Yoga and Core Stretch

a ridiculous type of exercise which includes ladies in black spandex sticking their butts up in the air, leaning on their sides with only one foot and one hand on the ground, and generally trying not to fart. you have to have good balance and be "connected to your core at all times." also, you listen to a lady talking abou "continuous movement" and saying "belly buttons and middle fingers," repededly. which leads me to wonder exactly what im supposed to be doing with my belly button and middle finger.