What causes tight quads?

While increased activity on your feet may lead to tight quads, so can inactivity. Sitting for hours reduces the amount of time you spend lengthening and shortening these muscles. With increased sitting, the quads become static and more resistant to lengthening or stretching.

When your quads are tight?

When your quads are tight, they pull down, which in effect, pulls your entire pelvic bone forward, into an anterior tilt. The spine normally wedges in between the two hip bones (in the back), so it is carried along with this forward movement.