Proper posture is imperative to optimal health and well being. We are told when we are children to stand up straight and to stop slouching. When it comes to posture, your mother did know best. Good posture keeps your body in proper alignment which reduces unnecessary stress on the muscles and ligaments.
When viewed from the side, your ear, shoulder, hip, knee, and foot should all be in line with each other, forming the plumb line of the body. The spine should have three normal curves: cervical (forward curve), thoracic (backward curve), and lumbar (forward curve). With proper alignment and spinal curvature, the forces absorbed by the spine can travel evenly throughout the vertebrae and disc.
When viewed from the front, the head should be straight and not tilted or rotated. The shoulders should be level with one another and in a down and back position. The feet should be hip width apart with toes slightly pointed outward. Weight should be evenly distributed with knees slightly bent. Tightening the abdominals will provide some stability.
Like standing, all three of the normal curves in the spine should be present. The curvatures in the spine determines the effect of the load that is transmitted throughout the rest of the body. Feet should be wide apart and flat on the floor. Knees should be level with hip. Shoulders should be relaxed and in line with ears. Sitting actively is the best way to protect the back. A good recommendation is sitting on a physioball. Often times, a backrest forces us to relax and over time slouch. As a result, we end up relying on our passive structures such as ligaments and joint capsules instead of our muscles.
Although good posture should be natural it may be uncomfortable at first. This is because our bodies have adapted to our poor posture for so long. The key is to be aware of what proper posture is and to practice it. Good posture puts the load as close to the center of the body as possible, making sitting and standing efficient. Incorporating stretching and strengthening exercises along with body awareness are important steps towards physical well-being.
Berg, Kristian (2011). Prescriptive Stretching: Eliminate pain and prevent injury.