Function: Clavicular head flexes and adducts arm. Sternal head adducts and medially rotates the arm.
Which muscle adducts and rotates the arm medially at the shoulder joint?
The deltoid, the thick muscle that creates the rounded lines of the shoulder is the major abductor of the arm, but it also facilitates flexing and medial rotation, as well as extension and lateral rotation. The subscapularis originates on the anterior scapula and medially rotates the arm.
What muscles medially rotate the shoulder?
The subscapularis, along with the teres major, another intrinsic muscle that is not part of the rotator cuff, and extrinsic muscles like the pectoralis major and latissimus dorsi, is responsible for medial, or internal, rotation of the arm.
What muscle rotates the arm at the shoulder joint?
The teres major provides internal rotation, extension, and adduction of the shoulder; it’s considered a fusiform muscle. The subscapularis muscle internally rotates the humerus; the upper portion of the muscle influences abduction, while the lower area influences adduction.
What are the motions that the shoulder can do?
The human shoulder is the most mobile joint in the body. This mobility provides the upper extremity with tremendous range of motion such as adduction, abduction, flexion, extension, internal rotation, external rotation, and 360° circumduction in the sagittal plane.
What muscle adducts and extends the arm?
Chapter 15 Muscles
|pectoralis major||adducts, flexes, rotates arm inward|
|masseter||closes jaw for chewing|
|biceps brachii||flexes forearm|
What are the three muscles responsible for lateral rotation of the shoulder?
The infraspinatus and teres minor both aid in lateral, or external, rotation of the arm at the shoulder.
What muscles are used in shoulder abduction?
The primary muscles involved in the action of arm abduction include the supraspinatus, deltoid, trapezius, and serratus anterior.