"Effectiveness of High Back and Backless Belt-Positioning Booster Seats in Side impact crashes"
* Belt-positioning booster seats provided a 58 percent overall reduction in risk of injury to 4-to 8-year-olds in side-impact crashes as compared with seat belts alone. (These findings support prior PCPS research, which shows booster seats to be 59 percent effective in reducing injury risk to 4-to 8-year-olds in crashes of all impact directions.)
* The risk reduction provided by booster seats in side-impact crashes varied by booster seat type: 4-to 8-year-olds riding in high back booster seats were at a 70 percent reduction in injury risk, while those in backless boosters did not experience a statistically significant risk reduction as compared with seat belts alone.
* However, both types of booster seats provided significant protection from "seat belt syndrome" injuries to the internal abdominal organs and lumbar spine. Most of the injuries to children seated in backless booster seats were head injuries.
* Possible explanations for non-significant reduction in injury risk for backless booster seats are that parents may be less likely to use to use the shoulder belt- positioner that comes with backless booster seats and that high back boosters have a contoured back that may better contain the occupant in side-impact crashes.