背面跳びが有利なのか？
腋を撮るのに有利なのか？W
https://i.imgur.com/3S5S2Um.jpg
https://i.imgur.com/91KV6gd.jpg
https://i.imgur.com/UIR5frp.jpg
https://i.imgur.com/IWOPukK.jpg
https://i.imgur.com/8u1SECG.jpg
https://i.imgur.com/sQxK2ex.jpg