Figure Drawing - Individual Muscles - Front Limb

The supraspinatus together create the rounded front edge of the shoulder form (located at the base of the side of the neck). In the ox, however, the supraspinatus alone creates the front of the shoulder form (the subclavius is deep).DOG AND FELINE• Origin: Outer surface of the front portion of the scapula and the adjacent cartilage. • Insertion: Inner and outer front corners of the top of the humerus. • Action: Extends the shoulder joint, advancing the limb. • Structure: The belly of the supraspinatus is thin where it begins, on the outside of the top of the shoulder blade;...
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Figure Drawing - Individual Muscles - Front Limb66 INDIVIDUAL MUSCLES > FRONT LIMB HORSE DOG Supraspinatus supraspinatus) and the supraspinatus together create the rounded frontHORSE AND OX edge of the shoulder form (located at the base of the side of the neck).• Origin: Outer surface of the front portion of the scapula and the In the ox, however, the supraspinatus alone creates the front of theadjacent cartilage. shoulder form (the subclavius is deep).• Insertion: Inner and outer front corners of the top of the humerus. DOG AND FELINE• Action: Extends the shoulder joint, advancing the limb. • Origin: Same as in the horse and the ox, except no scapular cartilage• Structure: The belly of the supraspinatus is thin where it begins, on the is present.outside of the top of the shoulder blade; it twists to face forward at the • Insertion: Single area of insertion on top of the humerus. Belly doesntfront of the shoulder joint, and then splits before inserting into the two twist or split before inserting.areas of insertion on the humerus. In the ox it is completely covered by • Structure: Although it is mostly covered by thin muscle, thethin muscles. In the horse a small piece of the middle of the belly comes supraspinatus creates the front form of the shoulder.to the surface, and the subclavius muscle (attached to the front of the INDIVIDUAL MUSCLES » FRONT LIMB 67 HORSE OX DOG Infraspinatus The trapezius and latissimus dorsi cover the upper portion of the mus-HORSE AND OX cle, and the deltoid belly and its wide tendon cover the• Origin: Outer surface of the rear portion of the scapula and the adja- lower portion. Only a small part of the infraspinatus reaches the surface,cent cartilage. although the portion covered by the wide tendon of the deltoid also• Insertion: Outer side of the top of the humerus. directly creates surface form.• Action: Rotates the arm outward; pulls the limb away from the body. DOG AND FELINE• Structure: The infraspinatus lies on the outer surface of the rear • Origin: Same as in the horse and ox, except there is no scapularportion of the shoulder blade. Its flat belly (lying on the flat surface of cartilage.the scapula) contributes to the planar quality of the shoulder region.68 INDIVIDUAL MUSCLES » FRONT LIMB DOG LION Teres major long head of the triceps. It can be seen directly where it is not coveredDOG AND FELINE by muscle, or indirectly through the latissimus dorsi, which is thin• Origin: Upper third of the rear edge of the shoulder blade. Feline: Also enough to reveal its form. The triceps is too thick to let the teres majorthe adjacent surface of the infraspinatus muscle. show through. In the dog, the elongated form of the teres major may be• Insertion: Short vertical line on the inner surface of the humerus evident on the surface under cover of the latissimus dorsi when it isapproximately one fourth of the way down the bone. The teres major and strongly contracted while pulling the arm backward. Because the thicklatissimus dorsi insert together via a common tendon on the humerus. triceps muscle begins high on the scapula in the horse and the ox, the• Action: Flexes the shoulder joint. teres major remains hidden from view (the triceps originates lower• Structure: The teres major is a narrow, slightly flattened muscle that down, on the rear edge of the scapula in the dog and the feline).comes to the surface only in the feline. In the other species, it is coveredby the latissimus dorsi and the triceps. As it descends, it dives under the ...