honeybee03
New member
Ok, so I thought I absolutely had to have a car seat with RFing tether. I've seen the crash test videos about how the baby's face slams into the seatback on rebound, and they scare the crap out of me.
But then I came across this info from this link
http://www.carseat.org/Technical/tech_update.htm#rearfacFF
Top Tether, rear-facing
Only a few CRs in the U.S. have tethers for rear-facing use, but these are common in some other countries. Australia has tethered the top of infant restraints to an anchor positioned behind the vehicle seat for many years, and the most popular rear-facing "capsule" will not work properly if it is not tethered. Australians have also generally kept infants rear-facing until only about 6 months, when they start to use a forward-facing and virtually-always tethered restraint. Tethering a rear-facing CR toward the rear of the vehicle, which describes the Australian method, limits the downward rotation of the restraint and child during a frontal crash but does nothing to affect initial stability, rebound, or rear-impact.
Sweden has always used rear-facing restraints for children up to 4 years old, when they are moved directly into boosters with lap-shoulder belts. These large rear-facing restraints, which are set several inches away from the vehicle seatback to provide leg room, must rest against a vehicle structure, such as the instrument panel (unless there is an air bag) or the back of the front seat to keep them from falling over. Since the CR and its occupant can be tall and heavy, the Swedes have also tethered the backs down to the floor to eliminate rearward rotation during rebound or rear impact. The Swedes also have some small infant-only restraints that are not tied to the floor but do use the shoulder portion of the lap-shoulder belt to wrap around the "front" (the child's back) of the restraint to limit rotation during a crash. This installation method is used throughout Europe for frontal crash protection, but there is little effect on rebound or rear-impact motion.
The first U.S. infant restraint, which is the model for subsequent ones, did not use a tether in either direction nor a shoulder belt, but it worked very well. During development, the engineers observed that it turned over toward the vehicle seatback after a crash test and, largely in order to justify what happened anyway, they called this the "cocoon effect." There was also some justifiable concern that the small infant's neck might be injured on rebound or rear-impact unless the restraint were allowed to freely rotate in this direction. Justified or not, this concept has remained and seems to make intuitive sense. The counter-argument that the infant's head will "slam" into the seatback and be injured on rebound has not been validated in over 30 years of crash experience.
Britax, which has operations in Australia, Sweden, UK, and Germany, as well as in the U.S., devised a means to tie a traditional U.S. rear-facing convertible down to the base of the front seat structure to give it a firm installation and help the parent achieve something close to a 45° back angle, or more upright as appropriate. This tether does achieve a very secure installation, which is reassuring for parents, but it does little, if anything, to improve protection in a frontal crash. Downward rotation will likely be limited more by the back of the front seat (see Rear-facing CR resting against front seat) than by any cushion compression achieved with a tight downward tether. Another concern is that parents may use the tether to make the CR too reclined. Finally, tests conducted by a competitor a few years ago showed that dummy neck loads increased significantly when the restraint was tethered to the floor in both frontal and rear impacts. This would be more of a concern with the youngest infants than with children over 9 months to a year, but the competitor decided not to offer rear-facing tethers.
The restraint models on which the rear-facing tether is offered, however, can accommodate a child up to 33 lb rear facing, and for this usage the limit on rebound or rear-impact motion may be beneficial. Although crash experience indicates that rebound of infant-only restraints in frontal impacts does not cause serious injury, similar movement of a rear-facing restraint can also occur during a severe rear impact or offset rear impact, which can result in serious injury or death if the infant's head hits the rear door pillar of a sedan, the rear window of a pickup, or some other hard surface. As larger and heavier infants are carried rear-facing, the chance of an infant's head hitting a hard part of the vehicle is greater. Tethering a rear-facing convertible CR to the floor can reduce the risk of head and facial injuries in rear and side crashes by reducing head excursion.
Britax also acknowledges that one can route the tether rearward (Australian method) to the normal top tether anchorage, but this configuration has been given second priority. Of the two methods, this one is likely to have the most benefit in a frontal crash if there is rotation room in front of the child restraint. In practice, however, convertible restraints barely fit into back seats anyway, so the rearward tether may have limited use, except in vans.
I don't understand a lot of this, but it makes it sound like tethering it is a bad thing??? I will be getting a Radian, with has tethering in the RFing postion. Should I not tether it until its FFing? My DD is 9 months old & 18lbs. It also made it sound like it was good for older children, but not younger babies??
Any techs, I could use your opinion. Also, which method (swedish or australian) is better, and why?
But then I came across this info from this link
http://www.carseat.org/Technical/tech_update.htm#rearfacFF
Top Tether, rear-facing
Only a few CRs in the U.S. have tethers for rear-facing use, but these are common in some other countries. Australia has tethered the top of infant restraints to an anchor positioned behind the vehicle seat for many years, and the most popular rear-facing "capsule" will not work properly if it is not tethered. Australians have also generally kept infants rear-facing until only about 6 months, when they start to use a forward-facing and virtually-always tethered restraint. Tethering a rear-facing CR toward the rear of the vehicle, which describes the Australian method, limits the downward rotation of the restraint and child during a frontal crash but does nothing to affect initial stability, rebound, or rear-impact.
Sweden has always used rear-facing restraints for children up to 4 years old, when they are moved directly into boosters with lap-shoulder belts. These large rear-facing restraints, which are set several inches away from the vehicle seatback to provide leg room, must rest against a vehicle structure, such as the instrument panel (unless there is an air bag) or the back of the front seat to keep them from falling over. Since the CR and its occupant can be tall and heavy, the Swedes have also tethered the backs down to the floor to eliminate rearward rotation during rebound or rear impact. The Swedes also have some small infant-only restraints that are not tied to the floor but do use the shoulder portion of the lap-shoulder belt to wrap around the "front" (the child's back) of the restraint to limit rotation during a crash. This installation method is used throughout Europe for frontal crash protection, but there is little effect on rebound or rear-impact motion.
The first U.S. infant restraint, which is the model for subsequent ones, did not use a tether in either direction nor a shoulder belt, but it worked very well. During development, the engineers observed that it turned over toward the vehicle seatback after a crash test and, largely in order to justify what happened anyway, they called this the "cocoon effect." There was also some justifiable concern that the small infant's neck might be injured on rebound or rear-impact unless the restraint were allowed to freely rotate in this direction. Justified or not, this concept has remained and seems to make intuitive sense. The counter-argument that the infant's head will "slam" into the seatback and be injured on rebound has not been validated in over 30 years of crash experience.
Britax, which has operations in Australia, Sweden, UK, and Germany, as well as in the U.S., devised a means to tie a traditional U.S. rear-facing convertible down to the base of the front seat structure to give it a firm installation and help the parent achieve something close to a 45° back angle, or more upright as appropriate. This tether does achieve a very secure installation, which is reassuring for parents, but it does little, if anything, to improve protection in a frontal crash. Downward rotation will likely be limited more by the back of the front seat (see Rear-facing CR resting against front seat) than by any cushion compression achieved with a tight downward tether. Another concern is that parents may use the tether to make the CR too reclined. Finally, tests conducted by a competitor a few years ago showed that dummy neck loads increased significantly when the restraint was tethered to the floor in both frontal and rear impacts. This would be more of a concern with the youngest infants than with children over 9 months to a year, but the competitor decided not to offer rear-facing tethers.
The restraint models on which the rear-facing tether is offered, however, can accommodate a child up to 33 lb rear facing, and for this usage the limit on rebound or rear-impact motion may be beneficial. Although crash experience indicates that rebound of infant-only restraints in frontal impacts does not cause serious injury, similar movement of a rear-facing restraint can also occur during a severe rear impact or offset rear impact, which can result in serious injury or death if the infant's head hits the rear door pillar of a sedan, the rear window of a pickup, or some other hard surface. As larger and heavier infants are carried rear-facing, the chance of an infant's head hitting a hard part of the vehicle is greater. Tethering a rear-facing convertible CR to the floor can reduce the risk of head and facial injuries in rear and side crashes by reducing head excursion.
Britax also acknowledges that one can route the tether rearward (Australian method) to the normal top tether anchorage, but this configuration has been given second priority. Of the two methods, this one is likely to have the most benefit in a frontal crash if there is rotation room in front of the child restraint. In practice, however, convertible restraints barely fit into back seats anyway, so the rearward tether may have limited use, except in vans.
I don't understand a lot of this, but it makes it sound like tethering it is a bad thing??? I will be getting a Radian, with has tethering in the RFing postion. Should I not tether it until its FFing? My DD is 9 months old & 18lbs. It also made it sound like it was good for older children, but not younger babies??
Any techs, I could use your opinion. Also, which method (swedish or australian) is better, and why?