Now that you have stretched those hip flexors, it would be good to stretch the lower back. Since those tight hip flexors pull on the lower lumbar spine, you may have tightness from the muscles working overtime. Or, by performing the stretches, this could have made those back extensors turn on.
A nice easy stretch can be done in the seat in which you spend the majority of time. Take a
break from work or binging Netflix, and simply spread your knees and lean forward to the floor.
If you feel the stretch halfway down, stop there and hold. If you are able to touch the floor comfortably, go there. Wherever you end, hold for 20-30 seconds.
Follow this with a nice figure 4 stretch sitting right where you are. Cross one ankle over the
other knee, and lean forward if you can. The stretch will be felt in the butt. You may have an additional pull down the leg. Just hold where you feel the tolerable stretch.
This is the muscle that, as it gets tight, pushes on the sciatic nerve and causes pain that can radiate down the leg.
Be sure to do both legs for 20-30 seconds each.
Check back for more stretches next time!