Download Glenohumeral Joint

Shoulder
A.A.A. Contest
Answer the Animated AnimaLS
 Throughout the slide show there will be slides with written questions.
 When you see a question, think of the answer, don’t answer it out loud --- this
way, everyone gets a chance to think.
 Some slides with a question will have animations of animals cross the screen.
When this happens, write down the answer on a post it note and quickly WALK it
up to post on the board at the front of the class.
 The first person to post the correct answer on the board is the winner!
You get to put a sticker on the “AAA Contest” board.
 The contest will continue throughout the quarter… at the end of the quarter,
the person with the most stickers wins!
Bones of Shoulder
Humerus
&
•The shoulder girdle:
Scapula
Clavicle
The shoulder girdle
attachment of the upper extremity to the trunk
It consists of two bones:
the scapula (shoulder blade)
clavicle (collarbone)
Shoulder Girdle
Scapula & Clavicle
• Link to Axial skeleton via sternoclavicular
joint
• Lack of posterior attachment to the axial
skeleton allows for a wide ROM
• Functions to allow attachment areas for
numerous muscles that move the shoulder
and elbow
What is the only true
synovial joint where there is
an articulation between the
humerus and the axial
skeleton?
Sternoclavicular joint
Landmarks of Scapula
• Borders
– superior, medial (vertebral), lateral (axillary)
• Angles
– inferior, superior
•
•
•
•
•
Acromion process
Spine of scapula
Glenoid fossa
Coracoid process
Supraspinatus fossa, Infraspinatus
fossa, Subscapular fossa
• Supraglenoid tubercle & Infraglenoid
Tubercle
Posterior View of Scapula
Anterior View of Shoulder Complex:
With Scapula, Humerus and Clavicle
Lateral View of Scapula (Sagittal Cross Section)
Posterior
Anterior
Learning Activity:
1)Label the landmarks of the
scapula
1st try from memory
(in a couple of minutes Zefire will
put up a labeled picture so you
can double check your answers,
make corrections and additions)
Joints of the
Shoulder Girdle
1. Sternoclavicular joint
2. Acromioclavicular Joint
3. Glenohumeral Joint
(4) Scapulothoracic Joint
- NOT really a synovial joint
– supported by muscles, not ligaments
Joints of the
Shoulder Girdle
1. Sternoclavicular
– Sternum and clavicle
– gliding joint
– ligaments
• anterior sternoclavicular ligament
• posterior sternoclavicular ligament
• costoclavicular ligament
• interclavicular ligament
Joints of the
Shoulder Girdle
2. Acromioclavicular
– Acromion Process of scapula and clavicle
– gliding joint
– ligaments
• coracoclavicular ligaments
–trapezoid ligament
–conoid ligament
• superior & inferior acromioclavicular ligaments
Acromioclavicular Joint
The joint is surrounded by a weak
capsule that is reinforced by strong
inferior and superior * acromioclavicular
ligaments.
Further strengthening occurs through the
coracoclavicular ligament formed of two
strong fibre bundles, the lateral trapezoid
and medial conoid ligaments.
Joints of the
Shoulder Girdle:
3. Glenohumeral
– Glenoid fossa and head of the humerus
– Ball and socket
• Joint that allows most movement of entire
body
• Allows movement in 3 planes
“Shoulder Joint”: Glenohumeral Joint
Process
Fossa
Fossa
Labrum:
a ring of fibrous cartilage surrounding the glenoid
stabilizes the joint (makes a deeper socket)
“Shoulder Joint”:
Glenohumeral Joint
Glenohumeral Joint:
What is the bony landmark
on the scapula that
articulates with the
humerus?
Glenoid Fossa
Movements allowed by the “Shoulder”
Glenohumeral Joint:
Flexion + Extension
ADduction + Abduction
Circumduction:
Flexion + Extension
+ Adduction + Abduction
Medial Rotation + Lateral Rotation
Horizontal ABduction
+ Horizontal ADduction
Movements allowed by
the Scapulothoracic “joint”
•
•
•
•
•
Abduction (Protraction)
Adduction (Retraction)
Depression: inferior movement
Elevation: superior movement
Downward (inward) rotation: inferior angle
moves medially
• Upward (outward) rotation
Movements allowed by
the Scapulothoracic “joint”
• Abduction (Protraction) – scapula move
away from spine
• Adduction (Retraction) – scapula move
closer to spine
Protraction
Reach fingers forward. A widening
between shoulder blades will occur.
Try to keep space between the
hands constant.
Retraction
Bring shoulder blades closer together.
A widening across front of collarbone
will occur.
Try to keep space between the hands
constant.
Movements allowed by
the Scapulothoracic “joint”
• Depression: inferior movement
• Elevation: superior movement
Movements allowed by
the Scapulothoracic “joint”
• Downward (inward) rotation:
inferior angle moves medially,
and acromion moves
downward
• Upward (outward) rotation:
inferior angle moves laterally,
and acromion moves upward
Scapular Movements in Action
What is the
movement at the
scapula as this man
contracts his
muscles?
Elevation
Superior movement of the
shoulder girdle; moving the
scapula up.
http://www.exrx.net/Articulations/Scapula.html#anchor73267
Scapular Movements in Action
Besides some
depression of the
scapula, what
other primary
motion is occurring
at the scapula
during the pull up? Downward Rotation
Rotary movement of the
scapula; Moving inferior
angle of scapula medially
and downward.
Scapular Movements in Action
Upward Rotation
Rotary movement of the scapula;
Moving inferior angle of scapula
laterally and upward.
Scapular Movements in Action
During the push-up
phase of the
movement, what is
the scapular action?
Abduction
(Protraction)
Forward movement away the
midline of the body; moving the
scapula away from the spine.
Scapular Movements in Action
What scapular
movement is
occurring during
contraction?
Adduction
(Retraction)
Backward movement toward
the midline of the body;
moving the scapula back
toward the spine.
The scapula moves normally on the
thorax only if the two joints by which it
attaches to the axial skeleton are also
free to move:
Sternoclavicular joint
Acromioclavicular joint
Sternoclavicular (SC) joint
movements:
CLAVICULAR ELEVATION AND DEPRESSION
Clavicular protraction and
Retraction
BACKWARD AND FORWARD ROTATION OF
CLAVICLE OCCUR
Acromioclavicular joint
Mobility at the AC joint allows the
scapula to move in three dimensions
so that it follows the contours of the
ribcage.
Scapular WINGING
TIPPING
UPWARD and DOWNWARD
ROTATION
During shoulder elevation, the
scapula and clavicle must
rotate upwardly
Humeral Flexion and Extension
http://www.biomech.jhu.edu/Projects/shoulder/Default.htm
There’s nothing like a good shoulder
Learning Activity:
Individually, without your notes
Take 10 minutes to write an outline of the
movements possible at the
 Glenohumeral joint
 Scapulothoracic “joint”
Then, answer these questions: Which of
these joints allows more movement: AC acromioclavicular joint or sternoclavicular
joint? In how many planes does this more
moveable joint allow movement?
Try drawing diagrams to see if that helps
Learning Activity:
2) In small groups, your answers; make
sure everyone understands.
3) With a scapula model, take turns, with
each person showing the
scapulothoracic movements on a group
member’s back (while other group
member(s) watch and help).