The upright position, at 90 degrees, causes disks to move the most, while the relaxed position (135 degrees) causes disks to move the least.
no sitting up straight is not good for your back leaning back is the best
Probably because your back is in the sitting position, and it gets stiff, then when you stand up, your back is transitioning into another position.
Well you should have sit up straight when you were younger so you are used to sitting up straight. But if that's not it then you could tape a ruler to your back. What I do is make my car seat vertical so my back stays straight the whole ride and I get more and more used to sitting straight.
Sitting up straight and not slouching helps. Also when you stand put your shoulders back,chin up and your back straight. Exercise helps too.
your spine\ back. when you bend over you can feel the different parts of your spine but when you sit up straight you can't feel the bumps in your spine. Your spine is straight then. Which means youre back is straight. Which means you are sitting up straight. I might not have got this right bnut i hope it helped.
Sitting up straight
yes
Restaurant booths are not as good for your back as a regular sitting chair. Restaurant booths usually has a gap between a person's back and back of the booth causing you to hold up your own posture.
both feet on the ground forward in the chair with back straight
One example of good posture is to stand with your shoulders back, knees straight and chest out. Another good posture example while sitting is to sit with your back straight and your shoulder back. Keep your feet flat on the floor and avoid sitting in the same position after 30 minutes.
tell them straight up that they are bad friends
It is important when doing exercises such as deadlift or squat to always keep what is called a "neutral" back. This is when you arch your back. If you do this, you do not have to worry so much about bending your knees. Yes, the "experts" tell us to keep the torso straight up and bend the knees when lifting but the true secret is to keep a neutral back to avoid back injuries--it doesn't matter if you stay straight up or not as long as your back is arched back.