The first drill relates to Kami shio, and Yoko shio gatame. Lying on your front with your legs wide, you reach forward as far as possible - then pull yourself forwards. It’s very important that for the end posture: your hips are down and your chest is up. You must force your weight through your forearms onto the tatami. As you open your chest forward, you should tighten your elbows to your sides, and drive your hips into the mat.