Muscle Types

There are three types of muscle in the horse’s body:

SKELETAL muscles are the ones we are mainly concerned with because they are attached to the limbs and have everything to do with movement of any type. Skeletal muscles are controlled by the brain and nervous system. The skeleton is the framework for the muscles to attach to. Muscles between each rib are called inter-costals. The ribcage protects everything inside it, the vital organs and/or body systems.

CARDIAC muscles are found in the heart.

SMOOTH muscles are controlled by the nervous system. There is a lot of smooth muscle in the digestive system of horses.

Muscle Fibres

Muscles contain millions of fibres. A few thousand can be damaged without initially causing the horse any pain BUT if the muscular stress continues the onset of an injury will occur.

Skeletal muscle is made up by fast and slow twitch muscle fibres.  Muscles contain three types of fibres:

  • Low-oxidative fast twitch
  • High-oxidative slow twitch
  • Slow-twitch (Arab horses are slow-twitch, good for endurance).  They are used when the horse is resting and have a slower contraction time and can take in more oxygen than fast-twitch muscle fibre.

SUPERFICIAL muscles are muscles that are near to the skin.  Superficial muscles are more involved with locomotion and are more prone to injury because of their location.  These are larger muscles in size and shape than the deeper muscles.

Underneath the skin there is a protective coating of superficial fascia, this blends together with the skin, where the entire body of the horse is “wrapped up” in this ordinary connective tissue. You can see where there is more in some places than others especially along the back and in the abdominal area. There is a lot of fascia around the stifle as well.

The above image is an artist’s impression representing a horse with its coat removed.  The areas of white represent the fascia.