Transverse Pectoral Muscle

​It's Muscle Monday again! Our post last week didn't make it up unfortunately. For the next couple of weeks we are going to be focusing on the muscles that make up the pectorals (chest muscles). There are four muscles that make up this group. They are the transverse pectoral, ascending pectoral, descending pectoral and subclavius. These muscles are commonly categorised into superficial pectoral (transverse and descending), deep pectoral (ascending) and subclavius.

This week we are going to look at the Transverse Pectoral.

L O C A T I O N:
Lies deep to the superficial pectoral muscles. It runs from the chest between your horse's front legs and under the ribcage. It's a very wide, thin structure.

F U N C T I O N:
- To support the trunk or abdomen of the horse and assists in stabilizing the shoulder joint.
- Connection between thoracic limb and trunk
- Aids in adduction (movement towards the body), protraction (extending away from the body), and retraction (brining back towards the body) of the thoracic limb.

S Y M P T O M S O F P A I N:
- Resistance to lift through withers (check spine for primary issues)
- Higher muscle tone leading to adaptation of a more base narrow posture.
- Sensitivity can be unilateral (one sided), demonstrated through how abduction of the associated forelimb during lateral movements being limited.

This is really important to know as your girth can affect how this muscle functions. It’s really important that the girth buckles never lie on the edge of this muscle. If the girth is too short it will sit just behind the elbow of the horse and can lead to pinching and pain. The pinching of the girth means the horse may not want to extend their front leg as it causes discomfort.