Shoulder/Arm Group #4 (Biceps Brachii, Triceps Brachii, Coracobrachialis)

Trochlea

"pulley" - more medial

Course of the musculocutaneous nerve

(C5-C7) - starts at terminal branch of lateral cord - Exits axilla by piercing coracobrachialis - goes between biceps brachii and brachialis

Course of Brachial Artery

- begins at inferior border of teres major - ends in cubital fossa opposite of radial neck w/ bicipital aponeurosis on top

course of lateral ante brachial cutaneous nerve

- distal to muscular branches - Emerges lateral to biceps brachii/brachialis, running with cephalic vein to start - descends along lateral border of forearm to wrist

Radial nerve perforates what?

- lateral intermuscular septum - enters cubital fossa - divides into superficial (cutaneous) and deep (motor) Brs

Shoulder Abduction

Agonist: Anterior Deltoid Antagonist: Lats

brachialis origin

Inferior 1/2 of anterior humerus

Blood Supply of Brachialis

Muscular branches of brachial artery Recurrent radial artery

Innervation of coracobrachialis

Musculocutaneous (C5, C6) - Pierces through muscle

innervation of brachialis

Musculocutaneous (C5,C6) radial nerve(C7,C8) - may be sensory

Blood supply to triceps brachii (long head)

Profunda/deep brachii artery Posterior circumflex humeral artery

Ulnar artery course around what

the medial epicondyle

Plantar Flexion

Agonist: Gastroc Antagonist: Tibilias Anterior

Hip Extension

Agonist: Gluteus Max Antagonist: Iliopsoas

Thigh Flexion

Agonist: Illiacus Antagonist: Glute Max

Adducts/lateral arm rotation

Agonist: Infraspinatus Antagonist: Supraspinatus

Shoulder Adduction/Rotation

Agonist: Lats Antagonist: delts/traps

Medial shoulder Rotation

Agonist: Pec Major Antagonist: Infraspinatus

Eccentric contractions

Muscle lengthens

Concentric contractions

Muscle shortens

Agonist movements

Muscle that provides the major force to complete the movement - "Prime Movers"

Isotonic Contractions

Muscles produce slightly more tension that the load we want to lift

Course of median nerve

- lateral root branches off lateral cord (C6-C7) and medial root branches off medial cord (C8-T1) - merge to form median nerve lateral to axillary Aa - adj to brachial Aa - Goes anterior to Artery; lies medial to cubital fossa

Anatomy of triceps brachii

3 heads: long, medial, & lateral - posterior upper arm

Coronoid fossa of humerus

Above trochlea

Hip extension and adduction

Agonist: Adductor Magnus Antagonist: Glute Med and Psoas

Trunk Extension

Agonist: Erector Spinae Antagonist: Rectus Abdominus

Trunk rotation

Agonist: External obliques Antagonist: Rectus Abdominus

Retracts Scapula

Agonist: Rhomboids Antagonist: Serratus Anterior

Neck Flexion

Agonist: Sternocleidomastoid Antagonist: Traps

Forearm Supination

Agonist: Supinator Antagonist: Pronator teres/quadratus

Dorsal flexion

Agonist: Tibialis Anterior Antagonist: Gastroc

Wrist flexion

Agonist: Wrist flexors Antagonist: wrist extensors

Knee flexion

Agonist: hamstrings Antagonist: Quads

Shoulder rotation and Elevation

Agonist: trapezius Antagonist: Lats

radial collateral Arteries

Anterior and posterior branches

boundaries of cubital fossa

Base: an imaginary line connecting lateral and medial epicondyle

BAN stands for

Biceps Artery, Vein, Nerve - running lateral to medial

Shoulder Flexion

Biceps Brachii Coracobrachalis

Big Mac

Biceps Brachii Musculocutaneous Nerve Brachialis Radial Nerve Brachioradialis

Elbow flexion

Biceps brachii

Forearm supination

Biceps brachii

cubital fossa contents from lateral to medial

Biceps tendon Brachial Aa- terminal portion Brachial V Median Nerve

Axillary cutaneous nerve (C5)

Branch of axillary Nerve

Inferolateral brachial cutaneous nerve (C5, C6)

Branch of radial nerve

Posterior ante brachial cutaneous nerve (C6)

Branch of radial nerve

Course of ulnar nerve

C8-T1, often C7 - larger terminal branch of medial cord - passes posterior to medial epicondyle - descends ulnar aspect of FA to hand

Back Antagonist muscle

Chest

Shoulder Adduction

Coracobrachalis

medial epicondyle of humerus

Cubital Tunnel is formed posterior to the condyle - Ulnar nerve passes through it "funny bone" - bigger of 2 epicondyles of humerus

Blood Supply of Anconeus

Deep brachial artery - recurrent interosseous artery

Olecranon fossa of humerus

Depression on posterior humerus - above trochlea

Actions of triceps brachii lateral and medial head

Elbow extension

Action of Biceps brachii

Elbow flexion Forearm supination Shoulder flexion

actions of anconeus

Extends elbow - supports elbow in full extension - abducts ulna during pronation

Tibialis anterior antagonist

Gastroc/soleus

superior ulnar collateral artery

Goes behind the elbow

What could happen to the radial nerve during humeral fracture?

Impingment/torn - Could tear deep brachial/posterior circumflex humeral artery as well

Biceps Tendonitis

Irritation of the long head tendon along the intertubercular groove - During IR/ER patient may feel popping or catching over the anterior shoulder - May indicate dislocation of long head tendon from the inter tubercular groove - transverse Humeral ligament may be weak/loose

cephalic vein

Large vein on the outermost side of the upper arm

Intercostalbrachial Nerve (T2)

Lateral cutaneous branch of 2nd intercostal space nerve

Abs antagonist muscle

Lower back

Isometric Contractions

Maintain Joint angle, increase work load

Ulnar Aa

Medial branches of brachial aa Supply forearm and hand

Innervation of Biceps Brachii

Musculocutaneous nerve (C5, C6)

Course of medial ante brachial cutaneous nerve

O: medial cord of brachial plexus, contributions from (C8,T1) - Pierces deep fascia of arm with basilic vein proximal to cubital fossa - descends medial aspect of FA in subcutaneous tissue to wrist

Triceps brachii insertion

Olecranon Process of ulna - Proximal End Fascia of forearm

Antagonist Movements

Oppose the agonist muscles Typically relaxes or slows down/stops a movement

lateral antebrachial cutaneous nerve

Originates: Off medial cord of brachial plexus

Big Mac (superficial to deep)

Pattie: Musculocutaneous N Bun: brachialis Mm Pattie: radial N Bun: brachioradialis Mm

Triceps brachii lateral head origin

Posterior humerus superior to radial groove

brachioradialis origin

Proximal 2/3 of lateral supra-epicondylar ridge of humerus

innervation of brachioradialis

Radial nerve (C5, C6, C7)

Innervation of Anconeus

Radial nerve (C7, C8) - possibly T1?

Insertion of Biceps Brachii

Radial tuberosity fascia of forearm via bicipital aponeurosis

Actions of the Coracobrachialis

Shoulder flexion Shoulder adduction

boundaries of cubital fossa in forearm

Superior: Imaginary line connecting medial and lateral epicondyles Medial: pronator teres lateral: brachioradialis

Medial brachial cutaneous nerve (T1)

Terminal branch of the medial cord of the brachial plexus

radial artery

The major artery in the forearm; it is palpable at the wrist on the thumb side.

Origin of Biceps Brachii

Tip of Coracoid Process ( short head) Supraglenoid tubercle (long head)

bicipital aponeurosis

Triangular membranous band

Antagonist Muscle of Biceps

Triceps

Elbow Extension

Triceps Brachii

insertion of brachialis

Tuberosity and coronoid process of ulna

radial fossa of humerus

above capitulum

bicipital aponeurosis merges with what

ante brachial fascia - covers flexor muscles in medial side of FA

radial notch of ulna

articulates with head of radius

head of radius

articulates with the capitulum and radial notch

Deep brachial artery goes where

behind humerus

Posterior brachial cutaneous nerve (C5,C6)

branch of radial nerve

Shoulders antagonist muscles

chest/back

brachial artery

continuation of axillary Aa - From lower border of teres major muscle - Goes until radial and ulnar Aa appear

coracobrachialis origin

coracoid process of scapula -tip of

Blood supply of triceps brachii (medial and lateral heads)

deep brachial Aa

main branches of brachial artery

deep brachial artery - superior and inferior ulnar collateral arteries

trochlear notch of ulna

deep notch that separates the olecranon and the coronoid process; articulates with the trochlea of the humerus

Course of the Ulnar Artery in the forearm

descends inferomedially

Destination of Lateral antebrachial Cutan.

divides opp the elbow joint into palmar and dorsal branches of arm

capitulum of humerus

dome on lateral side

anatomy of coracobrachialis

elongated muscle in superiomedial part of arm

Anatomy of the brachialis

flattened fusiform muscle deep to biceps

actions of coracobrachialis

flexes and adducts arm

Actions of brachialis

flexes forearm

Ulnar artery passes superficial to what?

flexor retinaculum at wrist in ulnar (Guyon) canal to enter hand

Quads antagonist muscles

hamstrings

Triceps brachii long head origin

infraglenoid tuberosity of scapula

radial tuberosity

insertion of biceps brachii

coronoid process of ulna

insertion of brachialis

olecranon process of ulna

insertion of triceps brachii

The inferior ulnar collateral artery goes where

it goes anterior to the elbow

Ulnar Artery originates from

larger terminal branch of Brachial Aa in cubital fossa

Course of the radial nerve (C5-T1)

larger terminal branch of posterior cord - exits posterior to axillary artery - posterior to humerus in radial groove with deep brachial Aa - between lateral and medial head of triceps

radial artery winds around what?

lateral aspect of radius - crosses floor of anatomical snuff box and pierces 1st dorsal interosseous muscle

After going between biceps and brachialis what does musculocutaneous become?

lateral cutaneous nerve of forearm

Anconeus Origin

lateral epicondyle of humerus

insertion of brachioradialis

lateral surface of distal radius proximal to styloid process

Action of Triceps Brachii long head

long head: elbow extension, adducts the shoulder, shoulder extension - Resist GH dislocation

insertion of coracobrachialis

middle shaft of medial aspect of humerus -middle 1/3?

Anatomy of Biceps Brachii

most anterior muscle of upper arm - has two heads: long and short

Blood supply to biceps brachii

muscular branches of Brachial artery

anconeus insertion

olecranon process - posterior ulna superiorly

Triceps brachii medial (deep) head origin

posterior humerus inferior to radial groove

Brachial artery becomes what?

radial and ulnar arteries

Innvervation of triceps brachii

radial nerve (C7-C8)

biceps brachii short head action

resist shoulder dislocation

Course of bicipital aponeurosis

runs from bicep tendon across cubital fossa

radial artery origin

smaller terminal branch of Brachial Artery in cubital fossa

Ulnar artery runs deep to what?

superficial pronator teres palmaris longus flexor digitorum superficialis - reaches medial side of forearm

origin of short head of biceps brachii

tip of coracoid process of scapula

Radial artery in Forearm lies lateral to what?

to flexor carpi radialis tendon in distal FA

Radial artery runs inferiolaterally to what?

under cover of brachioradialis

Actions of Brachioradialis

weak flexion at elbow - max power when forearm in midpronated position