When a person sits for long periods of time certain muscles tighten and others weaken. Sitting for a few hours per day will tighten your hip flexor muscles and hamstrings. Your glutes become weakened.
The hip flexor muscles attach in the hips and travel through the torso where they anchor to your lower back. If these muscles become tight, they will pull your lower back in and rotate your hips. If your back hurts, turn sideways and look in a mirror. If your belt is higher in the back, you have an anterior pelvic tilt, sometimes called "sway back.” This causes back pain.
Lets look at two simple stretches that can help.
When you try to stretch the hamstrings, people often reach for their toes and round their backs. This will only stretch the lower back.
THE VAST MAJORITY OF BACK PAIN IS NOT DUE TO THE BACK, THE SITE OF PAIN AND SOURCE OF PAIN ARE NEVER THE SAME.For this reason, we must focus on the hamstrings.
The hip flexors (psoas and rectus femoris) are the other muscles that cause lower back pain.
Regularly practicing these stretches will help correct your anterior pelvic tilt and battle the harmful effects of sitting.