New Muscle Monday – #6 Transverse Abdominal


NAME: Transverse Abdominal

ORIGIN: Transverse processes of the lumbar vertebrae

INSERTION: Xiphoid Cartilage

ACTION: Compress abdomen

OTHER INFORMATION: This large muscle overlaps two other major muscles that also support the horse’s topline: the external abdominal oblique and the internal abdominal oblique. When working on this muscle you are also affecting the others. We will look at these further on another blog post.

Doing ‘cookie tests’ and belly lifts will help determine how well this muscle is functioning in your horse. Not sure what those are? I will explain below.

If your horse is lacking topline, this is one of the muscles that needs to be strengthened. Polework, cavelleti, and hillwork will be your best friends for that! Don’t forget to check your saddle fit or have someone qualified to check it for you – an ill-fitting saddle or incorrect cinching can damage this muscle (as well as the other abdominal muscles).

transabdom2        transabdom3

To perform a cookie test, stand to one side and have your horse reach around with their head as you hold a cookie just out of reach – ideally, a horse should be able to reach around to their hipbone area without difficulty. If they cannot reach that far, or can only do so by tilting their head and twisting their neck, or just want to move their feet to get the treat, the transverse or other abdominal muscles may need to be addressed. Do both sides and see if one is better than another (likely there will be a ‘worse’ side).

To perform a belly lift, use your fingers or a blunt object and run them down the midline of your horse’s belly. A normal reaction will be for them to ‘suck’ in their belly muscles and lift up their back noticeably. If there is no such reaction, or you get an overreaction (an irritated horse, pinned ears, tail swishing, moving etc), then you know there may need to be some work in this area. If an irritated response is consistent with your horse, please consult the help of a certified therapist or vet who can help identify the source of pain.
It is common for stallions to not have much of a belly lift response.


New Muscle Monday #5 – Semitendonous and Biceps Femoris

Ready for a two in one doozy today?? I figured we may as well do the Semitendonous and the Biceps Femoris together, as they (along with the semimembranous) make up the horse’s hamstring group!! This powerhouse group of muscles is very important to the horse – follow along to see just how they affect our equines.




ORIGIN: Gluteal Fascia, Ishium

INSERTION: Lateral Femur, Cranial border of tibia, Calcaneal Tuberosity

ACTION: Extend and abduct limb

This muscle affects the stifle and the rest of the lower limb so if problems arise in these areas, chances are the biceps femoris is involved. This very powerful muscle is easily felt and massaged under the fascia. Remember that to ‘abduct’ means to bring away from the body – this muscle’s job is to extend and abduct the hindlimb.





ORIGIN: Caudal sacrum, CD 1 & 2, ishitic tuberosity

INSERTION: Tibia, Calcaneal tuberosity (point of hock)

ACTION: Extend hip and hock, flexes stifle

The semitendonous is the muscle I mentioned last week, not to be confused with the inner Semimembranous muscle. Part of where it originates from, the ishitic tuberosity, is what humans sit on when we ride.
A common injury with this muscle is Fibrotic Myopathy (or Myositis Ossificans). This is when a muscle is torn, commonly from trauma, and ossification occurs when the tissue heals. In acute cases, the injury site is warm and painful when palpated. Chronic cases show a gait abnormality that is no longer painful, with the affected leg demonstrating a hoof-slapping motion. This is usually most evident at a walk. Here is a youtube video to show you.

The hamstring group (biceps femoris, semitendonous, semimembranous) are also linked/affected by the horse’s colon. Coming from a chinese medicine viewpoint, if your horse is experiencing issues with digestion or any/all of the above muscles, chances are they are linked and treatment options should reflect this.


New Muscle Monday #4 – Semimembranous

My apologies for the delay in getting a New Muscle Monday post up again! We’ll be concentrating on the hind end for the next few posts. Enjoy!


NAME: Semimembranous

ORIGIN: Ishium

INSERTION: Medial border of the femur

ACTION: This muscle is a retractor of the hind limb. It extends the hip and adducts the limb.

OTHER INFO: The semimembranous is a powerful muscle of the hind end and is the inner, more sensitive muscle that could be confused with the Semitendonous (another retractor muscle that runs from the hock to the sacrum).
Careful when palpating this muscle as not all horses appreciate hands in this area 🙂
Some horses surprisingly enjoy massage to this muscle – this often helps horses who seem to be moving narrow behind (not necessarily those horses who are base narrow in conformation). Once this major muscle can relax, the horse can resume a normal gait.

New Muscle Monday #3 – Middle Gluteal

Happy dreary Monday, everyone! I hope everyone had a good weekend, despite the gloomier weather around here lately. Up next for New Muscle Monday is a very important driving muscle of the hind!

NAME: Middle Gluteal

ACTION: Retract the limb and extend the hip.

The Middle Gluteal is a major retractor muscle of the hind end and commonly mistaken as one of the three hamstrings (which are the semitendonous, semimembranous, and biceps femoris).

AFFECTED BY: This massive muscle has a lot of jobs, including being the force behind a backwards kick, forwarding momentum over the hind legs, and also for rearing. Issues in this muscle may keep a horse from extending his hind leg(s) fully, just as if you had tennis elbow and couldn’t use your arm normally.
The middle gluteal is also a muscle that should be examined (among other things) when a horse is showing a ‘hunter’s bump’ (when the sacrotuberous ligament becomes raised and creates a noticeable ‘bump’). See here for an example.

OTHER INFO: For the keeners of anatomy out there, this muscle originates from the gluteal fascia and inserts at the greater trochanter of the femur.
The middle gluteal muscle is linked with the Pericaridum meridian (which also goes by the names Heart Constrictor or Circulation/Sex Meridians) and an imbalance of this meridian can negatively affect it. Some signs of an imbalanced pericardium meridian include: respiratory and heart conditions, anxiety, and problems involving the forelegs and forefeet.


Most horses love the middle gluteal area to be masssaged/worked on. I often find this muscle to be extra tight in horses in disciplines such as jumping and dressage, where the horses rely on it moreso than say a pleasure horse would. It is not a superficial muscle, so when massaging it you are also working on the superficial gluteal and the fascia layers.

Any questions or comments are always welcome 🙂 Til next week!


New Muscle Monday #2 – Rectus Abdominus

Happy Monday everyone, here goes number 2! As always, questions and comments are welcome.

Rectus Abdominus

Name: Rectus Abdominus

Action: Flexes the spine

Affected by: ill-fitting cinches, improper carriage whilst under saddle

Other info: This muscle is one of the key muscles that are involved with rounding the back and achieving collection. When this muscle is too contracted, the horse will have a roach back.

A good exercise to activate this muscle on your horse from the ground is belly lifts. To do this, use your fingers on the belly of the muscle, starting about where the girth would sit, and apply pressure up, running down the length of the muscle. A normal response from the horse would be to contract the rectus abdominus muscle and you will see the spine flex.

A reminder that some horses are more sensitive to this and may react more then others!

If your horse doesn’t have much of a belly lift to speak of, there are ways of helping to strengthen the muscle. Regular belly lifts, exercises over poles/cavelleties, and riding up and down hills are all excellent to do routinely.
Having a strong rectus abdomnius muscle will make it way easier on your horse to collect and remain in a proper frame under saddle.

This muscle originates from the sternum and inserts at the cranial pubic ligament.

For those who may like some more reading, a fantastic article by Deb Bennett can be found below. The ‘ring of muscles’ outlined in the article are the key components to attaining collection in the horse. he rectus abdominus is one of these crucial muscles. Without these muscles in balance and being used effectively under saddle, there is no possible way for the horse to carry itself correctly.

New Muscle Monday #1 – Latissimus Dorsi

Well, it is time to jump back on the blog train after too long of an absence! Starting today, and every Monday following, I will write about one muscle in a new feature called ‘New Muscle Monday’.

Here goes #1 – as always, any comments, questions, and/or suggestions are always welcome.



NAME: Latissimus Dorsi

ACTION: Flexes the shoulder and retracts the limb.

AFFECTED BY: Saddle fit, girth/latigo issues (affects not only the muscle but the fascia as well). Pressure points, girths with elastic on one side only, knots in the
equipment, etc. can all affect this area.


This muscle is also linked with the Spleen meridian. Problems with this muscle may mean an imbalance with this meridian. An imbalance could show with any of the following:
– weakened immunity
– stifle and pelvis problems
– stocking up
– colic/diarrhea/digestive issues/weight issues

You can see in the below image where the meridian pathway sits and how the latissimus dorsi muscle could influence it.



There will often times be noticable knots in this muscle, as it sits just under the skin and fascia (also known as a superficial muscle).
Horses who show signs of discomfort while being brushed/saddled may be experiencing pain with this muscle (and oftentimes in other areas as well if saddle fit is an issue).

For those of you with a keen interest in anatomy, the latissimus dorsi originates from the thoracolumbar fascia and inserts at the medial humerous.

I hope everyone is having an enjoyable autumn. With the colder weather approaching (today I saw the first hints of snow on my car!) it is even more important to have regard for your horse’s health and well-being with proper warm-ups and cool-downs, suffiencient water intake, etc. All of that and more is for another post, though!