Below is my video that depicts a variation of an exercise used in internal martial arts referred to as wall squats or face the wall squats. Instead of facing a wall, one faces a pole in order to use the pole for balance. Note that the feet are together, side by side, in this exercise. Therefore, it is more difficult to do a full squat without falling backwards. If the feet were shoulder width apart, this exercise would be much easier in that regard. However, please keep the feet together.
A main goal of this exercise is to help open and loosen the yao, including the lumbar spine, the sacrum, the pelvis, and the hips. Keep relaxed during the exercise, and do not let the buttocks protrude. The head and torso should move together down or up as a single unit with the legs folding and unfolding naturally. Do not bend the legs purposefully, and do not push up from the ground. Try to depend on the pole as little as possible until you are able to do the exercise without using your hands on the pole. At that point, you can just do regular face the wall squats.
Here is the video, and do not forget to subscribe to my channel: