Hi Cecilie, I'm so sorry I must've missed your question earlier. Let me elaborate: The particular position was working on an eccentric (contraction during lengthening) of the deep hip flexors (psoas) along with the spinal extensors to balance- since the arms are holding overhead. When we activate those deep core support muscles in balance, we can often create enough stability in the pelvis that we can explore our own unique range of circumduction in the hip without the misalignment that leads to the "popping". It certainly is hard to explain in writing, I guess, but I'd love to hear if you've been practicing that exercise and if you've seen improvement or deeper understanding of your hips? Maybe that can be my next anatomy tutorial!!