Agreed. The issue of not allowing bracing against front seat is likely due to theoretical possibility of misuse (like manual saying no cats in the microwave or babies in the tumbler). One could theoretically brace something extremely heavy, not a car seat, against front seat which might not be a good idea.
Theoretical misuse is not the main concern we have been discussing as to why some newer vehicle owners manuals prohibit anything, including carseats, pushing the front vehicle seat forward and/or downward. It is because the sensors for the multi-deployment advanced frontal and side impact airbags are present there and can be fooled if a something applies force to the seat. That is a very real danger to the occupant in the front seat.
There are, however, very practical reasons why bracing may not always be a good idea. I've seen them first hand. A child seat arrives at a check and the parent could not tightly install it with the seatbelt. Their answer was to move the front seat back and then wedge the top of the carseat between the front head restraint and front seat back. Now, the carseat seems secure, but it will still move in a crash initially because the seatbelt is loose and the front vehicle seat back is not a fixed point, so it will also move. In addition, with a loose harness, the child's head is quite likely to slam into the back of the head restraint that is now protruding into the child seat head space.
Sure, in Sweden, with the carseats and vehicles and education present there, bracing may be always recommended, especially in the front seat. In the USA, it may be theoretically beneficial, or at least not harmful, most of the time. The problem is that a blanket statement at how great bracing is can be quite dangerous to an occupant in many cases. Given the great benefits rear-facing provides inherently, the incremental theoretical gain by bracing a RF seat in the back seat of a vehicle in the USA has not been widely endorsed for good reasons. It's better left to be a situational choice by a parent or technician when it is not prohibited by an owner's manual.
Rear facing car seats were constructed to brace against dash/front seat. We find that performance is better and installation easier when bracing. This is why bracing against dashboard is so great. The car seat stays in perfect position, chassi of the car absorb the forces.
The dash is quite different than a seat back. The dash is fixed, while a seatback will move forward in a crash, providing much less potential benefit. The seat back is also much softer than a dash, providing much less risk if the child seat does strike it. Of course, in the USA, we do not advocate placing children in the front seat until they are 13 years old. Obviously, if bracing is allowed or encouraged by the carseat and vehicle owners manuals, then by all means do so. If it is prohibited, then do not. It's rather simple and consistent with what every expert, technician and instructor will state. The manufacturers' instructions are the primary resource for installing the child restraint.
Admin said:
Litigation is an issue, though to be fair, in general, allowing something dangerous is more likely to result in a successful lawsuit than allowing something safe.
Well of course. But the implication being made is that the car seat manufacturers
which prohibit bracing in the US but not elsewhere is that they're being extra careful in preventing lawsuits by prohibiting a practice that they know is safe. No one will sue them if their kid was injured when braced if the manufacturer prohibits it in the manual, whereas they might if it is allowed even if the injury had nothing to do with the actual bracing (perhaps the seat was not installed properly at all and the bracing was used to get a tight install for example).
This comment has a lot of very questionable assumptions. I wouldn't stake the life of a child on all these implications about why a manfuacturer chooses to allow or prohibit something. Sure, it could be because they simply don't know or were afraid of potential lawsuits. It could also be because they found it to be dangerous in their own top secret, proprietary testing. Is a child's life worth a guess as to the reason? To advise parents to ignore a very clear instruction from an owner's manual without some first hand, specific information about their situation (that may in some cases justify ignoring some statement or warning) is not only irresponsible, but also puts children in potential danger from a generalization that may not be generally safe.