Questions and Answers on the Contemplative Practice of the Four Establishments of Mindfulness 5

Question: During the latter half of breath observation, I feel my spine being pulled tight, and sometimes there is a flow of qi at the Baihui acupoint (crown of the head). What is going on? 

Answer: This happens because after the mind has settled down, there is no longer any obstruction to the circulation of the breath, and the breath flows smoothly. The qi channels run from the dantian to the Weilü acupoint, and then from the Weilü acupoint surge upward along the Du meridian in the back, straightening the back. The qi channels may even surge up to the head, striking the Baihui acupoint, and finally exit the body from the Baihui acupoint. This shows that the Ren and Du meridians of the body are unobstructed, the body is relatively healthy, the mind can settle down, and meditative concentration (samādhi) is fairly good—all of which is conducive to contemplative practice (vipaśyanā-caryā) of the four foundations of mindfulness.