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KINESIOLOGY
SHOULDER
By Hermizan Halihanafiah
College of Allied Health and Science, Malaysia
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SHOULDER JOINT
• Glenohumeral joint
• Articulation surface – between head of
humerus and glenoid fossa of scapula
• Ball and socket joint – allows 3 degrees of
freedom
• Flexion/extension, abduction/adduction,
internal/external rotation, horizontal
adduction/horizontal abduction
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3.
Kinematics
Shoulder abduction/adduction
• Occur in the frontal plane/anteroposterior axis of
rotation
• Range of motion
- full abduction: 180 deg (120 shoulder abd + 60 deg
scapular upward rotation)
- adduction : vice versa (120 shoulder add + 60 deg
scapular downward rotation)
• Involve the head of humerus rolling superiorly and slide
inferiorly within glenoid fossa.
• Without inferior slide, the humeral head stuck into the
acromion ---- impingement (suprasapinatus tendon or
subacromial bursa) 3

4.
Shoulder Impingement
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Kinematics
Shoulder flexion/extension
• Occur in sagittal plane/medial-lateral axis of
rotation
• ROM
- full flexion: 120 deg shoulder flexion + 60 deg
scapular upward rotation
- extension : reverse action of flexion + 40 – 60
deg of hyperextension
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Kinematics
Shoulder internal/external rotation
• Occur in horizontal plane/vertical axis of rotation
• Rotation results in the anterior surface of
humerus rotates medially/internally (internal
rotation) or rotates laterally/externally (external
rotation)
• ROM
- external rotation : about 90 deg (80-100 deg)
- internal rotation : about 70 deg (65 – 80deg)
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Kinematics
Shoulder horizontal abduction/horizontal adduction
• SPECIAL MOVEMENT
• Occur when shoulder 90 deg abd, humerus will
move in horizontal plane
• Humerus move towards midline – horizontal
adduction
• Humerus move away form midline – horizontal
abduction
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Supporting Structure
• Shoulder joint – highly mobile (TRIAXIAL JOINT,
LARGE ROM) but less stability
• Due to large, rounded head of humerus and the
shallowness of glenoid fossa of scapula
• Strengthen by :
1. Rotator cuff muscles
2. Capsular ligaments
3. Coracohumeral ligament
4. Glenoid labrum
5. Long head of the biceps
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9.
ROTATOR CUFF MUSCLES
• ROTATOR CUFF MUSCLES – CENTRE OF
STABILITY
• Consist of SITS; Supraspinatus, Infraspinatus,
Teres minor and Subascapularis muscles
• Function – centralizing and stabilizing the
humeral head within glenoid fossa
• Surround humeral head anteriorly, superiorly
and posteriorly, and providing muscular force
that pulls the humeral head towards glenoid
fossa.
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Ligamentous Structure
Capsular lig
• Consist of superior, inferior and middle
glenohumeral lig, attaches between the rim of
gleoid gossa and anatomical neck of humerus
Coracohumeral lig
• Prevents inferior displacement of humeral
head, prevent excessive motion of flexion,
extension and external rotation, attaches
between coracoid process of scapula and
greater tubercle of humerus.
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Others Structure
Glenoid Labrum
• A fibrocartilaginous riing that encircles the edge
of glenoid fossa, deepen the glenoid fossa (nearly
doubling the function of glenoid fossa)
Long Head of the Biceps
• The proximal portion of the tendon wraps around
the superior aspect of the humeral head
(originates form supraglenoid tubercle), provide
anterior stability of shoulder joint.
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16.
Scapulohumeral Rhythm
• The full range of shoulder motion normally is combination
between the motion in glenohumeral and scapulothoracic joint.
• A natural rhythm/ratio between GH joint and scapulothoracic
joint --- 2:1
• That’s means for every 2 deg of shoulder abduction/flexion, the
scapula must upward rotate roughly 1 deg. (vice versa for
adduction/extension)
• The full ROM of shoulder abduction/flexion= 180 deg, which
combination between 120 deg shoulder abduction/flexion + 60
deg scapular upward rotation.
180 degrees of shoulder abduction/flexion =
120 degrees of glenohumeral joint abduction +
60 degrees of scapulothoracic joint upward rotation
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17.
Scapulothoracic (ST) Joint
• Not a truth joint
• Articulating between anterior surface of scapula to
posterior thorax (ribs 2-7)
• Movements : permits scapular elevation/depression,
protraction/retraction, upward/downward rotation
• Motion of ST joint is dependent on the combined
movement of the acromioclavicular (AC) and
sternoclavicular (SC) joint.
• The full 60 deg ST joint upward rotation = 30 deg of SC
joint elevation + 30 deg AC joint upward rotation
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18.
THE RELATIONSHIP BETWEEN
AC, SC, ST AND GH JOINTS MOTIONS.
180 degrees of shoulder abduction/flexion =
120 degrees of GHJ abduction +
60 degrees of STJ upward rotation
60 degrees STJ upward rotation =
30 degrees of SCJ elevation +
30 degrees of ACJ upward rotation
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19.
SCAPULOTHORACIC JOINT MUSCLES
Primary Elevators of ST joint
• Upper fiber of trapezius
• Levator scapulae
• Rhomboids
Primary Depressor of ST joint
• Lower fiber of trapezius
• Latissimus dorsi 19

20.
Upper / Superior
Fiber of Trapezius
• Origin – medial one third of
the superior nuchal line,
external occipital
protuberance and ligamentum
nuchae.
• Insertion – posterior border of
the lateral one third of the
clavicle.
• Action – scapular elevation
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21.
Levator Scapulae
• Origin – transverse process of
Superior four or five cervical
vertebrae.
• Insertion – superior vertebral
border of scapula
• Action – Elevates scapula and
rotates it downward.
• Nerve supply – dorsal
scapular nerve and cervical
spinal nerve
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22.
Rhomboid Major
• Origin – Spine of 2nd to 5th
thoracic vertebrae
• Insertion – vertebral border
of scapula inferior to spine of
scapula
• Action – elevates and
adducts scapula and rotate it
downward; stabilize scapula
• Nerve – dorsal scapular
nerve
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23.
Rhomboid Minor
• Origin – Spine of 7th cervical
and 1st thoracic vertebrae.
• Insertion – Vertebrae border
of scapula superior to spine
• Action – elevates and adducts
scapula and rotate it
downward; stabilize scapula
• Nerve – dorsal scapular nerve
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24.
Lower / Inferior Fiber of Trapezius
• Origin – spinous
process of T6-T12
• Insertion – spine of the
scapula
• Action scapular
depression and
adduction
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25.
Latissimus Dorsi
• Origin – Spines of inferior 6 thoracic
vertebrae (T6-T12), lumbar vertebrae
(L1-L5), crest of sacrum and illiac crest
of hip bone, inferior four ribs and
inferior angle of scapula.
• Insertion – Intertubecular sulcus of
humerus
• Action
– Extends, adduction and medial
rotation arm at shoulder joint.
• Nerve supply - Thoracodorsal nerve 25

26.
SCAPULOTHORACIC JOINT MUSCLES
Primary upwards rotators of ST joint
• Upper fiber of trapezius
• Lower fiber of trapezius
• Serratus anterior
Primary downward rotators of ST joint
• Rhomboids
• Pectoralis minor
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Serratus Anterior
• Origin – Superior 8 or 9 ribs
• Insertion – vertebral border and
inferior angle of scapula
• Action
– Abduction and rotates the
scapula upward
– Elevate ribs when scapula
stabilized.
– Also known as “boxer’s
muscles”
• Nerve supply
– Long thoracic nerve
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Pectoralis Minor
• Origin
– 2nd - 5th ribs, 3rd – 5th ribs
or 2nd – 4th ribs.
• Insertion
– Coracoid process of
scapula
• Action
– Abduction scapula and
rotates it downward
– Elevate the ribs during
forced inhalation.
• Nerve supply
– Medial pectoral nerve 28

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SCAPULOTHORACIC JOINT MUSCLES
Primary protractors of ST joint
• Serratus anterior
Primary retractors of ST joint
• Rhomboids
• Middle fiber of trapezius
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Middle Fiber of Trapezius
• Origin – spinous process
of T1 – T5
• Insertion – medial border
of the acromion process
of scapula, and superior
border of the spine of the
scapula.
• Action – scapular
adduction.
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31.
Glenohumeral Joint Muscles
Primary GH Joint Abductors
• Anterior fiber of deltoid
• Middle fiber of deltoid
• Supraspinatus
Primary GH Joint Adductors
• Latissimus dorsi
• Teres major
• Pectoralis major (sternal head)
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Anterior Fiber of Deltoid
• Origin – anterior border of
the lateral one third of the
clavicle
• Insertion – deltoid
tuberosity
• Action – abduction,
flexion and middle
rotation arm at GH joint.
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Middle fiber of Deltoid
• Origin – lateral border and
superior surface of the
acromion process of the
scapula
• Insertion – deltoid
tuberosity
• Action – abduction arm at
GH joint
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34.
Supraspinatus Muscle
• Origin – supraspinous fossa
of scapula
• Insertion – Greater tubercle
of humerus (anterior aspect)
• Action – initially abduction
(15 degrees) at shoulder
joint, stabilizing shoulder
joint
• Nerve supply -
Suprascapular nerve
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35.
Latissimus Dorsi
• Origin – Spines of inferior 6 thoracic
vertebrae (T6-T12), lumbar vertebrae
(L1-L5), crest of sacrum and illiac crest
of hip bone and inferior four ribs.
• Insertion – Intertubecular sulcus of
humerus
• Action
– Extends, adduction and medial
rotation arm at shoulder joint.
• Nerve supply - Thoracodorsal nerve
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Sternal origin of Pectoralis Major
• Origin – anterior surface of
sternum, costal cartilage of
2nd -6th ribs.
• Insertion – greater tubercle
and intertubercular sulcus
of humerus
• Action – extend arm at
shoulder joint.
• Nerve supply
– Medial and lateral
pectoral nerve
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37.
Teres Major
• Origin – Inferior angle of
scapula
• Insertion – Intertubecular
sulcus of humerus
• Action
– Extends arm at
shoulder joint
– Assist in adduction and
medial rotation of arm
at shoulder joint.
• Nerve supply
– Lower subscapular
nerve 37

38.
Glenohumeral Joint Muscles
Primary GH Joint Flexors
• Anterior fiber of deltoid
• Pectoralis major (clavicular head)
• Coracobrachialis
• Biceps brachii
Primary GH Joint Extensors
• Latissimus dorsi
• Teres major
• Pectoralis major (sternal head)
• Posterior deltoid
• Long head of triceps
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Clavicle origin of
Pectoralis Major
• Origin – medial half of anterior
clavicle
• Insertion – greater tubercle and
intertubercular sulcus of
humerus
• Action – Flexion, adduction and
medial rotation arm at shoulder
joint.
• Nerve supply
– Medial and lateral pectoral
nerve
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40.
Coracobrachialis
• Origin - Coracoid process of
scapula
• Insertion - Middle of medial
surface of shaft of humerus.
• Action - Flexion and adduction
arm at shoulder joint.
• Nerve supply -
Musculocutaneous nerve
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Short head of Biceps
• Origin – Coracoid process of
scapula
• Insertion – radial tuberosity of
radius
• Action – Flexion forearm at
elbow joint, flexion arm at GH
joint and supination at
radioulnar joint.
• Nerve supply -
Musculocutaneous nerve 41

42.
Long head of Biceps
• Origin – Tubercle above the
glenoid cavity of scapula
(supraglenoid tubercle)
• Insertion – Radial tuberosity of
radius
• Action – flexion forearm at
elbow joint, flexion arm at GH
joint and supination forearm at
radioulnar joint.
• Nerve supply -
Musculocutaneous nerve
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43.
Posterior Fiber of Deltoid
• Origin – inferior lip of the
crest of the spine of the
scapula
• Insertion – deltoid
tuberosity
• Action – extension and
lateral rotation arm at GH
joint.
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44.
Long head of Triceps
• Origin – tubercle below to
glenoid cavity of scapula
(infraglenoid tubercle)
• Insertion – Olecranon of ulna
• Action - Extends forearm at
elbow joint , Extends arm at
shoulder joint
• Nerve supply - Radial nerve
Posterior View
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Glenohumeral Joint Muscles
Primary GH Joint Internal Rotators
• Anterior fiber of deltoid
• Pectoralis major
• Latissimus dorsi
• Teres major
• Subscapularis
Primary GH Joint External Rotators
• Posterior deltoid
• infraspinatus
• Teres minor
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46.
Infraspinatus Muscle
• Origin – Infraspinous fossa
of scapula
• Insertion – Greater tubercle
of humerus (posterior
aspect)
• Action – Laterally rotation
and adduction arm at
shoulder joint
• Nerve supply -
Suprascapular nerve
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47.
Teres Minor
• Origin – Inferior lateral
border of scapula
• Insertion – Greater tubercle
of humerus (inferior aspect)
• Action – Laterally rotation,
extends and adduction arm
at shoulder joint
• Nerve supply – axillary
nerve
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48.
Subscapularis Muscle
• Origin – subscapular
fossa of scapula
• Insertion – lesser tubercle
of humerus
• Action – Medial rotation
arm at shoulder joint
• Nerve supply – upper and
lower subscapular nerve
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