Section 7: Shoulder complex

Shoulder joint is attached to the...

axial skeleton

Scapula movement occurs with the movement of the

humerus

The wide ROM of the shoulder joint in multiple planes requires....

laxity

Common instability problems of the shoulder

Rotator cuff impingement, subluxations, dislocations

Joints that are more mobile are less ______

stable (and opposite- more stable, less mobile)

What bones serve as an attachment for shoulder joint muscles?

scapula, clavicle, and humerus

Scapular landmarks

supraspinous fossa, infraspinous fossa, subscapular fossa, spine of scapula, glenoid cavity, coracoid process, acromion process, superior and inferior angle, and medial border

Humeral landmarks

Humeral head, greater tubercle, lesser tubercle, bicipital groove, deltoid tuberosity

The GH joint (shoulder joint) is a

multi axial ball and socket and enarthrodial

What ligament enhances stability in the shoulder

Glenoid Labrum

Glenohumeral ligaments provide stability... (position)

anteriorly and inferiorly

Inferior GH ligament

Glenohumeral joint is paired with shoulder girdle to accomplish...

total shoulder ROM

170-180 degrees of total shoulder abduction includes

60 degrees scapula upward rotation, 0-25 degrees scapula elevation, 95-120 degrees of gh abduction

Scapulohumeral rhythm ratio

2:1. for every 2 degrees of glenohumeral motion, 1 degree of scapula motion

Scapula position

20-30 degrees anteriorly angled. scapula can achieve adequate ROM when it sits appropriately.

GH flexion

40-60 degrees

GH extension

90-100 degrees

GH abduction

120 degrees

GH adduction

75 degrees across body

GH external/internal rotation

70-90 degrees

GH horizontal abduction

45 degrees

GH horizontal adduction

130 degrees

Diagonal abduction and adduction

GH joint is frequently injured due to its...

anatomical design

GH joint injury reasons

shallowness of glenoid fossa, laxity of ligament structures, weak muscles

Common subluxations and dislocations

anterior and anteroinferior

Rare dislocation

posterior

Ligaments are quite lax until...

extreme ROM is reached

Rotator cuff muscle group

subscapularis, supraspinatus, infraspinatus, teres minor

Rotator cuff muscles are

- not very large

- must possess strength & muscular endurance

- stabilize humeral head in glenoid cavity

Point of insertion for rotator cuff muscles enable

humeral rotation

Rotator cuff muscles attach to

front, top, and rear humeral head

Glenohumeral Internal Rotation Deficit (GIRD)

difference in internal rotation range of motion between an individual's throwing & non-throwing shoulders

GIRD increases the risk of injury by more than

20%, Stretching regains internal rotation and reduces likelihood of injury

Intrinsic GH muscles (stabilization)

deltoid, coracobrachialis, teres major, rotator cuff group

Extrinsic GH muscles (motion)

Latissimus dorsi and pec major

Anterior muscles

pectoralis major, coracobrachialis, subscapularis, serratus anterior

Superior muscles

Deltoid, supraspinatus

Posterior muscles

Latissmus dorsi, teres major/minor, infraspinatus

Brachial Plexus

C5-T1

Lateral pectoral nerve

C5, C6, C7, pectoralis major (clavicular head)

Medial pectoral nerve

C8-T1, pectoralis major (sternal head)

Thoracordosal nerve

C6, C7, and C8, Latissimus dorsi

Axillary nerve

C5 and C6, innervates deltoid and teres minor

Upper subscapular nerves

C5-C6, Subscapularis

Lower subscapular nerves

C5 & C6, subscapularis and teres major

Suprascapula nerve

C5-C6 Supraspinatus, Infraspinatus

Musculotaneous nerve

C5, C6, ,C7, coracobrachialis

Deltoid origin

anterior lateral third of clavicle, lateral aspect of acromion, and inferior edge of spine of scapula

Deltoid insertion

deltoid tuberosity

Pec Major origin

Medial half of anterior surface of clavicle and costal cartilages, adjoining portion of sternum

Pec Major insertion

Flat tendon 2 or 3 inches wide to lateral lip of intertubercular groove of humerus

Latissimus Dorsi origin

Posterior crest of ilium, back of sacrum and spinous processes of lumbar and lower 6 thoracic vertebrae, posterior distal surfaces from lower three ribs

Latissimus Dorsi insertion

Medial lip of intertubercular groove of humerus

Teres Major origin

inferior third of lateral border of scapula

Teres Major insertion

Medial lip of the intertubercular groove of the humerus

Coracobrachialis origin

coracoid process of scapula

Coracobrachialis insertion

middle of medial border of humeral shaft

Subscapularis origin

enter anterior surface of subscapular fossa

Subscapularis insertion

lesser tubercle of humerus

Supraspinatus origin

medial 2/3 of supraspinous fossa

Supraspinatus insertion

superiority on greater tubercle of humerus

Infraspinatus origin

posterior surface of scapula below spine

Infraspinatus insertion

greater tubercle on posterior side

Teres minor origin

posterior scapula lateral border

Teres minor insertion

greater tubercle of humerus on posterior side

Rotator Cuff muscles location

Shoulder girdle

Clavicle Landmarks

acromial end and sternal end

Sternoclavicular ligamentous support

costoclavicular and interclavicular ligaments

SC joint classification

synarthrodial classification

SC joint movement anteriorly

15 degrees with scapular protraction

SC joint movement posteriorly

15 degrees with scapular retraction

SC joint movement superiorly

45 degrees with elevation

SC joint movement inferiorly

5 degrees with depression

AC joint

arthrodial classification, 20-30 degree rotational/gliding motion

AC joint supported by

coracoclavicular, superior ac, and inferior ac ligaments

Subdeltoid bursa

large, located between deltoid muscle and joint capsule

Scapulothoracic joint (ST joint)

scapular moves on the rib cage

Scapula moves 25 degrees with

abduction-adduction

Scapula moves 60 degrees with

upward-downward rotation

Scapula moves 55 degrees with

elevation-depression

Scapula muscles...

stabilize scapula, provide stable base to exert forces

Scapula remains in a _______ position during shoulder joint actions

static

5 muscles primarily involved in shoulder girdle movements

upper and lower traps, serratus anterior, rhomboids, and pec minor

The 5 muscles primarily involved in shoulder girdle movements provide what type of stability for the shoulder?

dynamic stability

Scapula muscles are important in...

spinal posture

Scapula muscles contribute to what lumbar deformity

kyphosis

Scapula muscles maintain what in the spine?

Lumbar lordosis and keep head over trunk in balanced position

Good posture aids in easier...

breathing

Scapula winging affects which muscle

serratus anterior

Serratus is located where and does what actions

posterior and laterally, abduction and upward rotation

Pec minor is located where and does what action

anterior, abduction, downward rotation, and depression

Subclavius is located where and does what action

anterior, depression

Trap upper fibers action

elevation and extension of the head

Trap middle fibers action

elevation, adduction, and upper rotation

Trap lower fibers

adduction, depression, upward rotation

rhomboid action

adduction, downward rotation, and elevation

levator scapulae action

elevation