Diwuhui

What is GB42?

GB42, or Diwuhui, is a Gall Bladder channel point on the top of the foot, between the fourth and fifth long foot bones.

The name Diwuhui is usually translated as "Earth Fivefold Convergence". It is one of the small foot points on the Gall Bladder channel, sitting between GB41 (Zulinqi) behind it and GB43 (Xiaxi) in front of it.

In classical texts GB42 is linked to the side of the body that the Gall Bladder channel is said to run through: the ribs, the armpit, the breast, the ear and the eye. Older sources also list swelling and pain of the foot itself. It appears in the standard point lists, but it is a minor point. Many practitioners go years without using it, reaching for its better-known neighbours instead.

Here is the honest verdict on the evidence. No useful human research on GB42 specifically could be found, so nothing on this page should be read as a tested treatment. Acupressure research as a whole is mostly small, short and unblinded, and almost all of it studies famous points such as PC6, LI4 and ST36 rather than this one.

Two things are worth saying once, clearly, and they will not be repeated in every section below. First, a long traditional record is not evidence that a point works; people have used a point for centuries in many places where it does nothing measurable. Second, a long traditional record is not evidence that a point is safe either. Safety has to be judged from what is actually under your fingers, which here is skin, tendon, small veins, nerves and bone on the top of the foot.

Treat GB42 as a comfort practice you can try, not as therapy. If something is wrong with your foot, your ribs, your breast, your ear or your eye, that still needs a real assessment.

Where is GB42 and how do you find it?

GB42 sits on the top of the foot, in the groove between the fourth and fifth metatarsals (the long foot bones), roughly a thumb-width behind the knuckle of the fourth toe.

• Start at the fourth and fifth toes. Sit down and rest your foot on the opposite knee so you can see and reach the top of it. The fifth toe is the little toe; the fourth is the one next to it.
• Trace back into the web. Run a fingertip from the gap between those two toes backwards onto the top of the foot. You are following a shallow channel between two bones.
• Pass GB43. GB43 (Xiaxi) is right at the edge of the web, where the toes split. Keep going back from there, away from the toes.
• Find the knuckle line. About one to two centimetres back you will feel the rounded heads of the toe knuckles under the skin. GB42 is just behind the fourth toe knuckle, still in the groove between the bones.
• Drop into the hollow. Press gently side to side until your fingertip settles into the soft dip between the two bones. That dip, about one cun (one thumb-width) behind GB43, is GB42.

A useful cross-check: GB41 (Zulinqi) lies further back again, where the bases of the fourth and fifth metatarsals meet, closer to the ankle. If your finger is in that deeper junction near the midfoot, you have gone too far and are on GB41, not GB42.

You may feel a tendon running over the little toe side of the groove when you lift your toes. GB42 is described as sitting just to the inner side of that tendon. Feet vary, so work by feel rather than by ruler. If you land in the soft dip between the bones, a short way behind the fourth toe knuckle, you are close enough for finger pressure.

How do you apply pressure to GB42?

1. Get comfortable first. Sit in a chair and rest the ankle on the opposite thigh. Trying to reach your foot while standing or bending over a sink is how people strain a back.
2. Use the pad of a thumb or finger. Place the soft pad, not the nail, in the groove between the fourth and fifth foot bones. The space is narrow, so a fingertip often works better than a thumb.
3. Press straight down, slowly. Build pressure over two or three seconds rather than jabbing. There is very little padding here, so a small amount of force goes a long way.
4. Aim for firm, not fierce. You want a dull, bearable ache at roughly three or four out of ten. Sharp, burning or shooting sensations mean move off, not press harder.
5. Hold or circle for 30 to 60 seconds. Either hold steady pressure or make small slow circles. Breathe normally; people tend to hold their breath and tense the whole leg.
6. Release and repeat. Ease off over a couple of seconds, rest for about half a minute, then repeat two or three times. Do the other foot if you like symmetry.
7. Keep sessions short. Two or three rounds, once or twice a day, is plenty. More time does not buy more effect and does bruise skin.

Stop straight away if you feel numbness, pins and needles, a shooting pain into the toes, or any increase in swelling. Stop if the skin reddens and stays red, or if a tender spot is still sore the next day.

Do not use hard tools, pointed massage sticks or the corner of a phone on this spot. The bones and the small veins on the top of the foot are close to the surface, and a tool removes the feedback your own finger gives you.

If you are not sure whether pressure is safe on your foot, press somewhere fleshier instead and ask a clinician first.

What is GB42 traditionally used for?

• Rib-side and chest tightness. Classical sources link GB42 to pain and fullness along the sides of the chest, following the Gall Bladder channel. There is no human trial testing finger pressure at GB42 for this, so treat it as tradition only. New or severe chest pain is a reason to call for help, not to press a point.
• Breast swelling and tenderness. Older texts list breast distension and pain, often around the menstrual cycle, among the uses of GB42. No study has tested this point for breast symptoms. A lump, skin change, nipple discharge or one-sided pain that does not settle needs examining by a doctor.
• Armpit swelling. The classical record mentions swelling under the arm. That is an unevidenced traditional claim, and swollen armpit glands have real medical causes worth checking rather than massaging.
• Ear noise and ear fullness. Tinnitus (ringing or buzzing in the ears) appears in traditional indication lists for several Gall Bladder channel points, including GB42. Acupuncture trials for tinnitus overall are mixed and generally low quality, and none of them isolates GB42.
• Red, sore eyes. Tradition connects this channel to the outer corner of the eye, so eye redness and pain show up in the lists. There is no evidence that pressing the foot changes an eye problem. Painful red eye with blurred vision is urgent and needs same-day care.
• Sore, swollen top of the foot. This is the one local use, and it is the most plausible simply because the point is where the complaint is. Gentle self-massage around a stiff midfoot can feel good, but that is general massage comfort, not a specific GB42 effect, and it is not proof the point does anything special.

Across all of these, the honest position is the same: people report that steady pressure feels calming and distracting, and that is a real but non-specific effect seen with touch generally.

Are there tips for using GB42 effectively?

• Warm the foot first. A minute of rubbing, or doing this after a shower, makes the groove between the bones much easier to feel. Cold, tense feet hide their landmarks.
• Hunt with your fingernail, press with the pad. Use the edge of a nail to trace the gap between the fourth and fifth foot bones, then swap to the soft pad once you have found the dip. This stops you scratching the skin.
• Let the ache guide you. The spot that gives a dull, slightly tender ache is usually the right one. If every point on your foot is equally sore, stop looking and rest the foot instead.
• Keep the toes relaxed. Clawing or gripping the toes tightens the tendons over the top of the foot and narrows the space. Let the foot hang loose.
• Do both feet. Tradition treats the point on both sides, and it also stops you fixating on one spot. A minute per side is enough.
• Time it when you can sit still. Evening, on the sofa, with the ankle across the knee, beats a rushed thirty seconds before running out the door. Slow breathing is doing at least as much work as the thumb.
• Trim the nail you press with. A long nail turns steady pressure into a point load and can break the skin on a thin-skinned foot.
• Keep a short note. Write down when you pressed and how you felt afterwards. Over two weeks you will see whether anything is actually changing or whether you are remembering the good days.
• Use it alongside ordinary care. Supportive shoes, a rest day, a cold pack, or the treatment your doctor has already prescribed will usually do more for a sore foot than any point.
• Stop if it stops feeling good. There is no benefit to pushing through pain here, and nothing in the tradition asks you to.

What do people get wrong with GB42?

• Expecting a cure. This is the biggest one. No acupressure point cures tinnitus, breast pain or eye disease, and GB42 has no human trials behind it at all. Try it as comfort, judge it honestly, and keep your other care going.
• Pressing GB43 or GB41 by mistake. GB43 sits right at the web where the fourth and fifth toes split; GB41 sits much further back where the bases of those bones meet. GB42 is between them, just behind the fourth toe knuckle.
• Landing on bone. People press the hard ridge of the metatarsal instead of the soft groove alongside it. Slide sideways until your fingertip drops into the dip.
• Using a tool. Pens, massage sticks and knuckle rollers concentrate force onto thin skin over bone. Fingers give you feedback that a tool cannot.
• Grinding away for ten minutes. Long, heavy sessions produce bruising and a sore foot, not better results. Thirty to sixty seconds, repeated two or three times, is the sensible dose.
• Pressing an injured foot. A foot that is newly swollen, bruised, hot or painful to stand on may have a fracture, an infection or a gout flare. Pressure will not help any of those and may make things worse.
• Ignoring the symptom that sent them here. Using GB42 for a breast lump, a one-sided ear noise, or a red painful eye while delaying a medical appointment is the real risk on this page.
• Taking the old moxa warning as a safety rule. Some classical texts warn against burning herb on Diwuhui. That is a historical note about a heat technique, not a tested finding, and it says nothing about finger pressure either way.
• Assuming more pressure is more effective. Firm and bearable is the target. Pain that lingers overnight means you overdid it.

What does the research on GB42 actually say?

There is essentially nothing. A search for human research testing GB42 specifically turns up no controlled trials of acupressure at this point for any condition, and no trial where GB42 was the single point studied. Nothing honest can be built on that.

What exists instead is background. Acupressure as a field has a modest research base, and most of it shares the same weaknesses: small numbers of participants, short follow-up, and designs where people know whether they were pressed or not. That last problem matters, because expectation and attention alone shift self-reported symptoms like pain, nausea and anxiety.

There is one clear exception in the wider literature, and it is worth knowing so you can see the contrast. PC6 on the wrist has genuine controlled human evidence for reducing nausea and vomiting, including after surgery and in pregnancy. That is what decent evidence for an acupressure point looks like. GB42 has nothing resembling it.

Where GB42 appears in acupuncture studies at all, it is as one name in a longer list of needled points in a treatment protocol. Those studies involve needling by practitioners, which is not what this page describes, and a multi-point protocol cannot tell you what any single point contributed. Reporting that a trial needled a point is just describing what the trial did.

What does this mean for you? It means claims you see about GB42 for tinnitus, breast pain or eye problems are drawn from classical texts, not from tested results. Absence of evidence is not proof the point does nothing, but it does mean nobody can tell you it works. If pressing it feels pleasant and you keep your real medical care in place, the downside is small. If you are swapping it for treatment that has been shown to help, the downside is not small at all.