There is a so-called training method called the Alpha Rollover, which a few out-of-date trainers still swear by. It is suggested that when a dog becomes too aggressive or tries to assume the leadership role in your relationship, you should get down on the ground and use your hands or your body to pin your dog on his back so he can't move under your weight. Then, from that terrifying position, the trainer is meant to stare the dog down into submission.
Does it work? Ask my friend Michelle, a Canadian woman whose Jack Russell terrier stiffened up whenever she got close to his food bowl. Instead of systematically coaching her dog to accept her presence, she followed a trainer's advice to do the Alpha Rollover and pin her dog to the ground when he growled at her. She called me when she got back from the emergency room after her terrified dog had bitten her.
People tell me that the alpha rollover is natural, and that an alpha wolf or dog performs this technique to create submission in other pack members. That is absolutely not true! You may see a snapshot of a submissive wolf lying on his back in front of a higher ranking wolf. But if you'd seen the sequence of events that took place beforehand, you'd realize that nobody put the wolf in that submissive posture. He got there on his own, whether he was playing, or looking for acceptance from his leader.