Here is a great stretch for the hip flexors especially for anyone who sits all day or has anterior pelvic tilt. Here is the order of operations.
1. Two minutes passive stretch just breathing and sinking into true end range
2. Twenty second Contract of PAILs = quads driving into the ground.
3. RAILs = opposite of PAILS actively curling hamstring or glutes driving into hip extension.
4. Sink back into passive but should be in new end range where we breathe for 30-60 seconds.
5. REPEAT 2-3 times in a row and make sure to spend at least 60 seconds of passive breathing after the last round.