Kentaiichiyo “The fist and the body are one” is an important concept when delivering a strike with your body.
You don’t want to rely on strength or speed to deliver a strike since your training partner might be bigger/fast then you.
You can not control that variable so it is not a good concept to rely upon!
By delivering your strike with your entire body behind and in alignment with it, the issues of size and speed on both sides is negated Match the weapon “ken” to the movement and apply it to the kyusho.
It is important to not aim to strike the target, but actually aim to strike though and beyond it. You want to hit and keep moving. Don’t think of striking as a way of hurting or causing pain.
What is pain?
Relevant to the situation and person, some people don’t feel any pain. Think of striking as a way to unbalance your training partner, if it causes pain that is a bonus of sorts. Even the softest of strikes can “hurt”.
While we are on the topic of striking let’s take a look at right/left side. If you are right handed you are probably better at doing things with your right hand over your left. When striking your right hand might be quicker and stronger then the left, and this can be a disadvantage.
With punching there can be no strong/weak hand, you have to be good with both since you never know which side you will need in the moment, or if one hand gets hurt, etc.
This isn’t as much problem with kicking since we tend to use both feet equally throughout the day.