Angelina don't ignore it, but see that a lot is also related to luck.
These are repeatable experiments! Tight hip adductors will eventually affect the SI joint and cause postural issues. Inactive hip flexors will cause pelvic tilt, and so on. It's just what happens.
You won't feel it now because you're a teenager in peak condition. But pelvic imbalances, back pain, neck pain, knee problems and postural issues are what makes you "old", not age. Look after your body and especially your pelvis and spine, it's the only one you've got!