Are You Using the Correct Car Seat Harness Slots?

When your child is secured in his car seat, the only thing restraining him is the seat's five-point harness. But did you know, that as your child grows the proper placement of the car seat shoulder straps changes?

A five-point harness is the webbing portion of the seat that adjusts over your child to hold him in place. A five-point harness has five distinctive points of contact; it secures your child at both shoulders and across each hip, buckling between the legs. Your five-point car seat harness system will also include a chest clip that must always be positioned at armpit level.

Harness System Design

The harness system is designed to restrain your child and distribute crash forces evenly over a wide area of your child’s body. Here’s the breakdown: tight harness = less movement. By contrast, improper harnessing increases your child’s risk of injury. If the harness is too loose or improperly positioned, your child could move outside of the protection of the car seat, or even be ejected entirely.

Often parents are surprised to learn that the seat’s harness requires adjustments as their child grows. Or that some harnesses have multiple loops to either increase or shorten their length. So, what does all of this mean? 

Rear-facing Harness Positioning

When your child is REAR-facing, keep the harness positioned snugly AT or BELOW your child’s shoulders to prevent him from sliding up in the seat in a crash or sudden stop. Why? The majority of crashes are frontal crashes and in all crashes, everything, including your child, will move towards the point of impact (Newton 🍎). In the initial stage of the movement, your rear-facing car seat will dip down and allow your child to slide up within the car seat until he is stopped by the harness. Then, during the rebound stage of the crash - this occurs after the initial stage of the movement, the rebound is the stage where everything that moved towards the impact comes back and settles in place - your child will slide back down in the seat. That’s a lot of movement and potential for injury, so keeping him down and properly secured in his seat in the first place is vital.

If the harness straps are too high, they will not restrain your child securely and will subject the head and body to unnecessarily high forces. Whereas, a correctly positioned and properly tightened harness greatly reduces your child’s movement, limits the transfer of crash forces, and ensures that the forces are evenly distributed over the stronger parts of your child’s body (shoulders and hips), protecting the head, neck, and spinal cord.

Forward-facing Harness Positioning

When your child is FORWARD-facing, keep the harness positioned snugly AT or ABOVE your child’s shoulders to counteract the forward pull experienced in a frontal crash, and hold the chest back most efficiently. Straps coming from below your child’s shoulders will allow the torso and head to move too far forward in a crash and could compress down on your child’s spinal column. 

Harness tightness takes on greater importance for a forward-facing child. In order for your child’s seat to offer the maximum protection, the harness webbing must lay flat and snug up against your child’s body, so ensure you remove anything that gets in the way. When you add layers of uncompressed bulk from a winter coat or other non-approved products between your child and the seat’s straps, you are unable to ensure a tight and properly fitted harness. The extreme forces will flatten out any remaining bulk in a crash, resulting in the straps no longer being tight enough to keep your child safe and putting him at risk of injuries from excessive movement.

You see, once your child transitions to a forward-facing seat, the shell of the seat no longer cushions your child during a crash. Rather, the harness alone must do the job of restraining him and helping the body ride down crash forces. Forward-facing seats are designed to slow down your child’s body in a crash and prevent it from moving as far as it might, but not to cradle his head and neck in the same manner as a rear-facing seat.

Harness Fit

Setting harness height aside for a moment, let’s chat about fit. A study from the National Highway Traffic Safety Administration (NHTSA) noted that an estimated 46 percent of child car seats and booster seats include at least one error that “could reduce the protection of the seat in the event of a crash (1).” A car seat is a life-saving device, but it can only protect your child if it is installed and used correctly. Ultimately, a safety seat's harness will only be effective in a crash if it is properly adjusted to your child.

Harnessing habits begin at birth. Most parents don’t tighten the harness sufficiently on their newborn out of fear that they might hurt their little one! Let’s face it, it’s not an easy feat to secure a harness on a wiggly newborn! But here’s the good news: newborns are used to tight quarters (pregnant tummy!) and, barring any medical issues, they crave the security that comes from being restrained. It’s important to get into the habit of securing the harness properly from the start and push the notion of ‘over-tightening’ out of your mind.

After securing the crotch buckle, leave the chest clip open and lower it down as far as possible. Pull the harness up so that the straps lie flat against your child's chest and over his hips in a straight line without any twists or folds. Push down on the crotch buckle to remove the harness slack at your child’s hips, and pull up on the harness in the torso area to transfer the slack up towards the shoulders. Next, pull the harness adjuster strap at the bottom of the seat to tighten the straps. Once you have removed all visible slack from the harness, ensure that it passes the Pinch Test. 

Pinch Test

The Pinch Test is the best way to determine whether your child’s car seat harness is tight enough, and it should be performed every time you use your seat. After you have fastened and tightened the straps, try to pinch the harness webbing horizontally above the chest clip at your child’s collarbone. If you are able to pinch and hold any harness webbing between your thumb and index finger, the harness is too loose. The harness is considered tight enough when you are unable to pinch ANY webbing between your fingers.

Once you have pulled the harness snug (pass the Pinch Test), slide the chest clip up and secure it at armpit level. The chest clip must be positioned level with your child’s armpit height every single time.

PRO TIP: for exact chest clip placement every single time, the Road Coat features a red alignment marker stitched on either side of the zipper within the inner jacket panel of the Road Coat to help you correctly identify where the chest clip should sit on your child. This red marker provides a visual guide and should be visible below the bottom edge of your seat’s chest clip. It’s the little but life-changing features like this and the split collar construction that allows the car seat harness to safely pass through the collar without adding any bulk that is true game-changers!!


Harness Placement

Harness placement is more important than people appreciate. When a child is secured using the wrong harness slots, the seat cannot perform as designed. In the event of a crash, having the straps too high or too low can lead to excessive head movement, resulting in injuries that could have easily been prevented. In fact, having the harness straps incorrectly positioned can be equally dangerous to the straps being too loose.

Here’s the takeaway: Verify that the harness is snug every time you place your child in the car seat. Follow your car seat manufacturer’s instructions regarding when and how to adjust the harness, making sure to check the fit and readjust as your child grows. Take a moment and confirm that you’re using the CORRECT harness slots. You could save your child’s life!




Sean Linnenbruegger 

Child Passenger Safety Technician Instructor (CPST-I)