Kukkiwon TaeKwondo does not have this technique (I believe). There is no chamber involved, stiff-legged all the way through ,and no hooking at the end. It is Jong-Soo Parks addition to ITF. We also have a spinning hook kick in ITF ofc Now, is there any good reason to have a stiff legged spinning kick? Shane Fazen on Youtube claims that all it does is slow down the spin... Shane advocates bending in the wind-up always ,and hooking at the end. Worked for Badr Hari (I don't think he knows it's from ITF Taekwondo, but he executed it perfectly.