The discs of the spine are the cushioning between each of the vertebrae. To some extent they are like the shock absorbers in a car and protect the body when we cross rough terrain. The disc is mainly water and, as we age, the disc loses bulk. With reduced padding, nerves are exposed resulting in pain. In our early teen years, and maybe into our 20’s and early 30’s, we can abuse our bodies with all sorts of physical activity, contact sports, jumping out of planes, performing with the Cirque de Soleil and other activities more befitting a Navy Seal. As we age we can get away with less of what I call “impact” sports. To be recommended are activities that do not compress the body but lengthen it out, while at the same time strengthening the core muscles. Yoga and Pilates are good. Tai chi is good. Swimming is also good because the position of the body is protected by a jacket of water. Jogging and racket sports such as tennis and squash are not so good. With the action of jogging there is impact initially on the knees and eventually on the back. With the racket sport there is the added problem of constantly changing direction and the resulting torque.
In my reading I came across an interesting table of the vertebral disc load (pressure) during various activities. (Dr. Nikita Visniak) He demonstrates the importance of correct lifting technique on intervertebral disc pressure. Increased pressure means that there is an increased chance of injury and disc herniation or rupture. The pressure on the disc is at 100 when someone is standing correctly upright. While sitting upright with good posture, it is at 140. With 20 degrees forward bending while standing, it is at 150. Sitting with poor posture gives an intervertebral pressure of 185. Lifting a 20 kilo weight with good form (knees bent and back straight) gives a pressure of 300. However, lifting the same weight with bad form (back bent and knees straight) gives a pressure of 485.
Even beyond our ability to be top performing athletes, we can pay careful attention to our back and live without constant pain.