It stands to reason that having a hard bulky chest buckle on a child’s car seat is a significant factor in causing either thoracic or abdominal trauma in the event of an accident.
A toddler’s rib cage has not yet ossified and any trauma from a crash will penetrate through to the organs and arteries and not be dissipated around the rib cage.
A child’s chest experiences forces of up to 60g in the event of a collision at just 30mph. The chest buckle may not break on impact creating a hard surface that can add considerable force to a child’s internal organs.
Internal injuries are not easily identified in young children and hospitals are very reluctant to carry out CT Scans due to radiation risks to young children.
All car seats sold in Europe must comply with ece r44 regulations. In Europe the chest clip is illegal.
7.2.1.4. It shall be possible to release the child from the restraint by a single operation on a single buckle.
7.2.1.4.1. A clip connection between the shoulder straps of a harness belt is deemed not to comply with the single operation requirement given in paragraph 7.2.1.4. above.
Car seats in North America tend to be fitted with a chest clip, although it is not mandatory, creating additional risks. As recently as January 2011 a young baby in USA suffered a punctured lung due to the car seat chest clip.
Although the prime objective of the chest clip is to help prevent children slipping their harness, the problems include:
The simple design of the “5 point plus” helps prevent children slipping the harness from the shoulders and without the above issues!