# A Review of Seatbelt Technologies and Their Role in Vehicle Safety
## 3 Results
### Other Passenger Categories Injuries
Using a logistic regression modeling, the authors in [113] showed that occupants who were wearing seatbelt's were more likely to experience closed head injury without skull fractures in addition to mesenteric and gastrointestinal injury. Increasing body mass index (BMI) increased the incidence of seatbelt markings (\(p<0.01\)) and markings were more likely to be found in the presence of bilateral pelvic fractures. Thus, external seatbelt markings were observed in only a minority of seatbelt wearers, and more often in individuals with higher BMIs and with bilateral pelvic fractures. Further on, in [114], the authors focused their study on assessing and protecting far-side occupants, particularly the head and thorax, which are the most commonly injured areas in field studies of far-side impacts. While considerable research and safety standards have addressed near-side impacts, far-side occupant injuries remain a significant concern. The study used the 50 th percentile male Test Device for Human Occupant Restraint (THOR) in oblique and lateral far-side impact sled tests. The research analyzed regional body accelerations, forces, and moments recorded by load cells. The main objective of this study was to evaluate chest band-based deflection responses, contributing to a better understanding of injury mechanisms and enhancing occupant protection strategies for far-side impacts. A model of a disabled person, missing their left leg, who steers a vehicle using a specialized knob on the steering wheel, was analyzed in [115]. The research focused on a head-on collision at an initial speed of 50 km/h with a rigid obstacle. The study found that the activation of an airbag significantly mitigates the effects of seatbelt and body support point asymmetries for people with disabilities. Biomechanical parameters, such as head injury criteria, seatbelt contact force, and neck injury criteria, all supported the use of an airbag. Finite element head modeling was employed to simulate head kinematics and predict injury outcomes. Without the airbag, the resulting head injury was identified as a contrecoup injury, specifically a cerebral contusion, based on intracranial pressure levels. The study concluded that a frontal airbag can substantially reduce the risk of injuries, including cerebral contusions, for disabled drivers. Some research on the effectiveness of seatbelts on rear-seat passengers is presented in [116; 117; 118; 119; 120]. The results show that a seatbelt system capable of adapting to occupant size and body shape will improve protection for obese occupants in rear seats. The passenger with higher BMI sustains significantly higher body excursions and normalized chest deflections with a standard rear-seat three-point belt than those for lower BMI occupants. By optimizing the load limiter and adding pretensioner(s), it can reduce injury risks associated with obesity, though conflicting effects on head and chest injuries are observed. Reference [121] investigated the effect of different belt design and occupant parameters on lap belt-to-pelvis interaction. It is found that the lap-belt angle represents the most influential design parameter, followed by occupant parameters like the pelvis angle and the Poisson's ratio of the adipose tissue. With obesity and a thicker layer of soft tissue, the interaction effects between these parameters are synergistically accumulated resulting in an increased risk of belt slide over the pelvis.