Dorsal Scapular Region Muscles Flashcards
Purposeful Activity of Deltoids
Reaching arms overhead
Reaching for (anterior) and putting on (posterior) a seatbelt
Insertion of Deltoid
Deltoid tuberosity of humerus
Origin of Deltoid
Spine of scapula
Acromion
Clavicle
Same as trapezius insertions
Nerve innervation of Deltoid
Axillary nerve
C5, C6
Action of Deltoid
Anterior/Clavicular = arm FLEXION and HELPS WITH INTERNAL ROTATION
Lateral/Acromial = arm ABDUCTION
Posterior/Spinal = arm EXTENSION and HELPS WITH EXTERNAL ROTATION
Purposeful activity of Pectoralis Major
Reaching across the body into overhead cabinet
Putting on seatbelt
Origin of Pectoralis Major
Clavicular Head - Clavicle
Sternocostal Head -
-Sternum
-Costal cartilages 1-6
-External oblique muscle
Insertion of Pectoralis Major
LATERAL LIP of intertubercular sulcus of humerus
Nerve innervation of Pectoralis Major
Lateral and medial pectoral nerves:
Clavicular head: C5, C6
Sternocostal head: C7, C8, T1
Actions of Pectoralis Major
Humerus: ADDUCTION and INTERNAL/MEDIAL ROTATION
Scapula: PROTRACTION (draws scapula anteriorly and inferiorly)
Arm: HORIZONTAL ADDUCTION
Acting alone:
Clavicular head: Humerus/arm FLEXION
Sternocostal head: Humerus/arm EXTENSION from flexed position
Purposeful activity of Pectoralis Minor
Taking deep breath, walking with crutches
Origin of Pectoralis Minor
Ribs 3-5 near costal cartilages
Insertion of Pectoralis Minor
Coracoid Process
Nerve Innervation of Pectoralis Minor
Medial pectoral nerve: C8, T1
Lateral pectoral nerve: variable
Actin of Pectoralis Minor
Scapular PROTRACTION
-stablizes scap by drawing it inferiorly and anteriorly
While scapula fixed, ASSISTS TO ELEVATE thorax during forced inhalation
Purposeful activity of Teres Major
Toileting, perineal care
Origin of Teres Major
Posterior surface of scapula’s inferior angle
Insertion of Teres Major
MEDIAL LIP of intertubercular sulcus of humerus
Next to latissimus and pectoralis major! Lady b/w two majors!
Nerve innervation of Teres Major
Lower subscapular nerve
C5, C6
Actions of Teres Major
Shoulder ADDUCTION and INTERNAL ROTATION
Purposeful Activity Supraspinatus
Washing your hair
Origin of Supraspinatus
Supraspinous fossa
Insertion of Supraspinatus
Greater Tubercle of Humerus
Nerve innervation of Supraspinatus
Suprascapular nerve
C4, C5, C6
Action of Supraspinatus
Stabilizes head of humerus in glenoid cavity
INITIATES and ASSISTS deltoid in ABDUCTION
Purposeful activity of Infraspinatus
Playing racket sports or table tennis
Origin of Infraspinatus
Infraspinous fossa
Insertion of Infraspinatus
Greater tubercle of humerus
Nerve innervation of Infraspinatus
Suprascapular nerve
C5, C6
Action of Infraspinatus
Stabilizes head of humerus in glenoid cavity
Shoulder EXTERNAL ROTATION
Purposeful activity of Teres Minor
Washing back of your head and neck
Origin of Teres Minor
Lateral border of scapula
Insertion of Teres minor
Greater tubercle of humerus
Nerve Innervation of Teres minor
Axillary nerve
C5, C6
Action of Teres minor
Stabilizes head of humerus in glenoid cavity
Shoulder EXTERNAL ROTATION
Purposeful activity of Subscapularis
Toileting, donning a bra, throwing a baseball
Origin of Subscapularis
Subscapular fossa (most of scapula’s anterior surface)
Insertion of Subscapularis
Lesser tubercle of humerus
Nerve innervation of Subscapularis
Upper and lower subscapular nerves
C5, C6, C7
Action of Subscapularis
Stabilize head of humerus in glenoid cavity
Shoulder INTERNAL ROTATION
Purposeful activity of Serratus Anterior
Pushing open a heavy door, punching
Origin of Serratus Anterior
Lateral part of ribs 1-8 or 1-9
Insertion of Serratus Anterior
Medial Border of Scapula
Nerve innervation of Serratus Anterior
Long Thoracic Nerve
C5, C6, C7
Action of Serratus Anterior
Scapular PROTRACTION and UPWARD ROTATION
HOLDS scapula against thoracic wall