Equine Muscular System
Since the basis for equine massage is the muscular system, I thought it made sense to start here first.
I will be discussing the basics about how muscles work. This is by no means a complete study on
muscles. There is a lot more to know about them than I am able to provide you here. However, I will do
my best to include the most important things that you need to know about the equine muscular system.
It can be a lot to understand even with this condensed version, so don't worry if you don't understand
everything right away. Just try to get the basic idea.
Classes of Muscles
Click on Horse to
go to Anatomy Charts
There are three classes of muscles: Smooth, Cardiac and Skeletal.
Smooth and Cardiac Muscles are involuntary -
This means that they work without you being
conscious of it. They help your horse's body with
digestion, respiration, circulation, etc.
Skeletal Muscles are voluntary -
This means that we can make them move consciously.
They are the muscles responsible for movement.
There are two different types of muscle fibers:
Slow Twitch and Fast Twitch.
Slow twitch (red) fibers are aerobic -
meaning they need oxygen to function properly.
They are more dominant in horses that have more
strength and endurance.
Fast twitch (white) fibers are anaerobic -
meaning they do not need much oxygen to
function. They are more dominant in horses that
have quick speed, such as sprinters. However,
they are only able to perform for short periods of
All horses have fast twitch and slow twitch muscle fibers.
It is the ratio that is different and is determined genetically.
All skeletal muscles have one "belly" and two tendons. The tendons are attached on each end of the belly and are
labeled as an origin or insertion.
Origin Tendon - The tendon that anchors the muscle to the least movable bone. Usually
closer to the center of the body.
Insertion Tendon - The tendon on the most movable bone. Usually farther from the body.
When a muscle contracts, it brings the origin and insertion tendons closer together.
Tendons are very strong and can endure a lot of tension, usually more than the muscle can produce. However, they
are not as elastic as the muscle fibers and can become strained or damaged.
Massaging your horse to relieve muscle tension can help to keep the tendons healthy and able to do their job.
Below the hock and knee, horses are basically just bone and tendon. This is one of the reasons that horses have so
many leg issues. Without the muscle to be a "shock absorber", the tendon can become strained or injured.
Muscles work together in two different ways: Isometric Contraction and Isotonic Contraction.
Isometric contraction is when a muscle contracts, but doesn't provide much movement - such as
Isotonic contraction can be classified as either Concentric Contraction or Eccentric Contraction.
Concentric contraction is when a muscle shortens as it contracts causing movement.
Eccentric contraction is when a muscle gradually releases as it gets longer to control
Concentric contraction would be when the angle in a joint decreases, while eccentric contractions would be
occurring as the angle of the joint increases.
Proprioception occurs when the sensory nerve endings send impulses to the brain providing information about
position, movement, muscle tension, joint activity and equilibrium. These sensory nerve endings are called the
Golgi tendon organs and muscle spindles.
Golgi tendon organs are fibers found in the tendons and the muscle and tendon junctions.
They respond to increases in tension.
Muscle spindles are located primarily in the belly of the muscle. They monitor and respond to
sudden and excessive lengthening.
Sometimes the proprioceptors can get "stuck" and will hold the body in a position that is not in it's best interest.
Massage and other therapies can help to make changes in the muscle and then "reset" the proprioceptors.
Information presented is for educational purposes only and is not intended
to replace professional opinions or recommendations.
Consult your veterinarian for advice about any medical condition or
treatment needed for your horse
The most important thing you need to know about applying massage and alternative therapies to a horse
is the direction in which the muscles run and how they affect the movement of the horse. However, it is
also wise to try to understand how the movement is made.