If you are bothered by an uncomfortable riding position when you are cycling and can't turn around because your neck or back hurts, then you need to change something to achieve greater cycling safety. Only those who are focused on the road and don't have to worry about problems with their bike can cycle safely.
The SAFETY LEVEL is a safety classification for steering systems and seat posts on bicycles. ergotec products feature a SAFETY LEVEL from 1 to 6. The higher the level, the greater the safety. Here you can determine which SAFETY LEVEL you personally need.
The older you get, the harder it is to look over your shoulder. This is completely normal. Mirrors help you to keep an eye on the traffic area behind you. You can always see if a car or truck is approaching and then react accordingly.