정상자세를 알아야 poor posture를 논할 수 있다.
Without support from research, Wells (1963, p. 4) suggests the following criteria for optimal standing posture:
1. The total body weight is centered squarely above both feet or else is very slightly forward, but never backward.
2. The major weight-bearing segments of the body are aligned in a single straight line, either vertical or slanting very slightly forward from the ankles.
3. The pelvis is centered squarely above the feet and beneath the trunk, providing firm support for the latter.
4. The chest is slightly lifted but the elevation is not forced.
5. The head is erect with the profile vertical and the chin level.
6. The feet point forward or slightly outward.
7. The ankles, as seen from the front or back, are straight.
8. The total posture is maintained without evidence of strain or tension.
