Wangu

What is SI4?

SI4, or Wangu, is a point on the little-finger edge of the hand, in the hollow between the fifth hand bone and the wrist bones.

Its Chinese name, Wangu, means "wrist bone", which is simply a description of where it sits. In traditional Chinese medicine it is the yuan-source point of the Small Intestine channel, a category that classical texts treat as important for the whole channel. That gives SI4 a high traditional standing: it appears in the old texts and in modern teaching lists alike.

Traditional standing is not evidence that a point works, and it is not evidence that pressing it is safe for you. Those are two separate questions, and this page keeps them separate. You will see the same point described with great confidence in videos; that confidence comes from tradition, not from trials.

The honest verdict on the evidence: there is essentially no human research on SI4 specifically. Acupressure research as a whole is mostly small, short-term and unblinded, meaning participants knew what they were getting, which inflates reported benefit. Within that already thin literature, SI4 has not been singled out for study. A handful of points have decent trial support for one narrow use — PC6 for nausea is the clear example — and SI4 is not among them.

What that means in practice is simple. Pressing SI4 is a low-cost, low-risk thing to try for general hand, wrist and neck tension, as long as the tissue under your finger is healthy. It is not a treatment for an injury, an infection, an ear problem or anything else, and it should never replace a proper look at a painful or swollen wrist.

Everything described on this page is self-applied finger pressure. Nothing here involves needles, heat, scraping or anything that breaks the skin.

Where is SI4 and how do you find it?

Find SI4 in the dip on the outer edge of your hand, between the base of the little-finger hand bone and the wrist bones.

• Start at the little finger. Rest your hand on a table, palm down and thumb up, so the little-finger side faces the ceiling.
• Trace the hand bone back. Run a fingertip from the knuckle of your little finger back towards your wrist, along the long bone beneath the skin. This is the fifth metacarpal.
• Feel for the bump and the dip. About two-thirds of the way back you will feel the bone widen into a knobbly base, then drop into a small hollow before the wrist bones begin.
• Settle into the hollow. That hollow is SI4. It sits roughly 1 to 2 cm in front of the wrist crease on the little-finger side, on the border where the pale palm skin meets the darker back-of-hand skin.
• Check with pressure. Gentle pressure here usually feels slightly tender or full compared with the bone on either side. Tenderness helps confirm the spot, but it is not a diagnosis of anything.

Classical texts place SI4 at the junction of red and white skin, which is the old way of saying that palm-to-back-of-hand colour change. Use bones and creases rather than measuring, because hand size varies a lot.

Two sanity checks. SI4 is on the hand, in front of the wrist, not in the wrist crease itself — that neighbouring hollow is a different point. And confusingly, there is a second point also called Wangu behind the ear, on a different channel entirely; if a video shows someone pressing their skull, that is not SI4.

How do you apply pressure to SI4?

1. Get set up. Sit down and rest the hand you are working on flat on a table or in your lap, little-finger edge upwards. Short nails and clean, warm hands make this more comfortable.
2. Place the thumb. Put the pad of the opposite thumb into the hollow you located. Use the flat pad, not the tip or the nail edge.
3. Press in gradually. Lean in slowly until you feel a firm, dull ache. On a scale where ten is unbearable, aim for about three or four. Sharp pain means ease off straight away.
4. Hold or circle. Hold steady pressure for 30 to 60 seconds, or make small slow circles in the hollow for the same length of time. Breathe normally; do not hold your breath.
5. Release and repeat. Let go slowly, rest for about 20 seconds, then repeat two or three times. The whole session takes two or three minutes.
6. Do the other hand. SI4 exists on both hands. Many people work both sides even when only one feels tense.
7. Keep the frequency sensible. Once or twice a day is plenty. There is no benefit to grinding at it for twenty minutes.

Stop immediately and do not continue if you get pins and needles, numbness or an electric sensation running into the little finger and ring finger. The ulnar nerve (the one behind the "funny bone") passes close to this area, and nerves do not like sustained squeezing.

Also stop if the skin reddens and stays red, if you bruise, or if the wrist feels worse after the session rather than the same or easier. Pressure should leave at most a brief dull warmth. Anything lasting more than a few minutes means you pressed too hard.

What is SI4 traditionally used for?

• Wrist and hand discomfort. Classical texts list SI4 for pain, stiffness and cramping of the wrist, hand and fingers on the little-finger side. This is the most plausible use, because you are pressing tense tissue near the sore area, and local pressure often feels good briefly. No controlled trial has tested SI4 for this.
• Neck and shoulder stiffness. The Small Intestine channel is described as running up the arm to the neck and face, so points on it are traditionally used for a stiff neck. Evidence for distal hand points relieving neck pain is weak and mixed, and nothing has tested SI4 on its own.
• Headache. Tradition assigns SI4 to headaches affecting the back and side of the head. There is some general trial evidence that acupuncture helps tension-type headache, but that is a different intervention using many points, and it does not transfer to finger pressure on SI4.
• Ear symptoms such as ringing. Old sources list tinnitus and hearing problems for Small Intestine channel points. Human evidence for acupressure helping tinnitus is thin and inconsistent, and none of it isolates SI4.
• Fever and jaundice in classical texts. Several historical sources list SI4 for febrile illness without sweating and for jaundice (yellowing of the skin and eyes). These are historical claims only. Jaundice in particular is a sign of liver or gallbladder disease and needs medical assessment, not pressure on the hand.
• Finger contracture and spasm. Tradition mentions SI4 for fingers that will not straighten. Modern causes of this, such as Dupuytren's contracture or nerve damage, are structural problems that pressure cannot change.

Taken together: SI4 may feel pleasant and may briefly ease local tension. Treat anything beyond that as an untested traditional claim rather than a known effect.

Are there tips for using SI4 effectively?

• Support the hand first. Resting the hand on a table lets the wrist muscles relax, so your thumb sinks into the hollow instead of fighting a braced arm. It also stops you twisting the wrist while you press.
• Hunt for the tender spot. Move your thumb a few millimetres in each direction until you find the dull, slightly achy spot. That small search matters more than hitting an exact textbook measurement.
• Warm the hand before you start. A minute under warm water or a few slow fist-and-spread movements makes the area easier to feel and more comfortable to press.
• Favour consistency over force. Two or three calm minutes a day is more useful than one hard session. Harder pressure does not produce a bigger effect; it mostly produces bruises.
• Combine with gentle movement. If you are using SI4 for a stiff neck or tight hand, follow the pressure with slow range-of-movement stretches. Movement has better evidence behind it than the pressure does.
• Keep a simple log. Note the date, what you felt before, and what you felt an hour later. Over two weeks this tells you honestly whether SI4 does anything for you, which no article can tell you.
• Give it a fair trial, then stop. If a fortnight of regular use changes nothing, it is not working for you. Dropping it is a sensible result, not a failure.
• Use it alongside, not instead of. Keep taking prescribed medication, keep physiotherapy appointments, and keep using a splint if one was recommended. SI4 is an add-on comfort measure at best.
• Match the moment to the goal. Pressing during a work break or before bed suits tension-related aims. Pressing while rushed and tense tends to produce heavy-handed, uncomfortable pressure.

What do people get wrong with SI4?

• Expecting a cure. The commonest mistake by far. SI4 will not cure tinnitus, migraine, arthritis or a wrist injury, and anyone promising that is selling something. Expect, at most, a short period of feeling a little looser.
• Pressing the wrong Wangu. Two different points share the name Wangu: SI4 on the hand and another behind the ear on a different channel. Check that the video you are following is showing the hand.
• Landing on bone. People press the knobbly base of the little-finger hand bone instead of the hollow just behind it. Bone gives a hard, flat feeling with no dull ache. Slide back until your thumb drops into the dip.
• Confusing it with the wrist-crease point. SI4 is in front of the wrist crease, on the hand itself. The hollow right in the crease on the same edge is a different point entirely.
• Pressing far too hard. Bruising, redness that lasts, or soreness the next day all mean the pressure was excessive. Firm and dull is the target, not sharp.
• Ignoring nerve signals. Pins and needles or numbness in the little and ring fingers means you are compressing the ulnar nerve. That is a signal to stop, not to push through.
• Using it on an injured wrist. A wrist that is swollen, hot, deformed or painful after a fall needs imaging, not pressure. Some wrist fractures are easy to miss and get worse if loaded.
• Delaying proper care. Treating jaundice, unexplained fever, sudden hearing loss or new one-sided headache with hand pressure wastes time that matters.
• Pressing over a lump. Ganglion cysts are common near this part of the wrist. Do not squash one; have it looked at.

What does the research on SI4 actually say?

There is no useful human research on SI4 as a point in its own right. We found no controlled trial, and no credible single-point study, testing finger pressure on SI4 for any condition. That is the honest answer, and it is the usual answer for individual acupressure points.

Where SI4 appears in published work, it is almost always as one item in a multi-point needling protocol for hand, wrist or neck complaints, sometimes alongside nearby Small Intestine channel points. In that design, nothing can be attributed to SI4. If a group improves, the improvement could come from any point used, from the extra attention, or from the natural settling of the problem over time.

The wider acupressure literature has known weaknesses that apply here. Most trials are small, run for a few weeks, and cannot blind participants, who always know whether someone is pressing their hand. Expectation alone shifts self-reported pain and stiffness scores noticeably. Sham controls for acupressure are also imperfect, because pressing a "wrong" spot is still touch.

Two things are worth stating plainly for contrast. First, some points do have reasonable human evidence for a narrow use — PC6 acupressure for nausea and vomiting has been tested repeatedly in surgical and pregnancy settings and the signal there is real, if modest. Second, that evidence does not transfer. Being on the same arm, or near the same wrist, tells you nothing about whether SI4 does anything.

What this means for you: treat SI4 as a traditional practice you may find pleasant, not as a treatment with a known effect size. Keep your own two-week record and judge it on that. If something in your hand, wrist, head or hearing is getting worse, the research gives you no reason to persist with pressure instead of seeking assessment.