Home Car Seat Safety: 5 point harness is safest
Car Seat Safety: 5 point harness is safest

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When used correctly, 5-point harness car seats provide significant safety advantages over securing your child in a booster seat using the adult seatbelt.

* The crash forces are spread over the skeletal body
over five points rather than three.

* The crash forces are spread to the strongest parts
of the child's body.

* Forward head excursion (the distance the head is
thrown forward) are lessened.

* The child is secured in the correct seating position rather
than being able to wiggle around, lean forward etc.

Firstly, please view this video showing the comparison of a child secured in a forward-facing 5-point harness seat and a child seated in a booster seat using the adult seatbelt:

Crash Test Video

Notice how the child on the passenger side is secured and how much less movement there is in the head, upper and lower body compared to the booster seat child on the driver's side.

Many parents think that once their child reaches 40 lbs in weight, that they need to move into a Booster seat with an adult seatbelt restraint. There are many options available to keep your child safely restrained using a 5-point harness.

Children under 7-10 years of age should not be placed into a booster seat. This is because the child's iliac crests (hip bones) are not yet developed enough such that they prevent the adult seatbelt from resting on the soft abdomen. Therefore an adult seatbelt provides insufficient protection to the child and could result in internal injuries, possibly resulting in the death of the child. Source: Tom Bologa, President of Britax USA

The following is a piece written by one of our advisory Child Passenger Safety Technicians, Kris Abbink, discussing why a 5-point harness is the safest choice for your child:

"To me, the above all reason for trying to convince a parent to use extended 5-point harnessing over using a booster seat, is its safety. When a child is in a traditional belt that we, as adults use, they are only covered at 3 points.

My first worry with this is that the child doesn't have the shoulder part of the belt properly adjusted across their chest and shoulder. Belt positioning boosters often provide adjusters, but they are not always good adjustments for the child depending on their size.

Another point is the fact that a child doesn't like to sit still, thus making it likely for the child to move about and cause the belt to have slack in the line, or the belt to not fall across the child properly. For a belt to properly work you have to be sitting up and back, so that in the event of a crash, the belt emergency locking mechanism kicks in and holds the belt taught so that there is no slack in the line. If there is slack, it allows further excursion motion for the person riding behind the belt. When your child is reaching for his favorite toy, or starts to slide over asleep, they move out of the way of the proper position of the belt path.

What a seat belt is designed to do is help to hold you back in the vehicle and to spread the crash force over a widespread area of the body; the strongest parts of the body. How this works is with a 3 -point, lap/shoulder style belt, the crash is spread over the hips and one shoulder.

In a frontal crash at only a mere 30mph with a child just 20lbs, you would need 600lbs of resistance against the crash force to hold the child back. This is just 30mph and 20lbs. As the weight and speed increases, the amount of resistance needed gets greater. A seat belt provides that resistance, but as you can imagine, by the resistance needed, that is an awful lot of pressure to put on a body. Think of what that force would do if the belt wasn't sitting properly across that child who had just leaned forward to reach his toy off the seat and leaned over right at the time of impact? Place that same child in a 5-point, forward-facing child restraint and the crash force is now spread over 5 parts of the body. There is no slack in the belt line, there is more resistance, and the frontal excursion is reduced. With the belt properly placed, taught as it should be and covering 5 areas of the body, it helps that initial shock of the accident. When in an accident,the body will continue to move at the same speed as the vehicle was, until something stops it.

In 5-point child restraints, there is also the added safety of the top tether (so long as the vehicle has this feature). The top tether or top strap (as its sometimes called) helps hold the top of the child restraint back against the vehicle. In a frontal crash at 30mph with a car seat installed properly and no top tether, there is a 32" frontal head excursion. In the same seat, same crash, child restraint installed along with the top tether, you reduce that frontal excursion to 4-6", thus making it more likely that the child will not hit the seat in front of them.

From my training, I learned that 90-92% of child restraints are installed wrong, and that 40% of children are in no restraint at all.

The number one killer of children in America is vehicle crashes. The problem with that statement is that nothing is changing. Now if that statement was, for example, the number one killer is childhood cancer what would happen? The parents would be all over the doctors to find a cure. But the responsibility lays in the parents hands and nobody is doing anything about it.

Best practice is ABOVE the law, not just the law minimum. Children are not replaceable, so its worth it for a parent to take the extra steps to make their child safe. The saddest part is too many people worry about vanity and others' thoughts. They may think that their 6 year old will look too big for that forward facing child restraint, or that their best friend will nag on them about using a forward facing child restraint for their 8 year old. All a belt positioning booster seat does is lift a child off the vehicle seat to sit better behind the seat belt, both at the shoulder and how the belt lays across the hips. A 5-point forward facing child restraint provides all the extra safety that is above mentioned.

Extended harnessing, for those that are unaware, is the harnessing of a child past the traditional 40lbs. There are different child restraints on the market now that provide extended harnessing such as the Britax Regent that harnesses up to 80lbs, the Sunshine Kids Radian65 (65lbs) or Radian80 (80lbs). These are just a few.

Things parents need to keep in mind is that there is so much necessary knowledge needed to install a car seat, and so many different ways to do so. Locking clip or not? Pool noodles for rear-facing or not? LATCH? Tether anchors? The list goes on and on.

Kris Abbink Certified Child Passenger Safety Technician"

Now that we have established why a 5-point harness is the safest solution for your child, here are some important points to remember. Of utmost importance is to ensure that you have installed and are using your 5-point harness car seat correctly.

1. The seat must be tightly installed in the vehicle

After installation, grab the seat at or near where the car's seatbelt threads through the car seat belt path. Give a firm tug, not a yank, from side to side, and from the back of the car towards the front. The seat should not move more than 1 inch in either direction, and preferably as little as possible, or not at all. An untethered forward-facing seat will normally have a small amount of movement throughout the top of the seat - towards the front of the car and from side to side. This movement can be eliminated with the use of a tether, which comes standard on all forward-facing seats made after September 1, 1999. A tether should be used whenever possible.

2. On a forward-facing installation, the seat must usually be in the upright position

Convertible seats, the kind that face backward and forward, have a reclined position and an upright position. Check the instructions that come with your seat. Most seats must be in the upright position when facing forward. Combination seats generally only have one position - if a recline is offered, it can be used. Whenever possible, the upright position should be used, as it spreads crash forces out more evenly.

3. The safety harness must fit the child snugly

"As snug as a hug" is a good guideline. You don't want your child to have problems breathing, but a too loose harness could have devastating results. Many instruction manuals suggest that only one or two fingers fit under the harness at collarbone level, but this could be too loose, depending on the size of the fingers. Instead, use the pinch test: grabbing the harness at shoulder level, try to "pinch" the harness together from top to bottom. You should not be able to pinch a vertical fold on a snug harness.

4. For forward-facing installations, the safety harness must be AT OR ABOVE the child's shoulders, IN THE REINFORCED SLOTS

In a forward-facing seat, the harness will hold the child back and in the seat in a crash. The harness must be at or above the shoulders to do this properly. If the harness is below the shoulders, the shoulders can be compressed and the head can travel further forward in a crash. Many convertible seats REQUIRE that the top slots be used when forward-facing. This is because only the top slots are reinforced to hold the harness in the seat when forward-facing. NEVER use the middle or bottom slots on a convertible seat when forward-facing unless your manual specifically allows this. All harness slots are reinforced on combination seats and forward-facing-only seats, so use the set that is closest to at or above the child's shoulders. Read the instruction manual for your car seat!

5. In rear-facing installations the safety harness must be in the slots that are AT OR BELOW the child's shoulders

In a rear-facing seat, the harness will hold the child down and in the seat in a crash. The harness must be at or below the shoulders to do this properly. If the harness is above the shoulders, the child can "ramp up" or rotate toward the top of the seat, exposing the head and neck to possible injury. For newborns and very young babies, the bottom harness slot may still be above the shoulders. As long as the harness is in the bottom slots, and the harness is snug, this will protect the baby.

6. Chest clip must be at armpit level

The chest clip is designed to keep the harness straps properly positioned on the shoulders before a crash. This clip is ONLY for pre-crash positioning. A chest clip that is too high may interfere with the child's ability to breathe. A chest clip that is too low could allow the straps to slip off the shoulders before a crash, leaving the child free to slip out of the seat.

7. The back seat is the safest place

This doesn't just apply to rear-facing seats. Everyone would be safer in the backseat - in the middle, if possible. The back seat is safest because it is farther from any point of impact. A front seat passenger is 30% more likely to be injured or killed than a rear-seat passenger. Use the back seat position that offers the best installation. A good fit in an outboard position is safer than a poor fit in the middle.

*NOTE* In mini-vans, the safest position may be in the MIDDLE seat, as the rear has less "cargo space" to absorb a rear impact.

8. Avoid using add-on products

Anything that did not come in the box with the seat could potentially put your child at risk. Adding strap covers could cause the chest clip to be positioned incorrectly. An added head support cushion could compress in a crash, introducing slack in the harness and allowing the child to be ejected from the seat. In general, you want nothing under the child or between the child and the straps that is any thicker than a place mat. Adding NOTHING under, behind or between the child and the straps is the best. Also, keep in mind that any product you add that is not included with the seat can release the manufacturer from being responsible for any injuries your child may suffer in their seat.

9. The child must fit properly in the seat There are several conditions that must be met for a child to fit correctly in the seat

A child is too small for a forward-facing the seat if:
The child weighs less than the seat's lower weight limit.
The harness can not be adjusted to snugly fit.
The child is still small enough to be rear-facing.

A child is too large for the seat if:
The child weighs more than the seat's upper weight limit.
The top of the child's ears are above the top of the seat.
The top of the shoulders are above the top harness slots (except for the Radian car seats).

Some believe that when a child is too tall/heavy for a 40lbs convertible, they should move to a booster seat. This is untrue - continuing to keep your child harnessed for as long as possible is the safest solution.

10. Used seats may be dangerous

Never use seat that is damaged, under recall*, over 5-6 years old, or has an unknown history.

*Some recalls do not affect the safety of the seat, and the seat may safely be used to transport your child until the problem is fixed. You will need to contact the manufacturer to find out whether any recalls on your seat must be fixed before using it for transporting your child.

Source: CPSafety.com

Common Questions and Answers

Q: What advantages does a 5-point harness have over a seatbelt?

A: Child Passenger Safety experts agree that the 5-point harness is the safest, because it provides the snuggest fit and is suitable for the widest range of children.

5-point harnessed car seats offer a much snugger harness fit than an adult seatbelt. In all 5-point harness seats, the straps come down over the shoulders and across the hips to fasten to the buckle that comes up between the legs. The harness sits snugly against the bony parts of the pelvis (the crotch and hip straps) and across the shoulders and rib cage (the shoulder straps). When a child moves forward in the seat, as they would in a crash, the properly tightened harness is already "holding" the child and it immediately restrains them, spreading the crash force out across the strong bones of the body. The child does not move before loading the restraint.

A 5-point harness has several advantages for child of any age or size. The straps are placed on the child's shoulders and low on the hips, so that crash forces are absorbed by the strongest parts of the child's body instead of the soft abdomen (which could result in internal injuries and even death). Source: CPSafety.com

Q: My car seat says that it goes to 100lbs - doesn't that mean they can harness to that weight?

A: NO! There are only three seats on the market currently which harness to 80lbs - the Britax Regent, the Britax Frontier and the Sunshine Kids Radian80. Please carefully read the instructions for the child restraint that you intend to purchase - many combination seats are rated for use with the 5-point harness only to a certain weight, and thereafter you must switch to using the seat belt to restrain your child.


Here are good resources for finding seats beyond the 40lb weight limit, listing the various belt limitations for each model:

YouTube Videos - Children who passed because of use of Booster Seats


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