weird shoulder muscle development

[class]

suddenly, last night i realized that my horse had a weird bulging muscle that i never noticed before. it is the muscle kind of on top/in front of his shoulder but below the wither. it is the same on both sides. what am i doing that is causing this? he doesn’t seem heavy on the forehand or supporting himself on his shoulder, but it looks weird to me. i think his neck/shoulder connection should look smooth. i am wondering what this muscle is normally engaged for and what might cause it to look like this:

http://groups.msn.com/ArabClassy/shoebox.msnw?action=ShowPhoto&PhotoID=45

i don’t know how easy it is to see in the photo, so i also outlined the muscle that i am talking about:

http://groups.msn.com/ArabClassy/shoebox.msnw?action=ShowPhoto&PhotoID=46

thanks in advance for any advice, ideas, or insults!

[JB]

IMHO, it warrants a good massage therapist

[class]

i’m trying to understand how a massage therapist would help overdeveloped muscles? are they able to make muscles atrophy by massaging them? or do you think that a massage therapist would be able to tell me how and why my horse developed these muscles?

[JB]

They may be either

• overdeveloped muscles from lack of ability to use muscles in another area
• not “developed” at all, but rather knots/spasms as a result of not being able to use a body part correctly

[slc2]

The ‘double shoulder’.

[class]

slc, are you trying to offer information or somehow respond to anything that i asked in my post, or are you just trying to get to 19,000 posts before the end of this week?

[slc2]

the latter.

the horse just has a different kind of shoulder conformation with a larger scapula.

[class]

well… strange that i never noticed it before in the past 8 years.

[slc2]

Well, the photo is a little hard for me to see, but what you’ve circled appears to be Supraspinatus, I think.

[BaroquePony]

He is a dark horse and the photo is a straight-on side shot. Circling the muscle at least helps us to know what we are supposed to be looking at, but an angle shot might help more.

How much do these two muscles stick out ?

It does seem a bit strange. Just that muscle and not the surrounding muscles.

[Karoline]

It looks like the infraspinatus and the supraspinatus. They are the muscles that line each side of the spine of the scapula. How you know it is these for sure is by palpating. At the top of the shoulder, you can should be able to feel the shape of the head of the scapula also called cartilage of the scapula. Down the middle there is a ridge, that’s the spine of the scapula.

I found this great painted horse that shows the muscles clearly:

http://www.pecorfamily.com/Blog_202006_2D08_2D27_20Painted2.jpg

The supraspinatus (supraspinate muscle if you want to google) is the one located on the front of the shoulder.

Its role is to laterally support and extend the shoulder joint. I also found "maintains shoulder in extension.

If you have a problem with this muscle you would see loss of mobility at the shoulder joint, gait irregularity in the front hand.

The infraspinatus (infraspinate muscle) is the other muscle located on the side of the ribcage

Its role is abduct (lift) and rotate the leg and rotate it laterally ( external rotation). It acts asa lateral collateral ligament of the shoulder joint.

If you have a problem with this muscle the horse will be unwilling to cross the leg underneath itself, the leg may land outside of the track or look like its winging.

(thank you Equinology

You should look at wether this muscle development is even on both side or if its asymetric. You can palpate to see if the horse is showing any sign of soreness. You can palpate for muscle quality and tone - and compare both side. You can use the back of your hand and try and see if you identify some cold and hot zone. You can look at the quality of the hair and see if there are some differences between body part -coarser, dryer, longer, discolored, etc…You can lift the leg and do some circles and range of motion (always keep the knee bent) and see if you can feel restrictions one vs. the other. You can get on a stool, stand behind your horse and check if both shoulders are developed the same. And of course, you can go around the barn checking other horses so as to compare and contrast.

An experienced massage practicioner (bodyworker) can help identify wether the muscling is correct and if not, help the horse with restrictions through massage and range of motion as well as with recommending exercices, an experienced bodyworker should be able to do an assessment of the horse in hand/under saddle, look at your saddle ( that affects the shoulder a lot), look at feet. However, for a massage practicioner its much better to work with a clear diagnostic and at least in my program we prefer the owner has already spoken to a vet so we can work with a clear diagnosis and in fact, as much as possible, we like to work with the vet. In some states, the vet has to authorize the bodyworker. Its a great field and I am at the kindergarden stage learning wise, so bear with me.

I have a couple of great big books I will check for you but they are in my car so it wont be for a day or two. I will try and identify causes for hypertrophy -what you think it is -not what I know it is -

Dont know if this helps. Good luck with your horse.

Oh, and I found this really interresting paper for anyone who has a one sided horse - ie and asymetrically developed horse:

http://www.equinedesign.info/onesided.htm

[class]

[QUOTE=Karoline;3417676]
You should look at wether this muscle development is even on both side or if its asymetric. You can palpate to see if the horse is showing any sign of soreness. You can palpate for muscle quality and tone - and compare both side. You can use the back of your hand and try and see if you identify some cold and hot zone. You can look at the quality of the hair and see if there are some differences between body part -coarser, dryer, longer, discolored, etc…You can lift the leg and do some circles and range of motion (always keep the knee bent) and see if you can feel restrictions one vs. the other. You can get on a stool, stand behind your horse and check if both shoulders are developed the same. And of course, you can go around the barn checking other horses so as to compare and contrast. [/QUOTE]

i have done all of this stuff and it is even on both sides and he doesn’t have any trouble with his movement. i will ask my trainer what she thinks tonight and i will try to get some better pictures. thanks for all of your help!

[Karoline]

Udo Burger

Found a little mention of the scapula and muscles of the scapula in his book The Way to Perfect Horsemanship in the Diagnosis section p.245 and 246.

"Forehand

Signs of weakness

The outline of the scapula is visible as is also its spine (middle part). When the muscular braces of the neck and shoulder are weak the outline of the shoulder elbow region is hollowed; the muscles are flat in the angle of the shoulder-jointy and the forarm has a small circumferance. There is a marked gap between the elbow and the ribs and the girth groove is ill defined.

Good Points

THe scapula is concealed by bulky muscles; the base of the neck is broad. The extensor of the elbow (triceps) bulges between the scapula and the elbow. The lattissimus dorsi fills up the groove between the shoulder and ribs, thus preventing the saddle from slipping forward. The muscles at the front of the forearm are prominent while at the back they form a straight vertical line from the elbow down. The stability of the forehand depends on a strong forearm and careful observation of its state of musculature development must never be neglected.

Wasting of the shoulder muscles is rarely the result of strain and much more often due to insufficient relaxation. A well developed shoulder and forearm muscles will compensate for many defects of conformation, their strenght must be increased by long hacking at the walk, prolonged periods of galloping, riding over undulating terrain and, especially frequent jumping of small obstacles. Fluent movement at all gaits , and especially over jumps is essential to avoid concussion which is the most common frequent cause of lameness. During training, fatigue of muscles is easily avoidable. "

I will be interrested in finding out what your trainer thinks. Even development is a very good thing and the fact that you do not have any problems even better.

[ybiaw]

What a FANTASTIC picture, Karoline! That’s SUCH a great reference.

[DressageGeek_Ribbon]

Karoline - that was awesome!

Since it seems to be on both sides, whatever you are doing, you are doing symmetrically (if, in fact, it is caused by anything you are doing). Which, if it turns out to be a “bad” thing, means it can be undone. Because you know me, first thing in my mind when I saw the thread, was “OMG tumors.” Whew!!

[Karoline]

[QUOTE=ybiaw;3418735]
What a FANTASTIC picture, Karoline! That’s SUCH a great reference.[/QUOTE]

Thank you. I just want to be clear its not mine. I found it online but I can recognize its correct because I have done this exercice though not nearly as well

[Karoline]

[QUOTE=DressageGeek “Ribbon Ho”;3418767]
Karoline - that was awesome!

Since it seems to be on both sides, whatever you are doing, you are doing symmetrically (if, in fact, it is caused by anything you are doing). Which, if it turns out to be a “bad” thing, means it can be undone. Because you know me, first thing in my mind when I saw the thread, was “OMG tumors.” Whew!![/QUOTE]

I want to stress that I am really beginning to understand biomechanics a little (very little) and I am a long way from being any kind of expert. However, its very interesting to be able to relate muscle development and musculo-skeletal problems to riding.

For example someone mentioned having a horse who was beginning to step wide behind. Well one of the reason noted in Udo Burger’s book is incorrectly executed lateral work, especially leg yielding. The someone is learning leg yielding so while its not necessarily THE reason, its interesting that there could be a correlation.

Anyway, Class will tell us more when she knows more. I hope.

[preferred]

Karoline,

Thanks for the color pic. The best ever! I forwarded it to my therapist so she can add it to my file and show me what her findings are on a pic that I can easily understand.

Thanks so much for the enlightment!

[class]

my trainer thought that it could be two things.

she thought that it didn’t look like a bad thing, but thought that flexing him at the base of the neck in the warm up was building those muscles up and so, not really a good thing either.

she also thought that he must still be holding his neck in some places so the muscles don’t develop as smoothly as they should.

still wouldn’t hurt to have a massage therapist out i guess! and thanks for the awesome painted muscle horse picture.

[slc2]

Is the horse lame?

The muscles are first, the supraspinatus, and then below it, the infraspinatus. The muscles hold the horse’s shoulder in extension.

I sometimes see these muscles getting abnormally bulky when a horse is on his forehand alot. He has to quickly bring his shoulder into extension to provide himself with balance. Most correct muscle development is smooth and rounded, but depending on how the horse is built, a bulky looking muscle isn’t necessarily incorrect.

Maybe your horse is just getting into condition, and his muscles are developing, or are more obvious because he’s getting into condition.

I don’t think they would be affected by bending in warmup, but if the trainer isn’t in favor of me doing that and thinks it could cause problems i’d follow her lead.