Exploring Some Angles of the Angle Issue

This article originated in the July/August 2011 issue of Safe Ride News.

(This article, part one of a two-part series, looks at how proper rear-facing angle is assessed, especially for older children, and how to use “level to ground” lines on labels.  In the next issue, SRN will explore issues related to rear-facing CRs touching front seatbacks.)

After many years of knowing, from research and Swedish crash experience, that keeping children rear facing as long as possible is best, the CPS community now has strong support for this best practice from the American Academy of Pediatrics’ April policy statement on child passenger safety. Armed with that respected organization’s advice to keep kids rear facing until at least age 2, if possible, or even longer if they still fit, the community is doubly blessed by the accessibility of numerous CR models that will hold children up to these higher weight limits.  Such models are even available in today’s marketplace across all price levels.

One persistent (and, perhaps, worsening) problem plagues these otherwise heady times—the problem of fore-aft space with a tall, reclined, rear-facing CR.  As CR weight limits grow, the CR seatback naturally lengthens to fit the also-taller child. In the meantime, vehicle space has not grown, and, in fact, may have generally shrunk.  In many cases, therefore, the challenge of keeping kids rear facing to higher weights isn’t convincing the parents to do so or even finding a suitable and affordable CR.  Now, more and more often, the difficulty is getting the CR to fit in the vehicle while still following manufacturer’s installation instructions for the angle of recline.

Fore-aft space is mainly a problem because a rear-facing CR has to recline. For a matter that may simply be the difference of a few degrees, the issue of rear-facing angle is rather complex. CPSTs have been taught the basics of general crash dynamics, but also have to take into account the varied directions from CR manufacturers.  With the advent of the advanced air bag and concern for pressure on the back of the vehicle front seat, even some vehicle manufacturers weigh in on this subject.

The basics

Beginning with the standardized certification curriculum, CPST candidates are taught that CRs for young children have to recline because infants’ heads are heavy and babies have limited neck muscle control.  As described in the curriculum, if a baby’s CR is installed too upright, the heavy head might flop forward, which could block the airway.

The curriculum also notes: “As baby ages and obtains better head control, he/she may sit more upright.  This can actually provide for improved crash protection.”  This alludes to the fact that the more upright a rear-facing CR is during a crash, the more the force will be spread evenly across the back of the child (and less on the shoulders loading the harness).  Also, the head is less likely to ride up and out of the protective shell.

So, CPSTs learn that identifying the correct angle involves a trade-off between reclining just enough for safety during normal driving and not being reclined to an extent that the CR does not function properly during a crash. The range of appropriate recline angles is commonly understood to be 30 to 45 degrees from vertical (also noted in the curriculum).
Candidates are also taught to follow CR manufacturer advice regarding specific models.  (Interestingly, the curriculum instructor notes also say,  “Inform students to also look to be sure [the] angle is correct as some indicators may not give a true reading.”)

Manufacturers’ Instructions Vary

The curriculum aims to give CPSTs a good understanding of general principles, but makes it very clear that it is important to follow the instructions provided by manufacturers.  A survey of actual models makes it clear that there is little that can be generalized.

For any given CR model, angle guidance can be found in a number of places: depicted in the owner’s manual, on the label (usually in the form of a “level to ground” line), and/or on an angle indicator gauge on the CR or base.  The angle indictor feature (dial, bubble, etc.) is nowadays found on most infant seats, but usually not on convertible CRs.  A few rare models, such as the Learning Curve True Fit Deluxe and Baby Trend Flex-Loc, specify one range for the youngest occupants and a second, more-upright range for older babies/toddlers.

These days, the taller, convertible CRs more commonly have a line on the label with instructions that the line should be parallel to the ground or vehicle floor— the so-called “level to ground” line.  This angle guidance line has one important advantage:  it is extremely inexpensive.  This is a huge consideration these days, when price matters, but many user-friendly CR features tend to force prices upward. However, a disadvantage is that a line that must be parallel to the ground does not provide a range of acceptable angles—it dictates only one angle.

It is important to consult all manufacturers’ instructions, since the manual and label wording may provide details beyond the indicators on the CR.

Manufacturers Surveyed About “Level to Ground” Lines

The crux of many problems involves situations in which the CR has a tall seatback, and there’s not enough fore-aft space to fully recline to the angle indicated by the “level to ground” line.  Even in vehicles that do have enough space, some older babies/toddlers, who still fit rear facing, nonetheless object to being secured at an angle as reclined as 45 degrees.

In either of these cases, the caregiver or CPST often questions a “level to ground” line that reclines the CR to an angle that seems to be excessive for an older child.  The caregiver may be tempted to either ignore the angle line or turn the child forward facing.

SRN surveyed manufacturers to find out what additional advice they could give on this matter.  Though the individual responses varied, the message from those who responded was clear:  Do not second-guess the instructions.  Here are some other details:


On the current platform of convertible CRs, Britax provides a blue line on each side of the CR, which it calls an “angle guide line.”  The label and the owner’s manual indicate that the CR, when rear facing, can be installed between 30 and 45 degrees. When the blue line is level to the ground, this is in the middle of that range.  So, on the current platform of Britax CRs, the blue line gives a guide for the center of the acceptable range, and the CR may be installed off-level a bit in either direction, so long as the CR is reclined between 30 and 45 degrees.  (Editor’s Note:  It would be prudent to allow the seat to be more upright only for babies who can sit up well.)

On discontinued and Classic versions of Roundabout 50 and Marathon (still sold at Target), some models have wording in the owner’s manual like that in the current platform that says the CR, when rear facing, can be used between 30 and 45 degrees.  If that wording exists, and there is a “level to ground” line, follow the range as described in the guide.   Otherwise, if there is only a “level to ground” line, follow that exactly.

Though Britax has angle indicator devices on its infant seats, both the new B-Safe (see SRN July/August 2011, page 3) and Chaperone have “level to ground” lines on the CR for use when it is installed without the base.  Britax is very clear that, on these CRs without the base, this is a true “level to ground” line – not an “angle guide line,” as on the convertibles.  The subtle but important distinction between the two is that a “level to ground” line must be followed strictly, while an “angle guide line” allows some leeway as described in the convertibles above.  When using the infant CRs without the base, the line MUST be parallel to the ground; when used with the base, follow the angle indicator bubble.

Sarah Tilton of Britax made a point that was echoed by the other manufacturers when asked why instructions are so specific: because this is how the manufacturer has tested the CR and found its performance to be acceptable.


Evenflo strives to keep instructions simple to reduce confusion.  The instructions say to “adjust the restraint so that the level line is parallel with the vehicle floor.”  Evenflo urges CPSTs to continue to follow these guidelines and to not vary from them, because the instructions reflect how the CR has been tested.

Sunshine Kids

Sunshine Kids Radian convertibles do not have a “level to ground” indicator on the label, since the company says this is not needed.  According to Sunshine Kids, as long as the CR is used properly with the rear-facing base/foot properly attached, the CR cannot be installed at an incorrect/unsafe angle.


SRN was especially interested to hear from Dorel on this subject, due to the frequency with which vehicle fore-aft issues come up with its CRs, such as the Alpha Omega models.  The “level to ground” line is embossed on these CRs into the plastic of the booster-mode’s shoulder belt guide.  Many CPSTs find that strictly following this line places the CR at what seems to be an extremely reclined angle and often wonder if this should be considered an indicator of maximum recline only.

Though Dorel did not respond to SRN’s survey, important feedback on this subject was shared during Dorel’s July 15th webinar offered through Safe Kids.  According to Dorel’s Ryan Hawker, the line is to be followed exactly, not as an indicator of maximum recline, and added that he could not elaborate on why a more-upright angle could not be used for older children riding rear facing, other than to say that Dorel has been experimenting with this and has determined that using its CRs too upright could lead to “different problems.”  He added that Dorel is “working on it diligently here, and may have an announcement in the future.” In the meantime, he notes that setting the angle so the lines are level to the ground may be accomplished using either noodles or towels.

One Dorel product that shows promise as a design solution to this problem is the new Maxi-Cosi Pria 70.  This convertible CR, described in the March/April 2011 SRN, has a special structural insert that Dorel calls “Tiny Fit.”  With the CR installed in the more upright position preferred for older babies, the insert can be added to provide a more reclined seating position within the overall shell for younger ones.

Though other CRs have had inserts that reposition a baby (especially preemies or newborns), the Pria 70 insert is much more substantial than a typical padded insert.  Therefore, it allows a significantly more upright installation for the shell than a typical convertible, while optionally creating the needed reclined position within the shell for the period of time that the CR is used by a young baby.

Next issue:

We’ll explore the subject of recline and why some CRs require clearance between the CR and the front seat seatback.