# A Review of Seatbelt Technologies and Their Role in Vehicle Safety
## 3 Results
### Child Injuries  
Children are vulnerable occupants of motor vehicles during collisions, requiring special restraint systems, such as car seats or booster seats. Incorrect use or lack thereof can lead to severe injuries, especially to the head, neck, and abdomen. Seatbelts should be used in conjunction with special seats appropriate for the child's age and weight. In reference [76], the \"seatbelt syndrome\"--(SBS)--characterized by abdominal abrasions is mentioned. This is a specific indicator of internal injuries, but not very sensitive. In their paper, they address the diagnostic challenges arising from the use of booster cushion seats in children. Another researcher [22] indicates the need to balance the pretensioner force and seatbelt geometry to gain good pretensioner performance in both the pretensioner deployment phase and in the crash phase.  
Chance fractures are a type of vertebral fracture characterized by fracture lines through multiple vertebral structures and are often associated with seatbelt injuries. They are also common in children and may be associated with intra-abdominal lesions [77]. Studies such as those by [77; 78] emphasize the importance of correct use of child restraints.  
In frontal impacts, children sitting on reclining booster seats can suffer neck and spine injuries, according to [79]. Belt-positioning booster seats (BPB) and pre-pretensioner belts may be effective in preventing injuries from diving and head excursion in reclined children. The authors found an increase in forces, moments, acceleration, and rotational displacements to the large omnidirectional child spine as seatbacks were changed from the nominal position to a severe recline while the BPB was in use.  
The study in [80] suggested that reclined seating was preferred for autonomous vehicle occupants. Also, ref. [81] investigated the effect of seatbelt pre-pretensioners on rear-seated, child-sized anthropomorphic test devices during two types of run off-road events. The activation of the pre-pretensioner resulted in a reduction in lateral excursion of the Q6, Q10, and HIII 5 th percentile female dummies. This was due to the shoulder belt staying securely on the shoulder, providing additional support to the lower torso. These findings offer valuable insights into how pre-pretensioners can mitigate kinematic responses in complex run off-road scenarios, ensuring proper seatbelt positioning.  
Common injuries in children include the following:* Chance fractures are vertebral fractures caused by the force exerted by the seatbelt. These fractures are often associated with abdominal injuries and are known as seatbelt syndrome [76; 82; 83].
* Abdominal injuries can cause seatbelts to make abdominal abrasions, which are an indicator of internal injuries. Although seatbelt signs are quite specific for internal injuries, they are not always indicative and careful evaluation is necessary [76; 84; 85; 86]. The study in [87] shows that pediatric patients with seatbelt signs after motor vehicle collisions are more likely to have intra-abdominal injuries than those patients without seatbelt signs.
* Children seated in the back seat are said to be approximately 55% more likely to be injured by rear structure intrusion of the vehicle in a rear impact, according to [88].
* Children are also 27% more likely to be injured by compression into the interior of the front seat in a rear impact [88; 89; 90; 91].  
Regarding the correct seatbelt positioning for children, the study in [92] highlights that a superior-posterior position of the seatbelt relative to the anterior superior iliac spine increases the risk of submarining (slipping under the seatbelt). This issue is indirectly addressed also in [93; 94; 95].  
The authors in [96] emphasize that seatbelts have reduced the number of fatal head, facial, and chest injuries. They have, however, introduced a set of injuries comprising abdominal wall bruising, intra-abdominal injuries, and lumbar spine fractures collectively termed seatbelt syndrome.