Been told this before actually when I’ve swam that I look like I had poor mobility in hip regionsAlso hip flexor immobility is a massive issue for lower backs. Find some videos for psoas stretches. I had to have an operation on my iliopsoas as I had a nightmare tendinitis problem with mine from running. And my lower back took a large brunt of the pain too. Hope this helps.
I’m 27 and yeah had a new car recently