Chengshan

What is BL57 (Chengshan), and why do people press it?

BL57, called Chengshan — usually translated as "Supporting Mountain" — sits in the middle of the back of the calf, at the point where the two rounded bellies of the calf muscle taper together into the Achilles tendon. The name is descriptive: with the heel lifted, the calf rises like a mountain with a valley running down its centre, and the point sits in that valley where the slopes meet. It is the fifty-seventh point on the Bladder channel, the longest channel in classical Chinese medicine, which is described as running down the back of the body from the head to the little toe.

In traditional practice BL57 has two quite different reputations that sit side by side. The first is local and obvious: it is the calf point, used for calf cramp, calf tightness, aching legs after standing or walking, and heaviness in the lower leg. The second is distal and less intuitive to a modern reader: the Bladder channel is said to pass through the anal region, and BL57 is one of the classical points named for haemorrhoids and discomfort during bowel movements — a use recorded for many centuries and still taught in every standard point curriculum.

What can be said honestly is that BL57 is a straightforward, low-risk point that most people can find on themselves in a few seconds, and that firm thumb pressure into a cramping or fatigued calf is a familiar and generally comfortable form of self-care. What cannot be said is that pressing it treats or cures haemorrhoids, varicose veins, or any circulatory condition. Human trial evidence for BL57 specifically is thin and of modest quality. This document describes a traditional practice and how to do it carefully — not a medical treatment, and not a substitute for anything a clinician has prescribed.

One point deserves emphasis before you touch the area at all: the calf is a place where a genuine medical emergency can hide behind ordinary-sounding soreness. Read the safety section before you begin.

Where exactly is BL57 on the calf, and how do I find it on myself?

BL57 is a landmark point — you locate it by feeling the shape of your own muscle, not by measuring. The illustration shows a rear view of the calf with the point marked in the central groove, roughly halfway between the crease behind the knee and the heel.

• Sit with the leg out in front of you, or kneel, or sit on a chair and cross one ankle over the opposite knee so the back of the calf is easy to reach. Some people find it easiest lying face down with the foot hanging over the end of a bed.
• Find the crease behind your knee (the popliteal crease). This is the top reference point. Now find the back of your heel bone. BL57 lies roughly at the midpoint between the two, sometimes a little above midway.
• Make the muscle stand out. Point your toes hard, or push the ball of your foot against the floor as if rising onto tiptoe. The calf will bunch into two distinct rounded bellies side by side, with a shallow valley between and below them.
• Run your thumb up the midline of the calf from the Achilles tendon. The tendon is narrow and cordy near the heel, then widens and softens as the muscle takes over. BL57 sits in the notch at that transition — where the firm tendon gives way to the soft V between the two muscle bellies.
• Confirm by feel. When your thumb is on the point and you press in, most people notice a distinctive deep, dull, slightly achy sensation that is different from pressing the muscle an inch to either side. Traditional texts call this the arrival of the sensation; practically, it is your confirmation you are in the right groove.
• Both legs have one. The point is bilateral. For cramps, work the affected side. For general leg fatigue or the traditional distal uses, both sides are usually worked in turn.
• If you cannot find the notch — some people have very short or very long calf muscles — simply use the midline of the calf at the halfway mark. Precision to the millimetre is not required for finger pressure; a broad thumb covers a generous area.

A word on the classical measurement, in case you meet it elsewhere: older texts place BL57 eight cun below BL40 at the knee crease, where one cun is a proportional body-unit rather than a fixed distance. The muscle landmark above gets you to the same place with less arithmetic.

How do I actually apply pressure to BL57?

1. Check the calf first. Before pressing, look and feel. If one calf is noticeably swollen, warm, red or hard compared with the other, or if pain came on suddenly without exercise, stop and read the safety section — do not massage it. This ten-second check matters more than anything else on this list.
2. Get into a supported position. Ankle across the opposite knee is the most practical for self-application. Your back should be comfortable; if you are hunched and straining, you will tense the very muscles you are trying to release.
3. Warm the area briefly. Thirty seconds of gentle stroking or rubbing up the calf, or applying after a warm shower, makes deep pressure far more tolerable than going in cold.
4. Place the pad of your thumb on the point — the flat pad, not the tip, and never the nail. If your thumbs are weak or sore, use the knuckle of a bent index finger, or two fingers stacked one on top of the other.
5. Press inward and slightly upward, angling toward the knee, at right angles into the muscle. Build the pressure over five seconds rather than jabbing.
6. Find the right intensity. Aim for a firm, deep ache that you would rate about four to six out of ten — clearly felt, definitely not sharp, and never anything that makes you hold your breath or clench your jaw. If you cannot breathe normally, you are pressing too hard.
7. Hold for thirty seconds to two minutes, breathing slowly. Alternatively, use small circles or a slow pump — press for five seconds, release for two — for the same total duration. Both approaches are traditional; pick whichever feels better.
8. For an active cramp, combine pressure with a gentle stretch: keep your thumb on the point and use your other hand to draw the toes back toward your shin, straightening the knee if you can. Hold both together until the muscle lets go, then release the pressure slowly.
9. Release gradually and stroke the calf downward a few times. Sudden release of deep pressure can leave the muscle feeling startled.
10. Repeat on the other leg if you are working for general leg fatigue, then stand and walk a few steps.
11. Frequency: once or twice a day for a few minutes is a reasonable routine. For cramp-prone calves, many people prefer a short session in the evening. Stop for a day or two if the area feels bruised.

What is BL57 traditionally used for?

1. Calf cramps and spasm. This is the point's headline traditional use and the one for which the rationale is easiest to follow: it lies directly in the belly of the muscle that cramps. Practitioners use it for night cramps, cramps after exercise, and the tight, guarded feeling that lingers for a day afterwards. Firm sustained pressure into a cramping muscle is a widely used manual technique in many traditions, not only in acupressure.
2. Haemorrhoids and anal discomfort. BL57 is one of the classical distal points named for this in traditional texts, on the reasoning that the Bladder channel traverses the anal region. It is used for aching, itching and discomfort with bowel movements. This is a traditional indication with genuine depth in the written record and very limited clinical trial support. It does not shrink anything, and painless rectal bleeding, or bleeding that is new or heavy, is a reason to see a clinician rather than to press a point.
3. Tired, heavy, aching legs after long standing, long walking, or a long day on hard floors. Used together with general calf massage, this is the most everyday application.
4. Calf tightness in runners and walkers, as part of a post-exercise routine alongside stretching — not as a replacement for it.
5. Low back and sciatic-type discomfort that runs down the back of the leg. Because BL57 sits on the same channel that runs the length of the back, it is used as a distal point for posterior leg and lower back complaints in traditional practice.
6. Foot and heel tension, particularly where the whole posterior chain from calf to sole feels tight, often paired with points on the sole of the foot.
7. Constipation is listed in some classical sources, again via the channel connection to the lower bowel. This is a peripheral use even within tradition.

What BL57 does not do: it does not cure haemorrhoids, does not treat varicose veins, does not dissolve clots, does not correct an electrolyte problem or a medication side effect that may be causing your cramps, and does not replace anything your doctor has prescribed. If cramps are frequent, severe or new, the cause is worth investigating — dehydration, medication, thyroid and circulation issues are all common and all treatable.

Can regular work on BL57 help prevent problems before they start?

• Reducing the frequency of night cramps is the most commonly cited preventive use. A short evening routine — a minute of pressure on each BL57 plus a slow calf stretch — is a low-cost habit for people whose cramps wake them. It is a plausible and harmless routine, but treat it as a comfort measure rather than a proven prevention.
• Keeping calves supple in people who stand all day — retail, hospitality, nursing, teaching, hairdressing. Working the point at the end of a shift, paired with elevating the legs for ten minutes, is a sensible habit for tired legs.
• Post-exercise routine for runners and hikers. Included in a cool-down alongside proper stretching, it may help the calf feel less locked up the next morning. It is not a substitute for gradual training progression, which is what actually prevents calf injuries.
• Long journeys. On flights, coaches and long drives, working BL57 during a break gives you something to do that also gets you moving. Bear in mind that the genuinely protective measures on a long journey are getting up, walking, staying hydrated, and moving the ankles regularly — pressure on a point is an addition, not a replacement.
• Preventing the tightening cascade after a bout of unaccustomed walking, where a tight calf pulls on the Achilles and the sole of the foot. Keeping the calf mobile is genuinely useful here.
• Prompting better habits around haemorrhoid discomfort. Traditional practitioners typically pair the point with advice on fibre, fluid intake, not straining, and not sitting on the toilet for long periods. That advice is the part with real preventive weight; treat the point as the reminder attached to it.
• Body awareness. Regularly feeling your own calves means you notice change — a new lump, a difference between sides, unusual swelling — earlier than you otherwise would. That is a quietly valuable side effect of any self-massage habit.

What makes pressure on BL57 more effective and more comfortable?

• Warm the calf first. After a bath or shower, or after five minutes of walking, the muscle accepts deep pressure far more willingly. Cold, cold calves are unpleasant to press.
• Let the muscle stand out, then relax it to press. Point the toes to locate the notch, then let the foot go floppy before applying pressure. Pressing into a contracted muscle is uncomfortable and less effective.
• Use your body weight, not thumb strength. Lean into it. Thumbs that do all the work get sore within a week, which is the commonest reason people abandon the habit.
• Breathe out as you press in. A slow exhale on the deepening phase reliably makes the same pressure feel less intense.
• Work along the whole channel. Rather than treating BL57 in isolation, thumb slowly up the midline of the calf from the heel to the knee crease, pausing on any tender spot for a few breaths, and give BL57 the longest hold. Practitioners rarely use a single point alone.
• Pair it with a stretch. Pressure then stretch, or pressure during a stretch, is more useful for a tight calf than either alone. A simple wall calf stretch, thirty seconds each side, is a good partner.
• For night cramps, do it in bed, sitting up with the knee bent, immediately before lying down. Keep bedcovers loose over the feet — tight bedding that forces the toes to point is a classic aggravator.
• Use a tool if your hands are weak. The heel of the opposite foot, a tennis ball under the calf while sitting, or a rounded massage tool all work. Keep the pressure broad and controlled — avoid sharp-tipped gadgets on the back of the calf.
• Hydrate and check your minerals. Recurring cramps often track with dehydration or with medications such as diuretics. Addressing that is a bigger lever than any point.
• Be consistent rather than heroic. Two comfortable minutes daily beats one brutal ten-minute session that leaves you bruised and unwilling to repeat it.

What do people get wrong with BL57?

• Massaging a calf that should not be touched. This is the mistake that matters. A calf that is swollen, unusually warm, red or hard, or painful without an obvious cause, needs medical assessment before anyone rubs it. Do not press through that presentation.
• Pressing far too hard. The calf tolerates deep pressure, which tempts people into grinding at it. Bruising, next-day soreness and a tender spot that will not settle are the usual results. Firm ache, not pain.
• Using the thumbnail or a sharp tool tip. Broad pressure from the thumb pad or knuckle is what is wanted. A nail digs into skin without reaching the muscle.
• Hunting for a magic spot. People sometimes spend five minutes probing for exactly the right millimetre. The point is a region, not a pinhead; if you are in the central groove at mid-calf, you are on it.
• Pressing the Achilles tendon instead. Going too low puts you on the narrow cord above the heel. Tendon does not want the same treatment as muscle. Feel for where it widens into soft muscle and work above that.
• Expecting it to fix haemorrhoids. The traditional indication is real; the promise of resolution is not. Fibre, fluids, not straining, and a clinician's assessment do the actual work.
• Ignoring a cause. Cramps caused by a medication, low thyroid function, poor circulation or dehydration keep coming back no matter how well you press. Treating the point instead of investigating the cause wastes months.
• Skipping the rest of the leg. Isolated point work on a globally tight posterior chain gives thin results. Include the whole calf, and the sole of the foot.
• Doing it once, deciding it does nothing. Traditional use assumes repetition over time, not a single dramatic session.
• Continuing on a fresh injury. A recently torn or strained calf needs rest and assessment first, not deep pressure into the damaged tissue.

What does the evidence and experience actually show?

BL57 sits in an honest but awkward place: deep traditional standing, thin clinical trial evidence. It appears in the classical Chinese point literature across many centuries, is taught as a standard point in every modern acupuncture and tuina curriculum, and is named consistently for the same two things — calf disorders and haemorrhoids. That consistency across sources and centuries is a real form of evidence about what practitioners have observed and passed on. It is not the same kind of evidence as a controlled trial, and it should not be presented as though it were.

The published human research touching BL57 is mostly small, often conducted in a single centre, frequently using needling rather than finger pressure, and commonly combining several points at once — which makes it impossible to say what BL57 contributed. Studies in the area of post-operative anorectal discomfort and of muscle cramp have generally been too small, too varied in method, or too weakly blinded to support firm conclusions, and blinding manual therapies convincingly is a genuine methodological problem rather than an oversight. There is a broader and somewhat better-supported body of work on massage and manual pressure for muscle soreness and perceived recovery, which offers indirect plausibility for the calf-cramp use but does not validate the specific point.

In everyday clinical practice, what practitioners report is modest and short-lived relief: a cramping calf that releases sooner, legs that feel less heavy at the end of a shift, a person who sleeps through the night more often. Those are exactly the outcomes hardest to measure and easiest to attribute to expectation, rest and attention. That does not make them worthless — comfort is a legitimate goal — but it does mean nobody should describe BL57 as treating a condition.

Use it as what it is: a comfortable, low-risk traditional self-care technique for a tired or cramping calf. Keep investigating the cause of recurrent symptoms alongside it, keep taking anything your clinician has prescribed, and do not let a familiar routine delay a proper assessment of a calf or a bleed that is behaving unusually.