Recaro has issued a recall for more than 39,000 child car seats that can potentially allow a child's head to "move excessively" and result in injury during a crash, Cars.com reported.

The safety seat maker discovered the problem during testing, according to the Associated Press. The recalled ProSport model 385 car seats, which were manufactured from June 6, 2010 to Jan. 31, 2013, are unsafe when the seats are installed just with the lower latch anchors and not the top tether.

Recaro is unable to determine if the recall is connected with injuries, the company said in documents to federal regulators.

"The ProSPORT failed to meet required head excursion limits set forth by the National Highway Traffic Safety Administration when tested with a 52-pound, 6-year old dummy and installed with a latch belt only, no top tether," Recaro described the problem in a recall notice issued to owners. "Not using the top tether could result in an increased risk of head impact in the event of a crash and also contradicts the ProSPORT instruction manual that came with your child restraint."

The company sent instruction manuals to owners that explain how to fix the car seats, which should always employ the top tether restraint for safety. Recaro also advised parents to stop using the latch belt when a child reaches 40 pounds.

The recall involves issuing a new label for the car seat that explains how the seat should be properly secured; Recaro is covering the costs for the labels.

Owners can reach customer service at 1-888-9RECARO.

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