subscapularis and muscles of back
TRANSCRIPT
SUBSCAPULARIS
AND MUSCLES OF
BACK
Khaleel Alyahya, PhD, MEd
www.khaleelalyahya.net
OBJECTIVES
• Identify and describe the muscles of the subscapularis region.• Deltoid• Supraspinatus• Infraspinatus• Teres major and minor• Subscapularis
• Identify and describe the muscles of the back.• Trapezius• Latissimus dorsi• Levator scapula• Rhomboideus Major and Minor
• Clinical Notes
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RESOURCES
By Elaine Marieb and Suzanne KellerEssential of Human Anatomy & Physiology
By Frank NetterAtlas of Human Anatomy
3
By Richard Drake, Wayne Vogl & Adam MitchellGray’s Anatomy
MUSCLES OF SCAPULAR REGION
DELTOID
▪ A triangular muscle that forms the contour of the shoulder.
▪ Origin
• Lateral 1/3 of clavicle + acromion and spine of scapula
▪ Insertion
• Deltoid tuberosity of humerus.
▪ Nerve Supply:
• Axillary nerve.
▪ Action:
• Anterior fibers: flexion & medial rotation of humerus (arm-shoulder joint).
• Middle fibers: abduction of humerus from 15°-90 °.
• Posterior fibers: extension & lateral rotation of humerus.
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MUSCLES OF SCAPULAR REGION
▪ Supraspinatus and Infraspinatus.
▪ Teres Major and Miner.
▪ Subscapularis.
▪ Supraspinatus, Infraspinatus, Teres Minor and Subscapularis are known to be the Rotator cuff muscles.
▪ They are playing an important role in keeping the head of humerus in contact with the glenoid cavity during movements of shoulder joint.
▪ Also, they are playing an important role in stability of shoulder joint.
▪ Supraspinatus, Infraspinatus and Teres Minor are inserted into greater tuberosity of humerus.
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SUPRASPINATUS
▪ Nerve Supply:
• Suprascapular nerve; C5, C6 (upper trunk).
▪ Action:
• Abduction of arm (from zero to 15).
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INFRASPINATUS
▪ Nerve Supply:
• Suprascapular nerve; C5, C6 (upper trunk).
▪ Action:
• Lateral rotation of arm.
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TERES MAJOR AND MINOR
Teres Major
▪ Nerve Supply:
• Lower subscapular nerve.
▪ Action:
• Medial rotation and adduction of arm
Teres Miner
▪ Nerve Supply:
• Axillary nerve.
▪ Action:
• Lateral rotation and adduction of arm
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SUBSCAPULARIS
▪ Nerve Supply:
• Upper and lower subscapular nerves.
▪ Action:
• Medial rotation of arm.
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ROTATOR CUFF TEAR
▪ A rotator cuff tear is often the result of wear and tear from
daily use.
▪ Most tears are partial.
▪ It is sport injury during tennis and baseball.
▪ It also can happen suddenly if you fall on your arm or try to
lift something heavy.
▪ It’s usually treated with physical therapy and medication, or
you may need surgery.
Anastomosis around the Scapula
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ROTATOR CUFF TENDINITIS
▪ It is inflammation or irritation of a tendon that attaches to a
bone.
▪ It causes pain in the area just outside the joint.
▪ Common types of tendinitis include pitcher’s and swimmer’s
shoulder.
Anastomosis around the Scapula
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COLLATERAL CIRCULATION
▪ Suprascapular artery.
▪ Deep branch of transverse cervical artery.
▪ Subscapular artery.
▪ The branches of these arteries anastomose on the scapula
deep to: Subscapularis, Supraspinatus and infraspinatus
muscles.
▪ This anastomosis is adequate to carry blood to the upper
limb if the arterial trunk is obstructed between the 1st part
of subclavian and 3rd part of axillary arteries.
Anastomosis around the Scapula
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MUSCLES OF THE BACK
BACK MUSCLES
▪ First Layer:
• Trapezius.
• Latissimus dorsi.
▪ Second Layer:
• Levator scapulae.
• Rhomboideus major and minor.
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TRAPEZIUS
▪ Nerve Supply:
• Spinal root of accessory nerve, piercing sternomastoid muscles, then passing
in the posterior to trapezius.
• C3,4 sensory nerves.
▪ Action:
• Upper fibers: elevate scapula and shoulder.
• Middle fibers: retract scapula (pull scapula medially), and it braces back the
shoulder.
• lower fibers: depress scapula and shoulder.
• Middle & Lower fibers: help serratus anterior to raise arm above head
(abduction of arm more than 90.
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LATISSIMUS DORSI
▪ Nerve Supply:
• Thoraco-dorsal nerve (Nerve to Latissimus dorsi from posterior cord).
▪ Action:
• Extension, adduction and medial rotation of arm (at shoulder joint).
• When the arm is fixed above the head, it pulls the trunk upward as in climbing.
• It helps in violent expiratory efforts as coughing and sneezing.
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LEVATOR SCAPULAE
▪ Nerve Supply:
• C3, 4 nerves.
• C5 via dorsal scapular nerve (Nerve to rhomboids).
▪ Action:
• Elevates scapula and shoulder.
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RHOMBOIDEUS MAJOR AND MINOR
▪ Nerve Supply:
• Dorsal scapular (Nerve to rhomboids C5).
▪ Action:
• They retract the scapula (pull the scapula medially) and brace back the shoulder.
• They rotate the scapula to depress the shoulder.
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