敲中背

• 高(tall; high)ASSOCIATIVE
• 攴(hand holding stick; striking hand)RADICAL

A hand holding a stick tapping on something high creates a ringing sound—that is the action of tapping, tapping lightly.

• 口(mouth; rectangular frame)ASSOCIATIVE
• 丨(vertical line through the middle; axis)ASSOCIATIVE

An arrow hitting the center of a target frame is the bull's-eye—that's CENTER.

• 北(north)PHONETIC
• ⺼(flesh; body)RADICAL

The back is the meat on the rear side, like facing north with your back turned away from the sun.