Week 4 Flashcards
Humerus articulates with
The scapula at the shoulder and the radius and ulna at the elbow
Scapular landmarks
- supraspinatus fossa
- infraspinatus fossa
- spine of scapula
- glenoid cavity
- inferior angle
- superior angle
- medial border
- lateral border
- subscapular fossa
- coracoid process
- acromion process
Humeral landmarks
- Head
- greater tubercle
- lesser tubercle
- deltoid tuberosity
Which joint has the greatest ROM?
Glenohumeral joint
Has a significant amount of laxity
How big is the glenoid fossa compared to the humeral head?
Glenoid fossa is 1/4 the size of the humeral head
Glenoid Labrum
Cartilaginous ring that increases the contact area of the glenoid fossa to 70%
Glenohumeral joint problems
The price of mobility is reduced stability
- instability problems are common
- Rotator cuff impingement
- Subluxations and dislocations
Supporting structures of the glenohumeral joint
- Glenohumeral ligament
- Coracohumeral ligament
Glenohumeral ligament
- supports glenohumeral joint anteriorly and inferiorly.
- prevents anterior dislocation
Coracohumeral ligament
supports weight of arm
The only attachment of the shoulder girdle to the thorax is via the…
Clavicle
Which ligaments attach the shoulder girdle to the clavicle?
- Anterior sternoclavicular ligament to manubrium
- Costcoclavicular ligament to first rib.
Clavicle and scapula joints
- Sternoclavicular (SC)
- Acromioclavicular (AC)
- Scapulothoracic (ST) - movement of scapula on rib cage.
Acromioclavicular joint
Superior to GH joint
- Bony restriction - often injured - ligament support - coracoclavicular ligament - acromioclavicular ligament (sup, inf)
Scapulothoracic joint (ST)
Depends on SC & AC joint, lacks ligament support
Sagittal movements of the shoulder girdle
elevation/depression
Frontal movements of the shoulder girdle
upward rotation, downward rotation
Transverse movements of the shoulder girdle
abduction (protraction), adduction (retraction)
Rotator Cuff Muscles
SITS
Supraspinatus
-attach to greater tubercle from above (abduct)
Infraspinatus
-attach to greater tubercle posteriorly (ext. rot.)
Teres Minor
-attach to greater tubercle posteriorly (ext. rot.)
Subscapularis
-attach to lesser tubercle anteriorly (int. rot.)
Supraspinatus
Origin -medial 2/3rds of the supraspinatus fossa
Insertion- Humeral greater tubercle (superior)
Location- superior
Action- abduction
Most often injured (SITS)
-throwing, swimming
Infraspinatus
Origin- Infraspinatus fossa (posterior surface of scapula below the spine)
Insertion- Humeral greater tubercle (posterior)
Location- posterior/deep
Movements- Extension GH joint, external rotation GH joint, horizontal abduction GH joint
provides posterior stability
Most powerful external rotator
Stretch- internal rotation with extreme horizontal abduction
Teres Minor
Origin- posterior scapula, lateral border
Insertion- humeral greater tubercle (posterior)
Location- posterior
Movements- extension GH, external rotation GH, Horisontal abduction
Posterior stability
Subscapularis
Origin- entire anterior surface of subscapular fossa
Insertion- humeral lesser tubercle
location- anterior (scapula)
Movements- adduction GH, Extension GH, internal rotation GH, stabilization of humeral head in glenoid fossa
Works with latissimus dorsi and teres major (less powerful)
Sagittal plane movements of the shoulder
Flexion/extension
Frontal plane movements of the shoulder
abduction, adduction
Transverse plane movements of the shoulder
horizontal abduction/adduction
internal rotation/external rotation
Diagonal plane movements of the shoulder
diagonal abduction/adduction
Shoulder abductors
Pectoralis major (upper fibers)
Deltoid (all)
Supraspinatus
Shoulder flexors
Pectoralis major (upper fibers)
Anterior deltoid
Biceps brachii
shoulder adductors
Pectoralis major (lower fibers)
Latissimus dorsi
Teres major
Shoulder Extensors
Pectoralis major (lower fibers)
Latissimus dorsi
Teres major
Triceps brachii
Teres Major
Not SITS (Teres minor is in SITS)
Origin- Inferior 1/3rd of the lateral border of scapula
Instertion- Medial lip of the intertubercular groove of the humerus
Location- posterior
Movements- Adduction, extension, Internal rotation
Effective only when rhomboid stabilizes the scapula
Latissimus Dorsi’s little helper
Muscles that cause External rotation at the shoulder
Infraspinatus
Teres Minor
Muscles that cause internal rotation at the shoulder
Pectoralis major (both)
Subscapularis
Latissimus dorsi
Teres Major (resistance)
Diagonal and horizontal adductors at the shoulder
Pectoralis major (both)
Coracobrachialis
Anterior deltoid
Diagonal and horizontal abductors at the shoulder
Teres minor
Infraspinatus
Posterior deltoid
Pectoralis Major
Origin- Medial 1/2 of anterior surface of the clavicle (clavicular fibers) and anterior surface of the costal cartilages of first 6 ribs adjoining surface of the sternum
Insertion- Flat tendon 2-3 inches wide to lateral lip of intertubercular groove of the humerus.
Location- anterior
Movements-
- Clavicular fibers- internal rotation, horizontal adduction, flexion up to 60 degrees, Adduction below 90 degrees, abduction above 90 degrees. - Sternal fibers- adduction, internal rotation, horizontal adduction, extension.
Use powerfully - push-ups, pull-ups, throwing, tennis serve, bench press
Stretch- External rotation of the shoulder (upper-clavicular), horizontal abduction (lower, sternal)
Works closely with deltoid (lifting)
Anterior muscles that cause shoulder movement
pectoralis major
coracobrachialis
anterior deltoid
Posterior muscles that cause shoulder movement
Latissimus dorsi
Teres major/minor
Infraspinatus
Subscapularis
Posterior deltoid
Anterior deltoid
Origin- anterior lateral third of clavicle, lateral
Insertion- deltoid tuberosity (lateral humerus)
Location- anterior/superficial
Actions- abduction, horizontal adduction, flexion
Coracobrachialis
Origin- Coracoid process of the scapula
Insertion- middle of the medial border of the humeral shaft.
Location- anterior/medial
Action- adduciton GH joint, flexion GH joint, horizontal adduction
Posterior glenohumeral muscles
Latissimus dorsi
Teres major
posterior deltoid
teres minor
subscapularis
infraspinatus
Latissimus dorsi
Origin- spinous process (T6-L5), posterior crest of the ilium, sacrum
Insertion- anterior intertubercular groove of humerus
Location- posterior
Movements- adduction GH joint, Extension GH joint, internal rotation GH joint, horizontal abduction GH joint
One of the most important extensor muscles
Helps downward rotate scapula
Posterior deltoid
Origin- scapular spine (inferior edge)
Insertion- deltoid tuberosity (lateral humerus)
Location- posterior/superficial
Movements (GH joint)- abduction, horizontal abduction, extension, external rotation
superior glenohumeral muscles
Middle deltoid
Supraspinatus
Middle deltoid
Origin- lateral aspect of the acromion process
Insertion- deltoid tuberosity (lateral humerus)
Location- superior/superficial
Movements- abduction GH joint
Strongest GH muscles
Adductors, extensors
Middle-strength GH muscles
flexors, abductors
weakest GH muscles
internal and external rotators
Sagittal plane flexors
pec(upper), ant. deltoid
sagittal plane extensors
pec(lower), lats, teres maj, triceps (ant and post)
frontal plane abductors
Pec (upper), deltoid, supraspin (and and post and sup)
frontal plane adductors
pec (lower), lats, teres maj (ant and post)
Transverse plane internal rotators
pecs, subscap, lats, teres maj (ant and post)
Transverse plane external rotators
teres min, infraspinatus (post)
Transverse plane horizontal abductors (diag)
Teres min, infraspin, post deltoid (post)
Transverse plane horizontal adductors (diag)
Pecs, coracobrach, ant delt (ant/sup)
Muscles that cause flexion in the sagittal plane
pectoralis major (clavicular fibers)
coracobrachialis
anterior deltoid
Muscles that cause extension in the sagittal plane
Latissimus dorsi
posterior deltoid
teres major
teres minor
subscapularis
pectoralis major (sternal fibers)
Muscles that cause abduction in the frontal plane
Pectoralis major (clavicular fibers above 90 degrees)
deltoid
supraspinatus
infraspinatus (upper fibers)
muscles that cause adduction in the frontal plane
pectoralis major (sternal fibers)
latissimus dorsi
teres major
coracobrachialis
teres minor
subscapularis
infraspinatus (lower fibers)
muscles that cause external rotation in the transverse plane
infraspinatus
teres minor
posterior deltoid
muscles that cause internal rotation in the transverse plane
pectoralis major
subscapularis
latissimus dorsi
teres major
anterior deltoid
muscles that cause horizontal abduction in the transverse plane
posterior deltoid
infraspinatus
teres minor
latissimus dorsi
muscles that cause horizontal adduction in the transverse plane
pectoralis major
coracobrachialis
anterior deltoid