Shoulder Complex

Shoulder Complex

Shoulder Joint - Glenohumeral Joint

Shoulder Girdle - Scapulothoracic “joint” , Clavicular Joints

Highly mobile region

• Variety of muscles allow for movement of joint in many directions

Scapular Landmarks

Supraspinatus Fossa

Infraspinatus Fossa

Subscapular Fossa

Spine of the Scapula

Glenoid Fossa

Coracoid Process

Acromion Process

Inferior Angle

Humeral Landmarks

Head

Greater Tubercle

Lesser Tubercle

Intertubercular (Bicipital) Groove

Deltoid Tuberosity

Clavicular Landmarks

Sternal end (medial)

Acromial end (lateral)

Body of Clavicle

Glenohumeral Joint

• Glenoid Fossa of Scapula

• Head of Humerus

Enarthrodial (multiaxial ball and socket)

• All motions in all planes

Large ROM

• Decreased bony stability

• Stability enhanced by:

  • Glenoid Labrum

  • Glenohumeral Ligaments

  • Rotator Cuff Muscles

Glenoid Labrum

Fibrocartilage rim around glenoid fossa

Deepens fossa to better hold humeral head

Provides cushioning

Static stability

Glenohumeral Ligaments

Static Stability

Anterior and inferior translation most common due to bony structure

Middle and Inferior GH ligament - not tested

Glenohumeral Joint

Rotator Cuff provides dynamic stability

• SITS

  • Supraspinatus

  • Infraspinatus

  • teres minor

  • Subscapularis

Attach to the anterior, posterior, and superior humerus

Keep humeral head in correct approximation within glenoid fossa

Scapulothoracic “Joint”

Not a true synovial joint

Supported dynamically by its muscles

No ligaments support

Moves in conjunction with clavicular joints

• Increases Glenohumeral ROM

• Moves only in frontal plane

Acromioclavicular Joint

Arthrodial (gliding) Joint

• Small movements in all planes

Held to scapula via ligaments

• Coracoclavicular Ligaments

• Acromioclavicular Ligaments

Sternoclavicular Joint

Arthrodial (gliding) Joint

• Small movements in all planes

• More motion than the AC Joint

  • SC also sometimes referred to as a seller (saddle) joint

Held to sternum 1st rib via ligaments

• Sternoclavicular Ligaments

• Costoclavicular Ligament

Abduction (GH)

Upward lateral movement of humerus out to the side - away from body

Frontal Plane

Adduction (GH)

Downward movement of humerus medially toward body

Frontal Plane

Flexion (GH)

Movement of humerus strait anteriorly

Sagittal Plane

Extension (GH)

Movement of humerus strait posteriorly

Sagittal Plane

External Rotation (GH)

Movement of humerus laterally around its long axis away from midline

Transverse Plane

Internal Rotation (GH)

Movement of humerus medially around its long axis toward midline

Transverse Plane

Horizontal Adduction (GH)

Movement of humerus in a horizontal or transverse plane toward and across chest

Transverse Plane

Horizontal Abduction (GH)

Movement of humerus in a horizontal or transverse plane away from chest

Transverse Plane

Diagonal Abduction (GH)

Movement of humerus in a diagonal plane away from midline of body

Diagonal Plane

Diagonal Adduction

Movement of humerus in a diagonal plane toward midline of body

Diagonal Plane

Scapula Movement Diagram

Abduction (Protraction) (ST)

Scapula moves laterally away from spinal column

Frontal Plane

Adduction (Retraction) (ST)

Scapula moves medially toward spinal column

Frontal Plane

Upward Rotation (ST)

Moving inferior angle superolaterally away from spinal column

Frontal Plane

Downward Rotation (ST)

Returning inferior angle inferomedially toward spinal column

Frontal Plane

Elevation (ST)

Upward or superior movement, as in shrugging shoulders

Frontal Plane

Depression (ST)

Downward or inferior movement, as in returning to neutral position

Frontal Plane

Movements

Glenohumeral joint is paired with shoulder girdle to accomplish total shoulder range of motion

Scapulohumeral Rhythm

• Synergistic relationship

• 2 to 1 ratio

  • For every 2 degrees of glenohumeral motion, there is 1 degree of scapular motion

  • May vary within and between individuals

Movements Overview

Muscles (GH)

Intrinsic Glenohumeral Muscles

Originates on the scapula and clavicle

• Deltoid

• Coracobrachialis

• Teres Major

• Rotator Cuff Group

Extrinsic Glenohumeral Muscles

Originate elsewhere in the body

• Latissimus Dorsi (back)

• Pectoralis Major (chest)

Anterior Muscles (GH)

Pectoralis Major

Coracobrachialis

Subscapularis

Deltoid

Superior Muscles (GH)

Deltoid

Suprascapularis

Posterior Muscles (GH)

Latissimus Dorsi

Teres Major

Infraspinatus

Teres Minor

Deltoid

Abduction

Flexion - ant.

Extension - pos.

Internal Rotation - ant.

External Rotation - pos.

O - Anterior lateral 1/3 of clavicle, lateral acromion, inferior edge of scapular spine

I - Deltoid tuberosity

Pectoralis Major

Adduction

Internal Relations

Flexion

O - Medial ½ of clavicle, manubrium, and body of sternum, costal cartilage 1-6

I - Crest of greater tubercle of humerus (bicipital groove)

Latissimus Dorsi

Adduction

Extension

Internal Rotation

O - Posterior ilium, spinous processes of L spine, T7-12, lower 3 ribs

I - Medial side of intertubercular groove(bicipital groove) of humerus

Teres Major

Extension

Internal Rotation

Adduction

O - Dorsal surface of inferior angle of scapula

I - Crest of the lesser tubercle of humerus (bicipital groove)

Coracobrachialis

Flexion

Adduction - primary

Internal Rotation

O - Coracoid Process of scapula

I - Upper 1/3 of anterior humerus

Rotator Cuff Muscles

SITS

Supraspinatus - Attach to greater tubercle from above (Abduct)

Infraspinatus - Attach to greater tubercle posteriorly (Ext. Rot.)

Teres Minor - Attach to greater tubercle posteriorly (Ext. Rot.)

Subscapularis - Attach the lesser tubercle anterior (Int. Rot.)

Subscapularis

Internal Rotation - primary

Extension

Adduction

Stabilization of the humeral head in glenoid fossa

O - Subscapular Fossa

I - Lesser tubercle of humerus

Supraspinatus

Abduction

Stabilization of the humeral head in glenoid fossa

O - Medial 2/3 of supraspinatus fossa

I - Greater tubercle of humerus

Infraspinatus

External Rotation

Extension

Stabilization of humeral head in the glenoid fossa

O - Medial aspect of infraspinatus fossa below scapular spine

I - Greater tubercle of humerus

Teres Minor

External Rotation

Adduction

Extension

Stabilization of humeral head in the glenoid fossa

O - Upper 2/3 of lateral border of scapula

I - Greater tubercle of humerus

Glenohumeral Flexion

Agonists

• Deltoid - anterior

• Pectoralis Major - upper

• Coracobrachialis

Glenohumeral Extension

Agonists

• Teres Major

• Latissimus Dorsi

• Deltoid - posterior

Glenohumeral Abduction

Agonists

• Supraspinatus

• Deltoid - middle

Glenohumeral Adduction

Agonists

• Pectoralis Major

• Coracobrachialis

• Latissimus Dorsi

• Teres Major

Glenohumeral Internal Rotation

Agonists

• Latissimus Dorsi

• Teres Major

• Subscapularis

• Pectoralis Major

All attach anteromedially on humerus

Glenohumeral External Rotation

Agonists

• Infraspinatus

• Teres Minor

Both attach posteriorly on greater tubercle

Glenohumeral Horizontal Adduction

Agonists

• Abductors

• Flexors

• Internal Rotators

Glenohumeral Diagonal Abduction

Agonists

• Abductors

• Extensors

Glenohumeral Diagonal Adduction

Agonists

• Adductors

• Flexors

Muscles (ST)

5 muscles primarily involved in shoulder girdle movements

• Trapezius

• Rhomboid

• Levator Scapulae

• Serratus Anterior

• Pectoralis Minor

Trapezius

Retraction

Upward Elevation

Depression

O - Occipital Protuberance, Spinous processes of C1-7, T1-12

Levator Scapulae

Elevation - medially

Lateral Flexion of cervical spine

O - Transverse processes of C1-4

I - Superior angle to the medial border of scapula

Rhomboid Major & Minor

Retraction

Elevation

Downward Rotation

O - Spinous processes of C7 and T1-5

I - Medial border of scapula below scapular spine

Serratus Anterior

Protraction

Upward Rotation

O - Surface of ribs 1-9 at the slide of the chest

I - Anterior aspect of medial border of scapula

Pectoralis Minor

Protraction

Downward Rotation

Depression

O - Anterior surface of ribs 3-5

I - Coracoid process of scapula

Scapular Protraction - Abduction

Scapula move laterally away from spinous processes without rotation

Ex - push up & bench press

Agonists

• Pectoralis Minor

• Serratus Anterior

Scapular Retraction - Adduction

Return from abduction

Ex - Seated row

Agonists

• Middle Trapezius

• Lower Trapezius

• Rhomboids

Scapular Upward Rotation

Lateral and Upward Movement

Agonists

• Middle Trapezius

• Lower Trapezius

• Serratus Anterior

Scapular Downward Rotation

Downward and medial movement

Glenoid Fossa is rotated downward when downward movement of shoulder joint occurs

Ex - Lat pull-down

Agonists

• Pectoralis Minor

• Rhomboid

Scapular Elevation

Lifting scapular without rotation in anatomic position

Ex - Shoulder shrug

Agonists

• Levator Scapulae

• Upper Trapezius

• Middle Trapezius

• Rhomboids

Scapula Depression

Dropping scapula without rotation in anatomic position

Ex - Upward portion of dip

Agonist

• Lower Trapezius

• Pectoralis Minor