Did you already hear something about stabilization training? With this sort of training it’s possible to train the smaller and deeper muscles, which stabilize the joints. If you don’t use those stabilizers enough they loose their strength. Like all other muscles. Of course it’s very important to avoid that, to prevent posture damages or joint problems. And how to do that? By training them!
For the lower back and the hip muscles you can try this exercise: On all fours with shoulder wide arms and knees lift one leg by holding the knee bended till the thigh builds a line with the back. Than lift it a bit higher and back down. Repeat this a few times and than go on with the other leg.
Have fun stabilizing!