NEW HYDE PARK - A new study released today shows that nearly half of all booster seats tested pose safety risks to children.According to the report by the Institute for Highway Safety, six models that are currently on the market are not up to par and may not fit children properly. Nassau County traffic safety educator Christopher Mistron says if a booster seat doesn't fit right, it may result in a spinal or pelvic injury.Mistron says some of the seats listed as "not recommended" by the study were combination seats that convert from a car seat to a booster. Nearly half of the models tested fell into the "check fit" category, meaning that they might not fit properly with seat belts in all cars. However, a record number of seats tested, 31 out of 83, got the top rating for how they fit.Insurance Institute for Highway Safety