Transcript Function - PHYSIOVISION

Welcome
Everybody
To
My
Presentation
On
Shoulder joint
Introduction
It is a ball and socket type of synovial joint
It is a multiaxial spheroidal jt
Roughly hemispheric head of the humerus form
the ball and shallow glenoid fossa of scapula
form the socket.
Skeletally jt is weak. It depends for stability and
support on it’s surrounding muscle rather than
it’s shape and ligaments.
Only one third of humeral head is in contact with
the glenoid fossa at any time.
Angle of inclination: in the frontal plane, the axis of
the head and neck of humerus form an angle of 130°-140°
with the long axis of shaft of femur.Because of this
angulation, the centre of the humeral head lies about 1cm
medial to the long axis.
Angle of retroversion: an angle to the shaft of the
humerus, the axis of the head and neck is rotated
backwords against the shaft some 30°-40°, this is caled the
angle of retroversion.
Articular surface
Two articular surface:
 Glenoid fossa:
 glenoid fossa is situated at the supero-lateral angle of the
scapula
 faces laterally, anteriorly and slightly superiorly.
 Concavity of glenoid fossa is irregular and less deep
than convexity of head of the humerus.
 The articular surface the fossa is little more than the
head of the humerus
 It ls covered by hyaline cartilage
 Hyaline cartilage is thinner centrally and thickest
peripharally
Head of the humerus:
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It represents two-fifths of a sphere
It faces superiorly, medially and anteriorly
Covered by hyaline cartilage
On the humerus hyaline cartilage is thickest
centrally and thinner peripherally
Joint capsule
It is like a cylindrical sleeve and situated between
two bones
Majority fibres of the capsule passes
horizontally between scapula and humerus. But
some oblique and transversre fibres are also
found
On the scapula, the capsule attaches just outside
the glenoid labrum anteriorly and inferiorly
On the humerus, capsile attaches to the
anatomical neck,medial to the greater and lesser
tubercle
Continuation
Anterior part of the capsule is thickened and
strengthened by three glenohumeral ligaments.
Superoposterior part is strengthened by
coracohumeral ligament
In anatomical position of the arm the lower part
of the capsule is lax and forms a redundant fold.
In abduction of arm lower part become s taut
Continuation
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It is supported by the:
supraspinatus (above)
Infraspinatus and teres major (behind)
Subscapularis (in front)
Long head of triceps (below)
Capsule has two or three openings:
 Below the coracoid process
 Between two tubercles
 Inbursa undea the infraspinatous tendon
Synovial membrane
This lines the capsule and covers parts of the
anatomical neck
The synovial membrane is reflected from the
margin of the glenoid cavity over the labrum
The tendon of the long head of the Biceps
brachii passes through the capsule and is
enclosed in a tubular sheath of synovial
membrane
Glenonoid labrum
 It is lintra-articular structure
 It is a fibro-cartiliginous rim round the glenoid
fossa
 It is triangular in section
 4mm deep
 It’s base attaches to the margin of the glenoid
fossa.
 Outer surface attaches to the joint capsule
superiorly and posteriorly
 Inner surface is in the contact of head of humerus
 It protects the joint and assists lubrication
Capsular Ligaments
Glenohumeral ligament:
 Superior glenohumeral ligament:
 It is splender shaped
 It arises from upper part of the glenoid labrum
 It runs laterally parallel to the biceps tendon to
the upper tendon to the upper surface of the
lesser tubercle
 Middle glenohumeral ligament:
 Arises from below the superior glenohumeral
ligament
 Attaches to the humerus on the front of the lesser
tubercle below the insertion of subscapularis
Inferior glenohumeral ligamrent:
 It is best developed of the three ligaments
 It arises from the anterior border of the glenoid
labrum
 It descends slightly obliquely to the
anteroinferior part of the anatomical neck
 The antero-superior edge of the inferior ligament
is thickened and known as superior band
 The thickening of the anterior part of the capsule
to which inferior ligament attaches is known as
axillary pouch
Function of glenohumeral ligament:
 They have no stabilizing function
 Lateral rotation of the humerus put all three
ligaments under tension
 Medial rotation relaxes them
 In abduction only the middle and inferior
ligament become taut and superior ligament
become relaxed
Transverse humeral ligament:
 It is formed by some of the transeverse fibres of
the capsule
 At the upper end of the intertubercular groove,
the transverse humeral ligamentbridges the gap
between the greater and lesser tubercles.
 It hold the biceps tendon in the intertubercular
groove.
Intra- articular ligament
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These ligaments are considered as accessory
ligament
Coracohumeral ligament:
It is strong and broad
It arises from the lateral border of the coracoid
process near its root.
It passes laterally above the intertubercular
groove to attach to the anatomical neck to the
greater and lesser tubercle
Anterior part of the ligament is free. But laterally
it fuses with the tondon of subscapularis
It inserted in lesser tubercle
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Coracoacromial ligament:
It is not directly associated with the joint
It is a strong and triangular ligament
It forms with the coracoid and acromion
process, a fibro- osseous arch above the
head of the humerus
Its anterior and posterior part is thicker
than intermediate part.
Bursae
between the subscapular tendon and articular
capsule
Sometimes between the infraspinatous tendon
and capsule
Subacromial bursa: between deltoid and capsule.
On the superior acromial aspect
Between coracoid process and capsule
Sometimes behind coracobrachialis
Between teres major and the long head of biceps
Muscle
Deltoid (anterior fibre):
 Origin: Arises from the anterior border
and upper surface of the lateral third of
the clavicle
 Insertion:
 Function:
Deltoid (middle fibres):
 Origin: Arises from the lateral margin and
upper surface of the acromion.
 Insertion:
 Function:
Deltoid (posterior fibre):
 Origin: Arises from the lower lip of the
posterior border of the spine of scapula, as
far back as the triangular surface at its
medial end.
 Insertion:
 Function:
Pectoralis major:
 Origin:
 Insertion;
 Function:
Coracobrachialis:
 Origin:
 Insertion:
 Function:
Biceps:
 Origin:
 Insertion:
 Function:
Teres major:
 origin:
 Insertion
 Function;
Latissimus dorsi:
 Origin:
 Insertion:
 Function:
Supraspinatous:
 Origin: Medial two-thirds of the
supraspinatus fossa of scapula
 Insertion: Superiorly of the greater tubercle
of the humerus
 Function:
Serratus anterior:
 Origin: Originates on the surface of the
upper eight ribs at the side of the chest and
inserts along the entire anterior length of
themedial border of the scapula
 Insertion:
 Function:
Trapezius:
 Origin: Arises from theoccipital bone, the
ligamentum nuchae, the spinous process of the
seventh cervical, and the spinous processes of all
the thoracic vertebrae
 Insertion: It inserts on the lateral clavicle, the
acromion process, and into the spine of the
scapula.
 Function:
Infraspinatous:
 Origin: infraspinatus fossa just below the
spine of the scapula
 Insertion: Posteriorly on the greater tubercle
of the humerus
 Function:
Teres minor:
 Origin: Posteriorly on the upper and middle
aspect of the lateral border of the scapula
 Insertion: Posteriorly on the greater tubercle
of the humerus
 Function:
Blood and nerve supply
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Artial supply: it is from numerous sources
around the joint
Suprascapular branch of subclavian artery
Acromial branch of thoracoacromial artery
Anterior and posterior circumflex humeral
arteries
Three are all branches of axillary artery
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Venous drainage is by similarly named veins which drains
into the external jugular and axillary veins
Lymphetic drainage of the joint is to the lymph nodes
within the axilla and passes into subclavian lymph trunk
Nerve supply:
Suprascapular
Axillary]
Subscapular
Lateral pectoral
Musculocutaneous
Root value of C5,6 and7
Stability
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Factors responsible for stability:
The glenoid labrum- it deepening the glenoid fossa. And
make the joint surface congurent
Rotator cuffMost important factor
Very close it the joint and fuse with lateral part of capsule.
They act as ligaments
Inferior part of capsule is weak and unsupported. But as
the arm gradually abducted the long head of triceps and
teres major support this
 Muscle of pectoral girdle and humerus:
Long head of biceps: gives support over the
superior part of joint
Long head of triceps: gives support below
the joint
 Coracoacromial arch: it prevent upward
displacement of the head of the humerus
Movement
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Flexion :
Flexion and extension occur about an axis
prependicular to the plane of the glenoid fossa
In flexion the arm moves forward and medially at
an angle of 45° to the sagital plane.
Range is 110°-180°
It is produced by the anterior fibres of deltoid,
pectoralis major, coracobrachialis and biceps
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Extension:
In extension arm moves backwords and laterally
Range is 70°-90°
Extension is limited by greater tubercle of the
humerus coming into contact with the
coracoacromial arch
Extension is produced by the posterior fibres of
deltiod, teres major and latissimus dorsi
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Abduction:
In abduction the arm moves anterolaterally away from the
trunk
Total range is 120°
Only first 30° movement occurs without scapular rotation
The terminal part of the shoulder joint abduction is
accompanied by lateral rotation of the humerusIt is due to
provide further articular surface on the head of the
humerus for the glenoid fossa
Abduction of the medially rotated humerus is limited by
tension in the posterior capsule and lateral rotators
 First 20° abduction is initiated by
supraspinatus muscle and deltoid continues
the movement
 If deltoid is paralysed, supraspinatus is not
strong enough to fully abduct the shoulder.
 If supraspinatous is not functioning, deltoid
can not initiate abduction
Adduction:
 In adduction the arm moves anteromedially
 Adduction is produced by ecentric
contraction of serratus snterior, trapezius,
deltoid and supraspinatous
Rotation
Rotation is limited by the extent of articular
surface
The range of rotation varies with the
position of arm. It is greatest when the arm
is by the side. Decreasing to 90° with the
arm horizontal. And being negligible as the
arm approaches vertical
Medial rotation:
 Medial rotation causes the anterior surface
of the humerus to be turned medially
 The maximum range is 90°
 Medial rotation is produced by
subscapularis, pectoralis major, latissimus
dorsi, teres major and anterior fibre of
deltoid
Lateral rotation:
 In lateral rotation the anterior surface of the
humerus is turned laterally
 The range is 80°
 It is produced by infraspinatous, teres minor
and posterior fibre of deltoid