There should be serious scientific approach to such serious thing as female gymnastics, flexibility and contortion. So various smart people and handymen develop very nice devices which can enhance female flexibility and make a better gymnast of her. Unfortunately they can’t always find a real professional female gymnast to test their devices, but even with these women you can get an idea how these devices work and how they can be used for contortion training, posture improvement etc - just take look at the pictures: