Sitting on your rump..
I noticed many of my clients complain of several dysfunctions and honestly most pain is more due to sitting on your rump.
Driving, desk jobs or even the couch potatoes all this sitting is not at all good for many of your muscles. The tightness in your hips, lower back , outer and inner thighs are all being mashed, nerves are being pinched. http://www.massagetoday.com says sitting for more than 3 hrs a day can cause serious chronic pain.
I myself notice if I sit gazing off into Face book land playing silly games, or even just reading, everything from my lower back, hips and legs, all the way up to my shoulders are very irritated and become numb.