The Importance Of Muscle-Ups For Iron Cross

So I've heard Coach Sommer say that wide muscle-ups start to mimic the strain of an iron cross and that it is an excellent supplementary exercise, but I just can't seem to understand why. This could be due to my ignorance because I've never had a chance to try the iron cross, but I believe the stress on the elbows would be very different.

The muscle-up is a bent arm exercise and the iron cross is a straight arm exercise and even though the muscle-up has some stress on the elbows, it seems to stress the triceps tendon rather than the biceps tendon for the inner elbows and doesn't stress the outer elbows like the FL. I'd imagine the iron cross done with the shoulders rolled forwards would stress the inner elbows like in a planche and maltese and the iron cross with neutral shoulders (biceps facing forward) would stress the outer elbows in the same way as FL.

So my question would be is Coach referring to the stress on the shoulders and rotator cuff regarding the muscle-ups' imitation of the iron cross strain. I know the middle part of the transition in the wide grip muscle-up is like a bent arm cross so that sounds more like it than the elbow stress. Can it be the internal rotation strength as well since the wide arm MU transition is like pure internal rotation and you internal rotate in the iron cross too. I just thought this would be a good question to ask and topic to discuss since this has never be brought up before and it might help others understand more of the relation between the MU and iron cross.

I considered it quite obvious after reading the book and thread about elbow conditioning for cross. You have one list of progressions to prepare elbow and another to prepare shoulders and other needed muscles and here wide MUs come very handy. Eventually these two combined will lead to butterfly mount.

Flameous said:

I considered it quite obvious after reading the book and thread about elbow conditioning for cross. You have one list of progressions to prepare elbow and another to prepare shoulders and other needed muscles and here wide MUs come very handy. Eventually these two combined will lead to butterfly mount.

What/where is the list to prepare the shoulders and other muscles? I don't think the MUs stress the elbows in the same ways as an iron cross.

You are correct, the wide muscle up does not stress the biceps exactly like a straight arm an iron cross, which is why you will not get an iron cross by doing a bunch of muscle ups. However, bent arm exercises are useful for building strength so that you are more able to do straight arm training.  The muscle up specifically is very good shoulder prep and provides some elbow prep.  Idk if you have done a wide muscle up but it is fairly taxing on the entire arm when you use little to no lean.  Also way down the road a wide muscle up morphs into a butterfly.  

It is more obvious if you watch a slow motion wide muscle up.  During the transition the biceps take a great deal of the force as the shoulder rotates inward to support the upward motion.  

Is it exactly the same? No, but it does start to expose your body to forces towards the outside of your body while you are in the vertical plane.

The only other exercise I can think of off the top of my head that does this is the bulgarian dips, which also help prepare for iron cross.

My experience with the wide MU is that they are extremely hard on subscapularis, which is one of the primary stabilizers in an iron cross. I didn't feel much in my biceps, but as you get wider I imagine you would start to feel something somewhere in the elbow.

Shoulder prep for anything in cross is going to involve external rotator flexibility and internal rotation strength, along with coracobrachialis conditioning. And, technically, biceps conditioning, but that is included in the next sentence:

Elbow flexor/extensor conditioning and connective tissue conditioning in the elbow are also important.

Thanks for the informative replies guys! I can do fairly wide MUs with little lean and I know the no lean wide MU is a bent arm butterfly, but I don't feel any biceps working during the transition at all. I feel it mainly in the triceps tendon. I guess as you get a lot wider in the no lean MU then the more adductor (lats, chest, and triceps) and shoulder strength and also the subscapularis Joshua mentioned it uses which would be very helpful for the iron cross.