Zhibian (BL54): The Low Buttock Point for Sciatic Ache and a Sore Tailbone Area

Where Zhibian Sits

This point lies low in the buttock, level with the lower end of the flat triangular bone at the base of the spine, about four finger-widths out from the centre line. It is a deep, quiet spot, tucked into a part of the body most of us never touch on purpose. It deserves attention because a great deal passes beneath it.

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 head and down the back in two parallel tracks on each side of the spine. The outer track ends here. This is the last point of the back before the line turns down the leg, which is where its name, the edge of the order, comes from.

The old texts place it beside the twenty-first vertebra, counting down the whole spine, three units out from the centre. The modern standard from the World Health Organization describes the same place in today's terms: level with the fourth opening in the sacrum, three units out from the ridge of bone running down its middle. The sacrum is the flat triangle of bone at the back of the pelvis, between the two buttocks. Its fourth openings sit near its lower end, at about the level where the cleft between the buttocks begins. Three units is about four finger-widths of your own hand laid side by side.

Under the skin is the thick lower part of the large buttock muscle (the gluteus maximus). Beneath that lies a deeper, pear-shaped muscle (the piriformis) that runs from the front of the sacrum out to the top of the thigh bone and turns the leg outward. The point sits near its lower edge. Right there, the sciatic nerve, the largest nerve in the body, leaves the pelvis through a wide notch in the bone and starts its run down the back of the leg. The skin over the point is served by small nerves from the first to third sacral roots. That crowding of muscle and nerve is why this spot can be very tender, and why it must be pressed with care.

Why This Spot

On the anatomical side, this is a pinch point. The sciatic nerve leaves the pelvis under the pear-shaped muscle, and in some people part of the nerve even runs through it. When that deep muscle tightens, from long sitting, an awkward lift or a limp, it can press on the nerve and send an ache down the back of the leg. The lower buttock also takes much of your weight on a hard seat. People who sit for long hours, or who favour one side, often find a deep, tender knot here.

In this tradition, the line this point sits on carries the flow of the whole back. This point marks the place where the back ends and the leg begins. It is used when pain gathers deep in the buttock and seems to block the road between the back and the leg, and for complaints in the lowest part of the trunk.

The name describes its place in the line. Zhi means order, the sequence of points down the back. Bian means edge. This is the edge of that order, the last point of the back. The Vietnamese name Trật Biên carries the same idea.

What the Old Texts Say About Zhibian

The Systematic Classic of Acupuncture and Moxibustion, the Jiayi Jing, compiled by Huangfu Mi in the third century, places this point beside the twenty-first vertebra, three units out from the spine. The old way of counting ran from the top of the back all the way down into the sacrum, so the twenty-first sits low, in the bone at the base of the spine. That is the same place the modern standard describes with different words.

The Vietnamese handbook of points and channels by Ngô Trung Triều, published by Hồng Đức, follows the same count. It places the point on each side of the spine, below the twenty-first vertebra and three units out. To find it, the handbook says, take the line across the tip of the fourth sacral spine and meet it with a vertical line three units out from the centre; or start from the fourth sacral opening and move straight out. It lists the point for sciatic pain, weakness of the lower limbs, and complaints of the back passage and the pelvic organs.

Notice what ties that list together. Everything on it lies in the lowest part of the trunk or follows the nerve that leaves it. In the wider tradition, this point is one teachers use when the ache feels deep and heavy in the buttock rather than sharp in the back. That reputation rests on long use, not proof. It tells you where generations of practitioners found tender, useful tissue.

Points That Work With Zhibian

The first partner lies in the side of the buttock, higher and further out. Find the bony knob at the upper outer side of the thigh and move about a hand's width in toward the base of the spine. In this tradition the two are paired when the ache sits deep in the buttock and runs down the back and side of the leg. Both are pressed the same way, with a ball.

The second sits lower, in the middle of the crease where the buttock meets the back of the thigh, in line with the bony point you sit on. It is used with this one when the ache moves out of the buttock and down the thigh.

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 and leg pain in this tradition, and closes the sequence when the pain runs past the knee.

How to Find and Press Zhibian

Getting Into Position

Lie on your back on a carpeted floor or a firm mattress, with knees bent and feet flat, hip-width apart. A soft bed lets the ball sink away. If getting down to the floor is hard, stand with your back to a wall instead, feet about a foot from it, knees soft, and place the ball between the wall and your buttock. Standing gives you the most control, because you can step away at once.

How to Find It

Reach behind and find the top of the cleft between the buttocks. Lay four fingers of the same hand flat, side by side, starting at the cleft and pointing out toward the hip. The far edge of your fingers, at that level, is the area. Place a tennis ball there and lower your weight onto it slowly. A softer, well-used ball is gentler than a new one. If you prefer, a long-handled pressing tool with a rounded tip will reach the same spot from behind while you stand.

Shift in small steps, a little higher and lower, a little in and out. Much of the area will feel like plain pressure on muscle. One spot will sting: a small, sharp, pinpoint tenderness deep under the ball. That spot is the point. If you feel tingling, numbness or a line of pain running down the leg, you are on the nerve. Lift off, move the ball slightly upward or outward, and lower more gently.

How to Press It

Once you are on the stinging spot, stay with it. Rock your hips in small circles, about the size of a coin, roughly one each second, so the ball rubs the same spot without rolling away. Against a wall, bend and straighten your knees a little to make the same small movement. With a tool, hold the handle in both hands, place the tip on the spot and make small circles without sliding.

How Much Pressure

A sharp sting under the ball is right. When you lift off, 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 tingling or numbness down the leg. If you are holding your breath or clenching your jaw, you are pressing too hard. Take some weight onto your feet, or step a little closer to the wall, until you can breathe slowly through the sting.

How Long

One to three minutes on each side. Keep the first session short and gentle, about a minute, because the deep buttock is often more tender than people expect and can feel bruised the next day. Add a little time over the following days, up to three minutes. Work both sides. Once a day is usually enough. More time brings more soreness, not more benefit.

When to Do It

Morning suits a back and buttock that are stiff on waking. Late afternoon suits an ache that builds after long sitting or driving. Before bed works well too, as part of winding down. Do not press in the middle of the night. If pain wakes you, getting onto the floor with a ball will only wake you more. Keep it for the day and the evening.

What This Won't Do

It will not change what is irritating the nerve if the trouble sits in the spine. Most sciatic pain begins in the lower back, where a worn disc, a narrowed channel or thickened joints press on a nerve root. A ball in the buttock cannot reach that. Even when the deep buttock muscle is part of the problem, pressing alone rarely settles it; it responds best to regular walking, gentle stretches for the hip, breaks from sitting and a supportive seat. This point can give you local relief and a sense of doing something useful each day. Count that as a real but modest gain.

Some back and leg pain is an emergency. Go to hospital the same day if you have numbness in the saddle area, between the legs or around the back passage, or any new loss of control of your bladder or bowels, or difficulty passing water. Get seen urgently if a leg or foot turns weak, if the foot catches or drags, or if numbness is spreading. See a doctor promptly for pain after a fall, especially if your bones are thin, for pain with fever or unexplained weight loss, and for pain that worsens week on week.

Safety First

If you are pregnant, skip this one. The low back and the area beside the base of the spine carry a traditional caution in pregnancy. Do not press over skin that is broken, infected, badly bruised or rashy. Leave the area alone after a recent fall onto the buttock or a pelvic fracture, with a hip replacement in its first months, 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, less weight and shorter sessions, 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 Zhibian (BL54) pressure point? Zhibian (BL54) lies in the lower part of the buttock. Find the top of the cleft between the buttocks, then move about four finger-widths straight out toward the hip. The point sits there, level with the lower end of the flat bone at the base of the spine. In Vietnamese it is called Trật Biên.

How do I press a point I cannot see or reach? Let a tennis ball and your own weight do it. Lie on your back with knees bent and place the ball under the spot, then shift slowly until one spot stings. Standing with your back to a wall and the ball between wall and buttock works too. A long-handled pressing tool with a rounded tip is another option. None of these needs another person.

Is Zhibian (BL54) good for sciatica? In this tradition it is commonly used for sciatic ache and deep buttock pain. The large nerve of the leg leaves the pelvis close to this spot, under a band of deep muscle that can tighten. Pressing can ease that tight, tender tissue. It does not change what may be pressing on the nerve in the spine.

Can I press Zhibian while pregnant? No. If you are pregnant, skip this one. The low back and the area beside the base of the spine carry a traditional caution in pregnancy, and lying on a ball there is not wise either. Ask your midwife or doctor about safe ways to ease buttock and back pain.

How long should I press Zhibian? One to three minutes on each side. The first session should be short and gentle, about a minute, because this area is often more tender than expected. Build up a little over the following days. Once a day is usually enough.

My leg tingled when I lay on the ball. What does that mean? You are pressing on the nerve. Lift your hips off the ball at once. Move the ball a little higher or a little further out toward the hip, and lower more gently. The feeling you want is a small sting under the ball. Tingling, numbness or a line of pain down the leg means stop.

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: BL54 · Zhibian · Order's Edge · Trật Biên.)