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Latissimus Dorsi – Attachments & Action

image descriptionLatissimus Dorsi (Musculus latissimus dorsi):

 

A posterior view of Latissimus Dorsi and Trapezius, Deltoid, Gluteus Medius, Gluteus Maximus and Triceps Brachii muscles.
A posterior view of Latissimus Dorsi muscle.
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image descriptionAttachments of Latissimus DorsiOrigin & Insertion

Origin: (proximal attachment)
a. Spinous processes of T7 – L5 vertebrae.
b. Iliac crest of sacrum.
c. Thoracolumbar fascia.
d. Inferior angle of the scapula.
e. Lower three or four ribs.

Insertion: (distal attachment)
a. Floor of intertubercular (bicipital) groove of humerus.

 

A posterior view of Latissimus Dorsi and Trapezius, Deltoid, Gluteus Medius, Gluteus Maximus and Triceps Brachii muscles.
A posterior view of Latissimus Dorsi muscle.
A posterior and an anterior view showing insertion and the origin of the Latissimus Dorsi muscle.
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Actions of Latissimus Dorsi:

a. image descriptionAdducts the arm at the shoulder (glenohumeral) joint.

 

b. image descriptionMedially rotates the arm at the shoulder (glenohumeral) joint.

c. image descriptionExtends the arm at the shoulder (glenohumeral) joint.

Innervation of Latissimus Dorsi:

image descriptionNerve to the muscle:
a. Thoracodorsal nerve.

image descriptionNerve roots:
a. C6, C7, and C8.

The Thoracodorsal Nerve innervating the latissimus dorsi muscle.
Thoracodorsal nerve within the brachial plexus
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An overview of the anterior muscles of the arm:

An posterior view of the back and arm muscles with labels for Trapezius, Deltoid, Triceps Brachii (lateral and long head), Latissimus Dorsi and Extensor Carpi Radialis Longus muscles.
An posterior view of the back and arm muscles with labels for Splenius Capitis, Rhomboid Major, Rhomboid Minor, Triceps Brachii (long and lateral head) and Latissimus Dorsi muscles.
An posterior view of the back and arm muscles with labels for Splenius Capitis, Serratus Posterior Superior, Erector Spinae, Triceps Brachii (long and lateral head) and Latissimus Dorsi muscles.
An posterior view of the back and arm muscles with labels for Splenius Capitis, Levator Scapulae, Splenius Cervicis, Erector Spinae, Triceps Brachii (long and lateral head) and Latissimus Dorsi muscles.
An posterior view of the back and arm muscles with labels for Semispinalis Capitis, Levator Scapulae, Supraspinatus, Infraspinatus, Erector Spinae, Triceps Brachii (long and lateral head) and Latissimus Dorsi muscles.
An posterior view of the back muscles with labels for Supraspinatus, Infraspinatus, External Intercostals, Teres Major and Latissimus Dorsi muscles.
An posterior view of the back muscles with labels for Supraspinatus, Infraspinatus, Teres Minor, Teres Major and Latissimus Dorsi muscles.
An posterior view of the Latissimus Dorsi muscle.
A posterior view of trunk and arm bones showing the origin and anterior view of arm bones showing the insertion of the Latissimus Dorsi muscle.
Test yourself while observing the Latissimus Dorsi muscle
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