Hip Stability

https://www.youtube.com/watch?v=FeWa2G_xExw

Poor motor control of the hip/pelvis or "hip instability" is often the true cause of low back pain, gluteal pain, sciatica-like symptoms, etc.

Lack of proper hip stability occurs when you neglect performing certain movements in one plane of motion and overtrain movements in another.

This video gives you a brief explanation of why this is a problem, along with a simple exercise to correct it.