What is your horse’s topline?


Depending on what article you read, you might find that the topline of a horse is from ears to tail, or from withers to tail along the dorsal portion of your horses. Basically, the top of his back and neck, really. Topline really refers to the muscling along the dorsal portion of your horse, and many view this as a sign of fitness and strength.


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Muscles involved in the topline of your horse.


There are a few major muscles involved in the topline of horses. I totally encourage you to check out this website for more info and some amazing anatomy photos, if that’s your type of thing.




This muscle is flat and thin, and is directly under your horse’s skin. It’s also not very wide, even on heavily muscled horses. It runs from the neck to the shoulder blade, and has another portion that runs from the shoulder to the thoracic vertebrae. The thoracic vertebrae are under the saddle. Well, if you have tacked up correctly!


The trapezius functions to move the scapula (shoulder blade). The cervical portion of the trapezius moves the scapula forward, and the thoracic portion of the trapezius moves the scapula backwards.


This muscle is heavily involved in the wither area, which means it’s impacted by saddle fit and girth or cinch tightening. It’s location also means it’s involved with the neck, front legs, and back. A complicated fellow!



trapezius muscle location marked on a horse

Enjoy this lovely dirty horse with his trap area-ish marked.


Latissimus dorsi


The latissimus dorsi muscle is a bit further back. It starts as a large swath of connective tissue on the top of the spine between the thoracic vertebrae and your horse’s croup. The trapezius muscle is on top of it in some parts. It’s also a muscle that is just under the skin, so you can absolutely feel it above the rib cage.



You might guess that the latissimus doors attaches to the shoulder blade, but it actually attaches to the humerus, which is one of the upper bones of the front leg.


The function of the latissimus dorsi is to bring the front leg backwards, which propels your horse forward. It’s counterpart, the brachiocephalicus, brings the forelimb forward and works to help your horse turn his head. Hence – walking!


lattissiumus muscle marked on a horse back

Here is the same dirty horse, on a different day, with his lats pointed out.


The longissimus dorsi.


This bad boy muscle, at the most basic level, runs along part of the back. BUT it’s really a mix of several muscles, all stemming from your horse from the base of his neck all the way back.


As you follow this huge muscle towards the horse’s head, it ducks under the latissimus and the trapezius. At the most basic of levels!


The longissimus dorsi serves to do lots of things, like help your horse move his legs. This is the muscle that creates a buck in the hind end and a rear in the front end. It can extend and flex the spine – which is needed for lifting the belly and curving around a rider’s leg. The longissimus dorsi also helps the vertebrae balance. If you notice that some horses have a back dent doing from withers towards the tail, this is the result of the longissimus dorsi.


longissimus muscle marked out on a horse back

Finally! A clean horse with his longissimus dorsi area-ish pointed out.


What does the topline do for your horse?


When all of the muscles of a horse’s topline are considered together, they are responsible for some big-picture things. Think of them as your horse’s posture makers! They provide balance, strengths, self-carriage, and stability. Smaller picture things, like trotting and bucking and rearing are also topline muscle functions.

The topline also balances out the abdominal muscles of your horse. The four big muscles in a horse’s abdomen have critical functions, like supporting the back. Think of it as your own body – your core strength keeps your spine “in place”. This is why back pain in humans can often be supported by core strengthening exercises. Same for horses!

The abdominal muscles of a horse also help keep the internal organs in their right place, help with urination and moving manure, and giving birth. They also help your horse move forward, side to side, and back.


Why is the topline of your horse important?


The topline is important because it moves your horse. This is also where you sit. Topline is a crucial part of your horse’s core, which is the basis for his strength, comfort, fitness, and proper mobility. It’s his POSTURE – what holds up his body and allows you to sit on him and work below him.


How do you measure your horse’s topline?


There exists a system to measure your horse’s topline. The Topline Evaluation Score (TES) looks at three sections of your horse’s back to examine and judge the musculature. Fat deposits don’t count, and are a big sack of problems anyway.


The three sections are:


Withers. Use your hand to feel the tissue on either side of the withers. A hand that falls inward or is flat means the topline could use some work.


Loin. This is the area behind the saddle. You hand shouldn’t sink in, and you may be able to find that back dent.


Croup. This is the highest point of your horse’s hind end, look here and go down a bit towards the tail. Same deal here.


Once you have identified and examined the three sections, you can score your horse. An “A” score means the muscles are well developed in all three area. A “B” score means the muscles around the wither need developing. The loin muscles are good, and the croup muscling is okay. A “C” score means the withers and loins are concave, and the croup is okay. A “D” score means the entire topline is concave. The croup is often pointy.


I always suggest looping your Vet in here to help you evaluate your horse’s weight and topline. I can tell you from personal experience that I get “puppy dog” eyes around my horse and can’t ever see anything that isn’t perfect. A neutral opinion is best!


a hand pressing into a horse's back to feel for soreness

Get your hands on your horse!


Why do some horses lose their topline?




Aging can stink for some of us, as well as our horses. There’s a condition called sarcopenia that can happen as horses age. It’s generalized loss, and subsequent weakening, of major muscle groups. These groups include the topline, the forearm muscles, and the hindquarter muscles. You may see outlines of hip bones and vertebral processes a bit more.


Sarcopenia is usually seen in older horses that have less than ideal exercise and diet programs. Horses with with pituitary pars intermedia dysfunction (PPID) are also affected.


For the older horse with sarcopenia, exercise is the key. Lack of exercise exacerbates the condition, and exercise helps it. You may have heard of long and low? It’s key here to build up the topline muscles again.


Exercise type and quality.


Some horse lose their topline because of lack of exercise, too much exercise, or improper exercise. Obviously, lack of exercise won’t build muscle. And too much exercise can cause pain, injury, and reluctance to work. Too much exercise may also cause a horse to compensate elsewhere in his body to relieve any pain.


Improper exercise includes all sorts of things. From the misuse of tack “gadgets” like draw reins, to asking your horse to do things with his back hollow, to overdoing it, to asking too much of an unfit horse.


I’m going to step out on a limb and link this to saddle fit, too. A horse without a properly fitted saddle, bridle, and rider will never be comfortable. This is a huge problem, which causes horses pain. A horse will never be able to perform well and properly in pain. In some cases, a poorly fitted saddle physically interferes with his ability to move.


Horses that have limited turnout won’t have the same benefits of self-exercise and play as horses with more turnout. You also have the hooligan horse that finds new ways to almost kill himself daily in turnout, in which case his antics may be causing topline issues.



saddle fitter examining a horse

You are doing your horse ZERO favors with tack that doesn’t fit.




Obviously any injury that sidelines a horse is going to affect his topline. Stall rest, rehabilitation, and recovery all take time and for the most part, exercise is reduced.


But there are also the horses that have low grade conditions in the hind legs, like a touch of arthritis. Very often, the back and neck compensate for this and create a larger problem.

The back itself can also be injured. A horse that’s cast, overworked, has fallen or flipped can also create direct injury to the back and muscles involved in the topline.




It’s impossible to just say that exercise along creates a strong topline in horses. Muscle just doesn’t appear – it needs to be built. This is where diet comes in. Muscles are protein, and your horse needs to eat it. Amino acids are the building blocks of protein, and a horse’s diet needs to reflect the proper amounts of this. And it’s not just any ol’ protein will do – it’s quality.


The thing to know about amino acids and proteins is this – there are so many, many types and they need to be present in the correct proportions. It’s similar to finding supplements. Some overlap. Some have gaps. Some work for a group of horses, but not others. The best gift you could ever give your horse’s stomach is the diet formulation by an Equine Nutritionist.


horse looking at yellow bucket full of feed

Diet, diet, diet!


One more thing to think about. Suppose you find the “perfect” protein feed for your horse. But your horse gets fat! Or has too much energy! Or hates the taste! Again, the Equine Nutritionist is key here.

If you are wondering about cost, I’ve paid more for a pair of breeches than a customized diet from an Equine Nutritionist. With a Ph.D. Only one of these things I would do again.


Medical conditions


This is the biggie category of topline eliminating causes. And the biggest reason why your Vet needs to be involved here.


PPID is one reason. This pituitary gland condition will create a horse that can lose muscle. This condition interferes with your horse’s ability to take those amino acids and transform them into muscle.


Kissing spines is another reasons. This sometimes is a chicken and egg situation – what caused what, and will working on the topline help the spine? Or vice versa. The point is that kissing spines and topline are related.

Arthritis is another culprit behind loss of topline. Arthritis causes stiffness and pain, which alters how your horse moves. This can show up with compensation problems and a horse that doesn’t use his body as he should.


Some muscle diseases, such as polysaccharide storage myopathy (PSSM) create a loss of topline. With PSSM, the glycogen in muscles is altered. This can lead to muscles tying-up, muscle damage, and pain to the point to immobility. This disease can be managed with a proper diet and exercise routine.


How can you develop your horse’s topline?


Like so many things in the world, it’s diet and exercise. Perhaps the third most important thing is getting your Vet and saddle fitter involved, too!


Physically building the topline with exercise can start on the ground. A great place is with belly scratches to get your horse to lift the back and round over. Most equine chiropractic exams incorporate this into the treatment, and you can continue on your own.


Allowing your horse to eat from ground level is also helpful. This grazing stance keeps the topline muscles long and active.


Encouraging your horse to use his hind end during exercise also helps. The hind end only comes under the horse when his belly is lifted. This engages the core, including the topline. Even if you think riding in a sand box from letter to letter is the worst thing on the planet, it’s often the best thing for your horse’s topline. You don’t have to do dressage in a sandbox, either, and letters are optional.


rainbow over horse pastuer

Movement, diet, saddle fit, and exercise – it all works together.


Let your horse have as much free space to move about.


Did I mention saddle fit?


Use your farm’s terrain to your advantage. Hill work can be particularly beneficial to building topline strength, as can using ground poles and cavelletti. Working on hills changes your horse’s center of gravity, so he needs to work the core and topline to stay upright. Poles and cavelletti require the belly and back to be lifted so the legs can clear the poles without jumping.


But really, none of these exercises for improving your horse’s topline are going to work if your horse hurts. Rule out medical issues, work on your horse’s diet with a trained pro, and make sure your saddle is as comfortable and correct as possible.



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