Chapter 13: shoulder joint

infraspinatus: origin, insertion, action, and nerve

• O: infraspinatus fossa of scapula

• I: greater tubercle of humerus

• A: shoulder lateral rotation, horizontal abduction

• N: suprascapular nerve

supraspinatus: origin, insertion, action, and nerve

• supraspinous fossa of scapula

• I: greater tubercle of humerus

• A: shoulder abduction (stabilizes shoulder-

• N: suprascapular nerve

teres minor:  origin, insertion, action, and nerve

• O: axillary border of scapular

• I: greater tubercle of humerus

• A: shoulder lateral rotation, horizontal abduction (shoulder stabilizer)

• N: axillary nerve

subscapularis:  origin, insertion, action, and nerve

• O: subscapular fossa of scapula

• I: lesser tubercle of humerus

• A: shoulder adduction, medial rotation (shoulder stabilizer)

• N: upper and lower subscapular nerves

rotator cuff muscles

subscapularis, supraspinatus, infraspinatus, teres minor

triceps brachii: origin, insertion, action, and nerve

• O:

  • long head- infraglenoid tubercle of scapula

  • lateral head- inferior to greater tubercle on posterior humerus

  • medial head- posterior surface of humerus

• I: olecranon process of ulna

• A: shoulder extension, elbow extension

• N: radial nerve

teres major: origin, insertion, action, and nerve

• O: inferior axillary border of scapula near inferior angle

• I: medial lip of bicipital groove

• A: shoulder extension, adduction, and medial rotation

• N: lower subscapular nerve

latissimus dorsi: origin, insertion, action, and nerve

• O: thoracolumbar fascia, the spinous processes of T7-L5, posterior surface of iliac crest and sacrum, lower 3 ribs

• I: floor of bicipital groove

• A: shoulder extension, adduction, medial rotation

• N: thoracodorsal nerve

pec minor: origin, insertion, action, and nerve

• O: anterior surface 3rd-5th ribs

• I: coracoid process of scapula

• A: scapular depression, protraction, downward rotation, tilt

• N: medial pectoral nerve

pec major (sternal portion): origin, insertion, action, and nerve

• O: sternum, costal cartilage of first 6 ribs

• I: lateral lip of bicipital groove of humerus (superior to clavicular portion)

• A: medial rotation, adduction, horizontal adduction; shoulder extension from full flexion (180 degrees) when shoulder extension is resisted

• N: lateral and medial pectoral nerves

pec major (clavicular portion): origin, insertion, action, and nerve

• O: medial 3rd of clavicle

• I: lateral lip of bicipital groove of humerus (inferior to sternal protein)

• A: shoulder flexion (1st 60 degrees), medial rotation, adduction, horizontal adduction

• N: lateral and medial pec nerves

coracobrachialis: origin, insertion, action, and nerve

• O: coracoid process of scapula

• I: medial surface of humerus near midpoint

• A: shoulder flexion, adduction (stabilizes shoulder)

• N: musculocutaneous nerve

biceps brachii: origin, insertion, action, and nerve

• O:

  • longhead- supraglenoid tubercle of scapula

  • short head- coracoid process of scapula

• I: radial tuberosity of radius

• A: shoulder flexion, elbow flexion, forearm supination

• N: musculocutaneous nerve

anterior deltoid: origin, insertion, action, and nerve

• O: lateral 3rd of clavicle

• I: deltoid tuberosity

• A: shoulder abduction, flexion, medial rotation, and horizontal adduction

• N: axillary nerve

middle deltoid: origin, insertion, action, and nerve

• O: acromion process

• I: deltoid tuberosity

• A: shoulder abduction

• N: axillary nerve

posterior deltoid: origin, insertion, action, and nerve

• O: spine of scapula

• I: deltoid tuberosity

• A: shoulder abduction, extension, lateral rotation, horizontal abduction

• N: axillary nerve

force couple between deltoid and rotator cuff

• collaborates to stabilize and move the shoulder joint efficiently

• as deltoid pulls upward on humerus, the rotator cuff muscles glide the humeral head downward as it rolls upward and compress it into the GH fossa

force couple of deltoid muscle acting alone

• does not provide effective shoulder stability or mobility

• if the deltoid acted alone, it would pull the humeral head upward and impinge soft tissue between the head of the humerus and the acromion

shoulder joint muscles involved in flexion

anterior deltoid, coracobrachialis, pec major (clavicular)

shoulder joint muscles involved in extension

posterior deltoid, latissimus dorsi, teres major

shoulder joint muscles involved in abduction

all 3 deltoids, supraspinatus

shoulder joint muscles involved in adduction

pec major, teres major, latissimus dorsi, coracobrachalis

shoulder joint muscles involved in horizontal abduction

posterior deltoid, infraspinatus, teres minor

shoulder joint muscles involved in horizontal adduction

pec major, anterior deltoid

shoulder joint muscles involved in lateral rotation

infraspinatus, teres minor, posterior deltoid

shoulder joint muscles involved in medial rotation

latissimus dorsi, teres moor, subscapularis, pec major, anterior deltoid

glenohumeral ligaments

• superior glenohumeral ligament,

• middle glenhumeral ligament

• inferior glenohumeral ligament

what is this ligament in red?

coracohumeral ligament

what ligament is red highlighted part?

transverse humeral ligament

where is the infraglenoid tubercle?

infraglenoid tubercle

where is the supraglenoid tubercle?

supraglenoid tubercle

where is the glenoid labrum?

glenoid labrum

what structure is this?

surgical neck

where is the anatomical neck?

anatomical neck

where is the deltoid tuberosity?

deltoid tuberosity

where is the bicipital groove?

bicipital groove (or intertubercular sulcus)

where are bicipital ridges?

are bony ridges or lips that form the sides of the groove

where is the thoracolumbar fascia?

thoracolumbar fascia

where is the subdeltoid bursa?

subdeltoid bursa

where is the subacromial bursa?

subacromial bursa

closed pack position for shoulder joint

FULL abduction and lateral rotation

end feel for shoulder joint

FIRM (soft tissue stretch)

Open park position for shoulder joint

HORIZONTAL abduction and flexion

Closed pack position for sternoclavicular joint

full abduction, and lateral rotation

open pack position for sternoclavicular joint

Horizontal abduction and flexion

end feel for sternoclavicular joint

Firm (soft tissue stretch)