Do high and narrow seat and back bending provide good bike riding posture? I would like to ride a bike as part of daily commute on roads someday, as I  rode a bike to school in another country in the past. But I have been bothered by some uncomfortable points from the bikes that some or most people   ride in US. I value safety (both transportation and health) more than speed, but I guess that my different biking experience may be &quot;old-schooled&quot; and have rendered me ignorant about the biking reality in US.

I have seen some people adjust their seats  high. When I  sit on  their bikes, my feet can't touch the ground.
The reason why I want to land my feet on the ground is that I want to ride a bike in city traffic, where I often need to stop and restart biking. I was wondering how I can stop safely and easily without landing one or ideally both of my feet on the ground while sitting on a high seat?
(In US, most roads don't have bike lanes, and many car and truck drivers are not  used to driving past bikers, and may unleash  road rages towards bikers who block or partially block their ways. Some suggest to ride in the same lanes as cars, so that bikers can be noticed more easily by automobile drivers, but I will probably still ride to the rightmost as if there were bike lanes on the roads, even though that can mean that there are more  chances for irregularly-shaped small stones to damage the tires of  bikes.)

Some bikes have very narrow and small seats. Aren't they together with their high positions putting greater pressure on the crotches than slightly wider and bigger seats?

Also some people bend their backs forward when riding bikes, just like in Olympic bicycle competitions. That together with their high seats puts their butts in  more prominent positions than  their backs   straight-up or only slightly leaning forward. Isn't bending backs forward harmful for their backs?


Thanks.
You don't have to do any of these things to commute. If you value safety over speed I'd recommend a more upright bike (Dutch style) which
helps improve visibility and makes it easier to look around. They also allow you to ride in the clothes you want to wear at your destination. What you call old-school is current every-day practice in a lot of Europe.

You could lower your saddle so your feet can touch the floor but this isn't an ideal riding position usually. What would be more ideal is learning how to stop and set-off properly. You need to hop out of your saddle as you come to a stop and put your non-dominant foot down. Then use your dominant foot to put its pedal near to front and top of the stroke. When you set off you push down with your dominant foot on the pedal and at the same time lift yourself back into the saddle.

The saddle should support your sit-bones (at the bottom of the pelvis) which in men aren't all that far apart, hence the narrow saddles you see. However a hunched over riding position also means less weight is put on the saddle and more on the hands and feet than when using a more upright bike. Wider saddles can be more comfortable when you have more weight on the saddle but can be detrimental on longer rides. Your saddle type may depend on your commute length. Generally cheaper squidgy saddles are made to entice people by looking comfortable but are actually worse than a firmer, narrower saddle which is designed to support your sit bones properly.


You also mention riding in the debris-strewn area of the road. Another advantage of Dutch bikes is that they're designed to be robust, with heavier, wider, reinforced tyres.
I would recommend looking into various techniques for positioning yourself in the road, but I can't offer advice on the US since the streets are designed very differently from Europe. Hopefully there are US-specific resources out there.
Edit: I forgot to mention mirrors. I recently changed bike and my new one came with a mirror mounted on the end of the handlebars. It's helped enormously with being aware of my surroundings and traffic, so I'd thoroughly recommend one. Presumably a helmet-mounted mirror would be the same.