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The Australian Physiotherapy & Pilates Institute

Anatomy of the Shoulder and Upper Limb

The Australian Physiotherapy & Pilates Institute

Shoulder Complex

• Physiological joint between scapula and thoracic wall

• Shoulder complex (SC): sternoclavicular, acromioclavicular, glenohumeral, scapulothoracic joints

Scapulothoracic joint (STJ)

Equipment - Level Two

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Anterior Posterior

Bony landmarks of scapulae

Equipment - Level Two

Anterior Posterior

Equipment - Level Two

• Base for muscle attachments

• Correct orientation optimises length tension

relationship of deltoid with abduction

– Van der Helm 1994

• Orientates glenoid to facilitate optimal congruency of

GH joint

• Lateral rotation increases available ROM at GH joint

• Laterally rotates to elevate acromion and prevent

impingement with GH elevation

Role of the scapula

Equipment - Level Two

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ROM Movement Joint motion

0 – 60 Flexion Glenohumeral

0 – 30 Abduction Glenohumeral

> 60 Flexion 2:1 scapula to

humeral

>30 Abduction 2:1 scapula to

humeral

Greatest contribution amount of scapula rotation occurs between 80 –

140° of elevation in scaption ( Bagg & Forrest 1998)

Scapulothoracic rhythm

Equipment - Level Two

• The dynamic orientation of the scapula in a

position to optimise the position of the glenoid

and so allow mobility and stability at the

glenohumeral joint.- Mottram S 1997

Equipment - Level Two

Scapula setting

• Position STJ in ideal position

• Maintain with isometric contractions of serratus

anterior and lower trapezius

• Common substitution strategies to avoid:

– Retraction with maximum depression

– Retraction with elevation

Scapula setting

Equipment - Level Two

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• Position STJ in ‘ideal position’?

• Superior angle of scapula level with T2 or T3

• Vertebral border 5 – 6cm from the midline

• Root of spine level with T3 or T4

• Inferior angle level with T7 – T9

• 30° anterior from the frontal plane- Irrang et al 1992

• In upward rotation

• Medial border and inferior angle flat against chest wall

• Ideal position should also be resting position

Scapula setting

Equipment - Level Two

• Practical Session

Scapula setting

Equipment - Level Two

• Medial attachment: medial third of superior nuchal line, external occipital protuberance, ligamentum nuchae, spinous processes and supraspinous ligaments of C7 – T12

• Upper fibres insert to lateral third of clavicle

• Middle fibres run horizontally to attach to inner border of acromion and along length of crest of scapula

• Inferior fibres ascend and converge to a tendon which attaches medial end of the spine of scaplae

Trapezius muscle

Equipment - Level Two

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Functions:

• Upper fibres:

– elevate scapula? debatable

– Downwardly rotate scapulae

– Draw scapula backwards to elevate lateral end of clavicle and cause upward rotation of scapula

- Johnson et al 1994

• Middle fibres:

– retract scapula

– Stabilise during upward rotation

• Lower fibres:

– Depress scapula

– Upwardly rotate the scapula

– Resist lateral displacement of serratus anterior

Trapezius

Equipment - Level Two

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Serratus anterior

Equipment - Level Two

Anatomy:

• Originates external surface of upper 8 or 9 ribs

• Inserts anterior surface of medial border of scapula

Function:

• Major protractor of scapula

• Upwardly rotates scapula

• Elevates scapula

Serratus anterior (SA)

Equipment - Level Two

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• Upper and lower fibres of trapezius and SA work as force couple

to produce upward rotation if scapula- Palastanga et al 1994, Williams 1995

• As SA draws scapula laterally around chest wall, movement is

controlled by lower trapezius

• In elevation, this force couple works to counteract downward

rotation of deltoid on scapula

• Thus maintaining scapula in upward rotation and preventing

impingement

Muscle balance of STJ

Equipment - Level Two

Anatomy:

• Descends from C1 – C4 diagonally to insert on the medial superior border of the scapula

Function:

• Elevate, retract and downwardly rotate scapula

• Assists in stabilisation under load

- Mottram 1997

Levator scapulae

Equipment - Level Two

Anatomy:

• Minor: runs obliquely downwards

and laterally from the lower

ligamentum nuchae, C& and T1 to

attach on the medial scapula border

at the root of scapula

• Major: arises from T2 – T5 and

descends laterally to attach on the

medial border of scapula between

root and inferior angle

Function:

• Retract, downwardly rotate and

elevate scapula

Equipment - Level Two

Rhomboid minor & major

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Anatomy:

• Minor: Arises from R3 – R5 and

ascends laterally to insert onto

coracoid process

Function:

• Exerts strong pull on coracoid

process onto protraction and

downward rotation

Pectoral minor

Equipment - Level Two

Anatomy

• Arises from spinous processes of

inferior 6 thoracic vertebrae,

thoracolumbar fascia, iliac crest,

and inferior 3 or 4 ribs and inserts

into the intertubercular groove of

humerus

• Small slip to the inferior angle of

scapula

Function

• Extends, adducts, and medially rotates humerus

Latissimus dorsi

Equipment - Level Two

Suprapinstus:• Arises supraspinous fossa and

inserts into superior facet on greater tuberosity of humerus

• Initiates and assists deltoid in abduction of arm

Infraspinatus:• Arises infraspinous fossa and inserts into the

middle facet on greater tuberosity of humerus

• Laterally rotates arm and helps to hold humeral head in glenoid cavity

Terres minor:• Arises superior part of lateral border of

scapula and Inserts into inferior facet on greater tuberosity of humerus

• Laterally rotates arm and helps to hold humeral head in glenoid cavity

Rotator Cuff

Equipment - Level Two

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Subscapularis:

• Arises subscapular fossa of

scapula and inserts into

lesser tuberosity of humerus

Action:

• Medially rotates arm and

adducts it and helps to hold

humeral head in glenoid

cavity

Rotator Cuff

Equipment - Level Two

Sternocleidomastoid

Scalenes

• Anterior

• Middle

• posterior

Superficial neck muscles

Equipment - Level Two

The Australian Physiotherapy & Pilates Institute

Biomechanics of the Shoulder Complex

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The Australian Physiotherapy & Pilates Institute

Upper Limb ControlDepends on:• Strength of muscle• Angle of pull• Line of action of the resultant muscle

force• Rotary and stabilizing or dislocating

components• Shoulder girdle designed for mobility• ↓stability• Muscles provide stability• Strength vital with weakness related to injury

The Australian Physiotherapy & Pilates Institute

Scapular PostureNormal alignment:

• Vertebral border is parallel to the spine• Vertebral border is ~ 7cm from midline• located between T2 and T7• Scapula is flat against the thorax• Scapula is rotated ~30° anterior to the frontal plane – scapular plane

Sahrmann (2010)

The Australian Physiotherapy & Pilates Institute

Humural PostureNormal alignment includes:

• <1/3 of humeral head protruding in front of the acromion

• Neutral rotation should be present

• Proximal and distal ends are in the same vertical line

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The Australian Physiotherapy & Pilates Institute

Scapulo-Humeral Rhythm

• Without scapular motion humerus only abduct/flex 120 degrees• acromion prevents further motion.• scapula must rotate for humerus to clear acromion• ratio of 2:1• 2 degrees of glenohumeral rotation to every degree of scapular rotation• Maintains length – tension relationship• Key to efficient shoulder function.• Scapular upward rotation, posterior tilt and ER

Kibler and Sciascia (2009)

The Australian Physiotherapy & Pilates Institute

The Australian Physiotherapy & Pilates Institute

Scapular DysfunctionCan lead to :

• Impingement• Shoulder pain worse with overhead movements• Overuse injuries• Tendinopathies• Thoracic Outlet Syndrome• Weakness/numbness in arm and hand• Instability• Clicking and/or clunking, shoulder slips out• Cervical Pain

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The Australian Physiotherapy & Pilates Institute‘

Excessive scapular protraction ↓maximum rotator cuff strength by 23%.

Kebaetse et al (1999)

• Maximal rotator cuff strength achieved in a position of‘neutral scapular protraction/retraction’,• excessive protraction or retraction demonstrated decreased rotator cuff abduction strength

Smith et al (2002)

Scapular Dysfunction

The Australian Physiotherapy & Pilates Institute

Common Shoulder injuries

The Australian Physiotherapy & Pilates Institute

Common Shoulder Injuries

• Shoulder Impingement Syndrome (SIS)• Rotator Cuff Tear/Tendinopathy• Shoulder instability• Bicipital Tendonopathy• Labral tear• AC joint sprain• Clavicular fractures

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The Australian Physiotherapy & Pilates Institute

Upper Limb Anatomy

The Australian Physiotherapy & Pilates Institute

Movements of the Elbow

The Australian Physiotherapy & Pilates Institute

Movements of the Wrist

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The Australian Physiotherapy & Pilates Institute

Muscles of the Upper Arm

The Australian Physiotherapy & Pilates Institute

Key Pilates Points