腰椎

1. Origins, structure, and basic meaning

• Structure: 腰椎 (ようつい) combines lower back 腰 and vertebra 椎 to denote the lumbar vertebrae.
• Basic usage: It identifies the lower-spine bones shown on a model or strained by poor lifting posture.

2. Common pitfalls and similar expressions

• An anatomical structure, not the whole waist
  • 腰椎 specifically names the vertebral bones in the lumbar region rather than every muscle or surface area of the waist.