Muscles of the upper extremity

Upper limbmusculature

Scapula Muscles

• If the origin is on the scapula – moves the arm– Subscapularis– Supraspinatus– Infraspinatus– Teres Minor– Teres Major– Latissimus Dorsi (partial attachment)– Coracobrachialis

RotatorCuff

pg 656

Scapula Muscles

• If the insertion is on the scapula – moves the scapula– Rhomboids– Trapezius– Pectoralis Minor– Serratus Ventralis– Levator Scapulae

Use location of Insertion to determine movement!!pg 656

Arm Muscles

• Arm Compartments– Anterior Compartment (3 muscles)

• Flexors of forearm and arm

– Posterior Compartment (1 muscle)• Extensor of forearm and arm

pg 667

Remember: If you cross the shoulder, you move the arm; if you cross the elbow, you move the forearm

Arm Muscles

• Anterior compartment– Brachialis– Coracobrachialis– Biceps brachii

• Long head• Short head

pg 718 pg 715

Arm Muscles

• Posterior compartment– Triceps brachii

• Long head• Medial head• Lateral head

pg 717

Muscles of ArmMuscle Origin Insertion Action Innerv

Anterior Brachialis Ant shaft , distal humerus Coronoid process

/ulnar tuberosity

(ulna)

Flex forearm

Musculo-cutaneous

Biceps Brachii Long: supraglenoid tubercle (scapula)

Short: coracoid proc (scapula)

Radial Tuberosity (radius)

Flex forearm, Supination

Musculo-cutaneous

Coracobrachialis Coracoid proc (scapula) Medial surface midshaft (humerus)

Flex arm, Adduct arm

Musculo-cutaneous

PosteriorTriceps Brachii Long: Infraglenoid tubercle

(scapula)

Medial: Posterior Shaft

(middle humerus)

Lateral: Posterior Shaft

(proximal humerus)

Common tendon to olecranon (ulna)

Extend forearm

Radial

Forearm Muscles

• Cross elbow, wrist and finger joints• Movement of hand and fingers• Proximally are fleshy• Distally have long tendons• Flexor and extensor retinacula

– “wristbands”– Keep tendons from jumping outwards when tensed

pg 738

Forearm Muscles

• Anterior compartment– Superficial and Deep layers– Flexors of hand and fingers– Most flexors have common origin on medial epicondyle– Contains 2 pronator muscles

• Posterior compartment – Superficial and Deep layers– Extensors of hand and fingers– Most extensors have common origin on lateral epicondyle– Contains a supinator muscle

pg 732

Anterior Compartment of Forearm

Muscles Nerves– Superficial

• Flexor digitorum superficialis Median• Flexor carpi radialis Median• Pronator teres Median• Palmaris longus Median• Flexor carpi ulnaris Ulnar

– Deep • Pronator quadratus Median• Flexor pollicis longus Median• Flexor digitorum profundus Ulnar (med 1/2)

Median (lat 1/2)pg 738, 740

Posterior Compartment of Forearm Muscles Nerves

– Superficial• Brachioradialis Radial• Anconeus Radial• Extensor carpi radialis longus & brevis Radial• Extensor digitorum Radial• Extensor carpi ulnaris Radial• Extensor digiti minimi Radial

– Deep• Supinator Radial• Abductor pollicis longus Radial• Extensor pollicis longus + brevis Radial• Extensor indicus Radial

pg 746

Intrinsic Muscles of the Hand

Muscle Nerve• Pinky = Hypothenar muscles

– All digiti minimi Ulnar(Flexor, Abductor, Opponens)

• Thumb = Thenar muscles– Abductor pollicis brevis Median– Flexor pollicis brevis Median– Opponens pollicis Median– Adductor pollicis Ulnar

• Other Intrinsic Muscles– Palmar + Dorsal Interossei Ulnar– Lumbricals Median, Ulnar

Elevators

DeltoideusOrigin: Lateral half of clavicle ,

Scapular spine, acromion processInsertion: Deltoid tuberosity of humerusAction: Abducts humerus (also flexes, extends, rotates and adducts)Innervation: Axillary nerve

Deltoid

What You Should Know3: UPPER LIMB COMPLICATIONS• Origin, insertion, innervation and action of

the following (Cartmill pages 224-230)

• Trapezius

• Serratus anterior

• Levator scapulae

• Rhomboid major

• Rhomboid minor

• Latissimus Dorsi

• Pectoralis Major (Sternal, Clavicular) and Minor

What You Should Know4. THE SHOULDER 

Cartmill pages 231-237

Origin, insertion, innervation and action of the following:

Teres MajorSubscapularis

Teres minor Deltoid

Pectoralis MajorSupraspinatus

Infraspinatus

Musculature Crossing the Elbow Joint

Muscles moving the elbow all cross the joint and insert on the bones of the forearm.

They may originate from the scapula or the brachium (humerus).

Which muscle is NOT a flexor of the elbow?A

B

C

D

Answer =ACoracobrachialis

The Coracobrachialis makes up part of the mass of the upper arm but doesn’t actually cross the joint (scapula to humerus only).

Origin: coracoid process

Insertion: Humerus

Flexion and adduction of humerus.

Musculocutaneous nerve

Elbow extensors

Triceps brachii

(Radial Nerve)

Triceps =

Quadriceps

Cranial/dorsal

Origin:Long Head: Glenoid FossaMedial & Lateral Heads:Posterior surface of humeral shaft

Insertion:Olecranon process of ulna

Action: Extends elbow

Triceps Long Head

Triceps, Lateral Head

Elbow flexors

Brachii(brachial group)

(Here, spelling counts…)

Hamstrings =brachii

Caudal/ventral

Biceps brachii(musculocutaneous n.)

Origin:Short head: coracoid processLong head; glenoid fossa

Insertion:Proximal radius

Action: Flexes elbowsupinates

Brachialis(musculocutaneous n.)

Origin:Humeral shaft

InsertionProximal ulna

Action: flexes elbow

Corcobrachialis

Brachialis

Biceps

Brachioradialis(Radial n.* exception)

Origin: distal humerus

Insertion:Styloid process of ulna

Action: Flexes elbow

Brachioradialis

Flexor Carpi RadialisFlexor Digitorum

Superficialis

Flexor Carpi Ulnaris

FLEXORS of the Wrist

Flexors =Flexors

Caudal/ventral

Superficial Layer

Flexor carpi radialis Median n.

Origin: Medial epicondyle of humerus

Insertion:Base of 2nd & 3rd metacarpals

Action: Flexes wrist; abducts hand

Superficial Layer

Palmaris longusMedian n.

Origin: Medial epicondyle of humerus

Insertion:Palmar aponeurosis

Action: Flexes wrist

Superficial Layer

Flexor carpi ulnarisUlnar n.

Origin: Medial epicondyle of humerus

Insertion:Pisiform and base of 5th metacarpal

Action: Flexes wrist; adducts hand

Intermediate Layer

Flexor digitorum superficialisMedian n Origin: Medial epicondyle of humerus

Insertion:Middle phalanges of fingers 2-5Action: Flexes wrist and middle phalanges

Deep Layer

Flexor pollicis longusMedian n

Origin: Anterior surface of radius

Insertion:Distal phalanx of thumbAction: Flexes distal phalanx of thumb

Deep Layer

Flexor digitorum profundus Median n

Origin: Anteromedial surface ulna

Insertion:Distal phalanges of fingers 2-5Action: Flexes distal phalanges

Brachioradialis

Flexor Carpi RadialisFlexor Digitorum

Superficialis

Flexor Carpi Ulnaris

EXTENSORS of the Wrist

Extensors =Extensors

Caudal/dorsal

Superficial

Extensor carpi radialisbrevisRadial n.Origin: Lateral epicondyle of humerus

Insertion:Base of 3rd metacarpalAction: Extends and abducts wrist

Superficial

Extensor digitorum minimi Radial n.

Origin: Lateral epicondyle of humerus

Insertion:Distal phalange of little fingerAction: Extends little finger

Superficial

Extensor digitorum Radial n.

Origin: Lateral epicondyle of humerus

Insertion:Distal phalange of fingers 2-4Action: Extends fingers and wrist; abduct fingers

Extensor Carpi Radialis

Abductor Pollicis LongusExtensor Retinaculum

Extensor CarpiUlaris

Extensor Indicis

Extensor Digitorum

Superficialis

Deep

Extensor indices

Radial n.Origin: Posterior surface of distal ulna

Insertion:Extensor expansion of index fingerAction: Extends index finger

Deep

Extensor pollicis longusRadial n.

Origin: Dorsal shaft of radius and ulnaInsertion:Base of distal phalanx of thumbAction: Extends thumb

Deep

Extensor pollicis brevis Radial n.

Origin: Dorsal shaft of radius and ulnaInsertion:Base of proximal phalanx of thumbAction: Extends thumb

Deep

Abductor pollicis longusRadial n.

Origin: Posterior surface of radius and ulnaInsertion:Base of 1st metacarpalAction: Abducts and extends thumb

Muscles of Pronation

and Supination

Deep

Abductor pollicis longusRadial n.

Origin: Posterior surface of radius and ulnaInsertion:Base of 1st metacarpalAction: Abducts and extends thumb

Supination:Movement of the radius and ulna

Lateral rotation of the arm so palm faces superiorally

(anatomical position)

Ulna and Radius are parallel

 

Pronation:

Opposite of supinationMedial rotation of the arm so palm faces inferiorallyRelaxed position

Ulna and Radius are crossed

Supination

SupinatorRadial n.Origin: Lateral epicondyle of humerusInsertion:Proximal end of radiusAction: Supinates forearm

Supinator

Supination

Biceps brachii musculocutaneous n.

Origin:Short head: coracoid processLong head; glenoid fossaInsertion:Proximal radiusAction: Flexes elbowsupinates

Pronation

Pronator teresMedian n.

Origin:Medial condyle of humerusCoronoid process of ulnaInsertion:Lateral radius (midshaft)Action: Pronates forearm

Pronation

Pronator quadratusMedian n.Origin:Distal portion of anterior ulnarshaftInsertion:Distal surface of anterior radiusAction: Pronates forearm

Pronator Teres

Pronator Quadratus

What You Should Know1: Muscles Crossing the Elbow

Joint• Flexors (ventral)

• Extensors (dorsal)

2: Muscles Crossing the Wrist Joint

Flexors (ventral)

Extensors (dorsal)

What You Should Know3: Muscles of Elbow Extension,

Flexion• Origin and Insertion

• Innervation

3: Muscles of Pronation and Supination

• Origin and Insertion

• Innervation

What You Should Know3: Serial Homologs of Major

Groups

4: Functions of all Muscles Presented

5: A Summary of these muscles are in the Laboratory Manual and Cartmill’s Text.