Is my harness tight enough? We like to call this handy harness check the "pinch test!" 1: Buckle your child into his/her car seat, making sure shoulder pads are at armpit level and headrest is no more than one inch above your child's head. 2. Pull harness straps tight agaisnt your child's chest 3: Pinch the webbing of the harness under the shoulder pads with your thumb and index finger. If you're able to pinch extra slack, then pull the harness tighter until no extra slack can be pinched.