Location & How to Find

Anatomical Location: At the midpoint of the popliteal crease, between the tendons of biceps femoris and semitendinosus.

How to Locate:

  1. Bend your knee and locate the horizontal crease at the back of your knee
  2. Find the exact center point of this crease, between the two main tendons
  3. Gently press into the soft depression - this is BL-40
Location illustration for At the midpoint of the popliteal crease, between the tendons of biceps femoris and semitendinosus.

Primary Functions

Musculoskeletal System

  • Relieves lower back and knee pain
  • Treats sciatica and leg disorders
  • Strengthens lumbar spine
  • Reduces leg stiffness

Circulatory System

  • Improves blood circulation in legs
  • Treats varicose veins
  • Reduces leg swelling

Urinary & Kidney System

  • Supports kidney function
  • Treats urinary disorders

Select a point to learn about its location, primary functions, clinical applications, and protocols.

BL-40 Protocols

Acute Lower Back Pain Relief (3 minutes)

  1. Sit with legs extended or lie down comfortably
  2. Locate BL-40 (center of the popliteal crease, behind the knee)
  3. Press firmly with thumbs for 30 seconds on each leg
  4. Massage in circular motions for 1 minute to release tension
  5. Repeat pressure while breathing deeply to ease discomfort

Important Precautions

  • Avoid needling large blood vessels
  • Caution in bleeding disorders