Dorsal Scapular Region Flashcards
Where are the proximal attachments of the DELTOID?
Clavicle, Acromion, Spine of scapula
Where are the distal attachments of the DELTOID?
deltoid tuberosity of humerus
What nerves innervate the deltoid?
Axillary nerve C5, C6
What are the muscle actions of the DELTOID?
Clavicular part (anterior): arm flexion, arm IR
Acromial part (middle): arm abduction
Spinal part (posterior): arm extension, arm ER
What are the purposeful activities of the DELTOID?
doing yoga poses with arms overhead (all fibers)
reaching for (anterior fibers) and putting on (posterior fibers) a seat belt
What are the purposeful activities of the PECTORALIS MAJOR?
reaching across the body into an overhead cabinet, putting on a seatbelt
What are the muscle actions of the PECTORALIS MAJOR?
Humerus ADDUCTION
Humerus IR
Scapular PROTRACTION
(draws scapula anteriorly and inferiorly)
Arm HORIZONTAL ADDUCTION
When acting alone:
Clavicula head: Humerus flexion
Sternocostal head: humerus extension from flexed position
What are the proximal attachments of the PECTORALIS MAJOR?
Clavicular head: clavicle
Sternocostal head: sternum, costal cartilages 1-6, external oblique muscle
What are the distal attachments of the PECTORALIS MAJOR?
lateral lip of intertubercular sulcus of humerus
What nerves innervate the PECTORALIS MAJOR?
lateral and medial pectoral nerves; clavicular head (C5, C6), and sternocostal head (C7,C8,T1)
What are the purposeful activities of the PECTORALIS MINOR?
Taking a deep breath, walking with crutches
Where are the proximal attachments of the PECTORALIS MINOR?
Ribs 3-5 near their costal cartilages
Where is the distal attachment of the PECTORALIS MINOR?
coracoid process
What nerves innervate the PECTORALIS MINOR?
medial pectoral nerve (C8, T1); lateral pectoral nerve (variable)
What are the muscle actions of the PECTORALIS MINOR?
Scapular PROTRACTION
(stabilization by drawing it inferiorly and anteriorly against thoracic wall)
With the scapula fixed…
Assists to ELEVATE the thorax during forced inhalation
What are the 4 rotator cuff muscles?
Supraspinatus, infraspinatus, teres minor, subscapularis
What is the purposeful activity of the infraspinatus?
playing racket sports or table tennis
What is the proximal attachment of the INFRASPINATUS?
infraspinous fossa
Where is the distal attachment of the INFRASPINATUS?
greater tubercle of humerus
What are the muscle actions of the INFRASPINATUS?
Shoulder ER (GHJ)
Stabilize the head of the humerus in the glenoid cavity along with the other SITS muscles
What nerve innervates the INFRASPINATUS?
suprascapular nerve (C5, C6)
Who is “lats little brother”?
Teres Major
What are the purposeful activities of the TERES MAJOR?
Toileting and perineal care
What are the muscle actions of the TERES MAJOR?
Shoulder adduction
Shoulder IR (GHJ)
Where are the proximal attachments of the TERES MAJOR?
posterior surface of inferior angle of the scapula
Where are the distal attachments of the TERES MAJOR?
Medial lip of intertubercular sulcus of humerus
What nerve innervates the TERES MAJOR?
Lower subscapular nerve (C5, C6)
What are the purposeful activities of the SUPRASPINATUS?
painting overhead or washing your hair
What are the muscle actions of the SUPRASPINATUS?
Initiates and assists deltoid in abduction of arm
Stabilizes the head of humerus in glenoid cavity, along with the other SITS muscles
Where are the proximal attachments of the SUPRASPINATUS?
supraspinous fossa
Where is the distal attachment of the SUPRASPINATUS?
greater tubercle of humerus
What nerves innervate the SUPRASPINATUS?
suprascapular nerve C4, C5, C6
What are the purposeful activities of the TERES MINOR?
washing the back of head and neck
What are the muscle actions of the TERES MINOR?
Shoulder ER (GHJ)
Stabilize head of humerus in glenoid cavity
Where is the proximal attachment of the TERES MINOR?
lateral border of the scapula
Where is the distal attachment of the TERES MINOR?
greater tubercle of humerus
What nerves innervate the TERES MINOR?
Axillary nerve (C5, C6)
What are the purposeful activities of subscapularis?
toileting, donning a bra, or throwing a baseball
What are the muscle actions of the SUBSCAPULARIS?
Shoulder IR
Stabilizes the head of humerus in glenoid cavity
Where is the proximal attachment of the subscapularis?
subscapular fossa
Where is the distal attachment of the SUBSCAPULARIS?
lesser tubercle of humerus
What nerves innervate the SUBSCAPULARIS?
upper and lower subscapular nerves C5, C6, C7
What is the purposeful activity of the SERRATUS ANTERIOR?
pushing open a heavy door
What are the muscle actions of the SERRATUS ANTERIOR?
Scapular protraction (ST joint)
Scapular upward rotation
Holds scapular against thoracic wall
Where are the proximal attachments of the SERRATUS ANTERIOR?
lateral ribs 1-9
Where is the distal attachment of the SERRATUS ANTERIOR?
medial border of scapular
What nerve innervates the SERRATUS ANTERIOR?
long thoracic nerve (C5, C6, C7)
