Download Shoulder Joint2 - By Dr Nand Lal Dhomeja ( Anatomy

THE SHOULDER JOINT
LEARNING OBJECTIVES
At the end of the presentation, the student should be able to :
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Classify the type of shoulder joint.
Describe the structure of shoulder joint.
Name the muscles acting on the joint/rotator cuff muscles.
Explain the range of mobility.
know the movements of shoulder joint.
Explain clinical aspect of the joint
CLASSIFICATION ACCORDING TO THE DEGREE OF MOBILITY
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MULTIAXIAL
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CLASSIFICATION ACCORDING TO SHAPE:
BALL AND SOCKET
THE HUMAN SHOULDER
 Highly mobile joint.
 Large range of motion in all planes.
 Relies very little on bony & ligamentous structures for stability –
 Major support coming from muscles acting on the shoulder complex specially the rotators cuff.
THE SHOULDER JOINT
 Articular Surfaces:
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Spheroidal humeral head,
Concave glenoid cavity.
 Glenoid labrum deepens the cavity..
 Both articular surfaces covered with hyaline cartilage
THE SHOULDER JOINT
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Wide range of movements require significant amount of laxity.
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Price of mobility is reduced stability.
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If a joint is more mobile then it is less stable.
FACTORS STABILIZING THE JOINT
 Coracoacromial arch or
Secondary socket for the head
of humerus.
 Glenoid labrum.
 Musculotendinous cuff of the shoulder.
LIGAMENTS
 CAPSULAR LIGAMENT.
 CORACOHUMERAL LIGAMENT.
 GLENOHUMERAL LIGAMENT.
 TRANSVERSE HUMERAL LIGAMENT.
 GLENOID LABRUM.
ARTICULAR CAPSULE OF THE GLENOHUMERAL JOINT
 Loose fibrous capsule surrounds the joint.
 Attached medially to margin of the glenoid cavity.
 Attached laterally to the anatomical neck of the humerus.
 Superiorly,encroaches on the root of the coracoid process so that the fibrous capsule encloses the supraglenoid tubercle & hence attachment of the long head
of the biceps muscle within the joint.
ARTICULAR CAPSULE OF THE GLENOHUMERAL JOINT
 The inferior part of the capsule is the weakest area.
 The synovial membrane lines the fibrous capsule
 Synovial membrane forms a tubular sheath for the tendon of the long head of the biceps brachii muscle
LIGAMENTS OF THE GLENOHUMERAL JOINT
CORACOHUMERAL LIGAMENT
 Is a strong, broad band.
 Passes
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from the base of the coracoid process
to the anterior aspect of the greater tubercle of the humerus.
 This ligament resists the pull of gravity.
 Limits external rotation of the shoulder.
LIGAMENTS OF THE GLENOHUMERAL JOINT
GLENOHUMERAL (SHOULDER) LIGAMENTS
 Strengthen the anterior aspect of the articular capsule of the joint.
 CORACOHUMERAL LIGAMENT, which strengthens the capsule superiorly
LIGAMENTS OF THE GLENOHUMERAL JOINT
GLENOHUMERAL LIGAMENTS
 Three fibrous bands
 Evident only on the internal aspect of the capsule
 Reinforce the anterior part of the articular capsule.
 They radiate laterally and inferiorly from the glenoid labrum at the supraglenoid tubercle of the scapula
 Blend distally with the fibrous capsule as it attaches to the anatomical neck of the humerus.
LIGAMENTS OF THE GLENOHUMERAL JOINT
SUPERIOR GLENOHUMERAL LIGAMENT
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From Upper origin of the glenoid
To Anatomical neck of the humerus
This ligament is taut during external rotation and plays a small role in the stability of the shoulder.
LIGAMENTS OF THE GLENOHUMERAL JOINT
MIDDLE GLENOHUMERAL LIGAMENT
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From Upper origin of the glenoid
To Humerus
This ligament is taut during external rotation and plays a small role in stability of the shoulder.
LIGAMENTS OF THE GLENOHUMERAL JOINT
INFERIOR GLENOHUMERAL LIGAMENT
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Anterior edge of glenoid
Below the head of the humerus
This ligament is taut during external rotation, and plays a small role in stability of the shoulder.
LIGAMENTS OF THE SHOULDER JOINT
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The transverse ligament is not a “true” ligament of the joint.
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It is a broad fibrous band that runs more or less obliquely from the greater to the lesser tubercle of the humerus, bridging over the
intertubercular groove.
This ligament keeps the biceps tendon in its groove during movements.
GLENOID LABRUM
 Fibrocartilagenous rim which deepens the glenoid cavity.
 Slightly enhances stability.
SHOULDER JOINT
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Frequently injured due to anatomical design
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shallowness of glenoid fossa.
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laxity of ligamentous structures.
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anterior or anteroinferior glenohumeral subluxations & dislocations – common.
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posterior dislocations – rare.
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posterior instability problems somewhat common.
BURSAE
 Subacromial bursa(subdeltoid bursa)
 Subcapsular bursa, communicates with the joint cavity.
 Others related to corachobrachialis, long head of triceps
ROTATOR CUFF MUSCLES:
 Take origin from scapula and inserted to greater and lesser tubercles of humerus.
 Their tendons become flattened and blend with each other and the capsule while crossing the joint.
SUPRASPINATUS
O: Supraspinous fossa.
I: Superior facet on greater tubercle of humerus.
A: Initiates and assists Deltoid in abduction; acts with other rotator cuff muscles.
N: Suprascapular Nerve.
INFRASPINATUS
Origin: Infraspinous fossa.
Insertion : Middle facet on greater tubercle of humerus.
Actions: Laterally rotates the arm.
Nerve Supply: Suprascapular Nerve.
TERES MINOR:
Origin: Superior part of the lateral border of the scapula
Insertion: Inferior facet on greater tubercle of humerus
Actions: Laterally rotates the arm
Nerve supply: Axillary Nerve
SUBSCAPULARIS:
Origin: Subscapular fossa.
Insertion: Lesser tubercle of humerus.
Actions: Medial rotation of arm and adduction.
Nerve supply: Upper and Lower Subscapular.
MOVEMENTS:
MUSCLES
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ANTERIOR:
– Pectoralis major
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– Corachobrachialis.
– Subscapularis.
SUPERIOR:
– Deltoid.
– Supraspinatus.
DELTOID MUSCLE:
ANTERIOR FIBERS: Abduction, flexion, horizontal adduction, & internal rotation
POSTERIOR FIBERS: Abduction, extension, horizontal abduction, & external rotation
MIDDLE FIBERS: Abduction
PECTORALIS MAJOR MUSCLE:
UPPER FIBERS (CLAVICULAR HEAD):
Internal rotation, horizontal adduction, flexion, abduction (once arm is abducted 90 degrees, upper fibers assist in further abduction), & adduction (with arm below 90 degrees of
abduction)
LOWER FIBERS (STERNAL HEAD):
Internal rotation, horizontal adduction, extension, & adduction
LATISSIMUS DORSI MUSCLE:
ADDUCTION
EXTENSION
INTERNAL ROTATION
HORIZONTAL ABDUCTION
CORACOBRACHIALIS MUSCLE:
FLEXION
ADDUCTION
HORIZONTAL ADDUCTION
ROTATOR CUFF TENDONITIS
 Rotator cuff tendonitis, also knows as "BURSITIS" OR "IMPINGEMENT SYNDROME" OCCURS WHEN THE ROTATOR CUFF
GETS irritated on the undersurface of the acromion. Chief complaints are pain, popping, weakness and the inability to sleep on the
affected limb.
THANK YOU