A nerve runs beside this tendon: press gently, and ease off if it tingles.
委陽 Weiyang
“The Bent Yang” · BL39
Foot Taiyang · 39 of 67 · lower-he-sea of the san jiao
Where. At the outer end of the crease behind the knee, just inside the tendon there.
For. A stiff lower back; cramping legs; difficult urination.
Press. Sit with the knee bent and press with a fingertip, about a minute each leg.
Caution. A nerve runs beside this tendon: press gently, and ease off if it tingles.
委陽，三焦下輔俞也，在足太陽之前，少陽之後按 · Press with me
Six slow breaths
About a minute. Press as you breathe out, ease as you breathe in.
鄰 · Neighbouring leaves
Where Weiyang Sits Behind the Knee
The dataset locates Weiyang in a single breath: at the lateral end of the popliteal crease, on the medial side of the biceps femoris tendon. Unpacked for hands rather than rulers: the popliteal crease is the skin fold at the very back of the knee, the line the leg folds along whenever the knee bends. Its lateral end is where the fold thins away toward the outer edge of the leg — and unlike many stations whose records measure distances in cun, this address is given entirely by landmarks, with no measuring step at all. Medial side of the tendon means the flank facing the middle of the back of the knee, not the outer thigh: the point rests against the tendon on its inner face, right where the crease surrenders its last stretch to the corner.
What rests under the fingertip here is tendon meeting hollow. The biceps femoris is the outermost of the hamstrings, the group of muscles running down the back of the thigh, and near the knee its belly narrows into a firm cord — the tendon — that continues toward the small bone at the outer side of the knee. Just beyond the tendon lies the popliteal fossa, the diamond-shaped space behind the knee through which vessels and nerves travel between thigh and lower leg. That neighborhood is the reason every suggestion on this page keeps pressure light and aimed at the tendon edge, never plunged into the soft depths of the hollow: the working ground for self-care is the margin where muscle hands over to tendon, not the hollow itself.
Neighbors fix the address on the map. At the exact midpoint of the crease stands Weizhong (BL40), seated between the two tendon groups; at the lateral end stands Weiyang; and one cun straight above Weiyang, on the medial side of the same tendon, hovers Fuxi (BL38). All three belong to the bladder meridian, the longest pathway in the traditional cartography — sixty-seven stations strong, drawn from the inner corner of the eye, sweeping over the head, descending the whole back alongside the spine, crossing the buttock and the back of the thigh, and ending at the little toe. Five-phase teaching assigns the channel to water. One distinction sets Weiyang apart from its ordinary-looking companions: the licensed record labels it the lower-he-sea point of the san jiao, the triple burner — a rank the classical texts describe as the place where that organ’s activity gathers low on the leg, and a subject taken up below.
A Self-Palpation Walkthrough
Choose a posture that lets the back of the knee soften: sitting with the foot resting flat on a low stool, lying face down with a pillow under the ankle, or standing with the heel propped and the knee barely bent. Begin by letting the knee flex a little so the crease appears, then trace the fold outward until it fades at the outer edge of the leg — that fading corner is precisely Weiyang’s ground. Rest your fingertip there and feel for the firm cord of the biceps femoris tendon rising beside it; settle your pad on the cord’s inner side, the side facing the middle of the knee. Repeat the whole search on the other leg so both sides receive the same careful attention.
A few quiet confirmations help before any pressing begins. Touch feather-light and compare sides: most people notice a broad, dull awareness at the true spot and little sensation a finger-width away. Flex the knee gently against nothing at all — the tendon cord tightens and slides under the finger, confirming that your pad sits beside it rather than floating in soft tissue. Audit the horizontal placement too: if what you feel is the deep cushioned centre of the hollow, you have drifted inward and should return toward the tendon; if your finger rests on bare outer-leg muscle with no cord nearby, you have slipped past the tendon outward and should come back to its edge.
The classic mistakes are worth naming so they can be dodged. The first is stopping halfway, at the comfortable middle of the crease — plausible, symmetrical-feeling, and one famous neighbor away: the midpoint belongs to Weizhong. The second is climbing: drift a thumb-width up the thigh along the tendon and you arrive in Fuxi’s territory, a different station with a different story. The third is sliding outward past the tendon onto the bare outer leg. The fourth is sinking inward into the soft heart of the hollow, which this page treats as territory to skirt, never to press. And the fifth is pressing harder, hoping force will clarify what patience finds anyway; force teaches the fingers nothing here. Lighten the touch, slow the search, and let the corner and the cord announce themselves.
Reading the Name: the Bent Yang
The first character carries the pose of the whole knee. Wei 委 in classical usage means to bend, to bow, to yield — the posture of something folding rather than standing rigid — and by extension a gathering store, as grain collected into a storehouse was said to pile up. Commentators have connected both senses to this spot. The knee is the body’s great bending joint, and the hollow behind it appears only when the limb folds; the point waits at the outermost reach of that fold. The gathering sense fits too: the crease is where the structures of thigh and lower leg crowd together, and classical practice liked to imagine qi pooling at such crossings. Read either way, the name begins with the gesture of the knee itself.
The second character is an open secret of Chinese cosmology. Yang 陽 names the bright side — sunlit slopes, outer surfaces, the active and rising principle — and in the naming of points it usually marks a yang placement on the body. Weiyang qualifies twice over: it sits on the posterior, outer-facing territory the tradition counts as yang ground, and it serves as the lower-he-sea of the san jiao, while the san jiao itself is a fu — one of the six yang bowels — so the point carries its office’s yang banner as well. Together the pair reads naturally as the bent yang or the yielding yang: brightness gathered at the body’s great hinge. It is compact naming — posture plus polarity — doing work a paragraph of description would otherwise owe.
Pinyin renders the name Wěiyáng, and the tone marks repay checking against a dictionary rather than memory. The first syllable wei carries the dipping third tone — wěi — the voice sinking before lifting again, exactly as dictionaries give for 委 in this sense; the character’s other, first-tone reading belongs to different compounds and stays far from medicine. The second syllable yang carries the rising second tone — yáng — delivered with an upward lift, as dictionaries give for 陽. The hanzi pair 委陽 stays short enough to memorise at a glance, and like the gates, valleys, courtyards, and storehouses scattered along the channel, the metaphor does honest work: it marks a working corner of the landscape, not scenery.
Traditional Indications, Explained
The recorded indications read: abdominal fullness, difficult urination, stiff pain of the spine and lower back, contracture and pain of the legs and feet, epilepsy, and fever. Framed as tradition rather than promise, the first two travel together, and the point-class explains their company. Classical teaching describes the san jiao as the body’s network of passages through which water moves and warmth is distributed — a ministering system spread across the trunk — and each fu was honoured with a lower-he-sea station on the channels of the leg where its activity could be addressed from below. When water stalled, the reasoning ran, the san jiao’s own low station was a natural place to inquire; hence difficult urination stands first among the reasons classical writers gave Weiyang its office, with abdominal fullness — understood as qi and water failing to move freely through the middle and lower trunk — riding beside it.
The middle of the list returns to the road. The bladder channel descends the entire back flanking the spine, crosses the buttock, and continues down the back of the thigh and leg, so stiffness binding the spine and lower back, or cramping, contracted pain of legs and feet, sat squarely along its route and was approached at stations upon it. Fever belongs to a broader classical habit: early literature consulted points widely during febrile illnesses, and many stations carry fever entries inherited from that era of practice. Epilepsy asks for the most careful reading of all. Old records grouped sudden convulsive episodes under headings like this one, long before modern categories existed; the entry documents what classical authors reached for, nothing more. Today a seizure is always a matter for emergency medical care, and nothing on this page — least of all a pressure routine — has any place in responding to one.
It bears repeating plainly: these are the traditional uses recorded in a licensed dataset and classical literature, offered here for cultural and historical understanding. They are not claims that pressing this point treats disease, and nothing in this guide replaces assessment by a qualified clinician. Where modern research touches self-applied pressure at all, reviews suggest effects are modest and context-dependent, and evidence specific to any single point remains thin. Hold the tradition lightly, and hold the safety rules firmly.
Self-Care Acupressure at Home
With the point located by the walkthrough above, settle into position: seated with the foot on a low stool, or lying face down with the ankle supported and the knee soft. Curl your fingers and rest the pads — never the tips, and never an elbow or any tool — on the spot where the crease meets the tendon’s inner face. Begin with contact alone for a few breaths, then add small, slow circles, letting skin glide along the tendon edge rather than grinding toward the hollow. Pressure should register as pleasant dullness or mild warmth spreading along the tendon line, never sharpness. A common home rhythm is one to three minutes per side, once or twice daily, matched where possible to slow exhales, with both legs kept symmetrical.
Quality matters more than duration. Warm your hands first if they run cold, because chilled muscle guards. Choose a quiet corner over a screen and treat the practice as a pause rather than a task; people who keep it up often anchor it to an existing habit — after the evening walk, before bed — because consistency, not intensity, is what self-care traditions actually ask for. Pairing helps too: a minute of gentle pressure followed by easy movement, such as standing and bending the knee softly a few times, suits the folded landscape behind the knee far better than aggressive stretching of cold tissue.
Treat the exercise as a small ceremony of attention rather than a treatment session. Across weeks, notice what changes: perhaps the corner feels less guarded after long days standing, perhaps the pause becomes the evening’s quietest minute, perhaps nothing shifts except that you spend two minutes attending to your own knees. Every one of those outcomes fits the honest scope of self-acupressure. What does not fit is escalation — pressing harder, longer, or deeper to force a result. When curiosity pulls that way, return to gentleness or simply stop for the day; the corner will still be there tomorrow, exactly where the crease and the tendon said it would be.
Cautions and Safe Practice
This point carries a notably quiet record in the licensed data: the dataset lists no specific caution for Weiyang. Geography explains much of that calm. The point rests on solid ground — a tendon edge backed by thick muscle — with no delicate structure within reach of anything surface contact could exert. But calm deserves its footnote: immediately inward lies the popliteal hollow, the corridor through which the vessels and nerves of the lower leg pass, so home care keeps to the tendon margin and skirts the soft centre of the hollow entirely. A quiet record is permission for gentleness, not for force.
For fingertip acupressure the practical rules are simple. Use finger pads only, and keep pressure light enough to stay pleasant throughout; aim the attention at the tendon margin rather than downward into the knee hollow. Skip the point entirely over broken, bruised, or irritated skin, over visible veins that ache, during an acute flare of knee trouble, and for a stretch after any injury or surgery in the region until ordinary movement has been cleared by a clinician. Sharp, electric, or radiating sensation means stop at once and do not try again that day. Pregnant readers should consult a qualified practitioner before adding any new point practice, and anyone managing circulation problems or diagnosed nerve conditions of the legs does well to ask first too.
And the wider rule stands over everything: this page is educational, and acupressure is self-care, not diagnosis or therapy. Some stories around the knee, and around the waters this corner watches over, need prompt professional attention rather than any pressure routine: difficulty passing urine, or urine stopping altogether; numbness, tingling, or weakness that persists or spreads; one-sided swelling, warmth, or colour change in calf or knee; pain following a fall or accident; a seizure of any kind; or symptoms persisting without explanation beyond a few weeks. Seek licensed medical or East Asian medical care as suits the complaint — promptly, alongside self-care rather than instead of it. The safest gift Weiyang offers most people is a kinder acquaintance with the back of their own knee: attended regularly, pressed gently, and never rushed.
Weiyang, the Bent Yang, holds the outer corner of the crease behind the knee — right where the fold fades toward the outer edge of the leg, resting against the biceps femoris tendon. Classical practice reached for it in abdominal fullness, difficult urination, and stiff pain of the spine and lower back. This guide walks through finding it by touch and pressing it gently at home.
Self-care limits
Frequently asked
- How do I find Weiyang without memorising anatomy?
- Use the corner of the crease as your whole map. Let the knee bend softly so the crease appears, trace the fold outward to where it fades at the outer edge of the leg, and rest a fingertip in that corner. Feel for the firm tendon cord rising there and settle on its inner side, the side facing the middle of the knee. The dataset’s wording — lateral end of the crease, medial side of the biceps femoris tendon — simply encodes that same corner in technical language.
- Is pressing Weiyang myself actually safe?
- Gentle fingertip pressure held on the surface is generally reasonable self-care for healthy adults: the licensed record lists no specific caution for this point, because solid tendon and thick muscle lie beneath. The one refinement this page adds is direction — press the tendon margin, not the soft centre of the hollow behind the knee, where vessels and nerves pass. Respect the stop signals: sharp or radiating sensation means finish immediately.
- What did classical practice use Weiyang for?
- The traditional record lists abdominal fullness, difficult urination, stiff pain of the spine and lower back, contracture and pain of the legs and feet, epilepsy, and fever — a portfolio mixing water-and-trunk entries tied to its role as the san jiao’s lower-he-sea with back and leg entries tied to the channel it stands on. Those are traditional frameworks for understanding the body, documented for context — not evidence-backed treatment claims.
- Why does a point on the bladder channel belong to the san jiao?
- Because classical teaching built a second index over the channel map. Each of the six fu organs received a lower-he-sea station on the channels of the leg where its activity could be met from below, and these stations were deliberately placed away from their namesake channels — the san jiao’s was set on the bladder channel, at Weiyang. Classical authors explained the arrangement in different ways, but they practiced it consistently. It is traditional reasoning, recorded for understanding — not a modern treatment claim.
- How is Weiyang different from Weizhong next door?
- They share one crease and split its corners. Weizhong (BL40) sits at the exact midpoint, between the two tendon groups, and its record leans toward pain of the lower back and spine and troubles of the limbs; Weiyang holds the lateral end, beside the outer tendon, and leans toward fullness and water — fitting its office for the san jiao. Fuxi (BL38) hovers a thumb-width above Weiyang on the same tendon. Same stretch of road, different doors.
Sources
- 01WHO Standard Acupuncture Point Locations in the Western Pacific Region (2008), World Health Organization — nomenclature conventions.
- 02A Manual of Acupuncture, Peter Deadman, Mazin Al-Khafaji and Kevin Baker — point-name tradition, lower-he-sea theory, and bladder-channel context.
- 03aijiu-mpvue (MIT License) licensed dataset, entry for BL39 Weiyang — location, point class, actions, and indication record.
Last reviewed
牌記This leaf, for machines
Old books ended with a colophon saying who printed them. Every leaf here carries the same facts as structured data for agents and search, with no layout in the way.
- GET /en/points/bl39/leaf.json
- GET /zh-hant/points/bl39/leaf.json
- GET /zh-cn/points/bl39/leaf.json
- /llms.txt — the index of every leaf
- JSON-LD in the page: MedicalWebPage, MedicalEntity and FAQPage
{
"id": "BL39",
"name": {
"en": "Weiyang",
"gloss": "The Bent Yang",
"zh-Hant": "委陽",
"zh-Hans": "委阳"
},
"channel": {
"id": "BL",
"order": 39,
"of": 67
},
"location": {
"text": "At the outer end of the crease behind the knee, just inside the tendon there."
},
"for": [
"A stiff lower back",
"cramping legs",
"difficult urination"
],
"press": {
"text": "Sit with the knee bent and press with a fingertip, about a minute each leg.",
"seconds": 60,
"sides": "both"
},
"cautions": [
"A nerve runs beside this tendon: press gently, and ease off if it tingles."
],
"source": "Zhenjiu Jiayi Jing, book 3",
"url": "https://acupoints.com/en/points/bl39",
"lastReviewed": "2026-08-24"
}