1. 910 213 week 2 1 910 213 week 2 2
HUMAN FUNCTIONAL ANATOMY THE SHOULDER COMPLEX
213
SHOULDER MOVEMENT MANY JOINTS
INVOLVED
Glenohumeral
THIS WEEKS LAB:
Acromioclavicular
Shoulder and hip Joints Sternoclavicular
Scapulothoracic
In this lecture Costovertebral
The shoulder complex Costotransverse
Costochondral
Scapulo-thoracic Sternocostal
Glenohumeral
The Clavicle
Scapular movements and muscles
Elevation – Depression
Protraction – Retraction
Upward and Downward Rotation
Glenohumeral movements and muscles
Rotator Cuff Muscles Simultaneous movements of all these joints
Flexion – Extension Hard to voluntarily move one joint
Adduction – Abduction +ve can compensate for loss of range in one joint
Medial and Lateral Rotation -ve one painful joint can upset movements of the whole
complex.
Combined movements
Although there are many joints, we only normally refer
Readings to movements two joints.
1. Stern – Core concepts – sections 81 and 84 (plus Scapulothoracic or scapular movements
appendices) Glenohumeral
2. Faiz and Moffat – Anatomy at a Glance – Sections
32 and 34 We will examine the movements of the two joints
3. Grants Method of Anatomy – shoulder in joints of separately – but be aware that the movements occur
the upper limb together
910 213 week 2 3 910 213 week 2 4
SCAPULAR MOVEMENTS SHOULDER MUSCLES
The scapular slides on the body wall and can move in Scapular muscles
three directions (and combinations of the those 3) Levator scapulae
Serratus anterior
1. Elevation – Depression Rhomboids
2. Protraction – Retraction Pectoralis minor
3. Upward and Downward Rotation Trapezius
In humans and other animals with clavicles the
movements of the scapula is regulated by the clavicle. Glenohumeral
muscles
Animals with clavicles and without clavicles: Supraspinatus
Infraspinatus
Teres minor
Subscapularis
Teres major
Deltoid
Triceps long head
Biceps
Coracobrachialis
The clavicle is important in the use of the hand for
grasping and manipulation.
It acts as a strut that, with the muscles as “guy ropes”, Both Scapular and Glenohumeral (they don’t attach to the scapula)
forms a secure basis for movements of the arm. Pectoralis major
Latissimus dorsi

2. 910 213 week 2 5 910 213 week 2 6
SCAPULAR MOVEMENTS SCAPULAR MOVEMENTS
Elevation and Depression Protraction and Retraction
Elevation = Lifting the shoulders Protraction = shoulders forwards
As is shrugging (where the scapula moves) Maybe an actual movement or stopping the shoulder
Or carrying heavy objects (where the scapula stays still being pushed backwards.
or may even go down!)
Muscles involved: Muscles involved:
Levator scapulae Serratus anterior
Trapezius (upper fibres) Pectoralis minor
Rhomboids
Depression = lowering
the shoulders Retraction = shoulders back
May be an actual lowering, or merely May be an actual movement or …
preventing the scapula going up (as when you
support yourself with your arms) Muscles involved
Muscles involved: Rhomboids
Trapezius (lower fibres) Trapezius (middle part)
Pectoralis major and minor
Latissimus dorsi Rhomboids and serratus anterior form a couple that
Gravity control the mediolateral position of the scapula
910 213 week 2 7 910 213 week 2 8
SCAPULAR MOVEMENTS GLENOHUMERAL JOINT
Upward and downward rotation
The glenohumeral joint is a ball and socket joint.
Upward rotation = makes the glenoid cavity face Glenohumeral movements
upwards Flexion – Extension
Muscles involved Adduction – Abduction
Serratus anterior (lower part) Medial and Lateral Rotation
Trapezius (upper and lower parts) Bones
The bony socket is very shallow
Deepened by the glenoid labrum
The acromion, coracoid and coracoacromial
ligament form a secondary socket that prevents
upward dislocation.
The ligaments are very loose to allow free
movements, so the joint relies on muscles to
maintain its stability
The rotator cuff muscles
1. Act as dynamic ligaments to stabilise
the joint in all positions.
2. They attach very close to the joint
centre and so can not cause strong
movements of the arm.
3. They assist other muscles (synergists)
Subscapularis
Supraspinatus
Downward rotation = makes the glenoid cavity face Infraspinatus
downwards Teres minor
Muscles involved
Pectoralis major
Latissimus dorsi
Rhomboids
Gravity

3. 910 213 week 2 9 910 213 week 2 10
GLENOHUMERAL MOVEMENTS GLENOHUMERAL MOVEMENTS
Flexion and extension Abduction and Adduction
Sagittal plane movement Coronal plane movement
Flexion is the forward movement of the arm. Abduction is moving the arm
It may be an actual movement or just a stabilising action away from the body
Muscles involved It may be an actual movement or
Pectoralis major just a stabilising action
(clavicular part) Muscle Involved
Deltoid (anterior part) Middle part of Deltoid
Biceps and Rotator cuff muscles act as synergists
coracobrachialis
Extension is the backwards movement of the arm
Muscles involved
Pectoralis major
(sternal part)
Deltoid (posterior Adduction is bringing the arm to the body
part) Muscles involved
Latissimus dorsi and Teres major, latissimus dorsi
teres major Pectoralis major
Triceps (scapular Anterior and posterior deltoid
head) Gravity
910 213 week 2 11 910 213 week 2 12
GLENOHUMERAL MOVEMENTS EXAMPLES OF ACTUAL
Medial and lateral rotation MOVEMENTS
Medial rotation is rotation around the long axis of the It is important to learn the movements and muscles of
humerus that moves the anterior part medially. the scapular and glenohumeral components of the
May be the movement itself or a stabilising action like shoulder separately, and not to allow yourself to
when you carry something between two hands. confuse the two.
Muscles involved
Teres major and latissimus dorsi But, in practice the movements that we do involve
Pectoralis major and anterior both components acting together.
deltoid For example:
Subscapularis Raising the arm laterally to the vertical position
1. Glenohumeral movement can only perform half of
the movement.
2. The scapula must rotate laterally as well.
Lateral rotation is rotating the humerus outwards Pushing forwards with the hand as in opening a heavy
Muscles involved door
Posterior deltoid
Infraspinatus
Teres minor
1. Glenohumeral flexion (and elbow extension),
performs most of the action - but.
2. The Scapula must protract as well. This pushes the
whole shoulder forwards.
a. In people with paralysis of serratus anterior, as
they try to push forwards the scapula moves
backwards.

4. 910 213 week 2 13
SCAPULAR
MUSCLES AND MOVEMENTS
Elevate Depress Protract Retract Upward Down
rotate rotate
Levator
scapulae
Serratus
anterior
Rhomboids
Pectoralis
minor
Trapezius
Pectoralis
major
Latissimus
dorsi
GLENOHUMERAL
MUSCLES AND MOVEMENTS
Flex Extend Abduct Adduct Medial Lateral
rotate rotate
Supraspinatus
Infraspinatus
Teres minor
Subscapularis
Teres major
Deltoid
Triceps (long)
Biceps
Coracobrachialis
Pectoralis major
Latissimus dorsi