Sen Kalathari Starts at the navel and divides into 4 branches. Two travel up to the shoulder and down the middle of the arms to the hand, branching out to the tips of each finger. Two travel down the lower part of the body, through the middle of the legs to the feet, branching out to the tips of each toe.
The reason why the posture of cross-legged and hand gestures(mudra) is important for yogis seems to be related to the circulation and capture of energy radiating from the navel.
Study on body meridians
Navel, Symbolic meaning for Thai massage | Body approach of Buddhism from yogic theory