Sanjian (LI3): Hand Pressure Point for a Lower Back That Aches Most Days

Where Sanjian Sits

Make a loose fist and look at the back of your hand. The knuckle of your first finger stands up as a round dome. Slide a fingertip straight back from that dome toward your wrist, keeping to the thumb side of the bone. Within a centimetre your fingertip drops off the round into a small notch. That notch is the spot. Standard reference works describe it as lying on the back of the hand, in the depression on the thumb side. It sits right behind the joint where the long bone of the first finger meets the finger itself. In Vietnamese traditional medicine it sits on the same line as the better-known point further back in the web. That line runs from the first finger up the outside of the arm to the face, and is known in English as the Large Intestine channel.

What you are pressing against is bone on two sides. In front of you is the flared head of the long bone of the first finger; behind and under your fingertip is the narrower shaft. The hollow between them is small, and the tissue filling it is thin. It holds a slip of the muscle that pulls the first finger sideways, the tendon sheath running out to the finger, and not much else. This is a place where you can reach bone quickly, so the pressure here is lighter than in the muscle mound further back toward the wrist.

The skin over the area is supplied by a nerve that runs down the thumb side of the forearm (the superficial branch of the radial nerve). It carries signals from the sixth and seventh nerve roots of the neck, and small branches run out along the finger from there. Immediately beneath, the small muscle answers to a deeper nerve on the little-finger side (the deep branch of the ulnar nerve). That nerve comes from the eighth neck root and the first chest root. A vein from the network on the back of the hand often crosses this corner and can be visible under thin skin. Press on muscle and bone, not on a raised vein.

Why This Spot

The joint at the base of the first finger is one of the busiest hinges in the body. Every grip, every pinch, every turn of a jar lid loads it, and the small muscle and tendon running past the notch take that load hundreds of times a day. Tissue that works like that grows tender bands, and tender bands are what you feel when your fingertip lands in the hollow. Pressing there gives you a firm bony backing to work against, which is why a small notch is easier to work usefully than a broad soft area.

In this tradition the dip is described as the third station along the channel of the first finger. It is a place where the line is said to have gathered enough strength to affect the body away from the hand. The old writers grouped the stations at this depth with complaints of heaviness, and heaviness is exactly how most people describe a low back that has been aching all day. That is the reasoning behind its use. It is a system of correspondences from a much older world, and we pass it on as such, without dressing it up in modern language.

What the Old Texts Say About Sanjian

The framework this point belongs to is laid out in the Spiritual Pivot (Ling Shu), the second half of the Yellow Emperor's Inner Classic, compiled in the Han dynasty. Its chapter on the transport points describes each channel as a watercourse. It starts at the fingertip and grows as it runs toward the elbow. There is a well at the very tip, then a spring, then a stream, then a river, and finally a sea. The dip behind the knuckle is the stream — the third station, which is where its classical name comes from, a name that translates as the third space.

That classification is not decoration. The Classic of Difficulties (Nan Jing), also from the Han period, devotes its sixty-eighth chapter to what each of the five stations was used for. The line for the stream stations reads that they govern heaviness of the body and aching of the joints. Two thousand years later that single sentence is still the reason a Vietnamese practitioner reaches for a point on the hand. This is when a patient describes a back that feels heavy rather than sharp.

The first book to give the spot a settled address and its own list of complaints is The Systematic Classic of Acupuncture and Moxibustion (Zhen Jiu Jia Yi Jing). Huangfu Mi compiled it around the year 259, and it is the oldest surviving manual that works through the body point by point. It records this one for pain across the back of the hand, for a swollen and painful first finger and for aching in the lower teeth. It also lists sore throat and eyes that feel hot and tired.

In 1026 the Song court physician Wang Weiyi published the Illustrated Manual of Points on the Bronze Figure (Tongren Shuxue Zhenjiu Tujing). In 1027 two hollow bronze men were cast to go with it, with a hole at every point, waxed over and filled with water for examinations. The notch behind the knuckle was among the locations those statues pinned down. The address has hardly shifted since. The Great Compendium of Acupuncture and Moxibustion (Zhen Jiu Da Cheng, 1601) collected the older material into the form most practitioners still learn from.

Points That Work With Sanjian

The muscle mound in the web of the thumb. Slide further back along the same bone, toward the wrist. Stop when your thumb leaves the ridge and sinks into the springy muscle between thumb and first finger. This is the baseline point of the whole hand set and the one most people work first. Note that it carries a caution in pregnancy; the notch behind the knuckle does not.

The hollow at the base of the thumb. Stick your thumb out sideways. Two cords rise at the base of the thumb with a small hollow between them, right at the wrist fold. Reach for it when the wrist and thumb themselves ache, and use it after the notch when a stiff hand is part of the picture.

If your back has suddenly locked, rather than aching for weeks, the two points in the middle of the back of the hand are the page to read instead. If your back has ached for years, the foot point for lower back pain is another page to read.

How to Press Sanjian With Your Thumb

Getting Into Position

Sit upright with both feet flat on the floor and your back supported — a dining chair is better than an armchair here. Rest the working forearm on your thigh with the hand half closed, palm down, so the knuckles face you and the arm is fully supported. Shoulders down. If you find yourself lifting the hand toward your face to see it better, put it back on your thigh and work by feel.

How to Find It

Put the pad of the opposite thumb on the knuckle of your first finger. Roll it backward toward your wrist, staying on the thumb side of the bone, until it slides off the dome and drops into a notch. That drop is unmistakable once you have felt it: hard round bone, then a small step down into softer tissue, then hard bone again a few millimetres further back. Settle in the middle of that step.

Press in gently, angling slightly toward the thumb side rather than straight down. Most people describe a dull, tight ache that stays local — it does not spread far into the hand. Some feel a fine gritty or stringy band that rolls under the thumb pad. On a hand that does a lot of gripping, the notch is often noticeably more tender than the same notch on the other hand. That difference is the most useful signal you will get. If you feel a sharp, bright pain on first touch, you are on the joint line rather than behind it; move back another two or three millimetres toward the wrist.

How to Press It

Use the pad of the opposite thumb, never the nail, and support the underside of the hand with your other fingers so you can squeeze rather than shove. Angle the pressure down and slightly toward the thumb, so the tissue is pinned against the side of the bone. The area is small, so keep the contact small too — the middle of the thumb pad, not the whole flat of it.

The steady hold suits this point best. Sink in over two or three seconds, stay while you breathe out, ease off over two seconds, rest for a breath, repeat. If the notch feels thick and stiff rather than tender, small slow circles about the width of a grain of rice work better — one circle per second, no more.

How Much Pressure

Firm enough for a clear dull ache, light enough to keep talking. Because bone is close here, most people need noticeably less pressure than in the muscle of the web. Two tests. If you are holding your breath, ease off until your breathing carries on by itself. If the shoulder on the working side has climbed toward your ear, that is bracing, and bracing means you have gone past useful. Drop the shoulder, then press again only as deep as lets it stay down.

How Long

Five slow breaths pressing, one breath resting, three times through — about a minute on that hand. Then change hands and repeat, even if the second side feels like nothing at all. Twice a day is enough. If the notch is sore to the touch the next morning, you pressed too hard the day before; halve the pressure rather than skipping the session.

When to Do It

For a low back that stiffens overnight, work both hands while you are still sitting on the edge of the bed, before you stand up. For a back that aches by the end of the day, work them in the chair in the evening.

What This Won't Do

It will not change what is happening in your spine. If a disc is bulging, if a joint is worn or if a nerve is being squeezed, pressing a notch on your hand does nothing to any of those. Nobody honest will tell you otherwise. What people report is modest and worth having. A back feels less heavy when they stand up. A stretch goes a little further. An evening is easier to sit through.

Some back pain needs a doctor, not a hand point, and the difference matters. Get seen promptly if pain runs down your leg past the knee, or if your foot or leg feels weak or numb. Do the same if you have numbness around the saddle area between your legs, or if you lose control of your bladder or bowels. Get seen promptly too if the pain came on after a fall, if it wakes you every night, or if it comes with fever or unexplained weight loss. Those are not things to work through at home, and delay makes them worse.

Pressure work sits alongside medical care. Stay away from a joint that is hot, red and swollen, and get a proper opinion on finger joints that are changing shape or giving way under load. None of this replaces an examination or any medicine you have been prescribed.

Safety First

Do not work on skin that is broken, burned, infected, bruised or newly scarred, and stay off any raised vein you can see on the back of the hand. Keep off any joint that is hot and swollen. If you take blood-thinning medicine or bruise easily, use half the pressure you think you need. If you have had surgery on the hand or a fracture in the past few months, ask your surgeon before you begin.

Stop if the feeling turns sharp, electric, burning or numb instead of a dull ache — that is a signal to come off the spot, not to push through. This point carries no pregnancy caution. If you are pregnant and new to pressure work, speak to your doctor before starting anything, and read the full safety guide first.

Questions People Ask

Where is the Sanjian (LI3) pressure point? Sanjian (LI3) is in the small notch on the back of the hand, immediately behind the knuckle of the first finger, on the thumb side of the bone. Roll your thumb back from the round of the knuckle until it drops into a small hollow. That drop is the spot.

How long should I press Sanjian? Press for five slow breaths, rest for one breath, and repeat three times. That is about a minute on that hand. Then change hands and repeat. Twice a day is enough. If the notch is sore the next morning, halve the pressure rather than skipping the session.

How can a point on my hand have anything to do with my back? In this tradition the hand and the back are linked through a line of correspondences, not through anything you can see under a microscope. The honest answer is that the old texts group this dip with complaints of heaviness and aching joints, and that is why it is used this way. We make no claim about a mechanism.

Should I press the knuckle itself? No. The knuckle is the round end of the bone and there is nothing useful to press there. The spot is in the notch immediately behind it, on the thumb side, where the bone narrows and your fingertip drops into a small hollow.

My finger joints are knobbly and sore. Is this still safe? Stay off any joint that is hot, red or swollen, and stay off a joint that hurts sharply the moment you touch it. If the joints are merely stiff and achy, work the notch behind the knuckle rather than the joint line itself, and use light pressure. If you are not sure which is which, ask your doctor.

How soon should I expect to notice anything? Most people who notice anything at all notice it within the session — the back feels a shade looser when they stand up. If two weeks of daily work changes nothing, this is not your point, and there is no sense in grinding away at it.

Other Points in This Library

Each of these sits within reach of the same hand. They are often worked in the same sitting.

This page shares general information about a traditional practice. It is not medical advice and does not replace what your doctor has given you. If you are pregnant, managing a health condition, or unsure whether this applies to you, check with your doctor first.

The whole inner edge of the foot, laid out on one page with photographs, is in The Foot Map — the free book. For every point in this library, see the full pressure point index.

(Point shown: LI3 · Sanjian · Tam Gian.)