Possible Clues:

• Yoga pose on hands and feet
• Yoga pose
• Common yoga pose ... and a hint to hidden names in the answers to starred clues
• Depose?
• Popular yoga pose ... or something found seven times in this puzzle
• Yoga pose demonstrated three times in this puzzle?
• Pose also called Adho Mukha Svanasana
• Popular yoga pose ... or a literal hint to the ends of 3-, 7-, 9- and 21-Down
• Yoga pose with hands and feet on the floor
• Yoga pose, or a hint to 4-, 9- and 21-Down