By Jim Donovan

PHILADELPHIA (CBS) – Most parents would never leave home without their infant or child safely buckled into a car seat, but installing those seats isn’t always easy. As 3 On Your Side Consumer Reporter Jim Donovan finds, some parents may have more struggles than others. A new study finds that the issue may be with the hardware designed to secure the child safety seat inside the vehicle.

The Insurance Institute for Highway Safety and the University of Michigan Transportation Research Institute evaluated the anchors and tethers used to attach safety seats in nearly a hundred vehicle models and also observed volunteers trying to install them. Only 21 vehicles met the study’s criteria for being easy to use. Others experienced issues, like what Anne McCartt of the Insurance Institute demonstrated.

“This lower anchor is buried in between these seat belts, so that just finding the anchor is challenging. And then, being able to maneuver the hook to actually get it in there and connect it tightly is very difficult; it requires a lot of force,” McCartt says.

Volunteers were more likely to install seats correctly when the hardware was easier to use. But the study also found less than half of volunteers used the top tether to secure forward-facing seats. Many parents are not aware that it’s essential, but the top tether is an essential part of making the child restraint protect their child best. According to McCartt, “That top tether can ensure that the seat stays in the proper place, minimizing how much that seat moves side to side or back and forth in the event of an accident.”

For more information on the study, click here.