“According to Cornell University Department of Ergonomics, up to 90% more pressure is put on your back when you sit versus when you stand”
There are a number of reasons why this happens. One of these pertains to habitually sitting (at home, at work, or in the car), in ways that generate tension and imbalance in our neck and back. Indeed, sitting for extended periods of time can initiate a spectrum of events in our body’s core and legs, thus resulting in several issues .
Sitting down for a long time puts our hip flexors in a shortened position; and this can stop our glutes from firing, thereby rendering them weak, and causing the hamstrings to overwork. This scenario culminates in APT (anterior pelvic tilt), that is to say, an excessive tilting of the pelvis. Moreover, anterior pelvic tilt make our abs weak and underused, and this makes our pelvis tilt even further. Of note: “APT can cause low back pain, poor movement mechanics (when you walk, do sports, and many activities), and reciprocal inhibition (when one muscle on one side of a joint relaxes because the opposing muscle is engaged)” . To that end, it is important to book an appointment with a Pain Specialist who can use various types of conventional and cutting-edge treatments to ameliorate your pain. In addition to this, he/she will advise you on how you can use your body in a better way,
Other Health Issues
“Too much sitting overall & prolonged periods of sitting also seem to increase the risk of death from cardiovascular disease & cancer” 
As you are probably aware, whenever we sit down, our bodies use up less energy (calories) than we would if were standing up or moving about. Scientific studies have associated sitting for extended periods of time with various health concerns. These include: an increased risk of death from cancer and cardiovascular disease; obesity, abnormal cholesterol levels, excess body fat in the waist area, high blood sugar, and raised blood pressure.
So What Does the Research Say?
“Any extended sitting — such as at a desk, behind a wheel or in front of a screen — can be harmful” 
When thirteen different studies pertaining to ‘sitting time and activity levels,’ were examined by researchers, they concluded that: individuals who did not have any physical activity and sat down for over eight hours per day, had a corresponding risk of dying as those who are obese or smoke. However: this study of information from over 1 million subjects determined that: “60 to 75 minutes of moderately intense physical activity a day countered the effects of too much sitting” .
. Burr, R.J. (2019). “How Sitting Causes Back Pain.” Start Standing.
How Sitting Causes Back Pain – 6 Common Mistakes (startstanding.org)
. Laskowski, E.R. (2020). Mayo Clinic. “What are the risks of sitting too much?”
Sitting risks: How harmful is too much sitting? – Mayo Clinic