1. Anatomy of Shoulder Part 2

2. Ligaments Sternoclavicular Joint Ligaments
Extremely weak because of boney arrangement
Anterior sternoclavicular
Prevents upward displacement of clavicle
Posterior sternoclavicular
Interclavicular
Prevents lateral displacement of clavicle
Costoclavicular
Prevents lateral and upward displacement of clavicle

3. Ligaments
Consists of Anterior, posterior, superior, and inferior portions
Coracoclavicular ligaments joins the coracoid process and clavicle helps maintain the position of the clavicle relative to the acromion
Coracoclavicular
Divided into
Coniod and trapezoid ligaments
Coracoacromial ligament
Connects the coracoid to the acromion

4. Ligaments Glenohumeral Joint Ligaments
Superior Ligament
Middle Ligament
Inferior Ligament
Produce major restraint in shoulder flexion, extension and rotation

5. Ligaments Glenohumeral Joint Ligaments Anterior Posterior Middle
Tense in extension, abduction or external rotation
Posterior
Tension is in extension with external rotation
Middle
Tension in flexion and external rotation
Inferior
Tense in abduction, extended or externally rotated

6. Ligaments Glenohumeral Ligaments Inferior GH Ligament
Primarily a check against both anterior and posterior dislocation of humeral head
Transverse ligament
Retains the long biceps tendon within the bicipital groove

7. Muscles Dynamic motion
Establish stability to compensate for a great deal of mobility
Flexion, extension, abduction, adduction, horizontal adduction/abduction, internal/external rotation and circumduction

8. Muscles 1st group 2nd group Rotator cuff muscles
Originate on axial skeleton
Attach to humerus
Latissiumus dorsi
Pectoralis major
2nd group
Originates on scapula
Deltoid
Teres major
coracobrachialis
Rotator cuff muscles
Subscapularis, supraspinatus, infraspinatus and teres minor
Tendons adhere to the articular capsule and serve as reinforcing structures
Biceps and triceps
Attach on the glenoid and effect elbow motion

9. Muscles Scapular Muscles 3rd group
Levator scapulae
Trapezius
Rhomboids
Serratus anterior
Important in providing dynamic stability to the shoulder complex

10. Bursae Most important Subacromial Bursa Subacromial bursa
Between coracoacromial arch and glenohumeral capsule
Reinforced by the supraspinatus tendon
Subacromial bursa
Easily subjected to trauma in overhead position
Compressed under coracoacromial arch

11. Nerve Supply Spinal nerve roots Innervate muscles of upper extremity
5th cervical vertebra through 1st Thoracic vertebra
Create the brachial plexus
Innervate muscles of upper extremity
Axillary (C5-C6)
Musculocutaneous (C5-C7)
Subscapular (C5-C6)
Suprascapular (C5-C6)
Dorsal scapular (C5)
Pectoral (C5-T1)
Radial (C5-T1)

12. Functional Anatomy Rotator Cuff Muscles Supraspinatus
Subscapularis, infraspinaturs, supraspinatus and teres minor (along with long head of biceps)
Provide dynamic stability
Control position
Prevent excessive displacement of the humeral head
Supraspinatus
Compresses humeral head
Infraspinatus, teres minor and subscapularis
Depress the humeral head during overhead movements

13. Functional Anatomy Glenohumeral joint capsule
As muscle contracts they dynamically tighten the joint capsule
Which helps center the humeral head to the glenoid
Dynamic movement and stabilization of shoulder
Also needs scapulothoracic, acromioclavicular and sternocalvicular joint to move as well

14. Functional Anatomy
Muscles that produce movement of the scapula on the thorax help maintain the position of the glenoid relative to the moving humerus
Levator scapula and upper trapezius (elevate scapula)
Middle trapezius and rhomboids (adduct scapula)
Lower trapezius (adducts and depresses scapula)
Serratus anterior (abducts and upwardly rotates the scapula)

15. Scapulohumeral Rhythm
Describes the movement of the scapula relative to the movement of the humerus throughout a full range of abduction
Humerus elevates to 30 degrees: no movement of scapula
Setting phase
30 to 90 degrees: scapula abducts and upwardly rotates
90 degrees to full abduction: scapula abducts and upwardly rotates 1 degree for each 1 degree of humeral elevation
Clavicular movement must occur at both the SC and AC joints
Clavicle must elevate 40 degrees and rotate in a poster superior direction at least 10 degrees