Shoulder Flashcards
Heads of the pectoralis major
Clavicular and sternocostal
Muscles defining the axilla
Pectoralis major, Latissimus dorsi, teres major
The groove in which the cephalic vein runs
Delto-pectoral groove
Muscles between which the cephalic vein runs
Deltoids and pectoralis major
The vessel that lies in the delto-pectoral groove
Cephalic vein
The two heads of the pectoralis major can act independently. T/F
T
Muscle covering the pectoralis minor
Pectoralis major
Actions of the pectoralis major
Adduction and medial rotation of the arm; draws scapula anteriorly and inferiorly
Clavicular head: flexes humerus
Sternal head: extends humerus from flexed position
Actions of the pectoralis minor
Draws scapula anteriorly and inferiorly
Action of subclavius
Anchors and depresses clavicle
Action of serratus anterior
Protraction of the scapula, upward rotation of the scapula; For punching or reaching anteriorly
Insertion of the serratus anterior
Medial border of scapula
Boxer’s muscle
Serratus anterior
The fibers of the trapezius are divided into how many parts?
Three
Action of the trapezius
Descending part: elevates scapula, upward rotates scapula
Ascending part: depresses scapula, upward rotates scapula
Middle part: retracts scapula
Insertion of the trapezius
Lateral third of clavicle; acromion and spine of scapula
Weakness of trapezius muscle causes drooping of sholders. T/F
T
Actions of the latissimus dorsi
Extends, adducts and medially rotates humerus;
Raises body to arms when climbing
Levator scapulae acts synergistically with which part of the trapezius?
Descending part
Actions of the levator scapulae
Elevates scapula, downward rotates scapula
Actions of rhomboids
Retract and downward rotate scapula, fix scapula to thoracic wall
Origin of the deltoid
Lateral third of clavicle, acromion, spine of scapula
Insertion of deltoid
Deltoid tuberosity
Actions of deltoid
Clavicular (anterior) part: Flex and medially rotates arm;
Acromial (middle) part: Abducts arm
Spinal (posterior) part: Extends and laterally rotates arm
When does the deltoid become fully effective as an abductor of the arm?
After the first 15 degrees of abduction
Which muscle assists the deltoid in the first 15 degrees of abducting the arm?
Supraspinatus
Which parts of the deltoid are used in swinging the limbs during walking?
Anterior (clavicular) and posterior (spinal) parts
All except which of the rotator cuff muscles are rotators of the humerus?
Supraspinatus
Action of supraspinatus
Assists deltoid in first 15 degrees of abduction
Primary medial rotator of the arm
Subscapularis
Actions of subscapularis
Medially rotates and adducts arm
Actions of teres minor
Laterally rotates and adducts arm
