In 1944 alone, the United States built more planes than the Japanese did from 1939 to 1945. By the end of the war, more than half of all industrial production in the world would take place in the United States. Wartime production boomed as citizens flocked to meet the demand for labor.
Weight Machines. Machines that work out and build your butt muscles include the leg press machine, smith machine and hip extension. Traditionally, the squat has been the most common exercise for building the muscles in the lower body. The leg press and smith machines assist your body in performing variations of the squat correctly and without injury.
Chi Machines. As with whole body vibration, these machines shake the body from the ankles up. The big difference is that the moving and shaking goes on while you're lying down. How It Works: You lie on the floor (or a treatment table) and place your ankles on top of a small square box that basically vibrates your body from the feet up.