足腰

1. Origins, structure, and basic meaning

• Structure: 足腰 (あしこし) is a compound noun for the combined strength and condition of the legs and lower back.
• Basic usage: 足腰を鍛える makes the lower body the object strengthened through daily walks, while 足腰に疲れを感じる marks where fatigue is felt after a long slope.

2. Common pitfalls and similar expressions

• Training target and fatigue site
  • 足腰を鍛える concerns functional improvement, whereas 足腰に疲れ concerns accumulated strain. The compound does not isolate only the ankle or only the waist.