Maximizing impact in karate technique

Karate technique is based on the concept of Todome-finishing blow technique, executed in perfect timing, this is fighting by skill rather than exchange of techniques and brawling, which is to rely on strength and size.
Therefore, we need to study each technique, deeply rather than learn many techniques superficially. We need to understand many details and through understanding the complexity achieve simplicity. The technique has to become reflexive, we say that "there is no mind in the technique".

Force equal mass times acceleration, and shocking power, impulse, equal force divide by time, or maximum force delivered in shortest amount of time.

We also need to consider other factors beside achieving maximum impact power, such as we have to initiate a technique quickest and without back motion for it to be applicable, and the end of a technique has to be best condition for next, to eliminate space or readjustment between actions, we also have to remember that in most cases only small space is available, so we have to remove unnecessery action and our goal is to produce more force in less movement.

The following principles have to be applied to any kime technique, using any body action, from any stance:

Quickest start without back motion

This is achieved by two means:
Sharp turning from the spine, or spinal muscles, using ground reaction, therefore breath from the lower abdominal trigger the technique by controlling the spinal muscles while applying pressure and twisting to the feet. (turning from the big diameter of the hips is too slow).
Using inside muscle reaction, "reverse" exhale to draw the stomach toward the back, to apply pressure to the back and the floor as a base by changing the exhalation direction sharply, we release the loaded muscles and technique.
The breath is the trigger.

Muchimi, body like whip, total nody snap
This is most important acceleration, speed increases sharply as the body snaps like a whip from the center out, with the Sacrum as the base or the handle of the whip, and the expression at the contact area, via the twist of the forearm at the elbow joint or at the wrist.

Kime, at contact maximum pressure to floor and total bady contraction to technique line of energy
At contact using the breath and proper body alignment we apply maximum pressure to floor as a mean to deliver the total accumulated energy through the target, the pressure to the floor is also acceleration of the vody weight up to 2 to 3 times, which is very important force production especially in short space where momentum is limited. (we cannot change the body weight but can accelerate it using ground reaction0.
As we make pressure we make sharp contraction of the whole body, the body should be like steel for an instant, the purpose is to deliver the total energy in shortest time to make maximum shocking power.
To achieve total contraction we think of the torso muscles contracting like a tube to the spine and from the spine chain reaction to technique line, it is important that the contraction has the proper direction, since power with no direction is useless.

Zanshin
After technique keep mind, or mental and physical prearedness, when we make a technique we give everything without holding back, physically the more pressure to floor and the sharper contraction the more potential, so next technique starts as reaction, effortlessly, also mentally when we give everything the mind is free, it has no ressistance or contradiction, and can smoothly flow with the situation without gap, or space of decision and confirmation.