A good posture is simply balanced and upright. Anything aside from this is bad and will ultimately affect your health in the long run.
Good Posture vs Bad Posture: Standing Position
When standing, a good posture will have the head in the midline in line with, and on top of the shoulders. On the other hand, having your head held forward of the shoulders or being tilted to one side is bad posture.
Good posture will have the chin tucked in without poking or jutting forward. The shoulders are relaxed and the bottom tucked in. Hunch shoulders, sticking out bottoms, are characteristic of bad postures in the standing position.
The individual has to be able to stand with their feet slightly apart and in line with the shoulders. Total body weight also has to be equally divided because a failure, in this case, will cause the spine to tilt or curve sideways.
Good Posture vs Bad Posture: Sitting Position
To maintain a good sitting posture, you have to sit with the chin tucked in and the shoulders relaxed. The hips, knees, and ankles are also to be at right angles with the thighs in level with the knees.
You don’t want to poke the chin forward or sit with hunch shoulders. That is bad!
A good sitting posture will also have the head in the midline, the same way it would usually be in the standing position. However, maintaining a good posture is not limited to sitting and standing alone.
It extends farther into the way you walk, the way you lie down, etc. In all of these, it is important that you understand how necessary it is to keep the spine straight and in line.