Serratus Ventralis Thoracic (SVT)

This week's muscles is the SERRATUS VENTRALIS THORACIC (SVT).
The SVT is the second part of the Serratus Ventralis muscle. It is the section of the muscle that is located behind the shoulder in the region of the thoracic vertebrae as the name would suggest.
L O C A T I O N :
Inserts into the shoulder blade and attaches into ribs 1-8/9.
(Ribs 1-8/9 ------> Medial Aspect of the scapula cartilage)
R O L E :
• Draws the the scapula down and back thus, playing a part in extending the limb.
• Is part of the “Thoracic Sling” which suspends the horses chest cavity from the forelimb.
• Thought to contribute to the elastic properties of the forelimb.
D Y S F U N C T I O N :
Main Causes: Injury/strain through poor tack, lameness, direct trauma (falling onto shoulder) and discipline.
Examples:
• Discipline:
Jumping disciplines could predispose injury to the SVT due to the large concussive forces of landing that will increase the demand on the SVTs role in supporting and suspending the trunk from the forelimbs.
• Tack:
Ill fitting saddles that restrict shoulder movement, (i.e too tight) can prevent the scapula (shoulder blade) from moving back through direct restriction and/or pain which could result in SVT weakening.
Over girthing or poor girth quality can directly impair the SVT through pinching and direct pressure that ultimately results in pain, injury and tension.
• Lameness:
Chronic offloading of one forelimb to the other unilaterally increases the demand of the SVT in suspending the trunk thus, exposing it to abnormal strain.
S Y M P T O M S  O F  P A I N :
• Reduced forelimb stride length.
• Reduced shoulder extension & flexion.
• Poor respiration (Due to location of the SVT over the ribs tension & pain could hinder ribcage expansion).
• Girthing issues (i.e when tacking up)
• Poor turning particularly on the forehand.
• Refusal to jump.
Note: Not all symptoms may be present at once.