Middle of the Crook
委中 Wěi Zhōng · BL-40
About BL-40 Middle of the Crook
BL-40 Weizhong is one of the Four Command Points of acupuncture, specifically commanding the back and lumbar region. The classical saying 'for lumbar and back conditions, seek Weizhong' has guided practitioners for centuries, and the point remains one of the first selected for any form of back pain. Its location at the midpoint of the popliteal crease places it on the Bladder meridian's pathway through the posterior leg, far from the back itself, yet its effect on lumbar pain is immediate and often dramatic.
This is the principle of distal point therapy at its most powerful: by stimulating the he-sea point of the Bladder meridian where it runs through the back of the knee, the practitioner activates the entire posterior aspect of the channel, releasing stagnation and restoring qi flow through the lumbar and sacral regions. The Earth element designation of this he-sea point gives it a stabilizing quality that is particularly effective for acute back spasms and the intense pain of sudden lumbar strain.
Beyond back pain, Weizhong has a significant blood-cooling function. In classical practice, it was one of the primary points bled (using a lancet to release a few drops of blood) for conditions of blood-heat: skin eruptions, summer heat stroke, high fevers, and nosebleeds. For acupressure self-care, its blood-cooling action is accessed through sustained moderate pressure rather than bleeding, and it can help alleviate inflammatory skin conditions and heat-related symptoms alongside its musculoskeletal applications.
How to Find This Point
Bend the knee slightly. Find the crease at the back of the knee. The point is at the exact center of this crease, between the two prominent tendons you can feel on either side.
Technique
Press with the thumb into the center of the back of the knee crease. Moderate pressure -- the popliteal artery and nerve are nearby. Sustained pressure or gentle circular motions. Can also be pressed while seated with the knee slightly bent.
Pressure & Duration
Moderate (avoid deep forceful pressure) pressure for 1-2 minutes per side.
Benefits
Benefits the lower back, activates the channel, clears heat, resolves blood stasis, relaxes the sinews, cools the blood
Indications
Acute lower back pain, sciatica, knee pain, leg cramps, skin diseases with heat, urinary difficulty, heatstroke, nosebleed from blood-heat
TCM Actions
Benefits the lumbar region and knees, activates the channel, clears heat, resolves blood stasis, cools the blood, he-sea point of the Bladder meridian, one of the Four Command Points (for the back and lumbar region)
Self-Care Use
Press the center of the back of the knee crease for acute lower back pain. This is the Command Point for the back -- pressing it can provide rapid relief for back spasms and acute lumbar strain. Use moderate pressure (not deep) for 1-2 minutes per side. Also helpful for knee stiffness. For back pain, try pressing while slowly bending forward and straightening up to enhance the effect.
Contraindications & Cautions
Avoid firm pressure directly on the popliteal artery. Contraindicated in individuals with deep vein thrombosis in the leg or popliteal aneurysm. Use gentle pressure if there is a Baker's cyst behind the knee.
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Frequently Asked Questions
Where is the BL-40 Middle of the Crook acupressure point located?
BL-40 Middle of the Crook (Wěi Zhōng) is located at: At the midpoint of the transverse popliteal crease, between the tendons of the biceps femoris and semitendinosus muscles. Bend the knee slightly. Find the crease at the back of the knee. The point is at the exact center of this crease, between the two prominent tendons you can feel on either side.
How long should I press BL-40 Middle of the Crook?
Apply moderate (avoid deep forceful pressure) pressure to BL-40 for 1-2 minutes per side. Press with the thumb into the center of the back of the knee crease. Moderate pressure -- the popliteal artery and nerve are nearby. Sustained pressure or gentle circular motions. Can also be pressed
What are the benefits of stimulating BL-40 Middle of the Crook?
Benefits the lower back, activates the channel, clears heat, resolves blood stasis, relaxes the sinews, cools the blood
Is it safe to do acupressure on BL-40 at home?
Press the center of the back of the knee crease for acute lower back pain. This is the Command Point for the back -- pressing it can provide rapid relief for back spasms and acute lumbar strain. Use m Cautions: Avoid firm pressure directly on the popliteal artery. Contraindicated in individuals with deep vein thrombosis in the leg or popliteal aneurysm. Use g
Which meridian does BL-40 belong to?
BL-40 Middle of the Crook belongs to the Foot Taiyang Bladder Meridian, which is associated with the Earth (he-sea point of Water meridian) element. Its TCM actions include: Benefits the lumbar region and knees, activates the channel, clears heat, resolves blood stasis, cools the blood, he-sea point of the Bladder meridian, one of the Four Command Points (for the back and