Section 1: Injuries related to seat belts, seat positions, and booster seats

There are numerous safety experts and advocates, both in Canada and the United States, who currently recommend the use of booster seats in children who have outgrown their car seats, but are still too small to safely fit into an adult seatbelt.^8-13 These recommendations stem from evidence which shows an increased incidence of life altering injuries and deaths in children involved in MVCs. These injuries and deaths are most often a result of misuse of adult seat belts, misuse / lack of use of booster seats, as well as age-inappropriate seating positions.

The benefits of booster seats have been generally accepted, and proper use has been shown to reduce the risk of injury by 45% or more when compared with the use of just adult seat belts in children aged 4 to 8.^{14, 15} In a 2016 study conducted in Alberta, 23% of children were not using a booster seat, and of those who were, 31.8% were misusing the booster seat in at least one way.¹⁶ This study also highlighted the increased risk of injury that older children (up to age 7) face, as they were more likely to be inappropriately transitioned out of their booster seat (47.8%) versus children at 2 years of age (22.2%). A more recent study, published by Pitt, confirmed this finding. They found that children in Alberta who were restrained using adult seat belts were 21% more likely to be injured in a MVC, compared to children who were restrained in a booster seat.¹⁷

When a child is prematurely transitioned into an adult seat belt, there are often significant problems with seat belt fit, increasing the risk of serious injury. A vehicle seat belt fits correctly “when the lap portion of the belt rides low over the hips and is held in place by the upper pelvis”. A well-fit shoulder portion of the belt crosses the sternum and shoulder”.¹⁸

For children, the frequency of head injuries, brain injuries, spinal fractures, and other characteristic injuries labeled “seat belt syndrome” increase if placed in an adult seat belt. The term “seat belt syndrome” encompasses characteristic cervical and lumbar spinal cord injuries and intra-abdominal injuries resulting from ill-fitting or incorrectly positioned lap and shoulder seat belts.¹⁹ It is difficult for a child to sit properly against the back of the seat because the seat is long in relation to the child’s thigh. To compensate for this, children will often slouch, moving the correct placement of the seat belt. If restrained in an adult seat belt, slouching causes the lap belt portion to move up, over the abdomen instead of across the pelvis. In the event of a collision, direct force will be transferred to the abdomen and lumbar spine rather than the stronger iliac wings of the pelvis. This type of injury could result in serious fractures of the spine and even paraplegia. When the lap belt is worn high, the child is also at increased risk for sliding out of the lap belt during a collision.²⁰

Children have a smaller torso and narrow shoulders compared to an adult. This causes the shoulder portion of the seat belt to ride up and across the child’s neck or face. To compensate for this discomfort, children will either put the shoulder portion behind the back or under an arm, eliminating its protective function. Both of these practices increase the risk of injury to the bony cervical spine or to the spinal cord in the event of a collision.²⁰ Without the proper protection of a shoulder belt in a crash situation, the child’s torso remains unrestrained. Upon sudden deceleration, a child’s body will jackknife forward, placing full force on the pelvis or abdomen. Impact could be made between the head and knees, or with the vehicle’s interior, resulting in a head or brain injury.²⁰ The increased pressure on the abdomen also puts the child at risk for abdominal injuries and seat belt syndrome. When a child puts the shoulder belt under one arm, the resulting forces are known to result in serious internal injuries as well, a properly fitted booster seat eliminates the need to displace the shoulder portion of the seat belt, decreasing the rate of seat belt misuse by children.

Mature anterior superior iliac spines are strong enough to absorb the forceful velocity of the body in a collision. The bone composition of children is less developed, providing insufficient strength to properly anchor the belt. Virtually no child between 6 and 8 years would be big / strong enough to be adequately protected by an adult seat belt. It is not until children are 37 kg (80 lb) and at least 145 cm tall that an adult seat belt will fit correctly and provide adequate protection.^18-22

Section 2: Barriers to booster seat use

While the benefits of booster seat use are clear, and appropriate use of booster seats is increasing in Alberta, there are still a significant number of children who are improperly restrained in motor vehicles. It is important to address the barriers that exist as it relates to booster seat use, as removing these barriers can have a significant impact on usage rates.

Socioeconomic Status
A significant concern for many caregivers is the financial barrier of booster seat use, with many studies showing a correlation between socioeconomic status and the likelihood of proper booster seat use. One study, conducted in Michigan in 2006, found that low income households (earning less than $20,000 per year) were 3.5 times less likely to use a booster seat for their child, citing cost as the main factor.²³ The effect is further exacerbated based upon the number of children of booster seat age in the household.

Knowledge and Awareness
While availability of and access to booster seats and other child restraint systems can often be overcome, knowing which product to use and how to use it remains a major barrier to booster seat usage. In some cases, as much as 64% of parents surveyed have low knowledge of child restraint devices.²⁴

Many parents remain unaware of the specific age, height, and weight criteria for transitioning children from car seats to booster seats, often moving children out of booster seats prematurely based on perceptions of their child being "too old" or "big enough" for an adult seatbelt alone. Furthermore, a foundational misunderstanding of a booster seat's primary function - to properly position an adult seatbelt for a child's developing body, not merely to elevate them for visibility - contributes to underutilization.

Access to and the affordability of booster seats, coupled with clear and understandable information on how to use them, are critical components to compliance.²⁵

Section 3: Legislation

Booster seat legislation has been strongly recommended by child passenger safety advocates as a way to increase booster seat usage and reduce injuries and fatalities in children involved in MVCs.^{18, 9, 12, 18, 26} In Canada, booster seat legislation has been enacted in all provinces, with the exception of Alberta. This highlights a significant gap in Alberta’s approach, and commitment to child passenger safety, as a lack of provincial booster seat legislation corresponds with a higher rate of childhood fatalities related to MVCs.²⁷

An example of the positive impact of implementing booster seat legislation is illustrated in a study conducted in British Columbia. Researchers reported a 10.8% decrease in the rate of injuries in children 4 - 8 years of age after the province’s child restraint legislation was updated.²⁸ A similar trend was seen in the United States in states where booster seat legislation was extended to include children up to 7 years of age.²⁹

Booster seat legislation must be consistent with best practices and set a higher standard and vision of safety to which we strive to achieve. This should be considered as one of the first, and most important, steps in reducing childhood injuries and deaths related to MVCs.