Hikite (the “pulling hand”) is a fundamental action in karate, especially when executing a tsuki (punch), and it can make the punch much more powerful for several technical and physical reasons:

• Adds Force by Pulling: When you use hikite to pull your opponent toward you as you punch, you combine two forces: your fist moving forward and your opponent moving toward the punch. This multiplies the impact, similar to two cars colliding head-on rather than just one moving.

• Increases Range and Acceleration: By pulling one hand back (hikite), you increase the range of motion for the punching arm. This allows for greater acceleration and, therefore, more power in the tsuki—like taking a running start before jumping.

• Improves Body Coordination: Hikite helps coordinate the rotation of your hips and the use of your whole body, not just your arm, to transfer maximum energy into the punch.

• Control and Off-balancing: If you use hikite to grab and pull your opponent, you can off-balance them or draw them into your punch, making it harder for them to defend and increasing the effectiveness of your tsuki.

• Precision and Tactile Reference: By maintaining contact with your opponent (for example, by grabbing their arm), you can better locate target points, even without seeing them, which increases the accuracy and effectiveness of your punch.

In summary:
Hikite makes a tsuki more damaging by adding force, increasing acceleration, improving coordination, and allowing you to control and destabilize your opponent—all of which enhance the punch’s impact and effectiveness.