What will happen if feet push away from something on the floor in fsh during convulsions?

[Lextyle]

Will that reduce the pressure on the neck so much that person regains consciousness or the noose changes it's position and attempt fails? I read that carotids need only 5kg pressure to be blocked, do you think pressure will reduce that much? I plan to hang on pull up bar but there will be beam near me and sandbags high enough that my feet could touch them and push away from them