What is the Shoulder girdle?

What is the importance of Shoulder Girdle

Increase the ROM for Upper limb (up to 180°)

Provide More space to reach for upper limb

Provide an stable base for upper limb function

Four interdependent linkages for Shoulder ComplexFunctional Articulation: Scapulothorasic Joint (STJ)Anatomical Articulation: Sternoclavicular Joint (SCJ)Anatomical Articulation: Acromioclavicular Joint (ACJAnatomical Articulation: Glenohumeral Joint (GHJ)

What are the Joints of the Shoulder girdle?

Sternoclavicular Joint

What is the role of Sternoclavicular Joint

within shoulder girdle?Functional base for scapulaMovement in Clavicle and SCJ Movement in Scapula Thoracic

Movement in SCJ is due to the change in contact area

between

Clavicle

Sternocalvicular Disc

Manuberium

Sternoclavicular Joint Consists of two saddle-shaped surfaces butA plane Synovial Joint3 degree of freedomJoint Capsule3 Major LigamentsA Joint Disc4 joint’s area contact

Can You Describe the Sternoclavicular Joint?

Can you describe the function of Sternoclavicular Disc Joint?

A fibrocartilage joint disk, or meniscus, that increases congruence between joint surfaces

Acts like a hinge or pivot point during clavicle motion.

Act like axis in the SCJ In Elevation/Depression

Clavicle move against Manuberium and Disc Upper part of Disc act like axis)

In Protraction/Retraction Disc and Clavicle Move against Manuberium Lower part of Disc act like axis

the mechanical axis for these two movements located not at the SC joint itself but at the more laterally located costoclavicular ligament

How the disc Joint does provide stability for SCJ?

Disc has an Important Role in Joint Stability By Creation congruent between Joint

surface By absorption coming stresses to the

lateral end of clavicle

Three-Compartment SC Joint

Anatomic examination of the SC articulation has led to the proposal that there are three functional units 1. a lateral compartment between the

disk and clavicle for elevation and depression;

2. a medial compartment between the disk and manubrium for protraction and retraction;

3. a costoclavicular joint for anterior and posterior long axis rotation.

Sternoclavicular Joint Capsule and Ligaments

The SC joint is surrounded by a fairly strong fibrous capsule but must depend on three ligaments for the majority of its support. These are the sternoclavicular ligaments,

Can you name the Sternoclavicular

Ligaments? Sternoclavicular Lig (Ant & Post) Costoclavicular Lig (Ant & Post) Inter Clavicular Lig

Sternoclavicular (Ant & Post) Lig Strengthening of Ant and Post part of Joint Prevent of Ant and Post Movements of Clavicle

Costoclavicular (Ant & Post parts) Lig Very strong Lig Both parts resist against the 1) superior force from

SCM and 2) against elevation of the lateral end of clavicle

At the limit reach, they are responsible for inferior gliding of clavicle

Post part prevent of inward movement of clavicle (absorb of forces acts on the Disc from arm)

Inter Clavicular Lig Control 1) Depression of clavicle, 2) superior gliding

of clavicle and protect subclavian artery and Brachial plexus and

Weight bearing of upper arm by help of upper capsule

What is the function of Sternoclavicular Ligaments?

Clavicle ManuberiumSCJ Disc LigamentsCapsule

Three Major functions for SCJ1)Resist against Applied stress from Upper arm2)Provide Mobility for Upper arm3)Provide a Strength Base for Upper arm

Integrity of These elements

PROVIDS

What are the Sternoclavicular

Movements?

Elevation/Depression Protraction/Retraction Anterior/Posterior Rotation

Motions of any joint are typically described by identifying the direction of movement of the portion

of the lever that is farthest from the joint.

Can you describe Elevation/Depression

movements? Occur around the Ant-Post Axis which located in Costoclavicula Lig

In the plan that convex surface of clavicle glide against concave surface of manubrium and Disk

Opposite Movement of medial part of clavicle

Up to 48 degree Elevation and 15 degree Depression

Elevation of clavicle accompanied by elevation of scapula and its upward rotation

Small magnitudes of medial-lateral translation and superior/inferior translation in the medial aspect of clavicle

Elevation and Depression

Can you describe the Protraction/Retraction

movements? Occur vertical axis locate in

costoclavicula Lig In the plan that concave surface of

clavicle glide against convex surface of manubrium

In protraction, lateral end rotate anteriorly, and medial end slide anteriorly

15- 20 degree Protraction and 20-30 degree Retraction

Pro/Ret of clavicle is accompanied by Pro/Ret of scapula

Protraction and Retraction

Can you describe the Anterior/Posterior

Rotation? Occur around the longitudinal axis

of clavicle intersecting AC and SC Joint

An Spin movement saddle surface of medial part of clavicle and manuberium/first costal cartilage

Movement start from neutral position only toward posterior rotation

35-55 ° Post Rot and 10 ° available Ant Rot It serve the last 30 degree of upward

rotation of scapula.

Posterior And Anterior Rotation

■ Sternoclavicular Stress Tolerance

The Complex of bony segments, Capsuloligamentous structure, and the SC disk produce a joint with dual functions of mobility and stability.

The SC joint contribute to upper limb mobility, and withstanding imposed stresses.

Although the SC joint is considered incongruent, the joint does not undergo the degree of degenerative change common to the other joints of the shoulder complex.

Dislocations of the SC joint represent only 1% of joint dislocations in the body.

Acromioclavicular Joint

Acromioclavicular Joints Characteristics

Plan Synovial Joint 3 rotational and 3 transitional degrees

of Freedom Weak capsular joint Joint Disc Two Major Ligaments

Superior & Inferior Acromioclavicular ligaments

Integration of joint surface Provide horizontal stability

Coracoclavicular Lig. Its primary function included:

Primary function of ACJ

Primary function1. Allow the scapula additional range of

rotation on the thorax2. Allow for adjustments of the scapula

(tipping and internal/external rotation) in order to follow the changing shape of the thorax as arm movement occurs.

3. Allows transmission of forces from the upper extremity to the clavicle.

Articular Surface and Joint Disc of ACJ

The articular facets, considered to be incongruent, vary in configuration

Intra-articular movements for this joint are not predictable.

A Joint disk with variable in size between individuals exist in AC joint

It plays as a “meniscoid” fibrocartilage remnant within the joint to develop each articulating surface during upper extremitymovement

The Acromioclavicular Joint

Acromioclavicular Capsule and Ligaments

Capsule is weak and cannot maintain integrity of the joint without reinforcement by ligaments

The superior acromioclavicular Lig are reinforced by aponeurotic fibers of the trapezius and deltoid muscles and assists capsule by Apposing articular surfaces Controlling A-P joint stability. The fibers of

the superior AC ligament are the superior joint support stronger

than the inferior

Acromioclavicular Capsule and Ligaments Coracoclavicular Ligaments which

divided into: Lateral portion, the trapezoid ligament,

provides the primary restraint for the AC joint in the superior and inferior directions

Medial portion, the conoid ligament. Provides the majority of resistance to posterior

translatory forces applied to the distal clavicle. They are separated by adipose tissue and a

large bursa Both portions of the coracoclavicular

ligament limit upward rotation of the scapula at the AC joint

Transfer Medially directed forces on humerus to the SCJ

Transfer the rotational force of scapula to the clavicle and then cause Posterior Rotation at SCJ

When a person bears weight on the arm, a medially directed force up the humerus (1) is transferred to the scapula (2) through the glenoid fossa and then to the clavicle (3) through the coracoclavicular ligament

Acromioclavicular Motions

The primary rotatory motions of AC joint are Internal/external rotation, Anterior/ posterior tipping or tilting, Upward/downward rotation

These motions occur around axes that are oriented to the plane of the scapula rather than to the cardinal planes.

Small translatory motions of AC joint included: Anterior/Posterior, Medial/Lateral, Superior/Inferior.

Plane of AC joint Movements

What movement does occur in the

Acromioclavicular joint?1- Internal and External Rotation

Occurs around an approximately vertical axis through the AC joint

To Maintain contact of the scapula to horizontal curvature of the thorax during Protraction and Retraction

To orient the glenoid fossa toward the plan of humeral elevation

30 degree the total ROM An Anterior/Posterior translatory

movement

Internal and External Rotation

Internal and External Rotation at AC joint

Glenoid Fossa is the reference for naming the movement

Because of the thorax curvature, Internal/External Rotation is a necessary movement for protraction and Retraction

Anterior and Posterior Tipping Occurs around an oblique “coronal” axis

of joint Ant. tipping will result in the acromion

tipping forward and the inferior angle tipping backward during downward rotation and also Elevation of scapula

Posterior tipping will rotate the acromion backward and the inferior angle forward. during upward rotation and also Depression of scapula

To Maintain contact of the scapula with the contour of the rib cage and orient the glenoid fossa during arm flexion and abduction

30-40 degree the total ROM A Superior/posterior translatory

movement

Anterior and Posterior Tipping

The superior aspect of scapula is the reference of naming the movement

The acromion has slightly translatory anteriorly/posteriorly movement

Upward and Down Ward Rotation at AC Joint

Around an A-P axis (perpendicular to scapula)

Direction of Glenoid Fossa is the reference for the naming the movement

Acromion has a small medial/lateral Translatory movement

3-Scapula Upward and Downward Rotation

Help to orient the glenoid fossa upward or downward

Coraco-Clavicular Ligament limit this movement

Posterior rotation of clavicle lax the lig

So upward rotation can be done in the AC Joint

30 degree Upward Rot 17 degree Downward Rot

Acromioclavicular Stress Tolerance

AC joint is extremely susceptible to both trauma and degenerative change due to the its small and incongruent surfaces

Degenerative change is common from the second decade with narrowed joint space by the sixth decade.

Treatment of sprains, subluxations, and dislocations of this joint occupies a large amount of the literature on the shoulder complex

Acromioclavicular Stress Tolerance

Various classification of injury commonly Type I injuries consist of a sprain to the

AC ligaments, Type II injuries typically have ruptured

AC ligaments and sprained coracoclavicular ligaments

Type III injuries result in rupture of both sets of ligaments,

Types I, II, and III AC separations all involve inferior displacement of the acromion in relation to the clavicle caused by the loss of support from the coracoclavicular ligaments

Acromioclavicular Stress Tolerance

Various classification of injury commonly Type IV injuries have a posteriorly displaced

lateral clavicle, often pressing into the trapezius posteriorly, with complete rupture of both the AC and coracoclavicular ligaments

Type V injuries also involve an inferior displacement of the acromion and complete rupture of both sets of ligaments and are distinguished from type III by a severity of between three and five times greater coracoclavicular space than normal.

Type VI injuries have an inferiorly displaced clavicle in relation to the acromion, with complete ligament rupture and displacement of the distal clavicle into a subacromial or subcoracoid position.

Scapulothorasic Joint

Rotation at AC Joint

SCJ Elev/Dep and ACJ Rotation are necessary movements for Scapula Elevation and Depression

ACJ Rotation and SCJ Elev and Post Rotation are the necessary movements for Scapular

upward Rot

Position of Scapula on the Thorax2 inches from the midlineBetween 2nd and 7th ribs30-45 degree internally rotated from the coronal plane10-20 degree anteriorly tipping from vertical10-20 degree upward rotation, it is different among the individuals

Resting Position of scapula

What is the Movement of Scapula?

Upward Rotation/Downward Rotation

Elevation/Depression Protraction/Retraction

Scapula Upward and downward Rotation

Upward rotation of the scapula plays a significant role in increasing the range of elevation of the arm

Approximately 60º of upward rotation is available.

Considering the closed-chain relationship between the SC, AC, and ST joints, they contribute to scapula upward/downward rotation by: SC joint elevation/depression, SC joint posterior/anterior rotation AC joint upward/downward rotation

Most often, scapular upward/downward rotation results from a combination of the SC and AC motions.

Scapula Upward and downward Rotation

Scapular elevation and depression can be isolated by shrugging the shoulder up and depressing the shoulder downward.

It is described as translatory motions Scapular elevation, occurs by elevation

of the clavicle at the SC joint and requires Scapula adjustments in anterior/posterior tipping internal/external rotation at the AC joint to maintain the scapula in contact with the

thorax

Scapula Elevation/Depression

Scapula Elevation/Depression

Scapula Protraction and retraction are described as translatory motions of the scapula away from or toward the vertebral column, respectively.

However, if protraction occurred as a pure translatory movement, only the vertebral border of the scapula would remain in contact with the rib cage.

In reality during protraction, scapula follows the contour of the ribs by rotating internally and externally at the AC

joint and clavicular protraction and retraction at the

SC joint So, glenoid fossa facing anteriorly with

the full contact of scapula with the rib cage

Scapula Protraction/Retraction

Scapula Protraction/Retraction

Scapular internal and external rotation are normally not overtly identifiable on physical

observation but are critical to its movement along the

curved rib cage. The Movement normally accompany

protraction/ retraction of the clavicle at the SC joint

Isolated Scapula Int rotation at the AC joint, cause Prominence of the vertebral border of

scapula Loss of contact of scapula with the thorax. Which is referred to clinically as scapular

“winging” Excessive Int rotation may be indicative

of pathology or poor neuromuscular control of the ST muscles.

Scapula Internal/External rotation

Pathologic Scapula Internal Rotation

Anterior/Posterior tipping is normally not obvious on clinical observation

and yet is critical to maintaining contact of the

scapula against the curvature of the rib cage Movement occurs at the AC joint

normally will accompany anterior/posterior rotation of the clavicle at the SC joint

Isolated excessively Ant/Post Tipping at the AC joint will result in prominence of the inferior angle of the

scapula Ant. tipped scapula may occur in

pathologic situations (poor neuromuscular control) or in abnormal posture.

Scapula Anterior/Posterior Tipping

Pathologic Scapula Anterior Tipping

Final function of this Joint1. Adjustment of gelenoid direction 2. To Increased ROM for upper arm 3. To Provide an Strong Base to control

Rolling and gliding Movements for Humorous Surface

What are the Scapulathorasic

Functions?

Scapulothorasic Stability Scapula Stability on the thorax is

provided by 1. The structures that maintain integrity of

the linked AC and SC joints such as ligaments, capsule and joint disc.

2. The muscles that attach to both the thorax and scapula maintain contact between these surfaces

3. These muscles also provide stabilization by pulling or compressing the scapula to the thorax.

The scapula, with its associated muscles and linkages, performs mobility and stability functions so well that it serves as a premier example of dynamic stabilization in the human body