develop automobiles that accommodate these changing demographics. While digital human models have been successfully used to simulate human vehicle interaction (Chaffin, 2005; Ozsoy et al., 2015; Yang et al., 2007), the variability in ingress and egress procedures among drivers with different physical attributes poses a unique challenge to developing accurate models. The objective of this study was to apply inertial measurement units (IMUs) to compare ingress and egress characteristics of individuals of varying age and body type. Ninety-three participants, comprising a control group (aged 21–<65 years with body mass index [BMI] <30 kg/m2), a high-BMI group (aged 21–<65 years with BMI ≥30 kg/m2), and an elderly group (aged ≥65 years), performed ingress and egress trials in three vehicles (compact, sedan, and sport utility vehicle [SUV]) while wearing a wireless IMU system (Xsens MVN BIOMECH Awinda system, Xsens Technologies BV, Enschede, Netherlands). Native protocols of the IMU system were used to estimate the joint centers and motion paths of several bilateral body joints including the ankle, knee, hip, wrist, elbow, and shoulder. The transition of each joint center across the edge of the seating area at the door sill as the subject got into and out of the vehicles was measured. The start of the ingress process was defined as the time when the first joint center passed through the door sill into the driver’s seating area. The end of ingress was considered to be the time when the final joint passed back through the edge of the seating area. Two-way analyses of variance (ANOVA) examining the effects of population (control vs. elderly vs. high-BMI), gender, vehicle model, and their interactions on ingress and egress times were conducted. In general, the right ankle was the first body segment to enter each of the three vehicles followed by the right knee, right hip, right shoulder, left hip, left shoulder, left knee and the left ankle regardless of population group. Ingress time was observed to be affected by population (F2, 28 = 17.97, p < 0.001), and was characterized by a much slower ingress time among the elderly (mean = 4.33 secs), compared with controls (2.97 secs) and high-BMI participants (2.71 secs). Egress was also observed to be affected by population (F2, 28 = 8.85, p < 0.001), but in a slightly different manner. The control group (mean = 2.95 secs) was the fastest to egress the car, followed by the high-BMI group (4.42 secs) and the elderly (5.26 secs). The results indicate that IMUs may be successfully applied to characterize ingress and egress motion paths of different population groups and may be useful when designing seated applications, particularly for elderly and high-BMI populations.

A computational study of injury severity and pattern sustained by overweight drivers in frontal motor vehicle crashes

The objective of this study was to examine the role of body mass and subcutaneous fat in injury severity and pattern sustained by overweight drivers. Finite element models were created to represent the geometry and properties of subcutaneous adipose tissue in the torso with data obtained from reconstructed magnetic resonance imaging data-sets. The torso adipose tissue models were then integrated into the standard multibody dummy models together with increased inertial parameters and sizes of the limbs to represent overweight occupants. Frontal crash simulations were carried out considering a variety of occupant restraint systems and regional body injuries were measured. The results revealed that differences in body mass and fat distribution have an impact on injury severity and pattern. Even though the torso adipose tissue of overweight subjects contributed to reduce abdominal injury, the momentum effect of a greater body mass of overweight subjects was more dominant over the cushion effect of the adipose tissue, increasing risk of other regional body injuries except abdomen. Through statistical analysis of the results, strong correlations (p < 0.01) were found between body mass index and regional body injuries except neck injury. The analysis also revealed that a greater momentum of overweight males leads to greater forward torso and pelvic excursions that account for higher risks (p < 0.001) of head, thorax and lower extremity injury than observed in non-overweight males. The findings have important implications for improving the vehicle and occupant safety systems designed for the increasing global obese population.

Influence of obesity on mortality of drivers in severe motor vehicle crashes

Purpose The purpose of the study was to investigate the relationship between obesity and mortality of drivers in severe motor vehicle crashes involving at least one fatality. Basic Procedures Fatalities were selected from 155 584 drivers included in the 2000-2005 Fatality Analysis Reporting System. Drivers were stratified by body mass index, confounders were adjusted for, and multiple logistic regression was used to determine the odds ratio (OR) of death in each body mass index class compared with normal weight. Main Findings The adjusted risk of death from lowest to highest, reported as the OR of death compared with normal weight with 95% confidence intervals, was as follows: (1) overweight (OR, 0.952; 0.911-0.995; P = .0293), (2) slightly obese (OR, 0.996; 0.966-1.026; P = .7758), (3) normal weight, (4) underweight (OR, 1.115; 1.035-1.201; P = .0043), (5) moderately obese (OR, 1.212; 1.128-1.302; P < .0001), and (6) morbidly obese (OR, 1.559; 1.402-1.734; P < .0001). Principal Conclusions There is an increased risk of death for moderately obese, morbidly obese, and underweight drivers and a decreased risk in overweight drivers.