One of the largest ligaments in the body is something called the iliotibial band. It connects at the top of one of the sides of your waist and continues down into the side of the shin bone. Consider it the "ziplock plastic baggy that houses or surrounds the muscles that extend from you hip to your knee.
Your core is very strong...it needs to be! It supports 2/3 of your body weight. If there is unequal tension in the muscles or ligaments (myofascia is the fancy term), then every step you take could be an imbalanced step.
We all know how to stretch out our muscles, but smoothing out the wrinkles in the IT band is a different animal altogether. It takes specificity and consistency. So get your foam roll and get your IT band stretch on!