It refers to the proper modulation of force in techniques. Power is focused at the exact moment of impact, the rest of the motion should be economical, relaxed, and efficient. True skill comes from knowing when to be strong, when to be soft, and transitioning between them seamlessly.
力の強弱を知る者こそ、技を自在に操る。
Chikara no kyōjaku o shiru mono koso, waza o jizai ni ayatsuru.
“He who understands the balance of strength and softness controls technique freely.”
