Anatomy

Front 1

What is the classification and articulation of the shoulder joint?

Back 1

Glenohumeral joint: Synovial ball and socket joint. This means that there is lots of movement taking place at this joint. Synovial: Synovial fluid etc.

Articulates between the head of the humerus (ball) and the glenoid fossa of the scapula (socket). The glenoid fossa has a shallow surface, allowing more mobility than the hip joint. However this means there is less stability at the joint increasing the chance of impingement at the shoulder - e.g dislocation.

Front 2

Function of the glenoid labrum:

Back 2

A ligament that attaches around the rim of the glenoid fossa. It helps deepen the joint to increase stability and actually extends the glenoid fossa/socket by 50%. - allows a deeper contact with the humeral head. Thus increasing stability at that area.

Front 3

Humerous bony points:

Back 3

Greater tuberosity - attachment sites for muscles such as the rotatores.

Lesser tuberosity - attachment sites for muscles such as the rotatores.

Deltoid tuberosity - attachment for deltoid muscle.

Bicipital groove/intertubercle groove - where the long head of bicep brachii tendon inserts. Transverse ligament located also between the greater and lesser tuberosity, goes across the groove to keep long head of biceps brachii in place.

Head of humerus - this is covered in articular cartilage - reduces friction between the glenoid fossa and the head. - smooth controlled movement.

Anatomical neck of humerus.

Surgical neck of humerus - named this because it is a likely place of fractures. - for example commonly seen with the elderly when falls take place.

Posterior side of the humerus - Radial groove - where the radial nerve passes. - if fracture occurs at surgical neck then the radial groove and nerve are likely to be affected as well.

Scapula - supra glenoid tubercle of the scapula. - where the long head of biceps goes into. Long head of biceps tendon goes from the glenoid cavity, spiralling over humeral head into the bicipiital groove. Infra glenoid tubercle of scapula - bottom of the glenoid fossa - long head of triceps brachii will attach there.

Front 4

Ligaments of the Glenohumeral joint:

Back 4

Glenohumeral ligaments -

Superior - Sup aspect of the glenoid cavity to the anatomical neck of the humerous.

Middle - medial aspect of glenoid margin to the anatomical neck of the humerus.

Inf - inf aspect of glenoid margin to the anatomical neck of the humerus.

Transverse ligament - goes between the greater and lesser tuberosity - helps stabilise long head of biceps tendon into the biccipital groove on the humerus.

Capsule - surrounds and encloses entire joint.

Front 5

Movements of the shoulder joint:

Back 5

Flexion - Flex 180 degrees in the sagittal plane: splits half your body left and right.

Extension - ext 60 degrees in the sagittal plane.

Abduction - Abd 180 degrees in the coronal plane: splits your body front and back.

Adduction - Add 70 degrees in the coronal place: splits your body front and back.

Internal rotation - (medial rotation) - 100 degrees in the transverse plane: splits your body across.

External rotation - (Lateral rotation) - 90 degrees in the transverse plane: splits your body across.

Ensure that when demonstrating these movement with patient, that patient goes to full end of range as safely as possible.

Front 6

Stability of the glenohumeral joint:

Back 6

Static stabilizers: include the capsule and ligaments.

Dynamic stabilizers: include in particular the rotator cuff muscles:

- supraspinatus - the one on top: from supraspinous fossa to the superior facet on the greater tuberosity of the humerous.

-infraspinatus - the one on the back: from the infraspinous fossa to the middle facet on the greater tuberosity on the humerus.

-Teres minor - the one on the back: Lateral border of the scapula to the inferior facet of the greater tuberosity on the humerus.

-Subscapularis - the one on the front: Medial surface of the scapula into the lesser tuberosity.

There is one of these muscles at the front, two at the back and one at the top.

Front 7

Brachial plexus:

Back 7

This is where all the nerves that go into the upper arm, forearm, hands and fingers originate from. Formed by nerve roots C5-T.

The brachial plexus emerges from the scalenes muscles and the upper part of the clavicle. It then comes beneath the clavicle and into the axilla - this is the armpit itself.

It is subject to traction injuries causing damage commonly to the axillary nerve. This is normally done by elongating the brachial plexus - through side flexing the head and depressing the shoulder girdle.

Front 8

Axilla:

Back 8

This is your armpit: the space between the arm and the thorax.

Function: allows for passage of blood vessels and nerves to pass from the neck and the upper limb.

Can be dangerous with a dislocation due to the movement of the humerus out of the socket - can cause potential nerve impingement due to the way they lie on the shoulder joint.

Front 9

Subacromial space:

Back 9

is the gap between the coracoacromial arch (where the acromion meets with the clavicle ) and the head of the humerus.

This is where the superior part of the capsule ligament, the long head of biceps passes through, the supraspinatus tendon and the subacromial bursa exist. - If inflammation occurs with these structures under the arch, this can cause problems for atheletes that perform over head activities such as javilin.

7-14mm deep: This space can have potencial for friction and degeneration. - impingement syndrome. - caused by tendon catching in the subacromial space. rubs against the bone above causing pain and weakness when you raise your arm over your head. - therefore important for there to be space due to the amount of structures that pass through.

Front 10

Muscles that cause flexion of the shoulder:

Back 10

Deltoid (ant fibres) - Lateral clavicle to the deltoid tuberosity of the humerus. Supplied by the Axillary nerve.

Biceps brachii - Biceps means two heads: Long head and short head. Long head comes from the supraglenoid tubercle. Short head comes from the coranoid process and blends with the corocobrachiallis tendon. both attach into the radial tuberosity of the humerous. Supplied by the musculocutaneous nerve from the branches of the brachial plexus.

Pectoralis major (clavicular part)- This is a large muscle that forms the anatomical chest shape. supplied by both the medial and lateral pectoral nerves. from the medial clavicle to the crest of the greater trochanter on the humerus.

Corocobrachiallis - Corocoid process of the scapula to the medial surface of the humeral shaft. supplied by the musculocutaneous nerve.

Front 11

Muscles that cause extension of the shoulder:

Back 11

Deltoid (pos fibres): Inf aspect of the spine of the scapula to the deltoid tuberosity of the humerus. Supplied by the axillary nerve.

Lattissimus dorsi: Origin from the posterior illiac crest, Spinous processes of L5 to T7 and ribs 8-12 to the biccipital groove of the humerus. Supplied by the thoracordorsal nerve.

Teres major: Inf lateral border and inf angle of the scapula to the medial lip of the biccipital groove. supplied by the subscapular nerve from roots C5-7.

Pectorallis major: (costal fibres): From the sternum costocartilages to the crest of the greater tubercle. supplied by both medial and lateral pectoral nerves.

Front 12

Muscles that cause abduction of the shoulder:

Back 12

Deltoid (all fibres): Middle fibres = From the acromion of the scapula to the deltoid tuberosity of the humerus. Supplied by the axillary nerve.

Supraspinatus: from the Sup tubercle of the glenoid fossa to the sup facet on the greater trochanter. supplied by the suprascapula from nerve roots C5 to c6.

Pectorallis major (all fibres): - only used when patient lifts arm over head. Abdominal part: from the anterior part of the rectus sheath to the crest of the greater trochanter/tuberosity.

Front 13

Muscles that cause adduction of the shoulder:

Back 13

Pectorallis major

Lattissimus dorsi

Teres major

Biceps brachii (short head)

Corocobrachiallis

Front 14

Muscles that cause Internal rotation of the shoulder:

Back 14

Deltoid (Ant fibres):

Lattissimus dorsi:

Teres major

Subscapularis - Medial aspect of the scapula to the lesser trochanter of the humerus. supplied by the upper and lower subscapular nerves.

Pectoralis major

Front 15

Muscles that cause external rotation of the shoulder:

Back 15

Deltoid (pos fibres):

Infraspinatus: Inf tubercle of the glenoid fossa to the middle facet on the greater tuberosity.Supplied by the suprascapula nerve.

Teres minor:Lateral border of the scapula to the inf facet of the greater trochanter/tuberosity. supplied by the Axillary nerve from the brachial plexus.

Front 16

Muscles that cause horizontal abduction:

Back 16

Deltoid pos fibres:

Lattisimus dorsi:

Teres minor: Lateral border of the scapula to the inf facet of the greater trochanter/tuberosity. supplied by the Axillary nerve from the brachial plexus.

Infraspinatus:

Front 17

Muscles that cause horizontal adduction:

Back 17

Pectoralis major:

Deltoid (ant fibres):