expression, ichidan verb
take a solid stance; settle into a stable posture
Literally to put one's hips into a position; used in physical contexts like martial arts or heavy lifting where a stable lower-body stance is needed.
柔道では、まず腰を入れて構えることが大切だ。
In judo, it's important to first settle into a solid stance.
expression, ichidan verb
Figurative extension: to commit oneself fully to a task, similar to 本腰を入れる. Often used when someone finally starts working earnestly.
See also: 本腰を入れる
彼はようやく腰を入れて勉強を始めた。
He finally put his back into his studies and started.
腰を入れて仕事に取り組めば、結果はついてくる。
If you put your back into your work, results will follow.