Kaleido Star- Layla Hamilton’s shoulder injury

Layla Hamilton and her injuried shoulder in Kaleido StarLayla Hamilton

Layla Hamilton is the star of the Kaleido Stage and acts like an antagonist, friend, and mentor to Sora throughout the first season. In the final arc of the season Layla Hamilton and Sora are challenged with performing the Legendary Great Maneuver in order to save the Kaleido Stage. It is at this point that we get several stereotypical sports anime training episodes, involving rather insane and somewhat risky maneuvers like diving off cliffs and such. While some of the training exercises Sora and Layla Hamilton go through do make sense in the context of the Legendary Great Maneuver, I don’t think they had to do them at the Grand Canyon, of all places. Either way Layla Hamilton ends up injuring her shoulder on at least two separate occasions during the training and she continues to train despite the injury.

First Injury

You might be wondering how an experienced acrobat like Layla Hamilton got hurt in the first place, and here the show provides a logical answer. It is easier to perform the Legendary Great Maneuver if both partners have a similar weight. This is a bit of a problem for Layla and Sora because Layla is three inches taller, a year or two older, and presumably a good deal heavier than Sora as well. As a result, Layla Hamilton goes on a self-imposed starvation diet to lose weight in an effort to match Sora weight. Predictably this causes her to pass out in the middle of a training exercise, leading to the first injury.

Layla Hamilton

Second Injury

Layla Hamilton compounds the problem by continuing to train and starve herself, and the lack of food impaired her body’s ability to heal. The continued training also prevented the initial injury from healing properly. This leads to a second impact on an already damaged shoulder, when it gave out in the middle of another training exercise.

Layla Hamilton

Pulled muscle and a stress fracture

After their training we find Layla Hamilton at the hospital, where we finally discover just how bad her injury really is. The anime even goes as far as showing us an X-ray and giving us a diagnosis of a pulled muscle and a stress fracture.

Before I begin to look into the accuracy of Layla’s injury, I want to let everyone know that Dio Kobayashi, a famous Japanese circus performer, was brought in as a special advisor for the anime. In fact, the trapeze act Sora and the others perform in the second season was reminiscent of an act Dio himself performed in similar circumstances.

If you saw the previous post about Ken Robbin’s weak heart, you’ll remember that I was limited to speculating about several different possibilities in regard to what caused his weak heart. This meant I couldn’t go into as much detail or certainty about the cause of his heart problem. However, we are given much more detail about the nature of Layla’s injury, so it is possible to determine if the anime gets it right in regards to her injury supposedly (a stress fracture and pulled muscle) and the need for surgery to repair it.

The Shoulder

The human shoulder is a ball and socket joint made up of 3 different bones: the humerus (upper arm), clavicle (collar bone), and the scapula (shoulder blade).

These bones are joined by 10 ligaments. Ligaments are pieces of strong connective tissue that hold bones together.

On top of the bones and ligaments, you have the muscles that actually move the shoulder. There are 11 muscles that are in some way involved in the movement of the shoulder.

And there is one last set of structures in the shoulder called bursae. These are fluid filled sacs that act in a lubricating and cushioning fashion to help the shoulder rotate.

As you can imagine, there are a large number of possible shoulder injuries with so many different structures that can be damaged. However, the anime helps us in this regard as we actually see the injury take place which makes it much easier to determine the possible injury. Layla essentially injured her shoulder in a horizontal fall against the face of a cliff, but the mechanics of falling to the ground, or against the side of a cliff will be the same in this case.

The First Injury

Three of the more common injuries from a fall are broken wrist, broken collar bone, and dislocated shoulder. This is not the case here, as in those falls the arm is extended away from the body, as seen below in a rugby player.

Layla’s arm was held close to her body when she hit the cliff face, which makes another shoulder injury much more likely.

Layla Hamilton

That injury is a separated shoulder, which while still a dislocation in the area of the shoulder, is not damage to the shoulder joint itself.

As seen above, the AC ligament attaches the collar bone to the scapula, and helps to stabilize the shoulder. In a separated shoulder that joint is dislocated. There are six degrees of dislocation, and in the first type the ligaments holding the joint together are only stretched out and not completely separated. This makes the most sense because it would still allow Layla to continue training, but with pain and weakness. Of course there is the question of did she break anything and the answer there is no, because a broken bone would have been extremely painful and impaired Layla’s shoulder function to the point that she would not have been able to train, let alone perform.

The Second Injury

Layla Hamilton continued to train despite her previous injury, not giving it any time to heal, which compounded her first injury and led to a second blow to the shoulder.

Layla Hamilton

It is strongly implied in the show that Layla’s shoulder is significantly worse after the second injury. The question is what happened during the second injury that would impair her shoulder, but still not prevent her from training, and/or performing. Having her separated shoulder progress from a type 1 to a type 2 is a possibility, but it is unlikely because in a type 2 the acromioclavicular ligament is completely torn and the collar bone will be sitting a little higher than normal, creating a visible bump on the shoulder that Layla does not have.

It is more likely that by this point Layla Hamilton has also torn her rotator cuff, which can occur from both overtraining and blunt force impacts, which occurred in both of Layla’s injuries.


As stated previously, the anime gives Layla a diagnosis of a stress fracture and pulled muscle, but that doesn’t fit the X-ray that is shown in the anime, but I want to talk about the pulled muscle aspect of the diagnosis first. A pulled muscle or muscle strain is a muscle injury where the muscle fibers are being pulled apart damaging them, and like the separated shoulder there are levels of muscle strains.

As you can see from the image above you might call a grade 1 muscle strain a pulled muscle and a grade 3 muscle strain a torn muscle. So essentially the anime and I both agree on a muscle strain injury to the rotator cuff, we just differ on the severity, with the anime calling it a grade 1 muscle strain by its vernacular name of a pulled muscle, while I think it would be a more severe grade 3 muscle strain or a torn muscle. Now for the X-ray.

As you look at the X ray you will notice that the collar bone is pretty much missing, and it is not connected to the scapula. Here you can see a normal shoulder X-ray.

Now here is what a separated shoulder will look like.

Thus, the anime X-ray more closely resembles a separated shoulder X-ray. So, it looks like the doctor might have left a little something out of her diagnosis, and if it wasn’t clear before the final performance, it would be after, as it’s made pretty clear from Layla’s scream of pain at the end of the Legendary Great Maneuver that her shoulder is pretty much shot, and we can see her injured shoulder hanging much lower, which would happen in a completely separated shoulder.

Layla Hamilton

There is still the question of the stress fracture the doctor mentions. Stress fractures are minute cracks in a bone caused by repetitive stress being placed on a bone by frequent impacts. This usually occurs in the foot, ankle, and lower leg, because we are almost constantly using our feet. However, it is possible that Layla Hamilton could have developed a stress fracture in her hand or wrist with the number of times she was falling into and pushing herself off a cliff face during her training. While this is the most likely explanation, it is implied that the stress fracture is in her shoulder, which is highly unlikely, given we only see Layla Hamilton hit her shoulder twice during her training. It’s not a stretch to believe she might have hit her shoulder more than what we see in the anime, leading to a stress fracture, but I don’t think that is the case because she successfully completed the training.


We’re not given much in the way of treatment, beyond the need for surgery, which is possible in both a torn rotator cuff and a severely separated shoulder injury. Thus, I have to say Kaleido Star gets it completely correct.


I do have some issues with Layla’s off screen recovery, as it implied that the injury ended her career and yet she comes back to compete with Sora for the lead role in the Kaleido Stage production of Swan Lake. This of course begs the question of was it really a career ending injury in the first place, as implied at the end of the first season.

Layla Hamilton

This is probably due more to the needs of the plot of the show, than what might or might not happen in the real world. She is wearing some sort of brace so it is clear that whatever happened, she is not at 100%.  However, in the OVA which takes place sometime later she is no longer wearing a brace and seems just fine at an impromptu performance.

Layla Hamilton


In closing, I am going to call Kaleido Star’s description of Layla’s injury plausible given the circumstances given in the anime. I would have called it confirmed if the X-ray of Layla’s injury had been left out, which shows what I think to be a separated shoulder. Also I would like to think that any inconsistencies stemming from miscommunication between the technical adviser Dio Kobayashi, and the production staff, and/or mistakes/simplifications in translating the anime into English as I have only seen the English dub version of the show.


FYI- in the next few days I’ll turn this into a fake patient lesson that could be used during an Anatomy and Physiology class.
Thanks for reading and please leave any comments below.

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