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Mula Bandha Anatomy

Feeling and Controlling the Elusive Root Lock"

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anatomy of a mula bandha, piriformis, obturator internus, cocygeus, iliococygeus, pubococygeus, puborectalis

"Just engage your mula bandha!"

"You mean like this..."

Because mula bandha (or "Moola" bandha) is so close to the anus it's not the type of thing you go showing people in class. And it could also be construed as rude or innapropriate if you are found looking at someone elses.

"Hey, I was just checking out your root lock!"

"No worries, come to my house and we can check it out together..."

Bad humor aside the root lock or master key is described as an energy lock. Where uddiyana bandha sends energy upwards and jalandhara bandha catches it all, Mula prevents the downward flow of energy and is said to reverse it.

(Here's a look at the bandhas as tension control mechanisms.)

(To develop awareness of the belly and abdominal area as well as the diaphram you might be interested in reading about agni sara, nauli kriya and the respiratory diaphragm.)

Mula Bandha Helps You to Work More Efficiently

One way of looking at this definition of mula bandha is that it helps you to work more efficiently.

It could be like the difference between a highly tuned formula 1 racing car, and a beat up old Pinto. Hmm, that's probably not a good analogy since the pinto would probably use less gas, however, the Formula 1 car would be better at going faster with less effort...

Perhaps more to the point, in the F1 car, every connection, every fitting has tolerances. Each piece fits with the next exactly. Meanwhile the parts of the pinto's engine may be rattling oll over the place, particularly if it hasn't been looked after.

The finely tuned racing machine transmits energy efficiently and the result is a car that goes really, really fast. Meanwhile the old pinto, with bits and pieces rattling all over the place loses energy. Actually, any car with poorly fitting parts will lose energy.

So what's this to do with Mula Bandha? If it does save energy it probably does so by making a better connection between one part of the body and the next. One key to understanding this root lock is understanding what it ties together.

Pull Your Tail Bone Towards Your Pubic Bone

Generally root lock is described as a lifting of the anus or perineum. (Some would say that lifting the anus is more properly described as ashwani mudra.)

The perineum is a point just in front of the anus and so lifting the anus might be a useful reference for then learning to lift the perineum. (You do know where your anus is don't you?)

"Lift your anus!" the teacher commanded with a fiery look in his eyes.

"But I'm lifting my anus, teacher, I'm lifting as hard as I can."

"That is not good enough. You must lift it higher!!! You must lift it so high... that it touches the roof of your mouth."

"You are crazy teacher!"

"I am. So don't mess with me. Just lift."

One way to begin the engagement of mula bandha is to focus on pulling your coccyx towards your pubic bone.

hip bone and sacrum, side view of pelvis, sacrum, coccyx, greater sciatic notch, ischial spine, lesser sciatic notch

Forgetting any philisophical associations or meanings for now and focusing on anatomy, the muscle that you can use to accomplish this action is the pubococygeus.

Gregor Meaehel mentions this muscle in his book Ashtanga Yoga Practice and Philosophy but he doesn't say specifically how to contract it.

I would suggest that instead of trying to lift mula bandha, contract it instead.

"Hey, why are you doing that with your face?"

"I'm practicing my mula bandha!"

Anatomy of the Root Lock

anatomy of a mula bandha, piriformis, obturator internus, cocygeus, iliococygeus, pubococygeus, puborectalis

If you put your awareness in the region of a particular muscle it is easier to activate that muscle. It is even easier if you know the end points to which that muscle attaches. You can then contract that particular muscle by drawing one end point towards the other.

(The tail bone is also known as the coccyx!)

I would suggest that once you've found this beginner's mula bandha, practice smoothly and slowly engaging it and smoothly and slowly relaxing it.

The ability to relax it is just as important as the ability to contract it.

And so that you can do both it helps if you can feel when it is relaxed or contracted.

When contracting, focus on the bottom tip of your sacrum. Say about the bottom centimeter (or bottom 1/2 inch.)

Move your awareness around until you can feel a "muscular pulling sensation" when your tailbone forwards.

You may also find it helpful to focus on pulling the sides of your tail bone forwards.

What Does it Do?

"Uhhh, teacher, why are we doing this?"

"Do you see what I am doing now?"

"Uhhh, yes teacher, your eyes are opening really wide and you have a fiery look about you."

"Yes, that's right. You are doing this exercise because I told you to!"

So apart from a feeling of tension in your pelvic floor, what else does this mula bandha action do?

By pulling your coccyx, the bottom of your sacrum, forwards relative to your pelvis, you tilt the sacrum backwards which may initiate a straightening of the lumbar spine.

Usually to straighten the lumbar spine, I think of tilting the pelvis backwards relative to the ribcage so that the pubic bone moves closer to the sternum.

This action, mula bandha, straightens the lumbar spine by moving the sacrum relative to the pelvis (or at least trying to). This is as opposed to tilting the pelvis as unit rearwards. Another way to think about this action is that since drawing the tailbone forwards can help to cause the sitting bones to retract (move towards each other) while also causing the ASICs outwards, then this action actually temporarily"deforms" or changes the shape of the pelvis.

The effect is actually quite small. However it may be the start of more subtle muscular actions that help to shape the spine using more intrinsic muscles.

Another reason for doing this action is that it helps to lock the sacrum to the pelvis so that the two are easier to move as one.

Child Birth

Because of the way that the surfaces of the SI joint join together, when the top of the sacrum moves forwards, the upper wings of the pelvis move inwards at the same time. The whole top of the pelvis gets narrower from the sides and back.

At the same time the bottom of the pelvis gets wider. The tail bone moves back and the sitting bones move outwards, to the sides.

Tilting the sacrum backwards so that the top of the sacrum moves backwards causes the opposite to happen. The top of the pelvis gets wider while the bottom of the pelvis gets narrower.

For the top diameter of the pelvis to widen, the wings of the pelvis move outwards while the top of the sacrum moves backwards. Meanwhile the tail bone moves forwards and the sitting bones inwards so that the bottom diameter of the pelvis gets smaller.

Why is this relative to Mula Bandha?

Mula Bandha can be used to pull the tailbone forwards relative to the pelvis. This causes the sacrum to tilt backwards at the SI Joint.

At the same time you can pull inwards on your sitting bones so that sitting bones and tail bone all move inwards, towards each other. This "closes" the bottom of the pelvis while opening the top of the pelvis.

This may help to make the pelvis more stable. Not only does it pull the bottom of the sacrum more tightly into the bowl of the pelvis, it helps to push upwards on the base of the spine providing a better foundation for the base of the spine.

Feel Your Mula Bandha

"Hey, what are you doing?"

"I'm feeling my mula bandha!"

"I think you should do that somewhere a little bit more private!"

To feel your root lock muscles, practice activating them and then relaxing them. (This also applies when learning to feel any muscle. Practice controlling it and feeling it at the same time. You'll develop muscle control and body awareness.) Pull your tailbone towards your pubic bone and then relax. Then try pulling your sitting bones inwards at the same time. And then relax. Squeeze and release smoothly and slowly.

Can you feel your tailbone being pulled forwards, even a little bit?

If not try varying the direction of pull. Try pulling upwards and forwards, towards the top of your pubic bone or even towards your bellybutton.

If you have little or not success pulling your tailbone forwards, try "hooking" the front of your anus forwards, or forwards and up.

See if you can get some sort of sensation. Once you have some sort of sensation that you can create by yourself, then you can work on fine tuning and improving your control over your pelvic floor muslces.

More Anatomy, The Pelvic Diaphragm in a Little More Detail

Separating Piriformis and Obturator Internus

If you are up on your hip anatomy then you know that the upper sciatic notch is the gap that the piriformis passes through as it runs from the front of the sacrum to the top of the thigh bones.

The lower sciatic notch is the gap that the obturator internus wraps around. The obturator internus starts at the inside of the pelvis. It wraps around the back of the pelvis at the lower or lesser sciatic notch and then reaches forwards and up to attach to the top of the thigh bone.

The ischial spine acts as a sort of separator between the piriformis and the obturator internus.


So far I've talked about the pubococcygeus.

It connects tail bone to pubic bone and when activated it pulls the tail bone towards the pubic bone tilting the sacrum backwards.


Coccygeus attaches between the tail bone to the ischial spines.

The ischial spines are located just above the sitting Bones. They are tiny little points on each side of the pelvis that separate the upper sciatic notch from the lower sciatic notch.

The ischial spines are forwards and outwards with respect to the tail bone and so activating the coccygeus on only the right side pulls the tail bone forwards and to the right. Activating it only on the left pulls the tail bone to the left. The coccygeus can be used to wag our tails... even if all that we have left is our tiny tail bone.

Used on both sides at once the coccygeus pulls the tail bone forwards. It also pulls inwards on the ischial spines. Since these attach to the sitting bones, the sitting bones move inwards aswell.

And so the coccygeus can be used to pull the tail bone forwards and the sitting bones inwards.

Pulling Tailbone Forwards and Ischial Spines Inwards

To activate coccygeus, the feeling is akin to holding on to either side of a fairly wide door frame while letting your body hand back from your arms.

Your body can represent your tailbone and sacrum while the doorframe represents your sitting bones and ischial spines. Your arms represent coccygeus.

Use your arms to pull your body forwards and the doorframe inwards. In the same way use coccygeus to pull your tailbone forwards and your sitting bones inwards.


Within our pelvis the obturator internus covers the inside of the obturator foramen (the hole at the bottom of the pelvis below the hip sockte.)

This muscles is partically covered by connective tissue. The end of this span of connective tissue is marked by a "tendinous arch" to which the iliococygeus in part attaches. This tendinous arch spans the obturator internus from the ischial spine to the back of the pubic bone.

The illiococygeus attaches between the tendinous arch and the cocyx, creating a fan like shape when viewed from above or below, with the wide part of the fan towards the front of the pelvis. The handle of the fan attaches your tail bone.

Activate Coccygeus and then Iliococcygeus

Generally I try to activate coccygeus first by pulling the sitting bones or ischial spines inwards and backwards.

From there I try to radiate the tension forwards, towards the pubic bone, to activate illiooccygeus.

The cool thing about these two muscles is that they can be used to pull the sitting bones inwards while also increasing the forwards pull on the tail bone at the same time.

More Pelvic Floor Muscles

anatomy of a mula bandha, piriformis, obturator internus, cocygeus, iliococygeus, pubococygeus, puborectalis

Puborectalis Pulls Your Anus Forwards

One purpose of the muscles of the pelvic floor and mula bandha is to pull the tail bone forwards and the sitting bones inwards so that the top of the sacrum moves backwards relative to the pelvis. This action can be further helped by puborectalis which attaches from the pubic bone to the anus.

Levators Prostatae and Vaginae

(Not shown, but these are located in front of the anus)

Mula bandha can be deepened further by also activating levator prostatae or levator vaginae.

For guys this muscle ends just in front of the anus.

Rather than up, I'd suggest activating these muscles by pulling forwards.

You'll get a lift naturally as a result.

Sequencing Pelvic Floor Muscle Actions

The sequence of activations that I use for activating the pelvic floor is as follows:

These actions all helps to tilt the sacrum forwards relative to the pelvis.

Now while I said that it is easier to pull the tail bone towards the pubic bone, what you may feel with all of the above actions, is a pull backwards on your pubic bone. As a matter of fact, the "tension" may feel like a forward pointing triangle with the base from sitting bone to sitting bone and the point at the pubic bone.

The goal in doing these actions is not to keep them contracted, at least not all the time, but to be able to use them at will.

As an example, when you learn to drive a car, you learn to turn the steering wheel left to make the car go left. However, once you've learned you don't keep steering left unless you need to.

Likewise, with the muscle actions here, learn to activate them so that you can use them when you need them.

Effects and Implications

Mula bandha as an activation of the entire pelvic diaphragm has several affects. But first lets review a few things.

The weight of the spine cause the top of the sacrum to move forwards so that the tailbone moves backwards. By moving the tail bone forwards you actually resist the downward force of the spine on the sacrum. You cause the front of your sacrum to press upwards on the front part of the "bottom" of the lumbar spine.

Remember, this is more relevant when standing or sitting upright.

Several things may happen when you activate your pelvic floor muscles while upright.

More than anything, the importance of this action with respect to yoga poses is how it may help to stabilize the conection between pelvis and spine, and how it also can affect the hip joints, creating stability between the pelvis, spine and thigh bones.

Activating the pelvic floor can be "just the start" of activating mula bandha. You may want to create even more stability by activating piriformis and psoas.

Adding On the Piriformis

anatomy of a mula bandha, piriformis, obturator internus, cocygeus, iliococygeus, pubococygeus, puborectalis

Piriformis passes through the upper sciatic notch, above where the coccygeus attaches to the ischial spine. It is attached to the front of the sacrum and the top of the thigh. If the previously mentioned muscles form the floor of the pelvis, the two sides of this muscle form the back wall just above the coccygeus.

This muscle attaches to the sacrum above the coccygeus. Activating it can feel like you are sucking the middle part of your sacrum (from top to bottom) forwards.

Because it attaches to your thigh bones it may be easier to activate while standing. And with the thigh bones stable, it helps to pull the bottom of the sacrum forwards. It may also help to pull the lower sides of the pelvis inwards, but this may depend on what position the thighs are in relative to the pelvis.

I'd suggest that if moving the thighs back relative to the pelvis so that the front of the hip joints open, then this may be a position in which, when activated, the piriformis helps to pull the bottom sides of the pelvis (and sitting bones) inwards.

Because the spinal erectors attach to the back of the sacrum, activating the piriformis at the same time as these back muscles may help to give them a stable base from which to act on the spine.

This can be especially important in an action like lifting up into handstand and it may be helpful at certain stages in standing or seated forward bends.

When doing forward bends, I'd suggest using this action as you are trying to move deeper into the pose. You can then experiment with holding it or releasing it once you are as deep as possible. You could then reactivate to come out of the pose.

When lifting up into handstand use this "deeper" mula bandha in addition to tensing gluteus maximus to help lift your legs up.

In the context of the muscle actions listed so far, I'd suggest activating piroformis at the end of that list. Then, once pirifomris is activated or as you activate it, try adding on a psoas activation.

Note that this sequence is a way of getting used to activating theses muscles. Once used to it, vary the sequence and even which muscles you use.

Experiment to see what works for you.

Try these actions in combination with "opening" your hip joints. Also try them when trying to squeeze your buttocks. And stay tuned to the latest tips blog for updates on how to use these actions in different poses.

Psoas and Root Lock

Psoas passes forwards and down from the front of the lumbar spine. It wraps around the front of the and then from there reaches back and down to attach to the inside of thigh bones. The part of th thigh bone it attaches to is called the lesser tuberoisty. This is located towards the back of the thigh bone towards the back.

Like piriformis, psoas attaches the spine to the thigh bones.

Where the piriformis pulls the front of the sacrum forwards and the top of the thigh bones back, psoas pulls the lumbar spine forwards, the pelvis back and the thigh bones forwards. It pulls the pelvis back because of the way it bends around the front of the pelvis.

Because of this, Understanding the psoas and piriformis can be used against each other to stabilize pelvis, thighs and and spine.

If added to mula bandha these muscles all together can give better control of the hips, pelvis, sacrum and lumbar spine.

To add your psoas to the actions of mula bandha, suck your lumbar spine forwards after doing all the other actions.

Again, so far I've found this action helpful in standing forward bends and while lifting up into handstand.

More Mula Using the Spinal Erectors

The spinal erectors and transversalis connect to the back of the sacrum. These muscles can be used to pull the tail bone backwards relative to the spine. If you activate your spinal erectors first, and then activate your pelvis floor muscles you may actually tilt your pelvis forwards relative to your sacrum causing your pubic bone to move towards your tailbone.

Or you may help to stabilize spine, sacrum and pelvis making them one solid unit.

This can be very helpful in lifting actions where you are using your arms to lift the weight of your body. It may also be useful in weight lifting, such as when doing squats or deadlifts. If trying to integrate into weight lifting actions use light weight first and focus on feeling your body as you lift and lower. Notice differences in feeling between when you have mula bandha activated and not activated. Which feels stronger or more stable?


Quite often when mula is engaged the abs also engage.

One way to feel this dual activation and understand it is to lay on your back with your knees to your chest. Pull your knees in close so that the back of your pelvis lifts and your lower back rounds, then release.

Next, instead of using your arms to pull your knees in (or use them just a little) pull your tail bone towards your pubic bone, curl it off of the floor. Then "curl" the bottom pelvis off of the floor. You'll notice that the lower portion of your abs activates and what you may then feel is a continuous pulling sensation that extends from your tail bone towards your pubic bone and upwards from your pubic bone to a point midway towards your belly button.

You could think of this as uddiyana bandha.

Doing it While Sitting

You can try the same activation of mula bandha while sitting. Let your pelvis roll backā€¦ slouch. Pull your tail bone forwards and upwards, towards your pubic bone and feel the line of pull. Pull your lower belly in so that it feels like you are curling your lower belly towards the top of your sacrum. Then relax.

Allright, if this is mula bandha, what good is it?

So where can you use this action?

In a non-asana context, if you engage mula bandha with either your inhales or your exhales, (rest on the other phase) you can be supporting your internal organs from beneath. I say "inhales or exhales" because which one you contract on depends on the type of breath you are doing.

Engaging While Breathing

If you do belly breathing (or diaphragmatic breathing) so that your belly expands while inhales and contracts while exhaling, you may find it more natural to engage mula bandha during the exhales when you pull your belly in.

If you do reverse breathing or costal breathing or some breathing variation where you pull your lower belly inwards as you inhale then you might want to engage mula bandha on the inhales.

Why would you want to rest it?

Why not keep mula bandha engage constantly?

Because it is a muscle and muscles are designed to relax and contract. It's what they do.

It's kind of like sex. You have to pull out so that you can go back in, and there in is the enjoyment.

The Wheel and Mula Bandha

In an asana context, mula bandha as defined here tilts the base of the spine backwards relative to the pelvis. As a result it may be useful in backbends like wheel pose.

I'd suggest that while laying on your back and getting ready to get into wheel, engage your feet first, then as you lift your pelvis into bridge or while holding bridge, then find mula bandha, then bend your entire spine backwards as you go onto the top of your head. Then lift up keeping mula bandha engaged.

Doing mula bandha this way may help to prevent jamming your sacrum.

Sideways Tilting The Sacrum With Half Mula Bandha

One thing that you might want to experiment with while doing side bends is activating only one side of coccygeus. By doing so you can pull your tail bone to one side. To "wag" your tail bone try switching from side to side, activating coccygeus on one side and then the other. Then try holding one side active while doing a standing side bend to one side. If you are bending to the right then activate right side coccygeus. And try activating the muscles on the right side of your spine at the same time. You may find you can deepen your side bend as a result.

Published: 2011 09 23
Updated: 2020 11 04
Clearly defined poses, exercises and stretches for improving stability, body awareness and flexibility.
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