have you tried holding the knee for a frame to make the foot get faster on the next frame(and extending knee on next)?
if something dont work,try other way
just need speed and time to make a boom,it dont comes instantly.
i've already got 3 days spent on a single boom kick(old replay,but still),generally i take around 2 hours to make a destructive madman replay,and high part of that time is making the booms.
try to put turnframes on 5,if you see that the speed of a part is fast,try to make it ghost on uke body,but isnt because a foot is inside the wrist that the whole arm will dismember(unless you hit in a way to make the whole uke arm "squeeze").
you just need to make the thing get inside more than one part,like,make alot of contacts on the ghosting.
another thing is the way you tried to do it: the boom and dismembers isnt just about speed,momentum,but the aim is very important as well.
if you see on that replay,the only "pivot" you have on ground to make you get you to make speed is the knee,you have it,however,you need to make the foot get very deep on the joints,making more contacts.
i can see you grabbed on uke's hand,i guess you could grab some joint that is closer to where you want you kick to get in(like a hip,or even the torso,its not that far from uke legs).
contracting and just extending the knee sometimes can make it looks weaker,or even make it weaker,contracting,then holding the knee will avoid the full contraction,making the extending easier.
also,you dont need to hit 100% with the toes,if you make an boom kick with a ghosting of the ankle as well(and if you can avoid it breaking),it will make more damage/contacts.
remember that a replay isnt all about dismember.
PS; have you read
This before?
Last edited by victortb; May 5, 2016 at 09:55 PM.