SHOULDER AND ELBOW . Flashcards
● 20 muscles
● 3 bony articulations
● 3 soft tissue moving surface (functional joints)
● Permit the greatest mobility of any joint area found in the
body
Shoulder Complex
How many hand placements
16,000
only bony attachment of UE to
trunk
Sternoclavicular joint
○ Manubrium
○ Right and left clavicles
○ Right and left scapulae
● Incomplete girdle (does not have bony connection
posteriorly)
Shoulder Girdle
● Clavicular facet
● Sternal/jugular notch
● Facets for attachment
of the first ribs
Manubrium
● Clavicular facet
● Sternal/jugular notch
● Facets for attachment
of the first ribs
Manubrium
● Lateral strut to the
scapula and the
humerus.
● This increases
glenohumeral mobility
to permit greater
motion in reaching and
climbing activities.
Clavicle
● a flat,
triangular-shaped
bone
● 3 sides and 3 angles
● sits against the
posterior thorax.
● Lies on the posterior
ribs
● Conforms to the
upper thorax
● Does not lie in a
pure frontal plane
Scapula
Inferior angle of scapula
T7
Scapular spine
T3
● Dense fibrous
connective tissue rim
that surrounds the
glenoid fossa.
● Increase joint
congruence.
Glenoid Labrum
● Tilted 5° upward relative
to the scapular vertebral
border.
● Teardrop or pear-shaped
appearance
● Orientation: lateral,
superior, and anterior
direction (LAS)
● (Concave)
Glenoid Fossa
Head of humerus
○ Convex
○ 1/3 to ½ sphere
○ Orientation: medial,
superior, posterior
(PMS)
Humerus
Angle of inclination
humeral head is angled at
135° to the long axis of
the humeral shaft
Angle of torsion
30°
Resting position of the humeral head in posterior rotation
relative to the distal condyles of the humerus allows the
head to be aligned in the scapular plane while
maintaining proper elbow joint alignment; this relative
position of posterior rotation =
Retroversion
through which the LH
of biceps runs from
its proximal insertion
on the supraglenoid
tubercle.
Bicipital groove
● Circumferential area on the
proximal humerus.
● Distal to the bicipital groove
● Common site for humeral
fractures, especially in the
elderly, when a fall occurs and
the individual lands on an
outstretched arm.
Surgical Neck
are the result of
sternoclavicular and acromioclavicular joint movements.
Scapulothoracic motions
responsible for the majority
of the scapular movement.
Sternoclavicular joint
provides minimal movement
and acts more as a fine tuner of scapular motion than
a producer of its motion
Acromioclavicular joint
● The only joint that acts as
a strut to connect the
upper extremity directly
with the axial skeleton.
● Medial end of the clavicle
connects with the
manubrium of the
sternum and the medial
first rib.
Sternoclavicular Joint
● Plane synovial joint
● 3 DOF
○ Elevation/Depression
○ Abduction/Adduction
○ UR/DR
● Medial margin of the
acromion and the lateral
end of the clavicle
● Lined with fibrocartilage
Acromioclavicular Joint
● no bony articulations
● False joint/pseudo joint/functional joint
● Separating the scapula from the thorax are soft tissue
structures, including a large subscapular bursa.
Scapulothoracic Joint
● Shoulder joint
● Ball-and-socket
● 3 DOF
● Little bony stability
○ Convex: Humeral
head (PMS)
○ Concave: Glenoid
fossa (small/shallow)
(LAS)
● Labrum
○ From neck of glenoid
○ To anatomic neck of
humerus
● 10 to 15 mL
● Axillary pouch
Glenohumeral Joint
● Ligaments and tendons blend with and reinforce the
glenohumeral joint capsule for added stability.
○ Coracohumeral ligament
○ Superior, Middle, Inferior GH ligament
Capsular Reinforcement
coracoid process of the
scapula → greater and
lesser tubercles of the
humerus
● where it forms a tunnel
for the tendon of the
long head of the biceps
brachii.
Coracohumeral Ligament
● Capsular ligaments
● From the glenoid and its
labrum, form capsular
thickenings, and attach to
the humeral neck and
lesser tubercle
Superior, Middle and Inferior GH
Ligaments
Support the dependent
(hanging down) arm and
limit lateral rotation in the
lower ranges of
abduction
Coracohumeral, Superior and Middle GH
Ligaments
● Forms a hammock-like
sling with anterior and
posterior bands around
the lower portion of the
humeral head and is part
of the axillary pouch.
● Main stabilizer of the
abducted shoulder
Inferior Glenohumeral Ligament
● anterior acromion →
lateral coracoid process
● osteoligamentous arch
● roof of the glenohumeral
joint
Coracoacromial Arch
● Contains:
○ supraspinatus muscle
and tendon,
○ long head of the
biceps tendon
○ subacromial bursa
○ superior capsule
Subacromial Space
● Area under the
coracoacromial
● Formed by the neck of
the scapula, the acromion
process, the rigid
coracoacromial ligament,
and the coracoid process
Supraspinatus Outlet
● A bursa reduces friction
between two structures.
● 8 bursae within the
shoulder area
○ Subacromial bursa
Bursae
● Scapular plane
glenohumeral abduction
● Occurs 30° to 40°
anterior to the frontal
plane
Scaption
● LH of biceps tendon
● Retained by the
coracohumeral ligament
and by the transverse
humeral ligament
Bicipital Groove
● They found that the early phase of abduction was
individually variable.
Scapulohumeral Rhythm
This early stage of motion was termed the “setting
phase.” After about ____ of abduction, a ___ ratio occurred:
For every 2° of glenohumeral motion, 1° occurred at the
scapulothoracic joint.
30°; 2:1
Primary scapular protractor
● “saw muscle”
● lowest five digitations is the strongest portion of the
muscle
● XXX: Medial winging of the scapula
Serratus Anterior
● superficial muscle of the neck
and upper back
● “Shawl” muscle or “musculus
cucullaris”
● Full abduction with scapular rot:
All fibers
○ Mid = ret
○ Upper and Lower = upward
rot.
● XXX: Lateral winging of the
scapula
○ Elevation is limited to 120
degrees (only by GH)
Trapezius
● connect the scapula with the vertebral column lie under the
trapezi
● XXX: scapula in protracted position
● scapula positioned farther laterally from the thoracic
spinous processes
● than the normal 6 cm from the thoracic spinous processes.
Rhomboid Major and Minor
● located anteriorly on the upper chest by the pectoralis
major.
● XXX: Weakness of this muscle results in reduced
strength during scapular depression and downward
rotation of the scapula against resistance.
Pectoralis Minor