what muscles adduct the arm
Arm Abduction. Abduction of the arm is also called abduction of/at the shoulder. This motion actually can be divided into two motions: true abduction of the arm at the shoulder and upward rotation of the scapula. Muscles: supraspinatus (initiates abduction - first 15 degrees), deltoid (up to 90 degrees), trapezius and serratus anterior (scapular rotation, for abduction beyond 90 degrees).
In this article, we shall look at the anatomy of the muscles of the upper arm â their attachments, innervation and actions. There are three muscles located in the anterior compartment of the upper arm â biceps brachii, coracobrachialis and brachialis. They are all innervated by the musculocutaneous nerve. A good memory aid for this is BBC â biceps, brachialis, coracobrachialis.
The muscles that provide the movement for the shoulder and upper arm include the anterior muscles in the front, the posterior muscles in the back, and the shoulder muscles that are sort of in between. Pectoralis major: This muscle has two heads, or sections of muscle tissue, and covers much of the front of the thoracic cage.