Skip a calf that is suddenly swollen, hot or sore, and see a doctor.
合陽 Heyang
“Union of Yang” · BL55
Foot Taiyang · 55 of 67
Where. On the back of the calf, about three finger-widths below the centre of the knee crease.
For. Low back ache; knee pain; weak legs.
Press. Firm thumb pressure, about a minute each leg.
Caution. Skip a calf that is suddenly swollen, hot or sore, and see a doctor.
合陽，在膝約文中央下二寸按 · Press with me
Six slow breaths
About a minute. Press as you breathe out, ease as you breathe in.
鄰 · Neighbouring leaves
Where Heyang Sits on the Back of the Calf
Turn to the back of your own lower leg and the map draws itself. Behind the knee runs the transverse crease, and from its midpoint a straight line drops down the middle of the calf toward the heel — the route the dataset names when it locates Heyang: on the back of the lower leg, on the line connecting Weizhong (BL40) and Chengshan (BL57), 2 cun below Weizhong. A cun is the traditional proportional unit of Chinese point-location, taken from the person being examined rather than from a ruler; the width of the first joint of your own thumb is the usual working equivalent. So 2 cun below Weizhong means about two thumb-widths straight down from the middle of the crease, with the whole journey staying on the back of the calf, never wrapping toward the inner or outer side.
What the fingertips meet there is generous country. High on the back of the calf, the broad gastrocnemius — the muscle that gives the calf its familiar contour — sits at its fullest, thick and springy under the skin. Heyang rests in this upper reach, where the muscle still owns most of its substance, and the surface reads quite differently from the sinewy lower calf nearer the heel cord. Touched lightly, the area answers with a comfortable, meaty resistance rather than bone or tendon. Nothing delicate hides immediately beneath the surface here, yet the register of self-palpation stays the same everywhere on the body: patient, feather-light exploration first, pressure later — and then only the mildest. Landmarks announce themselves to waiting fingers far more readily than they yield to force.
Neighbors confirm the address. Above, at the exact middle of the crease, sits Weizhong, the gathering pool of the channel behind the knee; below, after a longer stretch of the same line, waits Chengshan, the next named station down the calf. Heyang stands early on that road — close enough below the crease that the two remain within easy reach of one hand. All three hang on one vertical thread, the bladder channel’s descent along the back of the leg, so if you can find the crease’s midpoint and hold a true line down the middle of the calf, the channel’s own geometry has already checked your work. Losing the spot simply means returning uphill to the crease and starting again.
A Self-Palpation Walkthrough
Choose a position that lets the calf relax and the landmarks show. Standing with your weight shifted onto the other leg, sitting with the foot flat on the floor, or lying face down with the feet hanging free all work; whichever you choose, let the knee stay softly bent rather than locked. Begin upstream: find the transverse crease behind the knee and walk your fingertips along it to its exact middle — that midpoint is Weizhong. From there, measure two thumb-widths straight down the back of the calf, keeping to the midline, and let your fingertips settle. Under them should lie full, yielding muscle — neither the crease itself nor the firmer territory much farther down.
A few confirmations earn their keep before any pressing begins. Rise slowly onto the balls of the feet, or press the toes gently into the floor, and feel the calf muscle gather and firm — the movement sketches the line in relief and tells you the search is in living territory. Compare sides with a feather-light touch: most people notice a faint, dull awareness at the true spot and little sensation a finger-width away. Check the line, too: the point should sit on the straight descent from crease-middle toward the heel, not drifted toward the inner or outer edge of the calf. If your fingers land where the muscle feels stringy or sharply tender, ease off, return to the crease, and measure again, slowly.
Two classic mistakes account for most missed finds. The first is staying too high — resting on the crease itself or just below it, where the tissue belongs to Weizhong’s neighborhood instead. Count the thumb-widths aloud if it helps: one, then two, then settle. The second mistake is wandering off the midline, following the muscle’s curve inward or outward until the spot dissolves among undifferentiated softness. The line connecting Weizhong and Chengshan runs almost like a plumb line down the back of the calf; trust it. And resist hunting with force: a hard-pressed calf tenses to guard itself and erases every difference you were trying to read. When in doubt, shake the hand out, let the leg rest, and begin again at the crease.
Reading the Name: Union of Yang
Two characters, and each does real work. He 合 means to join, to close, to unite — the stroke of things coming together, as lips close or rivers meet. Yang 陽 names the bright member of the pair yin and yang, and in the body’s traditional mapping the yang side is the back: the sunward exterior where activity gathers, set against the quieter yin of the front. Read together, Heyang is the union of yang, or the place where yang joins — a confluence marked on the sunny, posterior aspect of the leg. The hanzi pair 合陽 is plain enough to memorise at a glance, and like many channel names it is less decoration than instruction: come to the back of the leg, and look for the joining.
Why a joining here, of all places? The bladder channel carries the title taiyang — great yang — in classical nomenclature, and classical texts describe it making the longest descent in the body: from the inner corner of the eye, over the head, and down the whole back to end at the little toe. Along the way, the old accounts tell of its paths converging behind the knee before continuing down through the calf as one gathered stream. A point standing soon after that gathering, on the yang surface of the leg, wears the name naturally: the joined flow of the great-yang channel, passing this way. Whether the ancients intended precisely that reading is beyond recovering; generations of commentators have found it satisfying, and the geography supports the poetry.
Pinyin renders the name Héyáng, and the tones deserve a careful word. Both syllables carry the second tone — the rising tone, lifting like the tail of a confident question — so he rises and yang rises after it: a name that climbs twice. (The dictionaries add a second, rarely used reading for the character he — ge, on a falling-rising third tone — but the point name takes the ordinary rising he.) The hanzi 合陽 repay the small effort of learning them: two of the most frequent characters in the traditional lexicon, met again and again in point names, formulas, and philosophy. Learning this one name quietly teaches half the alphabet the tradition thinks in.
Traditional Indications, Explained
The recorded indications read: stiff pain of the spine and lower back, atrophy and paralysis of the lower limbs, knee pain, hernia, and uterine bleeding. Five entries, and the first casts the longest shadow. Classical texts describe the bladder channel descending the entire back in paired lines beside the spine — the longest channel road in the body — and a station on that road stood ready for trouble along it. Stiffness and aching of the spine and loins, the kind old books call strong pain when the back feels rigid and unwelcoming, were traditionally referred to the channel that governs the back’s whole length. When the lower back complained, practitioners consulted the gathered descent, and this point waited in its lower reaches.
The next two entries stay close to home. Knee pain follows the simplest logic of all: the point sits just below the bend of the knee, on the channel that passes it, and nearby troubles were brought to nearby stations. Atrophy and paralysis of the lower limbs is a broader classical category — weakness, wasting, heaviness, legs that will not answer — which the old texts approached through the leg channels and their gathering places. Read with modern eyes, that entry describes serious neurological territory: persistent weakness, numbness, or difficulty walking call for professional assessment first, whatever gentle practices accompany them at home. The tradition wrote these entries inside its own diagnostic world; translated honestly, they become understanding, not self-treatment.
Then come two entries that sound furthest from a calf: hernia and uterine bleeding. Classical medicine grouped under hernia a family of complaints involving protrusion or dragging discomfort, often in the groin; and it catalogued disruptive uterine bleeding in its own patterns of flooding and trickling. Why would a calf point appear in such company? Channel logic offered an answer — the great-yang channel was traditionally credited with governing certain deeper functions of the lower body, and distant stations served distant districts. Whatever the old reasoning, the modern instruction writes itself: a suspected hernia and any unusual uterine bleeding belong with a qualified clinician, promptly. These entries are recorded history, documented for cultural understanding — not claims that pressing this point treats either condition. 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.
Self-Care Acupressure at Home
With the point located, settle in. Sit with the feet flat, kneel, or lie face down with a pillow under the ankles — whatever lets the calf soften. Rest the pads of your index and middle fingers — never the tips, never a knuckle or tool — on the spot and begin with contact alone, a few slow breaths of doing nothing at all. Then add small, slow circles, letting the skin glide over the muscle beneath rather than grinding into it. Sensation should read as pleasant dullness or a mild spreading warmth, never sharpness. A common home rhythm is one to three minutes per side, once or twice daily, matched where possible to unhurried exhales so each circle rides the breath out. Swap hands or sides and finish evenly.
Quality matters more than duration. Light, patient, regularly repeated contact is the whole art this page practises; hard jabbing causes harm and teaches the body nothing. Warm your hands first if they run cold, because chilled muscle guards. Skip the session right after an unusually hard workout, a cramp, or a strain — let the calf settle, and return when the tissue welcomes touch again. Anchor the habit somewhere existing: after the morning shower, during the evening wind-down, alongside a stretch you already keep. Consistency, not intensity, is what self-care traditions actually reward, and two quiet minutes kept daily outrank ten forceful ones attempted once.
Hold the session as a small ceremony of attention rather than a treatment appointment. Over weeks, notice honestly: perhaps the back feels easier as you stand, perhaps the knee swings with a touch more freedom, perhaps nothing changes except that you spend two minutes attending to muscles that carry you everywhere and rarely receive thanks. Every outcome on that list fits the honest scope of self-acupressure. What does not fit is escalation — heavier thumbs, longer sieges, pressing through pain to force a result. The moment curiosity pulls that way, return to gentleness or stop for the day. The point has waited patiently for centuries; it will wait until tomorrow.
Cautions and Safe Practice
Honesty first: the licensed dataset records no caution entry for this point — unlike certain chest, neck, and facial points, no warning line accompanies its record, and this module echoes that silence deliberately. An empty caution field is a fact about the dataset, not a dare. The upper calf is muscular, well-padded country, and gentle surface contact respects its geography completely. Still, the same good sense that governs every self-care practice governs this one, and the rules below ask less of you than they may first appear: their essence is the discipline of stopping, and of knowing which symptoms travel to a professional rather than under a fingertip.
Practical rules for home practice, then. Keep contact light and strictly superficial — skin and surface muscle only, never driving deep into the belly of the calf. Use finger pads, never elbows, knuckles, or tools, and never press while holding the breath or through pain. Skip the point entirely over broken or irritated skin, over visible swelling or prominent varicose change, and during any feverish illness; leave it alone after recent calf injury or surgery until a clinician clears ordinary activity. Take special care with one-sided calf complaints: swelling, warmth, tenderness, or visible redness in a single calf — especially after long travel, surgery, or bed rest — belongs with a doctor promptly, not under a fingertip. Sharp, electric, or radiating sensation means stop at once and do not retry that day. Pregnant readers, and anyone living with circulatory conditions, should consult a qualified practitioner before adding any new point practice.
And the wider rule stands over everything: this page is educational, and acupressure is self-care, not diagnosis or therapy. Seek prompt medical care — not a pressure routine — for back pain after a fall or accident, weakness or numbness in a leg, loss of control of bladder or bowel, knee pain with locking, giving-way, or significant swelling, or any symptom that frightens you. Persistent back, knee, or calf complaints deserve proper assessment too, whichever gentle practices accompany them. The calves have carried their owners gracefully all their lives; treat yours as valued infrastructure, attend to it kindly, and let real symptoms take the real road to real clinicians.
Heyang — Union of Yang — waits two thumb-widths below the crease behind the knee, on the straight road the bladder channel travels down the back of the calf. Classical practice reached for it when spines stiffened, knees complained, and legs grew heavy. This guide walks you to the spot by touch and shows how to press it gently and safely.
Self-care limits
Frequently asked
- How do I find Heyang without knowing anything about cun?
- Let Weizhong be your anchor. Find the transverse crease behind the knee, walk to its exact middle, then come straight down the back of the calf about two thumb-widths — the width of your own thumb’s first joint standing in for one cun. Stay on the midline as you descend, and remember the line continues toward Chengshan farther down, which confirms you are tracing the right road. Rise onto the balls of the feet once to make the muscle speak, compare sides, and the neighborhood will identify itself.
- Is pressing Heyang myself actually safe?
- Gentle fingertip contact on the surface is generally reasonable self-care for healthy adults; the upper calf is thick, well-padded muscle, and surface work engages it far short of anything fragile. Respect the stop signals — sharp, electric, or radiating sensation means finish immediately — and give a swollen, warm, or one-sided painful calf to a doctor before giving it to your fingers. Light and brief beats heavy and long, every time.
- What did classical practice use Heyang for?
- The traditional record lists stiff pain of the spine and lower back, atrophy and paralysis of the lower limbs, knee pain, hernia, and uterine bleeding. The back and leg entries follow the channel map directly; the last two reflect older diagnostic categories best understood as history. These are traditional frameworks for understanding the body, documented for context — not evidence-backed treatment claims.
- Why is the bladder channel called the longest road in the body?
- Because of its itinerary. Classical teaching traces it from the inner corner of the eye, up and over the head, down the entire length of the back, and onward past the calf to finish at the little toe — no other channel travels farther. The back of the leg carries the final, gathered stretch of that journey, and Heyang stands near the top of it, a station on the channel’s longest mile.
- Can acupressure at Heyang replace seeing a doctor about my back or knee pain?
- No. Self-acupressure is a comfort practice, not a diagnostic tool, and back or knee pain carrying red flags — leg weakness or numbness, bladder or bowel changes, a knee that locks or gives way, pain after a fall — needs professional assessment promptly. Think of the two as different floors of one building: daily self-care lives downstairs, and the consulting rooms upstairs open for symptoms that persist, escalate, or frighten. Neither floor substitutes for the other.
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 and channel context.
- 03aijiu-mpvue (MIT License) licensed dataset, entry for BL55 Heyang — location, point class, actions, and caution 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/bl55/leaf.json
- GET /zh-hant/points/bl55/leaf.json
- GET /zh-cn/points/bl55/leaf.json
- /llms.txt — the index of every leaf
- JSON-LD in the page: MedicalWebPage, MedicalEntity and FAQPage
{
"id": "BL55",
"name": {
"en": "Heyang",
"gloss": "Union of Yang",
"zh-Hant": "合陽",
"zh-Hans": "合阳"
},
"channel": {
"id": "BL",
"order": 55,
"of": 67
},
"location": {
"text": "On the back of the calf, about three finger-widths below the centre of the knee crease."
},
"for": [
"low back ache",
"knee pain",
"weak legs"
],
"press": {
"text": "Firm thumb pressure, about a minute each leg.",
"seconds": 60,
"sides": "both"
},
"cautions": [
"Skip a calf that is suddenly swollen, hot or sore, and see a doctor."
],
"source": "Zhenjiu Jiayi Jing, book 3",
"url": "https://acupoints.com/en/points/bl55",
"lastReviewed": "2026-08-24"
}