But when we see an anteriorly tilted pelvis (like the picture below) it changes the game. The short hip flexors pull the front of the pelvis down. This by default causes the back of the pelvis where the hamstrings attach to be pulled up. It gives the hamstrings the sensation of being tight without even moving!
So that sensation of tightness, may not be true tightness at all! Stretching the hamstrings further won’t make a difference. You have to slack from the other side (loosen the hip flexors, or tilt the pelvis back), to settle the hamstrings back to normal length.
This is a game changer for rehab! If you can’t normalize that pelvis or get hip extension…the hamstrings will always take on more load when running, kicking, etc.