On a racing circuit or running track, a back straight is a straight portion opposite the finishing line.
no sitting up straight is not good for your back leaning back is the best
He is amazingly only 5" 5 but stands with a straight back. He is amazingly only 5" 5 but stands with a straight back. He is amazingly only 5" 5 but stands with a straight back. He is amazingly only 5" 5 but stands with a straight back. He is amazingly only 5" 5 but stands with a straight back. He is amazingly only 5" 5 but stands with a straight back.
u sit in a chair sraight with your back against the chair and your back becomes straight if you do it every day
If by "straight back" you mean "directly behind the aircraft" then the term is "6 o'clock" or "my/ your six".
A squat.
Because two 90o angles put back to back would create a straight that measures 180o.
your spine....
use
keeping your back straight, bend your knees and grip the load.
It means two consecutive hours, as in back-to-back. For example: I slept for two straight hours from 2-4.
Straight, curved are hard on your back.
standing up with your back straight.