Pin-up girls aren’t the only ones getting silicone implants.

Ford Motor Co. is working with prominent hospitals to develop more lifelike abdominal inserts for pediatric crash-test dummies.

“The major focus [with crash dummy testing] has always been on head and chest injuries,” the senior technical leader with Ford’s Passive Safety Research and Advanced Engineering Department, Steve Rouhana, said. “But the lack of an abdomen is not just a matter of priority. We really didn’t have the technology before to accurately measure abdominal response.”

The prototypical pediatric abdomen insert is similar in size and shape to the abdomen of a 6-year-old. Like cosmetic implants, it’s constructed of a silicone shell made up of multiple layers of liquid silicone.

Unlike the implants favored by the pinup girls, however, its inside contains a light-emitting diode and optical sensor surrounded by a high-viscosity, red or blue silicone fluid. The sensors measure penetration based on the amount of light absorbed by the silicone fluid.

According to Ford, the tests should help the company come up with better seat belts for children. The University of Virginia, one of Ford’s partners, has developed a custom test apparatus to measure how the prototypical pediatric abdomen responds to the strain of a seat belt in a car crash.