Please don't take my comment as argumentative, because I am not trying to be. I am just pointing things out from a perspective other than your own.
first of all, you havae no experience what so ever. 40 hours of observation? That doesn't give you any room to make an educated comment about this subject. Observing gives you no clue in this matter. You actually have to do the dental work to experience it.
There is a reason why people complain about back problems in dentistry. It involves physics - leverage and forces. Think of each vertebra as a fulcrum and the upper body as the weight that gravity is working on. If a dentist utilizes loupes and stays in proper posture, then gravity only works in line with the spine. But when improper posture (bent over) is used, there are great forces applied for many hours each day in a manner tht the spine was not designed for. Over time, the spine will begin to breakdown from its natural position - bone remodeling and disk bulging and herniation. This can / will lead to pinched spinal nerves and in worst cases affect the spinal cord. Although this posture did not involve lifting additional weight other than the dentist's body, the posture over time causes the problems to occur. You may feel people are whining because they didn't do manual labor, but they have legitimate reasons to be complaining. The results of bad posture are very painful and debilitating. These results are the exact same results that can result from a person who does manual labor for a living. The manual labor workers who have bad backs usually are injured because of usng incorrect lifting or they are hunched over on their hands and knees as what a person who does landscaping does. This hunched over position has the same forces applied as what a dentist experiences.
You are in high school now. You are invincible. Your body can handle things that your body CANNOT handle as you grow up. I am right at 35 years old. Although I put on a few pounds this year, I have led a very actve life. I have participated in many sports (baseball, football, snow skiing, bicycling, marathons, triathlons) and worked in back breaking jobs in a lumber yard and as a certified nurses aide in a nursing home. During those times, I had no problems putting my body in positions that are not considered safe. I would work out at the gym and power lift to train for snow ski season (racing). I would do dead lifts regularly without a problem. Now, I have out I am not so invincible. The forces that ad posture puts on a back causes me to experience pain some days. I don't sit around complaining. I use proper technique most of the time because it helps out a lot. When you get older (twice your age like me), you will realize that you are not as tough and invicible as you thought. If you use (as a dentist) improper technique just as a person who works a manual labor job who uses improper technique does and has back problems, then you too will have a bad back one day.
