A happy aspect of modern CR design is the near uniformity of the system that shortens and lengthens the harness webbing: a front-and-center adjuster strap with a nearby locking/unlocking mechanism.
This familiar system relies on the functionality of a simple lock, which is commonly called a central front adjuster, or CFA. When a CFA is undisturbed, a spring holds its toothed metal clamp onto the CR’s adjuster strap webbing, preventing the harness from moving in the direction that would allow it to lengthen, so it is locked; to unlock and lengthen the harness, simply use a finger to rotate or toggle the CFA so it no longer clamps onto the webbing.
Other systems, like push-button adjusters on the harness webbing or sawtooth adjusters at the back of the CR, have fallen by the wayside—and are not missed! A CFA is not only easier to use than most other alternatives for harness adjustment but having one design for nearly all CRs also allows CPSTs to teach the important skill of harness adjustment more effectively to caregivers.
However, a CFA must be relatively clean to work properly. If enough debris works its way into the mechanism, like food crumbs or bits of nature that a toddler may track into a vehicle, the CFA’s teeth may not clamp down properly to grip the harness adjuster strap. This is very dangerous; while the harness may seem snug on the child, it’s not actually locked.
Manufacturers can design CRs in ways that reduce the risk of this problem occurring. For instance, they may locate the CFA in a place on the CR where debris would not naturally land. Another approach is to cover the opening for the CFA, perhaps with CR padding, usually leaving a slit or flap for inserting a finger.
But, even when a CR has a design deterrent meant to keep bits of gunk from collecting on the CFA, debris can still sometimes work its way into the mechanism. This is more likely to happen when a child wears dirty shoes or eats while seated in their CR.
CPSTs should educate caregivers on how to avoid these problems. First, always be sure they understand how this important mechanism works. Show them how to check that the harness locks, especially on CRs that have been used by a toddler. If there is debris in the CFA, explain that they need to follow manufacturer instructions for cleaning. A helpful Graco video demonstrates a safe technique for this process.