Generally the chest and knee position correction is to correct fetal malposition during pregnancy, especially when breech presentation is corrected with chest and knee position. The best time for correction should be chosen after the 30th week of pregnancy, and if there is still no change in breech position during regular checkups, it should be corrected by chest and knee position. To do this, you should first empty your bowels, loosen the belt of your pants to the optimal, most comfortable position, lie prone on a hard bed or yoga mat with your knees on the ground to elevate your hips, thighs perpendicular to the calves, hands spread out flat on the ground, and your chest pressed against the ground as much as possible, 2-3 times a day for 15 minutes each time, and do this for a week before going for a follow-up ultrasound to see if it has been corrected.