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