Shoulder region, muscles of the scapula & posterior arm Flashcards
What is the name of the broad triangular flat muscle on the back?
a. Latissimus Dorsi
b. Trapezius
c. Levator Scapulae
d. Deltoid muscle
b. Trapezius
What are the 2 origins of the Trapezius muscles?
- Superior nuchal line of the occipital bone
2. Spinous process of C7-T-12
What are the 3 insertions of the Trapezius muscles?
Fibres attach to the
- clavicle
- acromium
- Scapular spine
What are the 2 innervations of the Trapezius muscle?
Accessory nerve (CN-XI)
C3-C4 cranial nerves
What are the 3 functions of the Trapezius muscles?
- Elevates the scapula
- Retracts the scapula
- Rotation of the scapula during abduction of the arms
How would you clinically test the Trapezius muscle and what does it test?
Ask patient to elevated the shoulder against resistance.
Tests the integrity of the muscle
What are the names of the two bone that make up the pectoral girdle?
Clavicle
Scapula
What are the 6 muscles that make up the pectoral girdle?
Rhamboid muscles Trapezius Subclaviculus Pec minor Latissimus dorsi
What is the name of the muscle that originates from the lower part of the back?
a. Latissimus Dorsi
b. Trapezius
c. Levator Scapulae
d. Deltoid muscle
a. Latissimus Dorsi
What are the 4 origins of Lattissimus Dorsi?
- Spinous process T6-T12
- Illiac crest
- Thoracolumbar fasciae
- Inferior 3 limbs
Where is the insertion of Lattissimus Dorsi?
The fibres converge into a tendon and attach to the intertubercular sulcus of the humerus
What is the innervation of Lattissimus Dorsi?
Thoracodorsal nerve (c6-c8)
What are the 3 action of Lattissimus Dorsi?
Extends, adducts and medially rotates the humerus
What is the blood supply to the Lattissimus Dorsi?
Thoracodorsal artery (branch of the suscapular artery which is a branch of the axillary artery)
What is the name of a muscle that has a multi-pennate arrangement?
Deltoid muscle
What are the 3 origins of the deltoid muscle?
Lateral 1/3 of the clavicle,
superior surface of the acromion
the spine of the scapula
Where is the insertion of the deltoid muscle?
Fibre converge into a thick tendon and insert into the deltoid tuberosity on the lateral aspect of the humerus
What is the innervation of the deltoid muscle?
Accessory nerve (C5-C6)
What is the blood supply to the deltoid muscle?
Thoracoacromion artery
What are the 3 action of the deltoid muscle?
- Abduction of the arm
- Rotates the arm medially and helps pec major flex the arm at the shoulder
- Rotates arm laterally and extends the arm with the help of latissimus dorsi
What is the name of the strap like muscle that begins at the neck and attaches to the scapula?
Levator Scapulea
What is the origin of the Levator Scapulea?
The spinous process of the first 4 cervicle vertebrae
What is the insertion of Levator Scapulea?
To the medial border of the scapula
What nerve innervates the Levator Scapulea?
Dorsal scapular nerve
What is the action of Levator Scapulea?
ELevates the Scapula
How would you test the functioning of levator scapula?
Asking the patient to shrug the shoulder against resistance
What is the origin of the Supraspinatus?
Originates from the supraspinatus fossa of the scapula
Where are the 2 insertions of supraspinatus?
Capsule of the shoulder joint
higher up on the greater tubercle of the humerus
What nerve innervated the supraspinatus?
Suprascapular nerve (C5-C6)
What are the 2 functions of the supraspinatus?
- Stabilise the shoulder joint
2. Abduction of the arm during contraction
What is the origin of the infraspinatus?
The infraspinatus fossa of the scapula and travels downwards
What is the insertion of infraspinatus?
Lower down on the tubercle of the humerus
What nerve innervates infraspinatus?
suprascapular nerve (C5-C6)
What are the 2 actions of infrapsinatus?
stabilise the shoulder joint
lateral rotator of the humerus
Where is the origin of teres minor?
Lateral border of the scapula
Where is the insertion of teres minor?
Greater tubercle of the humerus
What nerve innervates teres minor?
Axillary nerve
What are the 2 action of teres minor?
- Lateral rotator of the arm
2. Adducts the arm at the shoulder
What is the origin of teres Major?
Dorsal surface of the inferior angle of the scapula
Where is the insertion of teres major?
Medial lip of the intertubercualr groove of the humerus
What is the innervation of teres major?
Lower scapular nerve
What are the 3 actions of the teres major?
- Extends arm from flexed position
- Adducts the arms
- Medially rotates the arm.
What structures make up the pectoral girdle?
Scapula
Clavicle
muscles attached to them
Latissimus dorsi
What nerve runs against the humerus?
Axillary nerve
What nerve will get damaged from a posterior dislocation of the shoulder?
Axillary nerve
What nerve will get damaged from a fracture of the neck of the humerus?
Axillary nerve
What will damage to the axillary nerve cause?
Paralysis of the deltoid muscle
Area of numb skin on the lateral arm
What nerve runs in the spinal groove directly against he humerus?
Radial nerve
What nerve can be damaged by direct pressure or fracture of the humerus?
Radial nerve
What nerve passes behind the medial epicondyle of the humerus?
Ulna nerve
What kind of pain is felt by damage to the ulna nerve?
Pins and needles in the skin
