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Anatomy of an Iron X & Human Flag

Updated: May 20, 2023

Ok here it is. The absolute boss pole trick – the Iron X. We have been building up to this one now for months!! So if you haven’t already, then you absolutely MUST read the pre-requisite blogs for the Iron-X which are the Anatomy of an Ayesha and Anatomy of a Handspring blogs.

Why? Well funny enough, these two movements are your requirements before you can Iron-X so make sure you understand them in great detail first!

The first thing to discuss about the Iron-X is that it’s an open chain isometrically held position. This is one of the many reasons why it’s so challenging.

What’s in a hold?

Everything! Our Iron-X is a static hold which is quite a challenge to sustain. Imagine with our Iron-X we are trying to take our body right to the edge of a cliff. Then we are dangling half our body off of it, but not actually letting ourselves fall off! That’s kind of like our Iron-X: an incredibly hard balancing act between the muscles of our body and gravity!

In our Iron-X we want to lower our body down until it is ideally perpendicular to the pole. This is our cliff edge point. Lower down a tad too far and boom, no iron-X for you. Our body has to find the right position that we can lower down to before we lose control.

Let’s start to break down the anatomy of our Iron X now. Starting with the abdominals…

Tummy Time

To Iron X correctly our abdominals need to resist the downward weight of the hips/gravity as well as the rotational and extension based forces as we are mid air! This requires our abs to perform 3 different muscle actions! These actions are:

  • Anti-extension (flexion)

  • Anti-lateral flexion

  • Anti-rotation


Anti-extension engagement in an Iron X occurs via a posterior pelvic tilt using our rectus abdominis, obliques, hip flexor and gluteal muscles. Not sure what a posterior tilt is? Think about physically shortening the space between your pubic bone and belly button and that's a posterior tilt! Notice how we draw in through our abdominals and engage our glutes to perform this movement? That's exactly the feeling we need whilst in our Iron X!

Still not sure? Then check out these images below that show what I mean!

Posterior tilt
Anterior Tilt


Moving on to our next abdominal isometric engagement: anti-rotation. When performing an Iron X our muscles work together to create a sling! Amazing, right? Our Anterior Oblique Chain/Sling consists of the lower side external oblique, top side internal oblique, the top side adductor muscle, and the connecting adductor abdominal fascia. They work together to provide greater support to our trunk. The anterior oblique sling specifically plays a huge role in accelerating and decelerating the body during sport-specific movements and in pole helps to provide anti-rotation movements to resist gravity! There are a few other muscles that assist in this anti rotational pull including our gluteals, small muscles of the neck & spine, our rhomboids, serratus anterior & importantly latissimus dorsi (not pictured). Together these muscles do a fantastic job at isometrically resisting the rotational pull on us during an Iron-X.

Anti-Lateral Flexion

And lastly for the abdominals we look at our lateral flexors of the spine. In an Iron-X gravity exerts a considerable force to try pull us into a side bend and bring our legs to the floor. This gravitational force is exerted at 3 key points: our shoulders, waist & hips. But our lateral flexors play the important role in ensuring this doesn't occur.

In particular our obliques and adductors play an important role in resisting gravity. Our top external oblique and lower internal oblique act to create a sling across the body to contract and keep the hips up. These muscles are supported by the following muscles:

  • quadratus lumborum

  • rhomboids

  • serratus anterior

  • gluteus medius

  • gluteus maximus

  • adductors on our lower leg

And that’s a wrap with the abs. Moving on next to our shoulders!

Shoulders and arms: Same, same but different?

Over the past 2 anatomy blogs we have delved quite deeply into the shoulder stability, pushing & pulling requirements for an Ayesha & Handspring and it's helpful to know that the requirements for the shoulders in an Iron X are quite similar.

In our Iron-X, all we need to know is that our arms are abducted and flexed overhead to approximately 135 degrees. The top arm is engaging in a strong pull whilst the bottom arm is pushing. All whilst the shoulder stabilisers (rotator cuff and surrounding muscles) are working hard to ensure there is good upward scapular rotation and shoulder joint support. Because of the shoulder position there is more latissimus dorsi (adduction) engagement of the top arm but otherwise the shoulder engagement remains fairly similar to an Ayesha.

Shoulder Stabilisers

As the shoulder is an inherently unstable joint, with the humeral head (shoulder) about 1/3rd of the size of the glenoid, impingements and subluxations are common injuries that lower arm of an Iron X. The shoulder relies heavily on it's surrounding muscular and ligamentous support to prevent these style of injuries.

To control our shoulder during a Iron-X we use our:

  • Rotator Cuff Muscles: Supraspinatus, Infraspinatus, Teres Minor and Subscapularis muscles

  • Upper, Middle & Lower Trapezius (not pictured)

  • Rhomboid (not pictured)

  • Levator Scapulae (not pictured)

  • Serratus Anterior Muscles (not pictured)

And if these muscles are not working in harmony, our shoulder joint stability may be compromised and this can lead to potential shoulder injury

Shoulder Pushing Arm

To maintain our Iron X hold our bottom arm needs to not only hold us in place, but actively PUSH ourselves away! A common mistake I see here are polers not pushing enough! Our Iron X is just like a handstand position - we want to push by elevating our shoulder to the pole. This is assisted via our upper trap muscle! The main muscles we rely on to push through our lower arm in this position are:

  • Anterior and Middle Deltoid

  • Tricep

  • Pec Major & Minor

Shoulder Pulling Arm

And lastly we have our pulling top arm. Due to the horizontal nature of this move, there is specifically an increased load on our shoulder adductors to keep our body perpendicular to the pole. Our primary shoulder adductor that keeps us in this position is our Latissimus Dorsi, and it is supported by our surrounding pulling muscles. Our main top arm pulling muscles are our:

  • Biceps

  • Middle and Posterior Deltoid

  • Trapezius

  • Latissimus Dorsi

Easy right? Ha! Ok moving on.

It’s all in the hips

Our Iron X requires active engagement of our hip abductors, hip external rotators and hip flexors/abdominals (as previously discussed). Not only are these muscles important to make the straddle component of our Iron X look effortless, but the better the activation through our hips, the less strain through our trunk muscles to hold load this position. Effectively all our lumbopelvic muscles all need to work in harmony to produce this epic move. Without this control we simply won’t be able to hold our Iron X position or we will eventually experience an injury.

Ok so now we now understand the basis of Iron X anatomy, let’s talk specifics about technique!

Struggling to nail your Iron X? Shorten your lever!

So I want to prelude this section with the information that there are many different variations of Iron-X out there. And none of them are wrong. All of them are hard, and some are definitely harder. There are a few different names floating around for these, but most commonly an Iron X performed in a middle split position is referred to as an Iron K variation.

Whilst the Iron X requires gluteal extensor, abductor and external rotation strength, our Iron K variation takes these muscular engagements to a whole new level! There are some serious benefits of performing an Iron K over an Iron X, with the main one being that there is reduced leverage placed on the body as shown in the pictures above with the arrows. By bringing the feet closer to the pole, our body has a shorter lever away from the pole which means it’s easier for our body to hold this position against gravity.

This is definitely a trick where flexibility is your friend. If you have a wide middle split and strong active forward fold, this trick will be easier for you. It’s really important when starting out that we correctly lower into our Iron-X to reduce the body’s lever arm from the pole as shown above. The shorter the lever, the easier it will be to hold.

The second benefit of this position is that it increases active engagement of the hip flexors and abdominal muscles which improves trunk stability. So our Iron K definitely has it’s benefits.

Iron X - Is it all an illusion??

Let’s now delve into other variation of our Iron X/K. The first being the variation we usually achieve when starting out our iron-X training; and the second variation being the one we all strive for and would love to have.

Iron X Variation shown by @lama_rika
Iron X Variation shown by @jasiczka_poledancer

So whats the difference? Well in the first variation it’s quite obvious that the trunk isn’t actually facing front on! It is instead slightly rotated up towards the roof but from a distance and a front on view it will give the impression that the trunk is facing forwards.

It’s not until you check out a side or oblique view like we are that you realise that the body is not actually facing the front. What!?! Mind blown right! Only the most insanely strong pole dancers can Iron-X with their body completely completely perpendicular to the pole. Looking at the likes of @greshilovevgeny @dimitrypolitov and @dinekeminten to name a few pole machines.

For the rest of us polestar wannabes, there is nothing wrong with starting out with the first version and gradually strengthening our way to the second.

The IPSF Iron X - Correct vs Incorrect Technique

As mentioned earlier there is a textbook Iron X version that every poler should try to work towards. Whilst variations are fun to play around with, this version is the real deal!

What’s the main differences between the two positions?

In the first variation you will notice on side view that the lower back appears arched, rotated & extended. In fact, this is a clever muscle recruiting mechanism by the pelvis.

By placing our body into lumbar extension/rotation & anterior pelvic tilt in our Iron X, our back extensors are in prime position to increase their workload and are abdominal muscles have greater tension on them to perform the movement. However, like any move, we then risk not controlling this position and for want of better words what I term ‘dumping into the joints’. Over time if not strong enough, this position can stress out the spine and cause joint related pain or irritation.

Whereas in the second correct position, our pelvis is positioned neutrally engaging into a posterior tilt, feet are in line with the trunk, the torso is at a full 90-degree angle to the pole and the torso/abdominals are in a straight line facing away from the pole. This is all primarily driven by our gluteals & lower abdominals to help keep our feet in line with our trunk. The upper and lower back also maintain a neutral spinal position (i.e no flaring of the ribcage).

To get an idea of what I’m explaining, stand up tall with your feet wide apart and in slight turn out. Tuck your tailbone in slightly by engaging your abdominals. And that’s it. This is the position of a true Iron-X (plus arms overhead of course). So now imagine tipping this onto your side and holding it there mid air. Yep. Not easy at all!

So you can see why the second one is much harder to nail.

Iron X Recap

Well there you have it, our Iron-X deconstructed! So in it's basic form, to perform an Iron X we require:

  • 135 Degrees of Shoulder Abduction

  • Overhead Shoulder Stability

  • Overhead Pushing Strength (Bottom Arm)

  • Overhead Horizontal Pulling Strength (Top Arm)

  • Abdominal Anti-Extension and Hip Flexion Strength

  • Abdominal Anti-Rotation Strength

  • Abdominal Anti-Lateral Flexion Strength

  • Gluteal strength

Along with:

  • 180 Degrees of Elbow Extension/Stability

  • Wrist Extension & Ulnar Deviation of the lower hand

  • Good Proprioception (body awareness)

These last factors have been described in greater depth in our Anatomy of Handspring & Ayesha blogs

Anatomy of a Human Flag

Nailing your Iron X? Well you can always level up to your Human Flag or Iron T. Yes. We went there.

The adduction (closing) of the legs increases the leverage of the body away from the pole and reduces the activation our hip abductors and external rotators muscles. Both of these changes results in increased load on our shoulders, back and abds.

We do however get some additional help with our hip extensors and adductors. By squeezing the legs together in this position we improving our abdominal co-contraction which will assist! But if you want to do it tough, you should keep the legs just lightly touching.

In fact, some awesome calculations by @pole.technica recently compared the difference in torque between a standard iron X, flag and an iron K where the legs are in a complete vertical split.

They found a 100% decrease in torque at the hip joint in an iron K compared to iron X. and a 100% increase in torque in a flag. No surprise there right? They then went on to show similar changes in the waist by 43.6% and shoulders by 15.4%.

Image from @POLE.TECHNICA - Calculations of Torque of Iron X, Iron K & Flag

So it just goes to show exactly how much more challenging a flag is to an iron X!

Well there you have it, you’re Human Flag in all it’s badass glory!

If you have any questions or feedback make sure you comment on our Iron-X/Human Flag series posts on Instagram or Facebook to let us know your thoughts.


Have you been struggling to nail your Iron-X or Human Flag but not sure why? Or recovering with an injury and it’s getting in the way of your pole?

Online telehealth appointments can be booked with the Pole Physio via our ‘Book Online’ page that can be found here. Assessment and tailored rehabilitation are provided in accordance with best practice and evidence-based treatment to help you unleash your 'poletential'.

Until next time, train safe.

The Pole Physio x

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Please Note:

  • Any artwork on this or other pages of is copyrighted and is not be reproduced without written permission per the terms of use and conditions.

  • An Iron X/Human Flag is a high advanced/elite level trick and conditioning should ONLY be undertaken if your handspring is strong and consistent and your instructor has deemed you ready to work on this trick. This information is general advice only and we are not liable for any injuries that may occur during training.

  • This page has been created to provide wonderful knowledge with the pole community and sharing of this page to pole friends and pole related facebook groups is actively encouraged.


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