The Shoulder Joint
• Shoulder joint is attached to axial skeleton
via the clavicle at SC joint
• Scapula movement usually occurs with
Chapter 5
The Shoulder Joint
movement of humerus
– Humeral flexion & abduction require scapula
elevation, rotation upward, & abduction
– Humeral adduction & extension results in scapula
depression, rotation downward, & adduction
– Scapula abduction occurs with humeral internal
rotation & horizontal adduction
– Scapula adduction occurs with humeral external
rotation & horizontal abduction
Manual of Structural Kinesiology
R.T. Floyd, EdD, ATC, CSCS
5-1
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The Shoulder Joint
Bones
• Scapula, clavicle, & humerus serve as
• Wide range of motion of the shoulder joint in
attachments for shoulder joint muscles
many different planes requires a significant
amount of laxity
– Scapular landmarks
•
•
•
•
•
•
•
•
• Common to have instability problems
– Rotator cuff impingement
– Subluxations & dislocations
• The price of mobility is reduced stability
• The more mobile a joint is, the less stable it
is & the more stable it is, the less mobile
5-3
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supraspinatus fossa
infraspinatus fossa
subscapular fossa
spine of the scapula
glenoid cavity
coracoid process
acromion process
inferior angle
From Seeley RR, Stephens TD, Tate P: Anatomy and physiology, ed 7, 5-4
New York, 2006, McGraw-Hill
© McGraw-Hill Higher Education. All rights reserved.
Bones
Bones
• Scapula, clavicle, & humerus serve as
• Key bony landmarks
attachments for shoulder joint muscles
– Acromion process
– Humeral landmarks
•
•
•
•
•
5-2
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– Glenoid fossa
Head
Greater tubercle
Lesser tubercle
Intertubercular groove
Deltoid tuberosity
– Lateral border
– Inferior angle
– Medial border
– Superior angle
– Spine of the scapula
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5-5
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1
Glenohumeral Joint
Glenohumeral Joint
– Glenoid labrum
slightly
enhances
stability
• multiaxial ball&-socket
• enarthrodial
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5-7
Glenohumeral Joint
– Ligaments are quite lax until extreme
ranges of motion reached due to wide
range of motion involved
– Stability is sacrificed to gain mobility
• especially
anteriorly &
inferiorly
• inferior
glenohumeral
ligament
5-9
Glenohumeral Joint
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5-10
Glenohumeral Joint
– 90 to 95 degrees
abduction
– 0 degrees adduction,
75 degrees anterior
to trunk
• Determining
exact range of
each
movement is
difficult due to
accompanying
shoulder girdle
movement
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5-8
Glenohumeral Joint
– Glenohumeral
ligaments provide
stability
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5-11
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5-12
2
Glenohumeral Joint
Glenohumeral Joint
– 40 to 60 degrees of
extension
– 90 to 100 degrees of
flexion
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– 70 to 90 degrees of internal & external
rotation
5-13
Glenohumeral Joint
Glenohumeral Joint
– 45 degrees of
horizontal
abduction
– 135 degrees of
horizontal
adduction
© McGraw-Hill Higher Education. All rights reserved.
• Frequently injured due to anatomical design
– shallowness of glenoid fossa
– laxity of ligamentous structures
– lack of strength & endurance in muscles
– anterior or anteroinferior glenohumeral
subluxations & dislocations – common
– posterior dislocations – rare
– posterior instability problems somewhat
common
5-15
5-16
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Pairing of shoulder girdle & shoulder joint
movements
Glenohumeral Joint
Shoulder joint
Abduction
Adduction
Flexion
Extension
Internal rotation
External rotation
Horizontal abduction
Horizontal adduction
• Rotator cuff is frequently injured
– Subscapularis, supraspinatus, infraspinatus, &
teres minor muscles
– attach to the front, top, & rear of humeral head
– point of insertion enables humeral rotation
– vital in maintaining humeral head in correct
approximation within glenoid fossa while more
powerful muscles move humerus through its wide
range of motion
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5-14
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5-17
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Shoulder girdle
Upward rotation
Downward rotation
Elevation/upward rotation
Depression/downward rotation
Abduction (protraction)
Adduction (retraction)
Adduction (retraction)
Abduction (protraction)
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3
Movements
Movements
• Abduction
• Flexion
– upward lateral
movement of humerus
out to the side, away
from body
– movement
of humerus
straight
anteriorly
• Adduction
• Extension
– downward movement
of humerus medially
toward body from
abduction
– movement
of humerus
straight
posteriorly
5-19
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Movements
Movements
• Horizontal adduction
(transverse flexion)
• External rotation
– movement of
humerus laterally
around its long axis
away from midline
– movement of humerus in a
horizontal or transverse
plane toward & across chest
• Internal rotation
• Horizontal abduction
(transverse extension)
– movement of
humerus medially
around its long axis
toward midline
– movement of humerus in a
horizontal or transverse
plane away from chest
5-21
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5-22
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Movements
Muscles
• Diagonal abduction
• Intrinsic glenohumeral muscles
– movement of humerus
in a diagonal plane
away from midline of
body
– Originate on scapula & clavicle
– Deltoid, Coracobrachialis, Teres major
– Rotator cuff group
• subscapularis, supraspinatus, infraspinatus, &
teres minor
• Diagonal adduction
• Extrinsic glenohumeral muscles
– movement of humerus
in a diagonal plane
toward midline of body
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5-20
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– latissimus dorsi & pectoralis major
5-23
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5-24
4
Muscles
Muscles
• Anterior
• Superior
– Pectoralis major
– Coracobrachialis
– Subscapularis
– Deltoid
– Supraspinatus
• Posterior
• Superior
–
–
–
–
– Deltoid
– Supraspinatus
From Shier D, Butler J, Lewis R: Hole’s essentials of human anatomy and physiology, ed 9,
New York, 2006, McGraw-Hill.
5-25
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Latissimus dorsi
Teres major
Infraspinatus
Teres minor
From Shier D, Butler J, Lewis R: Hole’s
essentials of human anatomy and
physiology, ed 9, New York, 2006,
McGraw-Hill.
5-26
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Nerves
Nerves
• All shoulder joint muscles are innervated from
the brachial plexus
• Lateral pectoral nerve arising from C5, C6, &
C7
• Axillary nerve branching
from C5 & C6
– Deltoid
– Teres minor
– Sensation to lateral patch of
skin over deltoid region of
arm
– Pectoralis major (clavicular head)
• Medial pectoral nerve arising from C8 & T1
– Pectoralis major (sternal head)
• Thoracodorsal nerve arising from C6, C7, &
C8
• Upper subscapular nerves
arising from C5 & C6
– Latissimus dorsi
– Subscapularis
5-27
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5-28
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Nerves
Nerves
• Lower subscapular nerve arising from
C5 & C6
• Musculotaneous nerve
branching from C5, C6, &
C7
– Subscapularis
– Teres major
– Coracobrachialis
– Sensation to radial aspect
of forearm
• Suprascapula nerve originating from
C5 & C6
– Supraspinatus
– Infraspinatus
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5-29
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5-30
5
Deltoid Muscle
Anterior fibers:
abduction, flexion,
horizontal adduction,
& internal rotation
Pectoralis Major Muscle
Upper fibers (clavicular head):
internal rotation, horizontal
adduction, flexion, abduction (once
arm is abducted 90 degrees, upper
fibers assist in further abduction), &
adduction (with arm below 90
degrees of abduction)
Lower fibers (sternal
head): internal
rotation, horizontal
adduction, extension,
& adduction
Posterior fibers:
abduction, extension,
horizontal abduction,
& external rotation
Middle fibers:
abduction
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5-31
Latissimus Dorsi Muscle
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5-32
Coracobrachialis Muscle
Adduction
Flexion
Extension
Adduction
Internal rotation
Horizontal adduction
Horizontal abduction
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5-33
Rotator cuff muscles
5-34
Rotator cuff muscles
• Supraspinatus
• not very large
• must possess strength & muscular endurance
• conducting repetitious overhead activities
(throwing, swimming, & pitching) with poor
technique, muscle fatigue, or inadequate warmup & conditioning leads to failure of rotator cuff
muscle group in dynamically stabilizing humeral
head in glenoid cavity
• leads to further rotator cuff problems such as
tendinitis & rotator cuff impingement within
subacromial space
– 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 anterior (Int.
Rot.)
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5-35
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5-36
6
Subscapularis Muscle
Supraspinatus Muscle
Internal rotation
Abduction
Adduction
Extension
Stabilization of the
humeral head in
glenoid fossa
Stabilization of the
humeral head in
glenoid fossa
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5-37
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Infraspinatus Muscle
Teres Minor Muscle
External rotation
External rotation
Horizontal abduction
Horizontal abduction
Extension
Extension
Stabilization of humeral
head in the glenoid fossa
Stabilization of humeral
head in the glenoid fossa
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5-38
5-39
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5-40
Glenohumeral Flexion
Teres Major Muscle
• Agonists
Extension, particularly from
the flexed position to the
posteriorly extended
position
– Anterior Deltoid
– Upper Pectoralis Major
Internal rotation
Adduction, particularly from
the abducted position
down to the side &
toward midline of body
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5-41
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5-42
7
Glenohumeral Extension
Glenohumeral Abduction
• Agonists
• Agonists
– Teres
Major
– Latissimus
Dorsi
– Lower
Pectoralis
Major
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– Deltoid
– Supraspinatus
– Upper Pectoralis
Major
5-43
Glenohumeral Adduction
• Agonists
– Latissimus
Dorsi
– Teres Major
– Subscapularis
– Pectoralis
Major
• All attach
anteromedially
on humerus
5-45
Glenohumeral External Rotation
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5-46
Glenohumeral Horizontal Abduction
• Agonists
• Agonists
– Infraspinatus
– Teres Minor
– Posterior
Deltoid
– Middle
Deltoid
– Infraspinatus
– Teres Minor
• Both attach
posteriorly on
greater tubercle
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5-44
Glenohumeral Internal Rotation
• EX. Lat. Pull pull down
weights
• Agonists
– Latissimus
Dorsi
– Teres Major
– Lower
Pectoralis
Major
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5-47
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5-48
8
Glenohumeral Horizontal Adduction
Glenohumeral Diagonal Abduction
• Agonists
• Agonists
– Posterior Deltoid
– Infraspinatus
– Teres Minor
– Triceps Brachii
(Long Head)
– Anterior Deltoid
– Pectoralis Major
– Coracobrachialis
5-49
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Glenohumeral Diagonal Adduction
Web Sites
Radiologic Anatomy Browser
http://radlinux1.usuf1.usuhs.mil/rad/iong/index.html
– This site has numerous radiological views of the
musculoskeletal system.
University of Arkansas Medical School Gross Anatomy for Medical
Students
http://anatomy.uams.edu/anatomyhtml/grossresources.html
– Dissections, anatomy tables, atlas images, links, etc.
Loyola University Medical Center: Structure of the Human Body
www.meddean.luc.edu/lumen/MedEd/GrossAnatomy/GA.html
– An excellent site with many slides, dissections, tutorials, etc.,
for the study of human anatomy
Wheeless’ Textbook of Orthopaedics
www.wheelessonline.com/
– This site has an extensive index of links to the fractures,
joints, muscles, nerves, trauma, medications, medical topics,
lab tests, and links to orthopedic journals and other orthopedic
and medical news.
• Agonists - both
low & high
– Anterior Deltoid
– Coracobrachialis
– Biceps Brachii
(short head)
– Pectoralis Major Upper & Lower
5-51
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5-52
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Web Sites
Web Sites
Premiere Medical Search Engine
http://www.medsite.com/Default.asp?bhcp=1
– This site allows the reader to enter any medical condition and
it will search the net to find relevant articles.
Arthroscopy.Com
www.arthroscopy.com/sports.htm
– Patient information on various musculoskeletal problems of
the upper and lower extremity
Virtual Hospital
www.vh.org
– Numerous slides, patient information, etc.
Medical Multimedia Group
www.healthpages.org/AHP/LIBRARY/HLTHTOP/CTD/
– A Patient's Guide to Cumulative Trauma Disorder (CTD)
Baseball Almanac
www.baseball-almanac.com/chapters/cap-ch8.shtml
– Coaching Adult Pitchers
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5-50
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Lecture Topics in Kinesiology
http://moon.ouhsc.edu/dthompso/namics/shoulder.htm
– Shoulder articulations, movements, and muscles that are
within the shoulder girdle
The Physician and Sportsmedicine
www.physsportsmed.com/issues/2003/0703/depalma.htm
– Detecting and Treating Shoulder Impingement Syndrome: The
Role of Scapulothoracic Dyskinesis
Southern California Orthopedic Institute
www.scoi.com/sholanat.htm
– Anatomy of the Shoulder
FamilyDoctor.org
http://familydoctor.org/268.xml
– Shoulder Pain
5-53
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9
Web Sites
Web Sites
MedlinePlus
www.nlm.nih.gov/medlineplus/tutorials/shoulderarthroscopy/htm/
index.htm
– Shoulder arthroscopy interactive tutorial
MedlinePlus
www.nlm.nih.gov/medlineplus/tutorials/rotatorcuffinjuries/htm/ind
ex.htm
– Rotator cuff injuries interactive tutorial
American Physical Therapy Association
www.apta.org/AM/Template.cfm?Section=Home&TEMPLATE=/
CM/HTMLDisplay.cfm&CONTENTID=20448
– Taking Care of Your Shoulder
American Academy of Orthopaedic Surgeons
http://orthoinfo.aaos.org/category.cfm?topcategory=Shoulder
– Patient Education Library on the Shoulder
© McGraw-Hill Higher Education. All rights reserved.
Orthopaedic Research Institute
http://www.ori.org.au/bonejoint/shoulder/contents.htm
– Several web pages, text, and graphics on glenohumeral
instability
American Sports Medicine Institute
www.asmi.org/asmiweb/mpresentations/mmp.htm
– Biomechanics of the Shoulder during Throwing
American Sports Medicine Institute
http://www.asmi.org/SportsMed/throwing/thrower10.html
– Throwers Ten Exercises
Washington Musculoskeletal Tumor Center
www.sarcoma.org/main.php?page=shoulder
– Shoulder girdle surgery
5-55
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10
