Scapulocostal, Sternoclavicular, Aromioclavicular and Shoulder Joints Flashcards
which joint can be described as a physiological joint (no true articulation)
Scapulothoracic Joint
Scapula with Thoracic cage
movement of the scapulothoracic joint is permitted by
Any movement at the scapulothoracic joint will result in movement at both of these joints
- by the muscles around it
what is the Scapulothoracic Joint role? (4)
Provides a movable base for the Humerus, hence increasing arm ROM at the shoulder joint
Helps deltoid function with proper tension with the arm above 90°
Provides Glenohumeral stability for overhead work
Absorbs shocks to outstretched arms
what type of movement does the Scapulothoracic Joint permit? (6)
- Protraction – abduction away from the midline (spine)
- Retraction – adduction towards the midline (spine)
- Elevation (upward sliding on ribcage) towards ears
- Depression (downward sliding on ribcage) away from ears
- Rotation of scapula (reference is a glenoid cavity and inferior angle)
5a. Upward rotation – glenoid rotates superiorly, inferior angle rotates away from the midline
5b. Downward rotation – glenoid rotates inferiorly, inferior angle rotates towards the midline
what type of joint is the Sternoclavicular Joint
traditional synovial joint - modified saddle joint
The Articular Surfaces of the Sternoclavicular Joint include:
Facet on the medial end of the clavicle (aka acromial facet)
Facet on the manubrium of sternum
the articular disc of the sternoclavicular joint adds? Where is it located?
Protection and stability
Sits between the medial end of the clavicle and the sternum
- Additional fibro cartilaginous feature
- Only synovial connection of the upper limb to the axial skeleton, every other connection is with muscle
what are the three ligaments of the sternoclavicular joint
- Sternoclavicular ligament with capsule - reinforces joint capsule (front and back)
- Interclavicular ligament - reinforces the joint superiorly
- Costoclavicular ligament - anchors the medal end of the clavicle to the first rib
SC joint movements: elevation of the clavicle ROM
60
SC joint movements: depression of the clavicle ROM
5-10
SC joint movements: protraction and retraction ROM
25-30
SC joint movements: rotation of clavicle ROM
30
is there more ROM with elevation or depression of the clavicle? Why?
more with elevation, needed for inspiration
- when we exhale and it depresses - this is passive
With scapular protraction, the clavicle
retracts
With scapular retraction, the clavicle
protracts
The clavicle rotates __________ when you abduct
posteriorly
The clavicle rotates __________ when you adduct
anteriorly
Acromioclavicular joint (A/C Joint) Articular Surfaces
Facet on the lateral end of the clavicle (aka acromial facet)
Facet on the medial end of the acromion
type of Acromioclavicular joint (A/C Joint) and movement
plane synovial joint
movement: slide and glide
the AC joint only moves in response to what the ________ is doing
scapula
what are the three ligaments of the acromioclavicular joint?
- Acromioclavicular Ligament
- Trapezoid Ligament
- Conoid Ligament
A strong fibrous band that reinforces the superior aspect of the acromioclavicular joint
Acromioclavicular Ligament:
Extends from the coracoid process of the scapula to the trapezoid line on the inferior lateral end of the clavicle
Trapezoid Ligament:
Extends from the base of the coracoid process of the scapula to the conoid tubercle on the inferior aspect of the lateral clavicle
Conoid Ligament:
The trapezoid and the conoid ligaments make up the _______________, which anchors the lateral end of the clavicle and prevents superior dislocation of the AC joint
Coracoclavicular Ligament
movements of Acromioclavicular joint
Protraction - retraction
Elevation - depression
Axial rotation
where does “shoulder separation” happen?
Acromioclavicular joint
Glenohumeral (Shoulder) Joint Articular Surfaces
The glenoid fossa of the scapula and the head of the humerus
The articular surfaces of the Glenohumeral (Shoulder) Joint are covered by ______ cartilage (permits frictionless motion)
hyaline
what type of joint is the Glenohumeral (Shoulder) Joint? How many degrees of freedom does it allow?
ball and sock synovial joint
- multi-axial - 3 degrees of freedom
Movements of the Shoulder (Glenohumeral Joint)
flexion/extension, add/abd, internal/external rotation and circumduction
The shoulder, the proximal joint of the upper limb, is the most mobile of all the joints in the ________. It has 3 DOF and this allows it to move the upper limb with respect to the three planes in space.
human body
lateral axis, controls the movement of flexion and extension
median (midsagittal) plane
controls the movements of abduction and adduction.
antero-posterior axis
the______ axis controls the rotational movements
vertical axis
The head of the humerus is much larger than the glenoid cavity, only approximately ___ of the head of the _________ fits into the ___________
1/3 of the head
humerus fits into the glenoid fossa
is a ring of fibrocartilage attached to the margins of the glenoid cavity. It widens the cavity slightly but deepens it appreciably so as to make the articular surfaces congruent.
Glenoid Labrum
- Attached to bony glenoid to increase SA
Attaches to the margins of the glenoid cavity medially and to the anatomical neck of the humerus laterally.
It is covered from the inside by the synovial membrane.
Capsule of the Glenohumeral (Shoulder) Joint
Shoulder joint: The joint capsule is very loose and permits free movement. It is least supported inferiorly where dislocation commonly occurs. Such a dislocation may damage the closely related axillary nerve.
The capsular ligaments of the Glenohumeral (Shoulder) Joint
shoulder joint: Anteriorly the joint capsule is reinforced by 3 supplemental bands, called the ………, ……….., and the ……….. glenohumeral ligaments.
superior, middle and inferior
shoulder joint: posteriorly the joint capsule is reinforced by…
rotator cuff muscles and the physical scapula bone
Bridges the upper part of the bicipital groove of the humerus (between the greater and lesser tubercles), converts the intertubercular groove into a canal, and functions as a ‘retinaculum’ for the tendon of the long head of the biceps brachii, holding the synovial sheath and tendon in place during glenohumeral movements.
Transverse Humeral Ligaments - extrinsic ligament
An extrinsic, protective structure formed by the smooth inferior aspect of the acromion and coracoid processes of the scapula, and the coracoacromial ligament bridging the gap between them. This arch overlies the head of the humerus, preventing its superior displacement from the glenoid cavity.
Coracoaromial arch
what does the Coracoaromial arch restrict?
excess superior humeral movement
From the coracoid process of the scapula to the greater tubercle of the humerus. Intrinsic Ligament.
- helps reinforce the anterior part of the capsule
Coracohumeral Ligament - intrinsic ligament
what are the ligaments of the Glenohumeral (Shoulder) Joint?
Superior glenohumeral, middle glenohumeral, inferior glenohumeral, coracohumeral, transverse humeral and Coracoaromial arch
There are several bursae around the shoulder joint such as the ____________ bursa (Overlies the anterior joint capsule and lies beneath the subscapularis muscle).
subscapular
what is the function of the bursae
These bursae serve to decrease friction between the tendon and/or muscle and joint capsule.
what bursae is found between the acromion and the tendon of the supraspinatus muscle.
The subacromial bursa
what movement does the subacromial bursa facilitate?
It facilitates movements of the supraspinatus tendon under the coracoacromial arch and of the deltoid over the fibrous capsule and greater tubercle of the humerus. It is subject to impingement beneath the acromial arch if it is inflamed and swollen.
Is between the deltoid and the fibrous capsule. It may be continuous with the subacromial bursa.
subdeltoid bursae
what are the three types of bursa surrounding the shoulder joint?
- subscapular
- subacrominal
- subdeltoid
Flexion and extension (1): performed in a _______ plane, about a transverse axis. What is the ROM of motion for each?
sagittal
Extension: 45° to 50°.
Flexion to 180°
the movement of the upper limb away from the midline, takes place in a _______ plane, about an antero-posterior axis.
frontal
When abduction reaches _____ the arm is vertically above the trunk.
180°
when the arm is abducted 180 degrees, ___ occurs by rotation of the scapular and ____ by rotation of the humerus at the shoulder joint
180 = arm
60 = rotation of scapulalar
120= rotation of the humerus
lateral rotation of the shoulder joint ROM
80
0 degrees is just elbow bent and arm pointing straight infront
medial rotation of the shoulder joint ROM
95
- For medial rotation to reach this far, the forearm must be pulled behind the trunk, and this introduces a certain degree of extension.
0 degrees is just elbow bent and arm pointing straight infront
Horizontal adduction: range ____. Muscles involved: Ant. deltoid, subscapularis, pectoralis major, pectoralis minor, serratus anterior, coracobrachialis, and short H. of biceps.
140°
0 degrees is just arm straight out to side
Horizontal abduction : range ____. Muscles involved: Post. deltoid, infraspinatus, teres major, teres minor, rhomboid muscles, trapezius, latissimus dorsi.
30°
0 degrees is just arm straight out to side
