Changes

'''''Supscapularis'''''

'''''Supscapularis'''''

:'''Innervation''': Subscapular n. from the brachial plexus

:'''Innervation''': Subscapular n. from the brachial plexus

:'''Origin''': Deep surface of the [[Bones and Cartilages - Horse Anatomy|scapula]]

:'''Origin''': Deep surface of the [[Bones and Cartilages - Horse Anatomy#Scapula|scapula]]

:'''Insertion''': Lesser tubercle of the [[Bones and Cartilages - Horse Anatomy|humerus]]

:'''Insertion''': Lesser tubercle of the [[Bones and Cartilages - Horse Anatomy#Humerus|humerus]]

:'''Action''': Braces medial shoulder joint. Primarily acts as an extensor of the shoulder, but can contribute to maintaining flecion.  

:'''Action''': Braces medial shoulder joint. Primarily acts as an extensor of the shoulder, but can contribute to maintaining flecion.  

'''''Coracobrachialis'''''

'''''Coracobrachialis'''''

:'''Innervation''': Musculocutaneous n. of the brachial plexus

:'''Innervation''': Musculocutaneous n. of the brachial plexus

:'''Origin''': Coracoid process of [[Bones and Cartilages - Horse Anatomy|scapula]]

:'''Origin''': Coracoid process of [[Bones and Cartilages - Horse Anatomy#Scapula|scapula]]

:'''Insertion''': Proximal shaft of the [[Bones and Cartilages - Horse Anatomy|humerus]]

:'''Insertion''': Proximal shaft of the [[Bones and Cartilages - Horse Anatomy#Humerus|humerus]]

:'''Action''': Fixator

:'''Action''': Fixator

'''''Deltoid'''''

'''''Deltoid'''''

:'''Innervation''': Axillary n. of the brachial plexus

:'''Innervation''': Axillary n. of the brachial plexus

:'''Origin''': Caudal border and spine of the [[Bones and Cartilages - Horse Anatomy|scapula]]. One head in the horse, compared with two in species with an acromion (site of second origin.

:'''Origin''': Caudal border and spine of the [[Bones and Cartilages - Horse Anatomy#Scapula|scapula]]. One head in the horse, compared with two in species with an acromion (site of second origin.

:'''Insertion''': Deltoid tuberosity of [[Bones and Cartilages - Horse Anatomy|humerus]]

:'''Insertion''': Deltoid tuberosity of [[Bones and Cartilages - Horse Anatomy#Humerus|humerus]]

:'''Action''': Flexes shoulder

:'''Action''': Flexes shoulder

:In the horse, the aponeurosis of the deltoid is partially fused to the ''infraspinatus''.

:In the horse, the aponeurosis of the deltoid is partially fused to the ''infraspinatus''.

'''''Teres Major'''''

'''''Teres Major'''''

:'''Innervation''': Axillary n. of the brachial plexus

:'''Innervation''': Axillary n. of the brachial plexus

:'''Origin''': Dorsal part of the caudal [[Bones and Cartilages - Horse Anatomy|scapula]]

:'''Origin''': Dorsal part of the caudal [[Bones and Cartilages - Horse Anatomy#Scapula|scapula]]

:'''Insertion''': Teres major tuberosity midway down the [[Bones and Cartilages - Horse Anatomy|humerus]]

:'''Insertion''': Teres major tuberosity midway down the [[Bones and Cartilages - Horse Anatomy#Humerus|humerus]]

:'''Action''': Flexes the shoulder, supports adduction.

:'''Action''': Flexes the shoulder, supports adduction.

'''''Teres Minor'''''  

'''''Teres Minor'''''  

:'''Innervation''': Axillary n. of the brachial plexus

:'''Innervation''': Axillary n. of the brachial plexus

:'''Origin''': Distal third of [[Bones and Cartilages - Horse Anatomy|scapula]], deep to the deltoid

:'''Origin''': Distal third of [[Bones and Cartilages - Horse Anatomy#Scapula|scapula]], deep to the deltoid

:'''Insertion''': Teres minor tuberosity midway down the [[Bones and Cartilages - Horse Anatomy|humerus]]

:'''Insertion''': Teres minor tuberosity midway down the [[Bones and Cartilages - Horse Anatomy#Humerus|humerus]]

:'''Action''': Flexes the shoulder

:'''Action''': Flexes the shoulder

NB// There are no defined extensors of the shoulder. Those involved (''brachiocephalic'' m., ''biceps brachii'', ''supraspinatus'', and ''ascending pectorals'') have other, more primary roles.

NB// There are no defined extensors of the shoulder. Those involved (''brachiocephalic'' m., ''biceps brachii'', ''supraspinatus'', and ''ascending pectorals'') have other, more primary roles.