In rear-facing seats, the attendant should be sitting with their back and head firmly against the back of the jumpseat, their knees and feet together and slightly in front of or behind the knee (depending on the individual airlines procedures)—commonly referred to as "toes to tail". In European carriers, the hands can be placed behind the head and hands one on top of the other and the elbows brought in to meet, taking care that the forearm does not cover the ear and restrict hearing. This position provides the flight attendant protection to the face from any flying debris (as it will impact their elbows) yet still provides them with the ability to view the cabin and not muffle their commands. In the United States, the Federal Aviation Administration (FAA) does not recommend placing the hands behind the neck as their research suggests such actions can cause unnecessary loading on the neck and spine during an impact. Instead, US flight attendants are typically taught to sit on their hands, palms facing the ceiling, underneath their upper legs. Other variations include clasping the hands on the knees or using one arm to "hug" the opposing arm.