PT 750 - Superficial Back, Scapular, and Deltoid Regions

Anterior Scapula with Labels

Label the features of the anterior scapula

Posterior scapula with labels

Label the features of the posterior scapula

What do the both the ventral and dorsal rami innervate?

Ventral Rami innervate the superficial muscles of the back such as the Trapezius

Dorsal Rami innervate the skin of the back and the deep muscles

What are the movements of the scapula?

elevation, depression, protraction, retraction, upward rotation, downward rotation

What runs through the scapular notch?

The supra scapular nerve runs through the notch while the superior transverse scapular ligament converts it into a foramen

Anterior humerus with labels

Label the features of the anterior humerus

Posterior humerus with labels

Label the features of the posterior humerus

What directions does the humeral head face?

Posterior, medial, and superior (PMS)

What directions does the glenoid face?

Superior, anterior, and lateral (UFO, upward-superior, forward-anterior, outward-lateral)

Would a fx at the anatomical neck of the humerus require surgery?

Yes since a fx there is intra-articular meaning it is in the joint, no surgery could lead to improper healing and post traumatic arthritis

Would a fx at the surgical neck of the humerus require surgery?

No since it is outside of the joint, meaning it is extra-articular. Patient would be a placed in a sling to immobilize is all.

What are the extrinsic muscles of the back?

trapezius, rhomboid minor, rhomboid major, levator scapulae, latissimus dorsi

What do extrinsic muscles of the back connect?

These muscles connect the upper limb to the trunk

Do extrinsic muscles originate on the back?

No they do not

Trapezius Origin

external occipital protuberance, superior nuchal line, ligamentum nuchae, spinous process C7-T12

Trapezius Insertion

spine of scapula, distal clavicle, and acromion

Trapezius Innervation

spinal accessory nerve

Trapezius Action

upper fibers - elevate the scapula

lower fibers - depress the scapula

middle fibers - retract the scapula, upward rotation of the scapula

Latissimus Dorsi Origin

iliac crest, thoracolumbar fascia, lower thoracic and lumbar spinous processes, lower 3-4 ribs, inferior angle of the scapula

Latissimus Dorsi Insertion

intertubercular groove of the humerus

Latissimus Dorsi Innervation

thoracodorsal nerve, C6-C8

Latissimus Dorsi Action

shoulder extensor, adductor, and IR

Rhomboids Origin

spinous processes C7-T5

Rhomboids Insertion

medial border of the scapula

Rhomboids Innervation

dorsal scapular nerve, C5

Rhomboids Action

scapular retraction, scapular downward rotation

Levator Scapulae Origin

posterior tubercles transverse processes C1-C4

Levator Scapulae Insertion

superior angle of the scapula

Levator Scapulae Innervation

dorsal scapular nerve, C5

Levator Scapulae Action

scapular elevation, scapular downward rotation

What are the four muscles of the rotator cuff?

Supraspinatus (posterior)

Infraspinatus (posterior)

Teres Minor (posterior)

Subscapularis (anterior)

What is the function of the rotator cuff muscles?

To increase the dynamic stability of the glenohumeral joint

Which rotator cuff muscle passes under the coracoacromial hood?

The supraspinatus passes underneath

Supraspinatus Origin

supraspinous fossa

Supraspinatus Insertion

superior facet greater tubercle of the humerus

Supraspinatus Innervation

suprascapular nerve, C5-C6

Supraspinatus Action

shoulder abduction

(If there was an action in the transverse plane it would be ER)

Infraspinatus Origin

infraspinous fossa

Infraspinatus Insertion

middle facet greater tubercle of the humerus

(greater tubercle is a posterior structure)

Infraspinatus Innervation

suprascapular nerve, C5-C6

Infraspinatus Action

shoulder ER

Teres minor Origin

lateral border of the scapula

Teres minor Insertion

inferior facet greater tubercle of the humerus

Teres minor Innervation

axillary nerve, C5-C6

Teres minor action

shoulder ER

Subscapularis origin

subscapular fossa

Subscapularis Insertion

lesser tubercle of the humerus

Subscapularis Innervation

upper and lower subscapular nerves C5-C7

Subscapularis Action

shoulder IR

(also functions during overhead elevation)

Deltoid Origin

spine of the scapula, acromion, clavicle

Deltoid Insertion

deltoid tuberosity of the humerus

Deltoid Innervation

axillary nerve C5-C6

Deltoid Action

anterior fibers - flex/IR of the shoulder

middle fibers - ABD

posterior fibers - ext/ER, horizontal ABD

Teres Major Origin

inferior angle of the scapular

Teres Major Insertion

intertubercular groove of the humerus

Teres Major Innervation

lower subscapular nerve (C6-C8)

Teres Major Action

shoulder extension, adduction, and internal rotation

What exits the quadrangle space?

The axillary nerve and posterior circumflex humeral artery

What are the borders of the quadrangle space?

Superior: subscapularis (ant); teres minor (post)

Inferior: teres major

Medial: long head of the triceps

Lateral: surgical neck of the humerus

Which muscles does the axillary nerve innervate?

The deltoid and teres minor

What does the axillary nerve end as?

The superior lateral brachial cutaneous nerve

Discuss how you could test for axillary nerve damage with a fracture at the humerus.

Knowing that the axillary nerve ends in sensation, if it were to be damaged the patient would lose sensation around the superior lateral aspect of the arm. If you think it is damaged, you can test for this by touching the skin to examine whether sensation is present or not.