Sitting for too long causes your low back muscles and hip flexors (the muscles that allow you to lift your knees and bend at your waist) to become short and tight.
Slumping over in a chair all day at a desk also makes your abdominal muscles lose tone and causes your glutes (also known at the buttocks) to become overstretched and weak.
Another phenomenon that happens with prolonged sitting is an anterior (or front) tilt, which is a shortening of the hip flexor muscles. When moving from a prolonged sitting position to an upright one, the shortened hip flexors inevitably pull on the muscle attachments of the lumbar (low back) spine, causing an anterior shift in the hips.
This can put unwanted strain on the low back, exaggerate the lumbar curve and potentially cause a bulging or herniated disc.
If you have to sit for extended periods of time, maintaining good posture is key! Chronic slouching or leaning to one side, even if these positions make pain subside, are bad habits that propagate back pain. The National Institute of Neurological Disorders and Stroke recommends sitting in a chair with good low back support.
If sitting for a long time, you should rest your feet on a low stool. If possible, switch sitting positions and get up and walk around a bit throughout the day.
While you ARE sitting, though, try these 8 simple moves throughout the day to reprogram your body to sit correctly and with good posture. Your back will thank you!