Which BL point is at the back of the knee, in the popliteal crease toward its lateral end, in the depression medial to the tendon of the biceps femoris?

• A. BL 37
• B. BL 38
• C. BL 40
• D. BL 39

Answer: (D)

The question tests precise surface-location of the bladder channel points around the knee, specifically the Lower He-Sea point. In the back of the knee, inside the popliteal fossa, the point sits in the depression just medial to the tendon of the biceps femoris, near the lateral end of the popliteal crease. This combination of landmarks identifies the bladder channel’s lower He-Sea point. It’s distinct from the point at the center of the popliteal crease (a different bladder point) and from other bladder points located higher on the thigh or along the leg. This point is commonly used for issues related to the lower jiao and dampness along the bladder channel.