Vertically or obliquely 1–1.5 cun
Chengshan BL-57's functions are quit similar to Weizhong BL-40, in terms of removing obstructions from the Channel and relaxing sinews. It is mostly used as a distal point to treat lower back pain and sciatica. It is also useful for these patients who have difficulties to sit and stand for a long time.
Furthermore, it treats haemorrhoids as well.