Shenshu (BL23): The Waist-Level Back Point for a Tired, Aching Lower Back

Where Shenshu Sits

This point sits on the lower back, about two finger-widths out from the centre of the spine, at roughly the level of your waist. It lies in the thick band of muscle that runs up beside the spine, the band you can feel tighten when you bend forward and come back up.

It belongs to the line that Vietnamese and Chinese texts call the Bladder channel. That line begins at the inner corner of the eye, runs over the top of the head, and comes down the back in two tracks on each side of the spine. The inner track runs about two finger-widths from the centre and carries a row of points, one for each organ in this tradition. This one, the twenty-third stop, belongs to the kidney.

The old texts place it below the fourteenth vertebra, one and a half units out from the spine. The count starts at the top of the back, so the fourteenth is the second vertebra of the lower back. The modern standard from the World Health Organization says the same in today's words: level with the lower border of the second lumbar spinous process, one and a half units out from the midline. The spinous processes are the bumps you can feel down the middle of your back. One and a half units is about the width of your index and middle fingers laid side by side.

Under the skin is a tough sheet of connective tissue that wraps the lower back like a corset. Beneath it runs the long muscle that keeps the spine upright (the erector spinae). Deeper still, against the side of the spine, lies a square muscle (the quadratus lumborum) that links the lowest rib to the top of the hip bone and holds you level when you stand on one leg. The skin over the point is served by small back branches of the first and second lumbar nerves. Well below all of this, under the lower ribs and protected by them, sit the kidneys.

Why This Spot

On the anatomical side, this is a hard-working corner. The muscles here hold you upright all day, take the strain every time you bend to lift a bag or a grandchild, and stiffen when you sit for long hours. After fifty, the discs between the vertebrae lose height and the small joints at the back of the spine thicken. The muscles beside them often tighten to guard the joints. A tired, dull ache across the waist, worse after standing and stiff on rising, is common. This spot sits in the middle of that ache.

In this tradition, every organ has a transport point on the back, where its energy is said to come close to the surface. This is the one for the kidney. In Vietnamese and Chinese medicine, the kidney is described as the root of the body's strength and the owner of the lower back, the bones and the ears. A lower back that feels weak and heavy rather than sharp, knees that tire, and a faint ringing in the ears are all read as signs that this root has grown tired with age. That is why this point is one of the first a teacher reaches for when an older person says their back gives out by evening.

The name says what it does. Shen is the kidney; shu means to transport. Its Vietnamese name, Thận Du, carries the same meaning.

What the Old Texts Say About Shenshu

The Systematic Classic of Acupuncture and Moxibustion, the Jiayi Jing, compiled by Huangfu Mi in the third century, places this point below the fourteenth vertebra, one and a half units out on each side. That location has hardly moved in seventeen centuries. The modern standard and the old book describe the same spot with different words.

The Vietnamese handbook of points and channels by Ngô Trung Triều, published by Hồng Đức, follows the same count. To find it, the handbook says, draw a line across the tip of the second lumbar bump and meet it with a vertical line one and a half units out from the centre. It lists the point for lower back pain, bed-wetting, deafness and ringing in the ears, long-standing loose bowels, and irregular periods, among other complaints.

Notice how the list fits the old picture. The lower back, the ears and the passing of water are all things this tradition places under the kidney. The point is chosen less for the exact place it hurts and more for the kind of tiredness behind the pain.

In the wider tradition, this is the point for the back of later life: the ache that is worse at the end of the day, the back that will not straighten after gardening, the cold, heavy feeling across the waist. Practitioners often warm it as well as press it. That reputation rests on long use rather than proof. It tells you that generations of hands found this spot useful for exactly the kind of back most people in their sixties know.

Points That Work With Shenshu

The first partner sits on the centre line of the spine at the same level, in the small gap below the second bump of the lower back. In this tradition the two are often worked one after the other, the centre point first and then the points on each side, when the whole waist feels weak and cold.

The second sits further out on the same level, about four finger-widths from the spine, at the outer edge of the long back muscle. It is used with this one when the ache spreads across the side of the waist as well as beside the spine. A tennis ball reaches both in the same sitting.

The third sits in the middle of the crease at the back of the knee. It is one of the most used points for back pain in this tradition, and is easy to reach sitting in a chair. Pair it with this one when the back is stiff and the legs feel heavy.

How to Find and Press Shenshu

Getting Into Position

Be honest with yourself about reach. Most people cannot press the middle of their own lower back well with their hands, especially with stiff shoulders. That is normal. Stand with your back to a wall, feet about a foot out from it, knees soft, and use a tennis ball between your back and the wall. A stick with a rounded end, reached around the waist, is another way. If you can reach, you may also put your hands on your hips and press with your thumb tips, but the thumbs tire quickly.

How to Find It

Put your hands on your hips with your thumbs pointing back, resting on the top edge of the hip bones. The line between your thumbs crosses the spine at the fourth bump of the lower back. Count two bumps up from there. That is the second. The point lies on each side of the gap below that bump, two finger-widths out. A rough check: with your arms hanging by your sides, the point is about level with your elbows.

Place the ball there and lean back into it slowly. Shift in small steps, a little up, down, in and out. Much of the area will feel like ordinary pressure on muscle. One spot will sting: a small, sharp, pinpoint tenderness deep under the ball. That spot is the point. Two balls tied in a sock let you work both sides at once, with the spine resting in the gap between them.

How to Press It

Once you are on the stinging spot, stay on it. Bend and straighten your knees a little, so the ball rubs in small circles about the size of a coin, roughly one each second, without rolling away. With a stick, hold the handle steady, place the rounded tip on the spot and make the same small circles. With your thumb tip, press in and slightly toward the spine. Do not press on the bony bumps themselves.

How Much Pressure

A sharp sting under the ball is right. When you step away, it should fade within moments. If the pain stays after you lift off, spreads, or the area turns swollen, hot or red, stop and leave it for several days. Stop at once for any pain shooting down a leg or any numbness. If you are holding your breath, you are pressing too hard. Step your feet a little closer to the wall, so less of your weight goes into the ball, until you can breathe slowly through the sting.

How Long

One to three minutes on each side. Keep the first sessions to about a minute, because the lower back is often more tender than expected and can feel bruised the next day. Add a little time over the following days, up to three minutes. Work both sides, even when only one complains. Once or twice a day is plenty. Longer sessions bring more soreness, not more benefit.

When to Do It

Morning suits a back that is stiff on getting up. Late afternoon suits the tired ache that builds after standing, walking or housework. Before bed is a good time too, as part of winding down. Do not press in the middle of the night. If back pain wakes you at two or three in the morning, getting up to lean on a wall will only wake you further. Keep the pressing for the day and the evening, and mention regular night waking from pain to your doctor.

What This Won't Do

It will not undo wear in the spine. Thinner discs, thickened joints and a narrowed channel for the nerves are part of how backs age, and no point reverses them. Pressing can ease tight, tender muscle and give you a few minutes of relief, which is real and worth having. What changes a back over months is plainer: walking most days, gentle strengthening for the trunk and hips, breaks from sitting, a bed and chair that support you, and keeping a healthy weight. This point works best as one small part of that.

It will not do anything for your kidneys as organs, and it is no substitute for a diagnosis. Pain in the side of the back that comes with fever, shivering, or pain or burning when you pass water needs a doctor the same day, because it can mean an infection. Go to hospital at once for numbness between the legs or around the back passage, new trouble controlling your bladder or bowels, or a leg that turns weak. See a doctor promptly for back pain after a fall, especially with thin bones, for pain that worsens week on week, for pain that is worse lying still at night, and for pain with weight loss you cannot explain.

Safety First

If you are pregnant, skip this one. The low back carries a traditional caution in pregnancy. Do not press over skin that is broken, burned, infected, badly bruised or rashy. Leave the area alone after a recent back injury or fall, with a known fracture in the spine, after recent back surgery, or with unexplained swelling or a lump. If you take blood thinners, bruise easily, have thin bones or reduced feeling in your legs, use a softer ball, lean in less, keep sessions short, and ask your doctor first.

Stop at once if pain stays after you lift off, spreads, or brings tingling or numbness. Nothing here requires you to push through pain. For the full list of cautions and the situations where pressing on yourself is not appropriate, read the full safety guide before you begin.

Questions People Ask

Where is the Shenshu (BL23) pressure point? Shenshu (BL23) lies on the lower back, about two finger-widths out from the centre of the spine, level with the second bump of the low back. Put your hands on your hips to find the fourth bump, then count two bumps up. In Vietnamese it is called Thận Du.

How do I press a point on my back I cannot reach? Most people cannot press their own lower back well with their hands, and that is normal. Stand with your back to a wall and lean on a tennis ball placed over the spot. Two tennis balls tied in a sock will sit on both sides of the spine at once. A stick with a rounded end, held over the shoulder or around the waist, also works.

Can Shenshu (BL23) help back pain that wakes me at night? In this tradition it is commonly used for a weak, aching lower back, including the kind that wakes you in the small hours. Press it in the daytime and before bed, not in the middle of the night. If back pain wakes you regularly, mention it to your doctor, because night pain deserves a proper look.

Why is it called a kidney point? In this tradition each organ has a matching point on the back, and this is the one for the kidney. The name reflects old ideas about energy and the lower back, not the kidney organ you see on a scan. Pressing here does not test or change how your kidneys work.

How long should I press Shenshu? One to three minutes on each side. Keep the first sessions to about a minute, then add a little as the days go on, up to three. Once or twice a day is enough. Work both sides, even if only one side aches.

Can I press Shenshu while pregnant? No. If you are pregnant, skip this one. The low back carries a traditional caution in pregnancy. Ask your midwife or doctor about safe ways to ease back pain.

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: BL23 · Shenshu · Kidney Transport Point · Thận Du.)