Transcript Shoulder Anatomy and Injuries - PA

Shoulder Anatomy
Shoulder Anatomy - bones
• Scapula
• Clavicle
• Humerus
• greater tubercle
Scapula
Supraspinous
fossa
Infraspinous
fossa
Subscapular
fossa
Axillary
border
Inferior angle
Humerus
Shoulder Anatomy
Joints of the
shoulder
• Sternoclavicular
(SC) Joint
• Acromioclavicular
(AC) Joint
• Glenohumeral
(GH) Joint
• Scapulothoracic
Articulation
Sternoclavicular (SC) Joint
• Synovial Joint double gliding joint
• side to side & front to
back
• Ligaments
•
•
•
•
Anterior SC
Posterior SC
Interclavicular
Costoclavicular
SC Movements
• moves in many directions (but only in
small amounts)
•
•
•
•
Protraction
Retraction
Elevation
Depression
SC Joint Function
• Absorbs forces
• Distributes forces
• Allows movement of
clavicle
Shoulder Anatomy - joints
• Acromioclavicular
Injury –
“Separated
Shoulder”
Acromioclavicular joint (AC)
Support
a. Capsule - dense
but weak
b.
Acromioclavicular
ligaments
• Superior
and
inferior
c. Coracoclavicular
ligaments
•
•
TrapezoidLateral
Conoid Medial
AC Joint
Acromioclavicular Joint
• A-C Ligament:
strengthens A-C joint
along with fibers from
trapezius
• Coracoclavicular
Ligament: anchors
Clavicle to coracoid
process; strongest
ligament binding the
clavicle to scapula
Coracoclavicular Ligament
• Two Parts
• Conoid ligament
(medial)
• Trapezoid (lateral)
• A-C Separation
1-Stretch A-C
2-Complete tear of A-C;
partial tear of C-C
3-Complete tear of A-C;
complete tear of C-C
Shoulder Anatomy - joints
• Scapulothoracic
• muscular
attachments only
• The scapula meets
the rib cage!
Scapulothoracic Articulation
• Movements:
•
•
•
•
•
•
Protraction
Retraction
Elevation
Depression
Upward Rotation
Downward Rotation
Shoulder Anatomy - joints
• Glenohumeral
• ball and socket
• lacks bony stability (small glenoid, large
humerus)
• provides motion
• glenoid labrum (fibrocartilage)
• rotator cuff (muscular stability)
ROTATOR CUFF
Glenohumeral (GH) Joint
• “True Shoulder Joint”
• Synovial Joint - Ball and
Socket
• Glenoid fossa & labrum
with Humeral Head
• 3 Major Ligaments:
• Coracohumeral - coracoid to
greater tubercle (strong)
• 3 GH bands - thickenings of
articular capsule
• Transverse Humeral - greater
to lesser tubercle
Glenohumeral
Stability
• Glenoid Cavity
(shallow)
• Glenoid labrum (soft
cartilaginous rim that
adds depth and
stability)
GH Joint Support
• Capsule
• Ligaments
•
Anterior –
Glenohumeral
• Superior Coracohumeral
• Coracoacromial arch
• Bursae
• Subacromial
• Subdeltoid
• Subscapular bursa
Coracohumeral ligament
Glenohumeral ligaments
Glenohumeral Stability
• Anterior
Capsule
• Posterior
Capsule
• Glenohumeral
ligaments
• Superior
• Middle
• Inferior
GH Movements
• Sacrifices stability for mobility
•
•
•
•
•
•
Flexion
Extension
Abduction
Adduction
Internal Rotation
External Rotation
Upper Arm & Shoulder Muscles
deltoid
brachialis
triceps brachii
teres major
teres minor
supraspinatus
infraspinatus
teres minor
Rotator Cuff Muscles
subscapularis