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Medical Index
First Posted: Aug 8, 2010
Oct 13, 2012

Horse Muscles and Their Use


This article is a direct quote from Horse Muscles and Their Use article provided by Hayfield Riding Centre/Aberdeen, Scotland. There was no visible copyright on the site. I found this information to be so well done it is provided for visitors to HorseHints.org as an informational reference.

Massester (cheek muscle) - Opens and closes the jaw. Allows chewing.

Brachiocephalicus- Wide strap like muscle
  • Base of the skull behind the jaw
  • Below the point of shoulder to the humerus
  • Moves the head from side to side, pulls the scapula forward, raises it in collection, swings the foreleg forward.
  • Well developed for good movement. Too strong a rein contact stops free forward movement.
  • Jowl
  • Sternum
  • Moves the head and neck
  • Over developed in ewe or bull necked horses, difficult to get into a relaxed shape
  • Nuchal ligament
  • Scapula
  • Lifts shoulder and the forehand. Pulls the scapula forward
  • Behind the poll
  • Beginning of the Trapezius
  • Turns and extends the neck
  • Makes up the top line if well developed
Trapezius - Flat sheet like muscle.
  • Occipital bone
  • Spines of the 7th cervical and all the Thoracic vertebrae
  • Lifts shoulder and forehand
  • If this is well developed the horse is working in a good outline
Nuchal ligament
  • Poll
  • Withers
  • Helps muscles in the neck support the head
  • Scapula
  • Humerus
  • Flexes shoulder joint
  • If over developed it wil load the shoulder
  • Below the Trapezius
  • Point of shoulder
  • Maintains the shoulder in extension
Latissimus dorsi
  • Lower Thoracic vertebrae
  • Back of the humerus
  • Flexes the shoulder and pulls the foreleg back

Triceps - Flexes the shoulder and extends the elbow

Biceps - Flexes the elbow and extends the shoulder

Pectoral - Helps pull the foreleg foreward

Triceps Brachii - Extends the elbow joint

Biceps Brachii - Flexes the elbow joint

Extensor Carpus - Extend the knee

Flexor Carpus - Flexes the knee

Digital Extensor - Extends the toe and knee

Digital flexor - Flexes the toe and knee and extend the elbow

Muscles of the Trunk, Back and Ribs/Muscles support the spine together with 3 ligaments and abdominal muscles

Muscle or ligament

  • Origin; where it starts
  • Insertion point; where it finishes
Spinalis Dorsi
  • Beneath thoracic part of Trapezius
  • 4th cervical vertebrae
Lumbar muscles or Longissimus dorsi
  • Ilium
  • Vertebrae along the sine and the last 4 cervical vertebrae
  • Extends the spine and raises and supports the head, neck
  • Main muscle used in rearing, kicking, jumping and aids turning
  • Longest and strongest muscle, rider sits on them

Intercostal muscles - Spaces between ribs and aids breathing

External and internal abodominal oblique - Attach to ribs and pelvic bones; supports the internal organs Supraspinous ligament
  • Poll
  • Sacrum
  • Supports head and neck, traction force aids support in weak thoracic lumbar area
  • Spreads out, attaching to spines of the cervical vertebrae, Called nuchal ligament in the withers and neck area

Muscles in the Hindquarters

Hindquarters are the engine of the horse, they should be well developed, strong to move the horse forward, particularly in the competition horse.
Muscle or ligament
  • Origin - Where it starts
  • Insertion point - Wwhere it finnishes
Superficial gluteal
  • Croup
  • Bottom of the hip attached to the sacrum
  • Flex and extend the hip, pulls hindleg toward the body, used for rearing, galloping and kicking
  • More developed in a dressage horse
Biceps femoris
  • Behind gluteals
  • Bottom of the high attached to the patella and tibia
  • Maintains hip joint in extension
  • Main muscles over the hindquarters, part of the hamstring group, well developed in eventers, race horses
  • Behind biceps femoris
  • Back of the hindquarters
  • Extends the hip and hock joints
  • Part of the hamstring group, well developed in eventers and race horses

Semi membranosus - Part of hamstring group, well developed in race horses/eventers

  • Rear of the femur
  • Point of hock
  • Maintains hip extension
Peroneus tertius
  • Femur
  • Cannon bone
  • With superficial digital muscle moves the stifle and hock
Achillies tendon
  • Gastrocnemius
  • Over point of hock
Sacrosciatic ligament
  • Sacrum and coccygeal vertebrae
  • Pelvic bone

For More Information:

All About the Horse's Conformation/Part 1
All About the Horse's Conformation/Part 2
All About the Horse's Conformation/Part 3
Horse Skeleton
The Conservative Approach for Healing Horses

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