1. Sit and twist: Sit on the yoga mat, put your hands on your knees, slowly turn your upper body and feel the stretching of your waist and back.
2. Butterfly stroke: Sit on the ground, straighten your legs, put your hands around your knees, bend forward slowly, and feel the stretching of your waist and back.
3. Boat style: Sit on the ground, bend your legs, put your hands on your sides, slowly lift your hips and feel the stretching of your abdomen and back.
4. Supine leg stretching: Lie on your back on the ground, straighten your legs, and feel the stretching of the back thigh and calf muscles.