Chapter 18: The Shoulder
Complex
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• The shoulder is an extremely complicated
region of the body
• Joint which has a high degree of mobility
but not without compromising stability
• Involved in a variety of overhead activities
relative to sport making it susceptible to a
number of repetitive and overused type
injuries
• Movement and stabilization of the
shoulder requires integrated function of
the rotator cuff muscles, joint capsule and
scapula stabilizing muscles
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Anatomy
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Functional Anatomy
• Sternoclavicular (SC) joint
– Clavicle articulates with manubrium of the sternum
• Weak bony structure but held by strong
ligaments
• Fibrocartilaginous disk between articulating
surfaces
– Shock absorber and helps prevent
displacement forward
– Clavicle permitted to move up and down,
forward and backward and in rotation
– Clavicle must elevate 40 degrees to allow
upward rotation of scapula and thus
shoulder abduction
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Functional Anatomy
• Acromioclavicular (AC) Joint
– Lateral end of clavicle with acromion
process of scapula
• Weak joint and susceptible to sprain and
separation
– AC ligament, CC ligament, & thin fibrous capsule
• Posterior rotation of clavicle as arm elevates
– Must rotate approx. 50 degrees for full elevation to
occur
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Functional Anatomy
• Coracoacromial arch
– Arch over the GH joint formed by
coracoacromial arch, acromion and
coracoid process
• Subacromial space: area in between CA arch
and humeral head
– Supraspinatus tendon, long head biceps tendon, and
subacromial bursa
» Subject to irritation and inflammation as a result
of excessive humeral head translation or
impingement from repeated overhead activity
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© 2010 McGraw-Hill Higher Education. All rights reserved.
• Glenohumeral (GH) Joint
– Ball and socket, synovial joint in which round
head of humerus articulates with shallow
glenoid fossa of scapula
• stabilized slightly by fibrocartilaginous rim called
the Glenoid Labrum
• Humeral head larger than glenoid fossa
– At any point during elevation of shoulder only
25 to 30% of humeral head is in contact with
glenoid
– Statically stabilized by labrum and capsular
ligaments
– Dynamically stabilized by deltoid and rotator
cuff muscles
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• Scapulothoracic (ST) Joint
– Not a true joint, but movement of scapula
on thoracic cage is critical to joint motion
• Scapula capable of upward/downward rotation,
external/internal rotation & anterior/posterior
tipping
• In addition to rotating other motions include
scapular elevation and depression & protraction
(abduction) and retraction (adduction)
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• ST Joint
– During humeral elevation (flexion,
abduction and scaption) scapula and
humerus must move in synchronous
fashion
– Often termed scapulohumeral rhythm
• Total range 180°: 120° @ GH joint, 60° of
scapular mvmt
• Ratio of 2:1, degrees of GH movement to
scapular movement after 30 degrees of
abduction and 45 to 6 degrees of lfexion
– Maintain joint congruency
– Length-tension relationship for numerous muscles
– Adequate subacromial space
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• Scapulohumeral rhythm
– During humeral elevation
• Scapula upwardly rotates
• Posteriorly tips
• Externally rotates
• Elevates
• & Retracts
–Alterations in these movement
patterns can cause a variety of
shoulder conditions
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© 2010 McGraw-Hill Higher Education. All rights reserved.
© 2010 McGraw-Hill Higher Education. All rights reserved.
• Stability of shoulder joint
– Instability often the cause of many specific
shoulder injuries
– During movement essential to maintain
position of humeral head relative to glenoid
• Likewise it is essential for glenoid to adjust its
position relative to moving humeral head, while
maintaining stable base
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• Rotator cuff muscles along with long head of the
biceps provide dynamic stability
– control the position of humeral head
– Prevent excessive displacement or translation of
humeral head relative to glenoid
• Co-activation of rotator cuff muscles function to
compress humeral head into glenoid for
stability, as well as depress humeral head
– counteracts contraction of deltoid which is
elevating humeral head
» Imbalance between muscle components
will create abnormal GH mechanics and
injury
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• Scapular stability and mobility
– Scapular muscles play critical role in normal
function of shoulder
• Produce movement of scapula on thoracic cage
• Dynamically position glenoid relative to moving
humerus
– levator scap & upper trap=scap elevation
– middle trap & Rhomboids=scap retraction
– Lower trap=scap retraction, upward rotation and
depression
– Pec minor=scap depression
– Serratus anterior=scap abduction and upward rotation
» Only attachment of scapula to thorax is through
these muscles
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Prevention of Shoulder
Injuries
• Proper physical conditioning is key
• Develop body and specific regions
relative to sport
• Strengthen through a full ROM
– Focus on rotator cuff muscles in all planes
of motion
– Be sure to incorporate scapula stabilizing
muscles
• Enhances base of function for glenohumeral
joint
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• Warm-up should be used before
explosive arm movements are
attempted
• Contact and collision sport athletes
should receive proper instruction on
falling
• Protective equipment
• Mechanics versus overuse injuries
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Throwing Mechanics
•Instruction in proper throwing mechanics
is critical for injury prevention
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• Windup Phase
– First movement until ball leaves gloved hand
– Lead leg strides forward while both shoulders
abduct, externally rotate and horizontally abduct
• Cocking Phase
– Hands separate (achieve max. external rotation)
while lead foot comes in contact w/ ground
• Acceleration
– Max external rotation until ball release (humerus
adducts, horizontally adducts and internally
rotates)
– Scapula elevates and abducts and rotates
upward
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• Deceleration Phase
– Ball release until max shoulder internal
rotation
– Eccentric contraction of ext. rotators to
decelerate humerus while rhomboids
decelerate scapula
• Follow-Through Phase
– End of motion when athlete is in a
balanced position
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Assessment of the Shoulder
Complex
• History
– What is the cause of pain?
– Mechanism of injury?
– Previous history?
– Location, duration and intensity of pain?
– Crepitus, numbness, distortion in
temperature
– Weakness or fatigue?
– What provides relief?
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• Observation
– Elevation or depression of
shoulder tips
– Position and shape of clavicle
– Acromion process
– Biceps and deltoid symmetry
– Postural assessment
(kyphosis, lordosis,
shoulders)
– Position of head and arms
– Scapular elevation and
symmetry
– Scapular protraction or
winging
– Muscle symmetry
– Scapulohumeral rhythm
Insert 18-6
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Recognition and Management
of Specific Injuries
• Clavicular Fractures
– Cause of Injury
• Fall on outstretched arm, fall on tip of shoulder or
direct impact
• Occur primarily in middle third (greenstick fracture
often occurs in young athletes)
– Signs of Injury
• Generally presents w/ supporting of arm, head
tilted towards injured side w/ chin turned away
• Clavicle may appear lower
• Palpation reveals pain, swelling, deformity and
point tenderness
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• Clavicular Fractures (continued)
– Rehab concerns
• Closed reduction - sling and swathe, immobilize w/ figure
8 brace for 6-8 weeks
• Possible involvement of AC and SC joints
• Clavicle insertion for deltoid, upper trap & pec major
– Provide stability and neuromuscular control to
shoulder complex
– Must be addressed in rehab
• Removal of brace should be followed w/ joint mobilization
of clavicle, isometrics and use of a sling for 3-4 weeks
– AROM & PROM
• Occasionally requires operative management
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© 2010 McGraw-Hill Higher Education. All rights reserved.
• Fractures of the Humerus
– Cause of Injury
• Humeral shaft fractures occur as a result of a
direct blow, or fall on outstretched arm
• Proximal fractures occur due to direct blow,
dislocation, fall on outstretched arm
– Care
• Immediate application of splint, treat for shock
and refer
• Athlete will be out of competition for 2-6 months
depending on location and severity of injury
• Progressive ROM exercises as tolerated
• PRE exercises of shoulder & elbow after 4-6
weeks
• Maintain strength of elbow, forearm and wrist
musculature
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• Sternoclavicular Sprain
– Cause of Injury
• Indirect force, blunt trauma (may cause
displacement)
– Care
• PRICE, immobilization
• Immobilize for 3-5 weeks followed by graded
reconditioning
• Strengthen muscles in range that does not put
further stress on joint
• Low grade joint mobilizations after inflammation is
controlled
• Restore normal mechanics of shoulder complex
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• Acromioclavicular Sprain
– Cause of Injury
• Result of direct blow (from any direction), upward
force from humerus, fall on outstretched arm
– Signs of Injury
• Grade 1 - point tenderness and pain w/ movement;
no disruption of AC joint
• Grade 2 - tear or rupture of AC ligament, partial
displacement of lateral end of clavicle; pain, point
tenderness and decreased ROM
(abduction/adduction)
• Grade 3 - Rupture of AC and CC ligaments with
dislocation of clavicle; gross deformity, pain, loss
of function and instability
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– Care
• Ice, stabilization, referral to physician
• Grades 1-3 (non-operative) will require 3-4
days (grade 1) and 2 weeks of immobilization (
grade 3) respectively
• Aggressive rehab is required w/ all grades
– Joint mobilizations, flexibility exercises, &
strengthening should occur immediately
– Progress as athlete is able to tolerate w/out pain and
swelling
– Padding and protection may be required until painfree ROM returns
– Grade 1 & 2 often treated conservatively while grade
3 may require surgical intervention to reduce
separation although often treated w/o surgery also
– Grade IV, V & VI- require internal fixation to realign
fractured segments
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© 2010 McGraw-Hill Higher Education. All rights reserved.
• Glenohumeral Dislocations
– Cause of Injury
• Head of humerus is forced out of the joint
• Anterior dislocation is the result of an anterior
force on the shoulder, forced abduction,
extension and external rotation
• Occasionally the dislocation will occur inferiorly
– Signs of Injury
• Flattened deltoid, prominent humeral head in
axilla; arm carried in slight abduction and
external rotation; moderate pain and disability
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• Care
–
–
–
–
RICE, immobilization and reduction by a physician
Begin muscle re-conditioning ASAP
Use of sling should continue for at least 1 week
Progress to resistance exercises as pain allows
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• Shoulder Impingement Syndrome
– Cause of Injury
• Mechanical compression of supraspinatus
tendon, subacromial bursa and long head of
biceps tendon due to decreased space under
coracoacromial arch
• Seen in over head repetitive activities
– Signs of Injury
• Diffuse pain, pain on palpation of subacromial
space
• Decreased strength of external rotators
compared to internal rotators; tightness in
posterior and inferior capsule
• Positive impingement and empty can tests
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– Care
• Restore normal biomechanics in order to maintain
space
• Strengthening of rotator cuff and scapula stabilizing
muscles
• Stretching of posterior and inferior joint capsule
• Modify activity (control frequency and intensity)
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– Rotator cuff tear
• Involves supraspinatus or rupture of other
rotator cuff tendons
• Primary mechanism - acute trauma (high
velocity rotation)
• Occurs near insertion on greater tuberosity
• Full thickness tears usually occur in those
athletes w/ a long history of impingement or
instability (generally does not occur in athlete
under age 40)
– Signs of Injury
• Present with pain with muscle contraction
• Tenderness on palpation and loss of strength
due to pain
• Loss of function, swelling
• With complete tear impingement and empty
can test are positive
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– Care
• RICE for modulation of pain
• Progressive strengthening of rotator cuff
• Reduce frequency and level of activity initially with a
gradual and progressive increase in intensity
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• Shoulder Bursitis
– Etiology
• Chronic inflammatory condition due to trauma or
overuse - subacromial bursa
• May develop from direct impact or fall on tip of shoulder
– Signs of Injury
• Pain w/ motion and tenderness during palpation in
subacromial space; positive impingement tests
– Management
• Cold packs and NSAID’s to reduce inflammation
• Remove mechanisms precipitating condition
• Maintain full ROM to reduce chances of contractures
and adhesions from forming
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• Bicipital Tenosynovitis
– Cause of Injury
• Repetitive overhead athlete - ballistic activity
that involves repeated stretching of biceps
tendon causing irritation to the tendon and
sheath
– Signs of Injury
• Tenderness over bicipital groove, swelling,
crepitus due to inflammation
• Pain when performing overhead activities
– Care
• Rest and ice to treat inflammation
• NSAID’s
• Gradual program of strengthening and
stretching
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• Contusion of Upper Arm
– Cause of Injury
• Direct blow
• Repeated trauma could result in development
of myositis ossificans
– Signs of Injury
• Pain and tenderness, increased warmth,
discoloration and limited elbow flexion and
extension
– Management
• RICE for at least 24 hours
• Provide protection to contused area to prevent
repeated episodes that could cause myositis
ossificans
• Maintain ROM
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• Multi-directional instability
– When forces that are generated at GH joint
that stabilizing muscles are unable to
handle humeral head tends to translate
anteriorly and inferiorly
• Overtime cause structures to stretch
• Increase demands of posterior structures
– Eventual breakdown of these tissues
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• MDI rehab considerations
– Emphasis on anterior and posterior
musculature
– Promote neuromuscular control to assist
dynamic stability
– Patient must be compliant with exercises to
avoid instability and/or repetitive
subluxations
• Surgical intervention is sometimes required to
tighten joint capsule
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