upper arm - insertion, action, innervation Flashcards
trapezius - proximal origin
- occipital bone
- ligaments nuchae
- C7, T1-12
trapezius - distal insertion
- clavicle
- acromion
- scapular spine
trapezius - action
Superior fibres:
Elevation
Middle fibres:
Retraction
Inferior fibres:
Depression
> of scapula
trapezius - innervation
motor: CN XI (accessory)
proprioceptive: C3, C4
Latissimus dorsi - proximal origin
- aponeurosis of posterior layer of thoracolumbar fascia (attaches to all lumbar and sacral vertebrae)
- spinous processes of T7-T12
- posterior iliac crest
- fleshy digitations of caudal-most 4 ribs
Latissimus dorsi - distal insertion
curves around lower border of teres major to insert into intertubercular groove of humerus as a tendon
Latissimus dorsi - action
extends, adducts, medially rotates humerus
(Raises body towards arms e.g. climbing, chin-ups)
Latissimus dorsi - innervation
Thoracodorsal nerve (C6-C8)
(C6, C7 mainly)
Levator scapulae - proximal origin
transverse processes of C1-C4
Levator scapulae - distal insertion
superior portion of the medial border of the scapula from its superior angle to its spine
Levator scapulae - action
- Together with trapezius levator scapulae works to elevate, retract and stabilize the scapula.
- Also when working with trapezius, bilateral contraction produces extension of the neck, while one side produces lateral flexion of the neck.
- It is also active in resisted medial rotation of the scapula.
Levator scapulae - innervation
- direct branches from C3 and C4
- and a branch from dorsal scapular nerve (C5)
deltoid - proximal origin
- anterior border of lateral third of clavicle
- superior surface of acromion
- spine of scapula
deltoid - distal insertion
fibres convene into a tendon inserting laterally into deltoid tuberosity
deltoid - action
Anterior fibres: flexion and medial rotation
Middle fibres: abduction
Posterior fibres: extension and lateral rotation
> of shoulder
deltoid - innervation
axillary nerve (C5, C6)
supraspinatus and infraspinatus - proximal origin
supraspinatus and infraspinatus fascia and fossa
supraspinatus and infraspinatus - distal insertion
supra: The tendon inserts on the upper facet of greater tuberosity of the humerus
infra: The tendon inserts on the middle facet of the greater tuberosity of the humerus.
supraspinatus and infraspinatus - action
supra: initiates abduction, and as part of the rotator cuff, helps to hold the humeral head in the socket throughout its range of movement
infra: lateral rotation of the humerus, but its more important action is as a member of the rotator cuff
supraspinatus and infraspinatus - innervation
supra: Suprascapular nerve (C4, C5, C6)
infra: Suprascapular nerve (C5, C6)
teres major and minor - proximal origin
minor: lateral border of scapula
major: dorsal surface of inferior angle of scapula
teres major and minor - distal insertion
minor: inferior facet on greater tubercle of humerus
major: medial lip of inter tubercular groove of humerus
teres major and minor - action
minor: adduction and lateral rotation of the humerus
- and helps to oppose upward subluxation of the humerus due to the powerful actions of deltoid, biceps brachii, and triceps. Its main action is as a member of the rotator cuff.
major: extends the shoulder, adducts and medially rotates the humerus.
teres major and minor - innervation
minor: Axillary nerve (C5,6)
major: Lower subscapular nerve (C5, C6)
subscapularis - proximal origin
medial two thirds of the costal surface of the scapula, separated from the neck of scapula by subscapularis bursa
subscapularis - distal insertion
inserts on the lesser tuberosity, shoulder joint capsule, and the front of the upper shaft of the humerus
subscapularis - action
adductor and medial rotator of the humerus
subscapularis - innervation
both subscapular nerves (C5,C6,C7)
pectoralis major - proximal origin
- sternal half of clavicle
- upper half of sternum
- aponeurosis of external abdominal oblique
pectoralis major - distal insertion
converge towards anterior wall of axilla. all 3 parts of the muscle (clavicular, sternal, abdominal) end as a flat tendon inserting into intertubercular groove of humerus
pectoralis major - action
- primarily adduction of arm at shoulder
- also medially rotates the humerus and clavicular portion will help flex shoulder and adduct humerus medially
- sternocostal portion, along with latissimus dorsi and teres major can extend flexed humerus to side of trunk against resistance.
pectoralis major - innervation
medial and lateral pectoral nerves (C5-C8 and T1)
biceps brachii - proximal origin
short head - apex of coracoid process of scapula
long head - supraglenoid tubercle of scapula
biceps brachii - distal insertion
radial tuberosity
tendon also gives off a broad aponeurosis medially which fuses with deep fascia of forearm
biceps brachii - action
- powerful supinator
- flexor of the elbow, particularly if the forearm is supinated
- acts to some extent as a flexor of the shoulder
biceps brachii - innervation
C5, C6
coracobrachialis - proximal origin
originates from the tip of the coracoid process, medial to the short head of biceps
coracobrachialis - distal insertion
medial aspect of the mid shaft of the humerus
coracobrachialis - action
Flexes the arm forwards
adduction
coracobrachialis - innervation
Musculocutaneous nerve (C5,C6,C7)
Brachialis - proximal origin
distal half of anterior humerus
Brachialis - distal insertion
tuberosity and anterior surface of coronoid process of ulna
Brachialis - action
powerful flexor of forearm at the elbow
Brachialis - innervation
Musculocutaneous nerve (C5, C6)
triceps brachii - proximal origin
Long head: Infraglenoid tubercle of scapula
Lateral head: post. humerus, sup. to radial groove
Medial head: post. humerus, inf. to radial groove
triceps brachii - distal insertion
olecranon process of ulna
triceps brachii - action
Extension of the elbow joint
triceps brachii - innervation
Radial Nerve (C6, C7, C8)
Anconeus - proximal origin
Lateral epicondyle of humerus
Anconeus - distal insertion
lateral olecranon and superior posterior surface of ulna
Anconeus - action
- Assists in extension of elbow joint
- Abducts ulna during pronation
- WRIST DROP characteristic of radial nerve injury
Anconeus - innervation
Radial Nerve (C7, C8, T1)
Pectoralis minor - proximal origin
ribs 3-5
Pectoralis minor - distal insertion
coracoid process
Pectoralis minor - action
- protraction
- medial roatation
>of scapula
Pectoralis minor - innervation
medial pectoral nerve (C8, T1)
serratus anterior - proximal origin
ribs 1-8
serratus anterior - distal insertion
medial border of scapula
serratus anterior - action
- protraction
- depression
- lateral roatation
>of scapula
serratus anterior - innervation
long thoracic nerve (C5, C6, C7)
Rhomboid major and minor - proximal origin
Minor: nuchal ligament, spinous processes C7-T1
Major: spinous processes T2-T5
Rhomboid major and minor - distal insertion
Minor: medial end of scapular spine
Major: medial border of scapula
Rhomboid major and minor - action
- retraction
- medial rotation
>of scapula
Rhomboid major and minor - innervation
Dorsal scapular (C5) and cervical (C3, C4) nerves
