Why does the SI joint start having problems?

Potential causes of SI joint problems include degenerative sacroiliitis or SI joint disruptions. If the motion in your pelvis is asymmetric, then problems can occur in your SI joint. You could have asymmetric motion if your legs are significantly different in length or one leg is weaker than the other. These biomechanical conditions, or even wearing inappropriate footwear, can alter your gait and cause repetitive stress to your sacroiliac joint and related structures.