BL40 (Weizhong, “Middle of the Crook”) is the He-Sea (Earth) point of the Bladder Meridian. It is located at the midpoint of the transverse popliteal crease, between the tendons of biceps femoris and semitendinosus. It relaxes sinews, invigorates channels, alleviates pain, clears heat, cools blood.
At the midpoint of the transverse popliteal crease, between the tendons of biceps femoris and semitendinosus.
Perpendicular insertion 1.0-2.0 cun, or prick to bleed. Caution for popliteal artery and vein.
Relaxes sinews, invigorates channels, alleviates pain, clears heat, cools blood.
Low back pain, sciatica, muscular atrophy, pain, numbness and motor impairment of the lower extremities, abdominal pain, vomiting, diarrhea, erysipelas, urticaria.
Weizhong is a highly significant point, being the He-Sea (Earth) point of the Bladder meridian and the Command point of the back. It is renowned for treating all types of back pain, especially acute lumbar sprain, and is a primary point for sciatica and knee pain. Its ability to clear heat and cool blood makes it effective for skin conditions like erysipelas or carbuncles on the back, often used with bloodletting. It is classically paired with GV26 for acute low back pain.
BL40 is one of 67 points on the Bladder Meridian. Nearby points:
BL40 (Weizhong) is located at the midpoint of the transverse popliteal crease, between the tendons of biceps femoris and semitendinosus.
BL40 relaxes sinews, invigorates channels, alleviates pain, clears heat, cools blood. Common clinical indications include low back pain, sciatica, muscular atrophy, pain, numbness and motor impairment of the lower extremities, abdominal pain, vomiting, diarrhea, erysipelas, urticaria.
Perpendicular insertion 1.0-2.0 cun, or prick to bleed. Caution for popliteal artery and vein. Caution: ⚠ Major vessel/nerve nearby — palpate first; avoid deep insertion (near the popliteal artery).
BL40 is a point on the Bladder Meridian (Zú Tài Yáng Páng Guāng Jīng).