Scapular Region

Dr. Sama-ul-Haque Dr. Rania Jabr

Scapular Region

Objectives

Know the principal muscles of the scapular and scapulo-humeral regions.

Understand the mechanism of scapular rotation in relation with shoulder movements.

Bones of the shoulder region: The SCAPULA

Anterior

Posterior

These muscles connect scapula to humerus (move humerus through shoulder joint).

1. Deltoid.2. Supraspinatus.3. Infraspinatus.4. Teres minor.5. Teres major.6. Subscapularis.

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Posterior view

Anterior view

Muscles of The Shoulder Region

• Spine

Acromion (of scapula

Teres minormuscle

Teres majormuscle

Infraspinatusmuscle

Triangle ofascultation

Trapezius muscle

Surface Anatomy

Deltoid

Nerve supply:Axillary nerve

Action:Anterior fibers : Flexion, medial rotation Middle fibers: abduct arm from 15°- 90°.Posterior fibers : Extension, lateral rotation

Lateral third of clavicle, acromion, spine of scapula

Deltoid tuberosity of humerus

D

Abductors of shoulders:1. Supraspinatus 0-15 degree.2. Deltoid 15-90 degree.3. Trapezius & serratus anterior: abduction 90-180 degree.

4 Rotator cuff muscles: stabilize the shoulder joint.Supraspinatus, Infraspinatus,Subscapularis, Teres minor

Rotator Cuff Muscles

Supraspinatus

Infraspinatus:

Origin: supraspinous fossa.Insertion: greater tuberosity of humerus.Nerve supply: suprascapular nerve.Action: abduction of humerus from 0° - 15°.

Origin: infraspinaous fossa.Insertion: greater tuberosity of humerus.Nerve supply: suprascapular nerve.Action: lateral rotation of humerus.

Origin: lateral border of scapulaInsertion: greater tuberosity of humerus.Nerve supply: axillary nerve.Action: lateral rotation of humerus.

Origin: lateral border of scapulaInsertion: bicipital groove of humerus (med lip)Nerve supply: lower subscapular nerve.Actions: extension, adduction & medial rotation of humerus (swimming).

Teres minor

Teres major:

Origin: subscapular fossa.Insertion: lesser tuberosity of humerus.Nerve supply: upper & lower subscapular nerves.Action: medial rotation of humerus.

Subscapularis

Transverse scapular ligament

• Attach to suprascapular notch• Subscapular nerve (C5,6) below it and Subscapular artery above it,

Nerve supply: • Long thoracic nerve.Action:• Depression & protraction of

the scapula (boxing) • Raising the arm above 90

degree (climbing).• Accessory muscle of

respiration

Serratus anterior

Upp

er 8

ribs

Front of the medial border of scapula.

Injury of long thoracic nerve: Winged Scapula:

Subscapularis

Cause; Paralysis of serratus anterior as it is "big swing muscle" or "boxer's muscle”Antagonist of Rhomboids

Injury of long thoracic nerve

Complete abduction at the shoulder joint requires superior rotation of the scapula so that the glenoid fossa faces superiorly.

Glenoid fossa

• Superior rotation of Glenoid fossa: trapezius &

serratus anterior

Scapula rotates when we move our arms to allow more range of motion at the shoulder joint

Posterior scapula