Shoulder Girdle Muscles Flashcards
Upper Trapezius
O: Occipital bone, nuchal ligament on upper cervical spinous processes.
I: Outer 1/3 of the clavicle, acromion process
A: Scapular elevation, upward rotation
N: Spinal accessory n. (CN XI), C3-C4 sensory component
Middle Trapezius
O: Spinous processes C7-T3
I: Scapular spine
A: Scapular retraction
N: Spinal accessory n. (CN XI), C3-C4 sensory component
Lower Trapezius
O: Spinous processes of middle and lower thoracic vertebrae
I: Base of scapular spine
A: Scapular depression, upward rotation
N: Spinal accessory n. (CN XI), C3-C4 sensory component
Levator Scap.
O: Transverse processes C1-C4
I: Vertebral border of scapula between superior angle and spine
A: Scapular elevation, downward rotation
N: C3-C4 spinal nerve roots, Dorsal scapular n. (C5)
Rhomboids (Rhomboid Major, Rhomboid Minor)
O: Spinous processes C7-T5
I: Vertebral border of scapula between spine and inferior angle
A: Scapular retraction, elevation, downward rotation
N: Dorsal scapular n. (C5)
Serratus Anterior
O: Lateral surface of ribs 1-8
I: Vertebral border of scapula, anterior surface
A: Scapular protraction, upward rotation
N: Long thoracic n. (C5, C6, C7)
Pectoralis Minor
O: Anterior surface, ribs 3-5
I: Coracoid process of scapula
A: Scapular depression, protraction, downward rotation, tilt
N: Medial pectoral n. (C8, T1)
What are the primary muscles involved in scapular retraction?
Middle trapezius, rhomboids
What are the primary muscles involved in scapular protraction?
Serratus anterior, pectoralis minor
What are the primary muscles involved in scapular elevation?
Upper trapezius, levator scap., rhomboids
What are the primary muscles involved in scapular depression?
Lower trapezius, pectoralis minor
What are the primary muscles involved in scapular upward rotation?
Upper and lower trapezius, serratus anterior
What are the primary muscles involved in scapular downward rotation?
Rhomboids, levator scapula, pectoralis minor
What is the primary muscle involved in scapular tilting?
Pectoralis minor
What are the four muscles of the Rotator Cuff?
Supraspinatus
Infraspinatus
Subscapularis
Teres Minor
Anterior Deltoid
O: Lateral 1/3 of the clavicle
I: Deltoid tuberosity of humerus
A: Shoulder ABD., flexion, IR, and horizontal ADD.
N: Axillary n. (C5, C6)
Middle Deltoid
O: Acromion process
I: Deltoid tuberosity of humerus
A: Shoulder ABD.
N: Axillary n. (C5, C6)
Posterior Deltoid
O: Spine of scapula
I: Deltoid tuberosity of humerus
A: Shoulder ABD., extension, hyperextension, ER, horizontal ABD.
N: Axillary n. (C5, C6)
Pectoralis Major
O: Sternum, Medial 1/3 of clavicle, Costal cartilage ribs 1-6
I: Lateral lip of bicipital groove of humerus
A: Shoulder ADD, IR, horizontal ADD.
N: Lateral and Medial Pectoral n. (C5, C6, C7, C8, T1)
Latissimus Dorsi
O: Spinous processes T7-L5 via thoracolumbar fascia, posterior surface of sacrum, iliac crest, and lower 3 ribs.
I: Medial floor of bicipital groove of humerus
A: Shoulder ext., ADD., IR, hyperextension
N: Thoracodorsal n. (C6, C7, C8)
Teres Major
O: Inferior axillary border of scapula near inferior angle
I: Medial lip of bicipital groove on anterior surface of humerus
A: Shoulder extension, ADD., IR
N: Lower subscapular n. (C5, C6, C7)
Supraspinatus
O: Supraspinous fossa of scapula
I: Greater tubercle of humerus
A: Shoulder ABD.
N: Suprascapular n. (C5, C6)
Infraspinatus
O: Infraspinous fossa of scapula
I: Greater tubercle of humerus
A: Shoulder ER, horizontal ABD.
N: Suprascapular n. (C5, C6)
Teres Minor
O: Axillary border of scapula
I: Greater tubercle of humerus
A: Shoulder ER, horizontal ABD.
N: Axillary n. (C5, C6)
Subscapularis
O: Subscapular fossa of the scapula
I: Lesser tubercle of the humerus
A: Shoulder IR
N: Upper and lower subscapular n. (C5, C6)
Coracobrachialis
O: Coracoid process of the scapula
I: Medial surface of the humerus near the midpoint
A: Stabilizes the shoulder joint
N: Musculocutaneous n. (C5, C6, C7)
What are the primary muscles involved in performing shoulder flexion?
Anterior deltoid, clavicular head of pectoralis major
What are the primary muscles involved in performing extension?
Posterior deltoid, latissimus dorsi, teres major, sternal head of pectoralis major
What are the primary muscles involved in shoulder hyperextension?
Latissimus dorsi, posterior deltoid
What are the primary muscles involved in ADDuction?
Pectoralis major, teres major, latissimus dorsi
What are the primary muscles involved in shoulder ABDuction?
Deltoid, supraspinatus
What are the primary muscles involved in shoulder horizontal ABDuction?
Posterior deltoid, infraspinatus, teres minor
What are the primary muscles involved in horizontal ADDuction?
Pectoralis major, anterior deltoid
What are the primary muscles involved in shoulder ER?
Infraspinatus, teres minor, posterior deltoid
What are the primary muscles involved in shoulder IR?
Subscapularis, latissimus dorsi, teres major, pectoralis major, anterior deltoid
