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.

Surface Anatomy

• Spine

Acromion (of scapula

Teres minormuscle

Teres majormuscle

Infraspinatusmuscle

Triangle ofascultation

Trapezius muscle

AnteriorScapula.-angles, borders-glenoid cavity, -acromion, -coracoid process, -Subscapular fossa

Humerus.-Head,-Surgical neck-Anatomical neck-Greater tubercle-Lesser tubercle-Intertubercular (bicipital) groove

PosteriorClavicle.Acromioclavicular joint

Scapula.- Spine - Acromion- Supraspinous fossa- Infraspinous fossa

Humerus. - Head - Anatomical neck, - Surgical neck, - Deltoid tuberosity- Spiral (radial) groove.

Superior rotation of Glenoid fossa:

- Powerful muscles pull on bony struts.

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

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

Glenoid fossa

Deltoid

• Clavicular origin, acromial, and scapular origins, attach all to deltoid tuberosity

• Anterior fibers flexes• Posterior fibers extends and

laterally rotates• Middle fibers abducts the arm• Innervation C5,6 Axillary nerve

Delta= TriangleDeltoid=triangular in shape Principal abductors= Deltoid, supraspinatus

Subdeltoid / Subacromial bursa.

Bursa: a closed sac or envelope, lined with synovium and containing fluid, usually in areas subject to friction.

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

Rotator Cuff MusclesBecause the scapula is triangular deep bone, paddedwith thick muscles, injuries leading to scapular fractures Will be so severe , and most commonly we will have lots of multiple, or serious other fractures

Transverse scapular ligament

• Runs between Subscapular nerve (C5,6) and artery, which supply Supraspinatus and Infraspinatus muscles

• Artery above, nerve below

Serratus Anterior

Winged Scapula: (long thoracic nerve)

Subscapularis

"big swing muscle" or "boxer's muscle”Antagonist of RhomboidsAccessory muscle of respiration

Posterior view:- Trapezius- Latissimus Dorsi- Deltoid

Rhomboids:- minor and major- retract / inferior rotate scapula

Teres major:- inserts near latissimus dorsi- adduct / medially rotate arm

Rhomboids retract, so injury to the dorsal scapular nerve will make the

scapula further away from the midline on the affected side

Posterior scapula

Thank you