Download Anterior Deltoid

Kinesiology of the Glenohumeral
(Shoulder) Joint
• "Musculoskeletal Images are from the University
of Washington "Musculoskeletal Atlas: A
Musculoskeletal Atlas of the Human Body" by
Carol Teitz, M.D. and Dan Graney, Ph.D."
• "Copyright 2003-2004 University of Washington.
All rights reserved including all photographs and
images. No re-use, re-distribution or commercial
use without prior written permission of the authors
and the University of Washington
• Muscles that cross the anterior side of the
shoulder (front side) tend to create flexion,
horizontal adduction, and internal rotation.
• Muscles that cross the posterior side of the
shoulder tend to create extension, horizontal
abduction, and external (outward) rotation.
• Muscles that cross the lateral side of the
shoulder tend to create abduction.
Anterior Deltoid
• O: Ant. Lat. 1/3 clavicle
• I: Deltoid tuberosity
• A: Flexion, horizontal adduction,
internal rotation, and abduction
of shoulder (glenohumeral joint)..
N:Axillary n.
Middle Deltoid
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O: Acromion process
I: Deltoid tuberosity
A: Abduction of shoulder
N: axillary n.
Posterior Deltoid
• O: Spine of Scapula
• I: Deltoid tuberosity
• A: Extension,
horizontal abduction,
outward (ext.) rotation,
abduction of shoulder.
N: axillary
Coracobrachialis
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O: Coracoid process
I: Middle of the medial humerus
A: flexion, Adduction, horizontal adduction
N: Musculocutaneous n.
The Rotator Cuff
• A group of muscles deep inside the
shoulder.
• Most important for holding head of
humerus in glenoid fossa.
• Supraspinatus, infraspinatus, teres minor,
subscapularis
Supraspinatus
• O: Supraspinous fossa
• I:Top of greater tubercle of humerus
• A: Abduction, stabilizes humeral head in
glenoid fossa.
N. Suprascapular
Infraspinatus
• O: Infraspinous fossa
• I: Posterior greater tubercle
• A: External rotation, horizontal abduction,
extension of shoulder
• N. Suprascapular
Teres Minor
• O:Lateral border of scapula
• I:Post. Greater tubercle
• A:External rot., horizontal abduction,
extension of shoulder.
• N: Axillary
Subscapularis
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O: Subscapular fossa
I: Front of lesser tubercle
A: Int. rotation, Adduction, extension
N:Subscapular
– Lower and upper
Teres Major
• O: Just above inferior angle on Lat. Border.
• I: Medial lip of bicipital groove
• A: Internal rotation, Adductor, Extensor of
shoulder
• N: L. Lower Subscapular
Latissimus dorsi
• O: Iliac crest, sacrum, SP T6-L5, lower 3
ribs, (inf. Angle scapula).
• I: Medial lip of bicipital groove
• A: Adduction, internal rotator, shoulder
extension, horizontal abduction
• N. Thoracodorsal
The latissimus dorsi: the most
important muscle on the posterior
side of the trunk.
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Most powerful shoulder extensor
Most powerful adductor
Most powerful internal rotator
These are all throwing movements, so the
lats are critical for throwing.
Clavicular Pectoralis Major
• O: med. 1/2 clavicle.
• I: Lateral lip bicipital groove
• A: flexion, internal rotation,
• horizontal adduction, adduction
(after having been abducted), and
abduction of shoulder.
N: Lateral pectoral
Sternal Pectoralis Major
• O: Costal cartilage ribs 1-6,
sternum.
• I: Lateral lip of bicipital
groove.
• A: extension, horizontal
adduction, internal rotation,
adduction of shoulder
N: Medial pectoral
The Pectoralis Major: Most
important muscle on front of
trunk.
• Most powerful horizontal adductor.
• Note that both parts of PM are used in
Horiz. Add and Int. Rot..
• Bench press: best exercise for overall PM
development.