This video shows a bunkai drill for the final sequence of Seipai kata. It was filmed at an event in the Netherlands in September 2015.
In this bunkai drill, Seipai kata is firstly teaching us how to move the enemy’s limbs in order to initiate predictable motion and land strikes. Seipai then concludes with a rather brutal neck crank. Do not practise this technique unless you are under the supervision of a suitably qualified and experienced person.