So first of all, the video:
Now the explanation:
The video starts with three kanji (symbols used to express ideas in japanese language): 肝心要. As a whole word it means important, crucial. As separated words, the first one is used to refer to the liver 肝臓, the second one to the heart 心臓, and the third one to the pelvis 腰. So, for the body, these three parts are very crucial, according to the video.
Ant then it focuses on the pelvis kanji: 腰, comparing it to a fan. The pivot of the fan holds all the pieces together, that is his importance. "Thanks to the pivot, the fan can show it's beauty".
It then makes an analogy to the human pelvis, as it works as a pivot for the whole body.
Here's is an image of a pregnant woman and the fan interposed at the pelvis height. The video explains that more than 90 percent of the people has some kind of pelvic displacement. If a woman has some kind of displacement when is pregnant, the possibility that the baby will also have a pelvic displacement will be very high.
Then it shows a couple of images, the first one is a normal person, with the axis of the body making an angle of 90 degrees with the pelvis line (no displacement). But if there's a displacement in the pelvis then the one leg will look shorter than the other, one of the shoulders will be higher, and the column will be curved.
After showing how to measure a pelvic tilt, it then shows a couple of images of the same person with left pelvic displacement. The first one, because of the pelvic misalignment, is supporting more body-weight on the right leg (the 'longer one') than on the left. If this pelvic displacement remains untreated, then the body weight will shift to the other leg, hence curving even more the spine.
Here's a chart on how the pelvic displacement affects the whole body. The upper part of the chart refers to the upper part of the body, and the same with the lower part.
For the upper part the pelvic displacement affects the the spine, shoulders, elbows, wrists and finally the fingers.
For the lower part it affects the hipbones, the knees, the ankles and finally the toes.



