The waist is the region of the human trunk located between the lower margin of the rib cage and the top of the hip bones. In everyday language it is often identified with the narrowest part of the torso, but anatomically it refers to the area bounded by the ribs above and the pelvis below. For contextual references, see the lower abdomen area, the rib cage structure, and the hips bones.
Anatomy and characteristics
The waist includes layers of skin, subcutaneous fat, muscle groups such as the obliques and transversus abdominis, and connective tissue. Its external shape varies widely with body build, age, sex and genetics. In medical and ergonomic contexts the waistline is located relative to fixed landmarks: the lowest rib and the iliac crest of the pelvis.
Measurement and assessment
Waist circumference and related ratios are practical measurements used in clinical and fitness settings. Common practices measure the girth at the narrowest point or at a standardized level around the abdomen. These measurements help assess body composition and are combined with other indicators to evaluate metabolic risk.
Cultural, clothing and practical roles
- Clothing uses: the waistline is a key reference for garment fitting—dresses, pants, belts and corsetry historically alter or emphasize this area.
- Fashion and identity: silhouettes and silhouettes preferences change across cultures and eras.
- Practical uses: belts, tool harnesses and ergonomic supports depend on an accurate waist position.
History and notable facts
Across history, societies have modified or highlighted the waist with garments and devices—from supportive underclothes to modern shapewear—often reflecting changing ideals of form and function. Clinically, the waist remains an accessible, informative anatomical landmark with both cultural and health-related importance.
