Equine
Massage
Lesson
Two
In
this lesson we will be learning about the muscles, how they hold the skeleton
together and how they work.
It will be of value now to have an equine
anatomy book, or several, available. A
good knowledge of equine anatomy, both skeletal and muscular, is imperative if
you wish to give a good equine massage with specific intent, rather than just
giving a pleasant rubdown.
Here are books I’ve found clear and
helpful. The first one is required, but
it is helpful to have more than that, especially if you are planning on doing
equine massage professionally, since each shows the skeleton and muscles in
slightly different ways. The first four
on the suggested list are easiest to find. They do comparative anatomy between
horses and other animals. The Cyclopedia
Anatomicae compares anatomy between horses, other
animals and humans.
There is one required textbook
for this course:
• Horse Anatomy
Coloring Atlas, Robert A. Kainer **Visit Amazon to order the book: https://a.co/d/fPJmJli
Suggested:
• The Horse Anatomy Workbook,
Maggie Raynor
•
Color Atlas of Veterinary Anatomy - The Horse Volume 2: Raymond R
Ashdown and Stanley H. Done
• The Anatomy of the Horse: Robert F.
Way and Donald G. Lee, Breakthrough Publicat
• The Visible Horse, DVD
• An Atlas of Animal Anatomy for
Artists: W. Ellenberger, H Dittrich & H Baum, Dover Publications Inc., New
York, N.Y
• Cyclopedia Anatomicae:
Gyorgy Feher, Black Dog & Leventhal Publishers, New York, N.Y.
ANATOMICAL
BALANCE
When horsemen refer to balance in a
horse, they can be speaking of many different kinds of balance. They might be talking about the balance the horse
exhibits when moving free, or perhaps the way the horse organizes and uses its
body when under saddle in the various styles of riding and work. These are
forms of dynamic balance – balance while moving.
There is also static balance. Static balance is about how the horse holds
its body when standing still.
But there is another way of looking at
balance. Both dynamic balance and static balance are
dependent upon how the bones of the skeleton are arranged—how the muscles hold
the bones in place and how the joints function.
Each joint in the body has its own
design and specific movement pattern. There is a specific way in which each
bone is formed in order to fit against the other bones. As with any well designed piece of machinery,
it works best when the design of the joint is not abused or compromised.
Anatomical balance has to do with the
specific design of the joints in a body and how the muscles hold the bones of
the skeleton together in such a way that the joints work within the parameters
of their design. This balance is based
upon the way the structure (skeleton and muscles) is designed to work. When
opposing muscles of a pair have equal tension on either side of a bone - no
muscle tension pulling the joint in any direction - we refer to this as anatomical
balance or anatomical position; the bone is stabilized between the two
opposing muscles of a pair with equal tension.
Movement away from that position is done
by the contraction of one of the muscles of that pair--this muscle is called
the agonist. The agonist is directly responsible for causing or affecting movement.
The other muscle of the pair, on the
other side of the bone, the antagonist,
produces the opposite movement.
Even when there are multiple pairs of
muscles working to make a specific movement in a body, one group, the agonist,
will move the bone, and the other group, the antagonist, will move it
back. There will be more about this in
the section on how muscles work. The
important thing to know here is that when a body is standing still, the best
balance is the one where the agonist and antagonist have equal tone. This is the balance that will give optimum
results with the least amount of wear and tear on the muscles and joints of a
body. Anytime there is some kind of
unequal tension in muscle pairs or groups of muscles, movement, comfort and
health can be compromised.
Abnormalities in the bones themselves or
injuries that damaged bones, joints and muscles are two common reasons for
improper and balanced movement (these are beyond the scope of this
course). On the other hand, incorrect
tension in the muscles and tendons that support and move the joints is a much
bigger factor than most horse owners realize, and this is where massage can be
of great value.
Good anatomical balance and movement is
greatly dependent upon correct tension in the muscles that operate the joints
and move the skeleton. A well balanced
horse is going to have better movement overall.
The entire field of the physiology of
muscles and how they work is, again, far beyond the scope of this course. These processes are quite complicated. We will learn a shortened version of some
aspects of muscle function that will be sufficient information for what we need
to know and understand in order to do equine massage in a competent and
professional manner.
You will learn how muscles work to move
bones (we touched on this briefly when describing anatomical balance), how
muscles contract and how muscles protect themselves from injury caused by
over-stretching. You will learn these
processes as they relate to a single pair of muscles, but in reality, most
movement involves many pairs of muscles working in together.
DEFINITIONS
These are some definitions that you
should know as anatomy books and other professionals will use these terms.
There are two terms that define distance
in the body. They are proximal and distal.
Proximal is defined as “nearest to the center
part of the body” and it usually refers to the end of a bone or muscle that is
closest to the center of the body or the spine.
Distal is the opposite of proximal when
speaking of bones and muscles—located farthest from the center of the body and
closer to the feet or tail.
You also will hear the terms cranial and caudal.
Cranial
describes the end of a
muscle or bone that is closest to the head (cranium)
Caudal
describes the end of a
muscle or bone that is closest to the end of the spinal cord and beginning of
the tail otherwise known as “caudus equina”
The following define the three parts of
a muscle: the origin, the belly and the insertion.
Origin: one of the ends of a muscle that is
usually closest to the center of the body (proximal)
and is characterized by stability and the closeness of the muscle fibers to the
bone from which it originates.
Belly: the center portion of the muscle that
contains the muscle fibers and does the work.
Insertion: the end of the muscle that attaches to
a second bone that is farther from the center of the body (distal). In many cases, the
insertion may be a tendon.
HOW
MUSCLES
There are two terms that you will need
to know for understanding how muscles work to move the bones of the body.
These terms are agonist and antagonist. These are the broad, general terms for
muscles that work in a pair to move bones.
All muscles work in pairs to move bones
and these muscles will be on opposite sides of a bone. In a correctly working pair, one of these
muscles (the agonist) will contract
to initiate some kind of movement. As it
does so, the other muscle of the pair (the
antagonist) will stretch in order to allow the desired movement to
happen. When we want to return the bone
to its previous position, the process will reverse; the antagonist will
contract and the agonist will lengthen.
There are two types of
agonist/antagonist muscle pairs – flexors/extensors
and abductors/adductors.
Flexors
and extensors are on
the front side and back side of bones
and move the bones forward and backward. The flexors initiate movement of a bone and
the extensors return the bone to its normal position. The muscles on the back of the legs are
generally flexors. The muscles on the
front of the legs are the generally extensors.
The other types of agonist/antagonist
muscles that you need to know about are the abductors/adductors.
These move the legs out to the side,
away from the body and then back to the body.
The abductors are the ones
that initiate this sideways movement (take away
= abduct) away from the body; the
adductors move them back to the
body. The muscles on the inside of the
horse’s upper hind legs are adductors.
Most lateral work that horses do involves using the abductors and
adductors.
As an agonist contracts in order to
initiate a movement, it will move one bone closer to another at the joint
between the two bones. This makes the
angle between these two bones smaller.
This works in horse’s bodies as well as in humans.
Here are two examples – one human, one
horse.
Let your arm hang by your side and
notice that the angle of the elbow joint between your upper arm and your
forearm is 180 degrees. Now, bring your
lower arm up toward your shoulder and see how that joint angle gets smaller.
Next, notice that when your horse is
standing, the angle between its cannon bone and the upper foreleg, at the knee
joint, is 180 degrees. When you pick up
the horse’s foot the knee bends, making the angle at the joint smaller than 180
degrees.
Correct function of a muscle pair means
that both muscles contract and extend and do so in conjunction with one
another. When one is contracting, the
other has to extend. If this does not
happen, there will be a restriction in the movement of the bone.
If a muscle has, for some reason, lost
some of its capacity to stretch and stays in a semi-contracted state, it will
inhibit the movement of the bone. This
is referred to as a co-contraction
pattern (one muscle stays in contraction even when it should be stretching,
so both muscles of a pair are in contraction simultaneously).
When one muscle attempts to contract
while the opposing muscle stays in a contracted state it makes the desired
movement difficult.
In time these muscles have to work
harder and harder to make movement happen—they are working at cross-purposes
instead of together. A common term for
this phenomenon is muscle bound. When this happens, the range of motion of the
joint controlled by these muscles becomes restricted because the muscles do not
allow the joint to work to the full range.
Many movement problems are the result of co-contraction patterns. In the horse, one of the most noticeable
examples of this type of restricted range of motion can be seen in the hip
joints often due to hamstring tightness.
When muscles contract, most people
probably visualize it as a process whereby the muscle fibers tighten and bunch
up as they shorten. This is not the way
it really happens. When muscles
contract, the normal process involves the sliding of one type of muscle fiber
over another type of muscle fiber. This
sliding action allows for a fluid motion in the contraction and an equally
fluid motion in the lengthening.
This means that both contraction and
lengthening can happen with ease and suppleness rather than with a tight,
cramped movement that is so often seen when conscious effort is made to force a
movement by deliberate contractions.
Deliberate contractions, such as seen in human body builders, will
increase the size of the muscle fibers by creating scar tissue in the
fibers. This scar tissue will eventually
interfere with the correct working of the muscles and great care needs to be
taken to keep muscles that are used in this way supple by a specifically
planned stretching program.
The same is true with horses. When
conditioning and building muscles in their training, it is important to have a
stretching routine. This will help you avoid sore and tight muscles that will
interfere with the training program. *Stretching should be done by a
knowledgeable professional with great sensitivity so as not to cause injury to
the horse.
Just as the contraction process can be
forced, so can the stretch process.
When this happens there is always a
chance that a muscle could be damaged or torn by over-stretching, but the body
has a process called the stretch reflex
to protect muscles in that event.
When a muscle is in danger of being
pulled beyond its capacity to stretch safely, the stretch reflex is activated
and over-rides the stretch, causing the muscle to contract instead. So, any kind of over-stretching, whether
accidental or even in a planned stretching program, could result in muscles tightening instead of lengthening.
When the stretch reflex is activated and
results in muscles tightening, the muscles will stay in a contracted state
until something resets the muscles tension and allows the muscles to return to
their normal state. Massage is very
effective in dealing with this type of muscle problem.
Muscles can be tight in a contracted
state and not stretch well (this is what we usually think of when we talk about
tight muscles), but they can also be tight in the extended state, with capacity to contract. Both conditions present problems—one muscle
needs to learn to contract with greater ease, one needs to learn to stretch
with greater ease. And it is usually the
case that if one muscle of a pair is tight in contraction, its opposite will be
tight in extension. This is particularly
true if the muscle problem has been present for an extended period of time.
MUSCLES,
TENDONS
We need to learn the difference between muscles, tendons and ligaments.
A muscle
is composed of individual muscle fibers that are wrapped with connective
tissue; then groups of these muscle fibers, wrapped in their individual
connective tissue, are bundled together and wrapped with more connective
tissue. This grouping and wrapping goes
on until a specific muscle is formed.
Then, muscles doing the same type of work may be wrapped together by
connective tissue, so you can begin to see that there is a lot of connective
tissue involved. One good example is a
ham. It shows quite clearly the white
connective tissue that surrounds the various muscles that make up the ham.
Some muscles go from one broad surface
to another, so they are broad at both their origin and their insertion (the
Rhomboid is a good example). Click
here to see a picture of the superficial equine muscles.
But sometimes a large muscle’s insertion
may attach to a much smaller bone or to a very small point on a bone. For that to be possible, somehow that end of
the muscle has to come to a small point so that it can attach to a small
point. It does this by losing the muscle
fibers that produced the bulk in the muscle as it comes closer to its insertion
point, and what remains is all of the connective tissue that had surrounded the
muscle fibers. (Think about all of that
white fibrous tissue at the end of the ham bone—those are tendons.) From this you can see that a tendon is an integral part of a muscle,
not something separate. Because it is
composed of only connective tissue, this tendon portion of the muscles is quite
strong, but, without the muscle fibers, it lacks the great elastic quality of
the muscle belly.
Look at your anatomy charts and you can
find numerous examples of muscles with tendon extensions. The Latissimus dorsi is a good one in
horses.
The horse’s lower legs, front and hind,
are basically operated by tendons that extend down from muscles that originate
either in the upper portions of the legs or in the lower areas of the shoulder
or haunch. This is also true in humans;
our lower legs and our forearms have numerous tendon attachments. One of the easiest examples to find is in the
four big muscles on the front of our thighs—the quadriceps. These are four muscles large enough to cover
the entire front of our thigh bone (femur) and they all converge into one
tendon that attaches to our knee cap.
Because of its lack of muscle fibers, a
tendon does not have the good blood supply and circulation that the muscle
belly has. For that reason, a tendon
injury can take longer to heal than if the injury is to the body of the
muscle. (Anyone who has ever had a horse
bow a tendon knows all about this.)
Bowed
Tendon
Ligaments are really a completely different
category from muscles and tendons. They
are very strong bands of rather inelastic tissue whose primary job is support,
not movement. They hold things in place. The
horse’s lower legs are full of ligaments that support the tendons and prevent
injuries caused by excessive or abnormal movement. These make up a large part of the “stay apparatus”
that allow the horse to sleep while standing.
The horse’s neck is supported by a large
ligament system, part of which runs from the poll to the withers and then there
are the supporting ligaments on the sides of the neck that go from the withers
to the neck vertebrae. Ligaments have a
poor blood supply and circulation. If
injured they take much longer to heal than muscles or tendons.
SKELETAL
ANATOMY
Even though this course is about massaging
muscles, you also need to know the horse’s basic skeletal anatomy. The job of the muscles is to move the
bones. The skeleton and muscles together
are an integral system, essentially a lever and pulley system with the bones as
the levers and the muscles as the pulleys.
There are also bony landmarks that will aid you in finding specific muscles in
your learning process. Click
here to see the equine skeleton.
In the descriptions of the skeleton and
the muscles we will use as many common names and horse related terms as
possible rather than medical terminology, though for the muscles we will use
their Latin names. This will help you cross reference names in your anatomy
books, with your own knowledge and out in the field while working.
You
will need an equine anatomy book for reference while you are studying this. After we have gone through the horse’s
skeleton, we will start learning the major muscles that will be important for
the horse’s movement; the primary ones that you will be massaging.
There will be occasional and interesting
comparisons to the human body, however we will keep our primary scope of
learning equine.
Axial
Skeleton
The axial
skeleton consists of the skull, spine and tail of the horse.
- SKULL
The skull of the horse is composed of two sections. The larger section houses the brain and
the upper portion of the face and jaw.
The other section is the lower jaw that hinges to the upper portion
of the skull just below the ear.
This is called the TMJ or temporal mandibular joint Familiarize
yourself with where this joint is on the horse. There will be many times you will do
massage work in this area. Watch as
a horse chews, this will help pinpoint the jaw joint.
- CERVICAL
(neck) The neck of both horse and
human is composed of seven vertebrae. They are designated C-1 through C-7,
with C-1 being commonly called the Atlas.
The shape of these vertebrae is the same in both humans and horses; only
the size is different. A common
thought is that the cervical area is located at the upper portion of the
neck below the mane. It is located in the lower portion of the neck and
the bones can be felt with soft flat hand pressure in that area and on
most horses we can see a wider area at C-4-5.
- THORAX
- LUMBAR
Next in line, behind the thoracic
vertebrae are the lumbar vertebrae.
In humans we call this area the low back, in horses we call it the
loins. Horses have six lumbar
vertebrae. This section of the
spine has no bony stabilizing structures, such as ribs or pelvic bone, to
support it. All of its support
comes from muscles. This lack of
support is one of the reasons why horses and humans have numerous problems
in this area; the trade-off for both is flexibility.
- SACRUM
- COCCYX
(tail bones). Finally, at the end of this column of
bones, are the tail vertebrae or coccyx.
The average horse has 18 tail vertebrae, but this can vary by one
or two.
Appendicular
Skeleton
The name appendicular skeleton comes from the word appendages that in the
case of the horse are legs and hooves.
FORELEGS
1.SCAPULA
(shoulderblade) We think of the scapula as the first bone of the arm. This
bone is a flat and triangular shaped. It lies on the rib cage and is attached
by muscles only. The horse’s scapulae lie up against the
sides of the rib cage. This limits the forelegs of the horse to primarily
forward/backward motion. This position
against the rib cage helps stabilize the front legs for their job of supporting
the front portion of the horse.
2.
HUMERUS Attached to the
scapula at the shoulder joint is a
sturdy bone called the humerus. In the
horse this bone goes from the point of the shoulder (shoulder joint and bony landmark) to the elbow. The humerus lies against the ribs and is
supported by them and is held in place by muscles. This arrangement provides a front to back
motion of the humerus, but only a very small amount of side-to-side movement;
and this is possible only as the humerus swings forward. In the horse, this shoulder joint has traded
mobility for stability (in keeping with its support function) and injuries to
the humerus and this joint are infrequent.
3. RADIUS
4. CARPAL
BONES At the end of the radius and ulna in the human skeleton is a group of
small bones (carpals) that form our wrist or carpal joint. The horse has
a similar group of bones in the foreleg, often called the horse’s knee. There
may be confusion in different texts about this joint however please understand
that regardless of the fact that we often call this joint a “knee”, it is the
same joint as our carpal or wrist joint.
(The horse does actually have a true knee joint on the hind legs and we
call it the stifle).
5. METACARPALS
(canon bone and splint bone) The canon bone is the large bone below the knee
(carpal joint)and alongside is the splint bone. The splint bones are the
vestigial remains of the other two metacarpals that the horse had when it was
originally a three-toed animal. These
splint bones have lost all function and the canon bone is the primary means of
bony support for this lower leg region.
6. PHALANGES
(long pastern, short pastern and coffin bone) In the horse, below the
metacarpal (cannon bone) are also three bones that are the equivalent of our
finger bones. We call them the long
pastern bone, the short pastern bone, and the coffin bone. You will hear them referenced to as P1, P2
and P3. In the horse, these bones have a greater range of motion than do our
fingers. This range of motion
accommodates the forward/back swing of the front legs. What is a fascinating
thought in studying the horse’s forelegs, is that the horse is essentially
standing on the tip of a finger!
HINDLEGS
The horse has a
thighbone (femur) and hip joint
exactly like a human. There is also a knee joint (called the stifle in the horse), a tibia and fibula (these are the bones
of our lower leg), a heel/ankle joint (the hock
of the horse) and a corresponding arrangement of its lower leg (cannon
bone, fetlock, pastern, hoof) similar to its lower front leg. The bones of the
horse’s hind legs are basically the same as those of the human leg. They are
also long in comparison to the front legs just as our legs are longer than our
arms. The horses angulation of the hind legs has to be more acute in order to
bring it into some kind of balance with the forehand. This greater angulation of the bones under
the horses body gives the horse greater pushing power for propulsion.
1. FEMUR The
femur (thighbone) attaches to the
pelvis at the hip joint and angulates slightly forward to the stifle joint.
2. STIFLE JOINT The horses stifle joint is exactly the
same as the human knee joint—same shape, same function (remember that what we
call the knee in the horse is actually the equivalent of the human wrist). This joint has the same structure, the same
ligaments, the same muscles attached to it and it has the same bony protection
in front of the joint (the knee cap or patella)
as does the human knee.
3. TIBIA
4. HOCK JOINT The hock
(bony landmark) is the same joint as the ankle in a human. This can be a troublesome joint for many
horses.
5.
HIND LOWER
Muscle
Anatomy
This section describes some of the major
muscles involved with movement in the horse’s body that are accessible to
massage, as well as what these muscles do and some of the problems that can
occur when these muscles are not working properly. (This is not intended as an in-depth
anatomical lesson)
You
will need to refer to your anatomy books as we go through this section.
I will not be describing any lower leg
muscles and function. The legs below the
knee and hock are primarily composed of tendons and ligaments and because of
the tough, inelastic nature of these, techniques for working on them are
limited, and if not done correctly, can do damage.
There are two major layers of muscles on
the skeleton that are going to be our focus.
They are the superficial (those
just under the skin) and the next layer, the deep, just under the superficial layer. These second layer muscles are sometimes
easily accessible in many areas of the horse’s body and sometimes not.
★ A
note about the torso—in the human body the torso is considered the area from
the shoulders to the bottom of the pelvis, but for my description of the
horse’s muscular anatomy I will consider the torso to be the thoracic portion
of the spine (the thoracic vertebrae and rib cage) and the lumbar vertebrae
(loins). I will discuss the pelvis in
conjunction with the hind legs. Because
of the way the horse’s hind legs fold under the pelvis, this seems a better way
to view it.
★★All the muscles described occur on both
sides of the body. They are mirror
images of each other.
THE TORSO
The muscles of the torso connect the two
ends of the horse, the rider sits on them and many of a horse’s problems start
in its back. Even when problems
originate in other areas, soreness and tightness can be referred into the back.
The five important muscles in the torso
are:
- Long back muscles (Spinalis, Longissimus dorsi, Iliocostalis)
- Latissimus dorsi
- External oblique
- Internal oblique
- Rectus abdominis
1.Long
back muscles. Click
here for picture. These muscles are some of the most important ones that
you will deal with in massaging a horse.
They are the major support and protection for the spinal vertebrae and
are subject to major problems involving tightness, soreness and muscles spasms
from multiple sources. They are also the
extensors that have to lengthen when the abdominal muscles contract. There are
three of these muscles on either side of the spine.
Starting closest to the spine and moving
outward, they are the Spinalis,
Longissimus dorsi and the Iliocostalis.
The forward (cranial) attachments
of these muscles are to the withers, the ribs and under the scapula. They run the entire length of the back and
attach to the forward (cranial) edge
of the pelvis.
The Iliocostalis This is easy to feel where it attaches to the
pelvis because its attachment is on the point
of the hip (bony landmark see equine
skeleton Tuber coxae) and its outer edge, between the point of the hip and
the last rib; it feels like a hard, ropey ridge. Some equine anatomy books show these as one
single muscle, but there are really three.
The human body has these same muscles, positioned in the same way and
their purpose is the same—support and protection of the spine and to extend as
the abdominal muscles contract.
2.
Latissimus dorsi This
is a large flat muscle, somewhat triangular in shape, that connects the horse’s
back to the humerus in the lower portion of the shoulder. The origin portion of
this muscle, which attaches along the spine, is connective tissue. This is why we can palpate the long back
muscles under it.
The middle portion contains the muscle
fibers. The insertion portion (attaching
to the humerus) is tendon (no muscle fibers).
This is a good example of a large muscle narrowing down to a tendon in
order to attach to a small point.
This muscle offers support and control
to the movement of the shoulder in its forward/back swing. As the shoulder swings forward, this muscle
extends; its contraction helps bring the humerus backward. Because this muscle connects the back to the
front legs, over-stretching of the front legs can put excess stress on a
horse’s back, and, conversely, problems in the back can affect shoulder swing.
3.
External oblique
Click
here for picture. This is a large, relatively thin muscle that covers much
of the rib cage. It starts out narrow at
the point of the hip and spreads out over the ribs. The top edge attaches to the individual
ribs. The bottom edge merges into a band
of fascia (connective tissue) that then merges into the abdominal muscles. This fascia provides a direct link between the
external oblique and the abdominal muscles and gives a rider a way of
initiating a contraction of the abdominals.
The External oblique is the muscle that lengthens and shortens the sides
of the horse as it moves. These muscles, on both sides of the horse, are
important for correct bending. The
movement in the lower edge of this muscle is easy to see when a horse is trotting. These muscles also expand and contract in
time with a horse’s breathing. In a
horse that has heaves, the lower edge of this muscle is very noticeable in its
contraction; we call it the “heave line”.
4.
Internal oblique Click
here for picture. This muscle could
be thought of as both a muscle on the side of the horse and one in its lower
torso area (belly line). The loin/flank
area of the horse has no bony support other than the lumbar vertebrae; there
are only muscles supporting and holding up this portion of the abdomen (akin to
out lower abdomen). The major muscle in
this area, and one accessible for massage, is the Internal oblique. It starts out narrow at its attachment to the
point of the hip and then broadens out as it swings down to the mid-line of the
belly. It acts as a sling, holding up
the contents of the abdominal cavity. It
encompasses the area we call the flank and groin. Tightness and muscle spasms are common in
this area and it is an important area to work on, but it is also one of the
most difficult. Many horses, in response
to pressure here, will kick first and ask questions later. Work in this area should be approached with
care.
5.Rectus
abdominis The
Rectus abdominis (abs) are a line of muscles on either side of the center line
of the belly. They are connected to the
lower edge of the External oblique by fascia.
In both horses and humans the Rectus abdominis are long, relatively
narrow muscles that attach to the pubic bone of the pelvis, run along both
sides of the center line of the belly and then attach to a number of the
ribs. In the horse their contraction
exerts a pull on the pubic bone that draws the pelvis down as the hind legs
swing forward. Their contraction also
lifts and supports the long back muscles, supporting and holding the torso up
from underneath. Good abdominal muscle
tone is as important for the horse as it is for humans in keeping the back
healthy and working correctly. Our term
for a horse with poor abdominal strength is “hay belly”; for people the term is
“pot belly”. Click
here for picture – chest and abdominal muscles.
THE HIND QUARTERS WITH THE HIND
The muscles of the hindquarters are
listed below. The muscles of the haunches are bulky, dense, powerful muscles
whose primary function is propulsion.
These are power muscles; their job is to send the horse forward. They are easy to massage because of their
size and accessibility.
1. Gluteal muscles—Gluteus medius and Gluteus
maximus
2. Tensor fascia latae
3.Quadriceps—Rectus femoris, Vastus medialis, Vastus Intermedius, and
Vastus lateralis
4.Hamstrings—Bicepts femoris, Semitendinosus,
Semimembranosus
5.Adductors
6.Gaskin
7.Gastrocnemius and lower hamstring attachments
Click
here for picture of superficial haunch muscles.
Click
here for picture of deep haunch muscles.
1.Gluteal
muscles There are
three gluteal muscles, but one, Gluteus minimus, is
deep and not accessible to us for massage.
The other two, Gluteus medius and Gluteus
maximus, form the bulk of the muscle mass on the top of the haunches. (Other names you might see for these muscles
are middle glute for Gluteus medius and superficial
glute for Gluteus maximus.) Together
these two muscles attach to the edge of the pelvic bone where it joins the
loins (iliac crest) and along the edge of the sacrum. They both converge and attach to the upper
portion of the femur at the hip joint.
Their contraction and extension works to stabilize the forward/backward
swing of the horse’s hind legs..
2.
Tensor fascia late This muscle is important in the working of
the stifle. It originates from the point
of the hip as a muscle and then becomes fascia (connective tissue) as it
approaches and covers the outside of the stifle. It helps to support the stifle. Its contraction, along with the contraction
of the quadriceps, pulls the stifle forward and its extension allows the stifle
to move backward. The best results from
massage on this muscle would be in its upper portion where there are muscle
fibers.
3.
Quadriceps In the horse these are four large muscles on
the front of the femur that are important for correct functioning of the
stifle They are covered by the fascia of
the Tensor fascia latae, but they are still
accessible for massage. They are the
three vastus muscles (Vastus medialis,
Vastus intermedius, Vastus lateralis) and the Rectus femoris. They work in
conjunction with the Tensor fascia latae to bring the
stifle forward. The best access to these
muscles is an area just in front of the hip joint and on the inside of the
stifle joint. Humans have these same
muscles and they do the same job of bringing the human knee forward, but there
is one significant difference. In the
human, all four muscles converge into one large ligament that crosses the knee
and is known as the patellar ligament.
In the horse the attachments of these muscles at the stifle are separate
and distinct.
4.
Hamstrings If the quadriceps and the Tensor fascia latae pull the stifle forward, something has to pull it
back; the hamstrings do this. They are a
group of three muscles that run down the back of the horse’s haunch. Starting on the outside of the haunch and
moving around to the inside, they are the Biceps
femoris, Semitendinosus, and Semimembranosus. The Biceps femoris is a large, fairly broad
muscle with its origin on the sacrum. It
crosses over the hip joint and swings to the outside of the haunch for its
lower attachment. The Semitendinosus and
Semimembranosus are long, but bulky muscles, also with their origins on the
sacrum, that go down the back of the haunch.
Their lower attachments are in the area where the haunch tapers into the
hind leg. When these muscles contract
they pull the leg backward. The
agonist/antagonist action of these two muscle groups (quadriceps and
hamstrings) produce the swing of the hind legs in both horses and humans. But there is a major difference in horse and
human anatomy in the arrangement and position of the hamstrings. In humans the hamstrings have their upper
attachment (origin) at what we refer to as our “seat bones” (Ischial
tuberosity). With the attachment here,
our legs swing from the hip joint without changing the vertical position of our
pelvis. In the horse these muscles
continue on past the Ischial tuberosity (the point of the buttock, or the
horse’s seat bones) and attach to the sacrum.
With the hamstrings positioned in this way, when they lengthen in
response to the contraction of the quadriceps, this extension goes all the way
up to the sacrum, not just to the point of the buttock. Lengthening in this way allows the horse’s
pelvis to be pulled downward from its normal horizontal position and sets the
horse’s hind legs up for a powerful reach under the body and then a powerful
push that sends the horse forward. This
dropping of the pelvis as the hind legs come forward is what creates
“engagement”. These three muscles are
fully accessible and respond well to massage over their entire surface.
The last three muscles, or muscle
groups, of the hindquarters are easy to find and massage.
5.
Adductors The adductors are the big muscles of the
haunch that are between the hind legs.
The biggest muscle, and the one you’ll make the most contact with, is Gracilis. Tightness in these adductors can restrict the
swing of the hind legs. These muscles
are positioned the same in humans.
6.
Gaskin Horsemen use
the term “gaskin” for two small muscles on the front of the hind leg just above
the hock. The gaskin is actually two
small muscles whose tendons run all the way down the front of the hind leg to
the hoof. These muscles are important
because any tightness or soreness in them can exert tension on their tendons in
the lower leg. Release of tension in
these muscles can help relieve tension on the tendons.
7.
Gastrocnemius The
gastrocnemius is on the back of the hind leg.
It is also a small muscle with an important tendon. You’ll find the muscle belly just below the
hamstring’s lower attachments. Its
tendon attaches to the top of the hock.
In humans this is known as the Achilles tendon. Tension in this muscle can stiffen hock movement.
THE
FOREHAND, SHOULDERS
This section of the lesson on muscle
anatomy is not intended to deal with all
the muscles of the horse. This is
especially true of the forehand because many of the muscles are not accessible
to us for massage. It is only the
important muscles that we can get to that will be described.
What we call the forehand of the horse
is actually the front portion of the rib cage (from the withers and shoulders
to the front of the chest), the shoulders and the front legs.
Some of the muscles of the forehand
support the bottom of the rib cage, some are responsible for moving the
shoulder blades and front legs, and some hold the shoulder blades in place
against the ribs. You will see these
three divisions in the descriptions.
Support
Muscles
There are four pectoral muscles in the chest
area and three of these are the major support for the bottom of the rib
cage. The Rectus abdominis muscle
supports the torso from the pubic bone to the beginning of the rib cage. The
largest of the pectoral muscles takes over support where the Rectus abdominis
ends. It is a long, fairly large muscle
that attaches along the entire length of the breast bone (sternum) and then,
close to the elbow joint, it attaches to the humerus. When this muscle contracts, it elevates the
rib cage at the withers. This muscle
acts in much the same way as the human Pectoralis major.
Two other pectoral muscles also attach
the front legs to the body of the horse; they also go from the rib cage to the
humerus. One can be found directly
between the front legs. The other is in
the front of the chest; what we would normally call the chest muscle.
These muscles are easy to find and
massage.
Muscles
That Move the Shoulder Blade and Front Legs
The concept in moving the front legs is
simple—the muscles located in front of the shoulder pull the humerus forward;
muscles behind the shoulder pull the humerus back. The major muscles involved in pulling the leg
forward (ones that we can access and massage) are the Biceps brachii and the lower portion of the Brachiocephalicus.
The Biceps brachii is in the front of
the chest, next to the chest pectorals and distal to the shoulder joint.
The Brachiocephalicus
is a long muscle that originates just behind the horse’s ear—on the first
cervical vertebrae (the Atlas). It goes down the entire length of the lower
neck, following the contour of the neck vertebrae, then over the point of the
shoulder and inserts on the humerus. It
is a prime mover in the process of bringing the leg forward.
Massage on the lower portion of the neck
and lower portion of the shoulder will relieve tension in the lower portion of
this muscle as well as other important muscles of this area.
The important muscles that pull the leg
back are the Latissimus dorsi and
the Triceps. I described the Latissimus dorsi when
describing the muscles along the back of the horse’s torso because of its
attachment, as fascia, along the thoracic vertebrae. Its muscle belly (the portion with muscles
fibers) is behind the shoulder and its strong tendon attaches to the
humerus. Its contraction exerts a strong
backward pull on the humerus. Because
the muscle fibers of this muscle are behind the shoulder and just under the
skin, massage to this area can be beneficial in increasing shoulder mobility.
The Triceps pull the front leg back in a
different way. This muscle forms the
back portion of the shoulder (the big, fleshy portion behind and below the
scapula) and is triangular in shape. Its
origin attaches all along the back edge of the scapula and also at two points
on the humerus, and then all the muscle fibers converge to attach at the point
of the elbow. When this muscle contracts
it closes the angle between the scapula and the humerus, and thereby pulls the
humerus backward.
Muscles
That Hold the Scapula Against the Rib Cage
There are two groups of muscles that
keep the scapula in place against the rib cage.
One group is between the rib cage and
the scapula. The other group is on the
outside of the scapula. In both
instances (inside or outside) the process of stabilizing the scapula against
the rib cage occurs at the top of the scapula—leaving the bottom free to swing
forward and back.
The important muscles between the
scapula and the rib cage are the Rhomboid
and Serratus.
The Rhomboid attachment to the scapula
is on the inside upper edge. The other
end of this muscle attaches to the withers.
So, the scapula is hanging from the withers, and the Rhomboid is the
attachment between the two. Tightness of this muscle in the horse can adversely
affect the balance of the entire forehand.
There is also a neck portion of the Rhomboid, which I will discuss with
the neck muscles.
Below the Rhomboid attachment on the
inside of the scapula is the attachment of the Serratus. At its origin at the top of the scapula it is
a small, dense muscle mass that then divides into 13 long, slender muscles. These 13 muscles attach the top of the
scapula to the middle of the rib cage on the first nine ribs and to the last
four neck vertebrae. This arrangement of
the Serratus is important because when the Serratus is working correctly it
causes the neck to stretch down and helps to bring the back up. Much of this muscle arrangement is cover by
the scapula or heavy, dense muscles, but we have access to some portions of
these individual muscles that attach to ribs six through nine, and can also
make contact with those attaching to the lower neck vertebrae.
Because these thirteen “fingers” of the
Serratus all originate from a common muscle mass, we can have a positive effect
even on the sections we can’t reach if we can get some of these “fingers” to
release tension. This is why relaxing
the neck helps soften the rib cage and vice versa..
Click
here to see the serratus with the shoulder blade in place.
Click
here to see the serratus with the shoulder blade removed.
Click
here to see the serratus in the extended state.
Click
here to see the serratus in the contracted state.
There is only one major muscle on the
outside of the scapula that holds it in place—this is the Trapezius. It stabilizes its
top portion, while still allowing the bottom to swing with the movement of the
front legs. The form and function of the
Trapezius is the same in humans and horses.
It is a big triangular muscle that originates along the spine of the
scapula and fans out in two directions to attach to the horse’s topline. One section attaches to the withers and the
area of the back just behind the withers.
The other section goes up the crest line of the neck covering most of
the Rhomboid muscle. This muscle is a
powerful anchor and stabilizer for the scapula, as well as support for the
neck.
The Trapezius is an extensor and when
working correctly the extension of the Trapezius allows the neck to arch out in
front of the horse’s torso. But if the
Trapezius contracts it will cause the neck to arc upward, resulting in what
horsemen call ewe-necked’ or “star-gazer”.
This contraction of the Trapezius will also pull the horse’s back down
in the portion under the saddle. (Notice
that the result of this contraction is the opposite of what happens when the
Serratus contracts and lifts the back.)
There are two other muscles of the
shoulder that I want to mention because their purpose is different than the
others I’ve described and they are big enough that massage can be beneficial
even though they are covered by other muscles of the shoulder. They are Supraspinatus
and Infraspinatus.
These are long muscles that run
lengthwise down the scapula, one on either side of the spine of the
scapula. They are attached to the
scapula along almost their entire length so that there is very little extension
possible except at their tendons. These
strong tendons cross the shoulder joint (point of the shoulder) and attach on
the humerus side of this joint. The
purpose of these muscles and their tendons is to support the shoulder joint in
its proper position against the rib cage.
As you have probably gathered, there is
a complexity of muscles contained in a fairly small area in the shoulders, and
often it can be difficult to isolate exactly which muscles you may be
massaging. Fortunately, massaging the
bulk of the shoulder and the areas behind it and in front of it will benefit
all of them.
The reason for describing them in detail
as I did was to give you a better understanding of how the shoulders and front
legs are organized in relationship to the rib cage and how they work to produce
movement.
THE
NECK
Neck
Comparing human and horse anatomy in the
neck will show basic similarities in muscles and structure, but the extension
of the neck hanging out in space in front of the horse requires some special
adaptations, especially in deep muscles and ligaments.
At the deep level these systems of
supporting ligaments and muscles are not accessible for massage and, in the
case of ligaments, do not readily respond to massage.
Only the superficial and second levels
that we can massage are being described, but releasing tension in these
superficial muscles can gradually have an effect on the deeper muscles as well.
Muscles along the crest are going to be
support muscles, muscles that hold the neck up.
There is a very strong ligament that forms the crest line of the neck
(the Nuchal ligament); it runs from
the withers to the poll, and it is to this ligament that the supporting neck
muscles attach.
The important muscles attaching to this
ligament are the cervical (neck) portions of the Rhomboid, Trapezius and
the Splenius.
The Rhomboid and Trapezius attach to the
Nuchal ligament and connect the crest line of the neck to both the rib cage and
the scapula. The Splenius supports the
side of the neck; it starts at the withers and spreads out to attach to the
upper neck vertebrae. All of these
muscles are easy to massage. Click
here for picture.
Supporting the vertebrae of the lower
portion of the neck is the cervical
portion of the Serratus. (Remember
that the Serratus attaches to the ribs as well as to the neck vertebrae.) This cervical portion of the Serratus goes
from its origin on the under side of the scapula to
the last four neck vertebrae. This is a
very important muscle for obtaining correct carriage of the neck. Its attachments to the neck vertebrae occur
where the neck has its downward arch. If
these muscles have correct tension, their contraction will lift these lower
neck vertebrae, causing the crest line muscles to extend and allow the topline
to lengthen.
If muscle tone is poor in these cervical
Serratus, it allows this portion of the neck to “sag”, causing a dip in the
crest line of the neck. Horsemen refer
to this configuration as “ewe-necked” or “star-gazer”. Correct function of the Serratus has a
significant effect on how the horse is able to use the rest of its body.
The Serratus attachments to the lower
neck vertebrae are under the Brachiocephalicus, but can be massaged through it.
The Brachiocephalicus
is a long muscle on the lower side of the neck.
It starts behind the horse’s ear, follows the contour of the neck
vertebrae, goes over the point of the shoulder and finally attaches to the
humerus. Its contraction is involved
with the forward/back swing of the front legs as well as giving support to the
neck from the bottom, much as the abdominals and pectorals support the torso.
There is one other muscle that can cause
tension in the neck. This is the fourth
pectoral, the Cranial Deep Pectoral. You will remember that the other three
pectorals attached the humerus to the rib cage.
This fourth pectoral lies lengthwise along the front edge of the scapula
and forms another attachment of the scapula to the humerus. It can be felt as a long, tight ridge in
front of the scapula, and tension in this muscle can easily prevent any
softening and lengthening of the neck.
Massage to all of these neck muscles
produces positive responses not only physically, but mentally as well.
Head
Because of its endorphin points, massage
to the head, especially the ears and poll, can be a powerful and relaxing
experience for the horse. I have been
told that cavalry officers would “pull” their horse’s ears in between cavalry
charges to relax them. This relaxing
head massage can be especially beneficial for nervous horses and is also a nice
finishing touch to any kind of equine massage, except pre-event stimulation
massage.
The work we will do on the head is
primarily to release tension in the jaw line and balance the jaw joint (Tempro mandibular joint or TMJ) and
poll.
There is a long, thin muscle Zygomatic that runs from the corner of
the horse’s mouth up into the ridge of the cheekbone. Pressure to this muscle where it meets the
big cheek muscle Masseter will
produce a relaxation of the horse’s mouth and jaw line. This relaxation in the mouth helps when you
are doing work on the TMJ joint. The TMJ
of the horse is found in the same place as you would find it on the human
skull, it is a bony prominence just in front and slightly down from the ear.
Working to release the TMJ doesn’t
involve so much of massaging muscles, but more of releasing the joint itself.
In addition to the massage work that
involves the jaw, there are numerous small muscles around the poll—behind it,
on the forehead and around the ears, and it is important to loosen these if you
are going to obtain good poll flexion.
Poor poll flexion can stiffen a horse throughout its entire body.
The other muscles I address when there
is tension in the poll are the ones of the throatlatch. Even when the poll muscles are capable of
extending to give good poll flexion, tight muscles in the throatlatch area can
prevent this flexion. I think of it as
trying to flex the head when there’s a tennis ball in the throat area.
Horses that crib often have difficulties
with poll flexion because of over-developed, tight muscles in the throat area.
This brings us to the end of this survey
of skeletal anatomy and the major muscles important for support and movement
that are accessible for us to massage.
Lesson three will cover the horse’s
gaits and movement patterns.
Assignment:
The aim of this assignment is to enable
a student to become so familiar with the horse’s muscular and skeletal anatomy
that they can put a hand any place on a horse’s body and know what muscle is
under their hand, what the shape of that muscle is, where the origin and
insertion attachments of the muscle are, what bones are under that muscles and
what the job of the muscle is – what movement of the bones does the muscle
activate.
Use your anatomy books as you do this
assignment.
You are not looking for a comparison of
the conformation and muscle density. You
will need to look at a minimum of three horses in order to practice on for this
assignment.
On three horses, find the bones of the
skeleton that we covered in the lesson.
If a bone is covered by substantial muscle mass, be able to visualize
where it is and its shape. Touch the bones where ever
possible. Follow the progression of the bones,
starting with the head and going back to the tail. Also, with finger tips, trace leg and foot
bones – fronts and hinds.
On three horses, find muscles of the
horse’s body that we covered in the lesson.
Touch these muscles, tracing
the outlines with your finger tips whenever
possible. Start at the head and work
back to the tail.
After your exploration of the horse’s
bones and muscles, write a report describing your thoughts, ideas and any new
awareness about what you are feeling – perhaps new things you did not know
about horses and their bodies.
Did you have any “ah ha” moments about
things that suddenly made sense to you that you may not have understood
before?
I would like any thoughts that occur to
you as you are turning the descriptions of the muscles and bones in the lesson
into a tactile journey of the horse’s body.
Send your report to: pegasus.simat@gmail.com