Latissimus dorsi

This week’s muscle is the Latissimus dorsi.
This muscle begins at the lower thoracic vertebrae and is inserted (or attaches) into the humerus. It supports the back, pulling the body of the horse forward when the front leg is placed on the ground, and flexes the shoulder (scapulohumeral joint). Last week’s muscle, the Trapezius, lays just on top of the Latissimus dorsi (second picture).
A lot of saddle problems can be related to this muscle. Look at the third picture. The bars of the saddle fit directly over this muscle. The rest of the muscle is over a lot of the rib cage of the horse. But look at where the rigging sits - right over the latissimus dorsi. So if there is pressure over the rib cage from poorly designed or attached rigging hardware or poorly tied or twisted latigos, this is the muscle that will be affected.
So can the saddle and how it is attached cause problems with how the front leg of the horse moves even if the bar tip has enough relief built in for uninhibited shoulder blade movement? You better believe it!