To check and become more aware of tension in the hips and back sit with your knees at about a straight angle and push one of the feet into the ground (not in mud). Note if the other leg lifts up in the air and if so than your hips are tensed up or you are tensing the hips due to tensed and or raised shoulders and spine, so lift them and let them drop into place using your breath and play with the leg pushing in various angles (for example with your back on the ground and your legs resting on the wall (clean your legs or wear sock and remember Zero Residual Signature is a good thing most of the time))
It is important to pay attention to the knee elevation above or below the hips.