When it comes to any sort of defense against a long-range attack – against a weapon or against a long-range kick, strike or takedown – timing, distance and your recognition and reaction time will dictate what you can and can’t do.
If you are late in reading and reacting to the attack, and the attacker has passed the apex or high point of his attack and now the energy is committed and coming forward and down, you CANNOT intercept or jam this sort of attack. Going straight at the attacker and attempting to stop or jam the energy will end badly. When faced with this situation, it is best to blend and deflect the energy, rather than clash with it.
In this video, 7th Degree Black Belt Master Frank Ley shares how to use the principle of deflecting or redirection against an overhead attack: