Muscles of the Upper Limb

Muscles of the Upper Limb
Muscles equal movement…
What muscles do you already know?
 What are the three types of muscle contractions in the body?
 How can you remember which muscles move a specific joint?
 What happens to the muscles at a specific joint during each
type of muscle contraction?
 Hint: choose a joint, then figure out the muscles that move it
and the movements it makes. Then, apply this knowledge to
each type of muscle contraction.
Posterior View of Back
Levator Scapulae
Rhomboid Minor
Teres Minor
Latissimus dorsi
Rhomboid Major
Motions of Muscles
 Trapezius
 Scapular elevation, adduction, retraction, upward rotation and
depression, also extends neck
 Latissimus Dorsi
 Adductor, extensor & internal rotator of arm
 Rhomboids
 Assist trapezius in downward rotation of the scapula and
adduction or retraction of scapula
 Levator Scapulae
 Elevates the scapula and helps rotate the scapula downward
Muscles of the Rotator Cuff
Teres minor
Subscapularis - Sits on anterior side of Scapula
Motions of Muscles for Rotator Cuff
 Supraspinatus
 Abducts the shoulder
 Infraspinatus
 Laterally Rotates the Shoulder
All three of these
muscles help stabilize
the shoulder joint
 Teres Minor
 Laterally rotate the shoulder
 Subscapularis
 Rotates humerus medially, stabilizes the shoulder
Muscles that Move the Humerus
Pectoralis Major
Deltoid (anterior
and lateral heads)
Motions of Muscles
 Deltoid
 Anterior Head
 Flexes and medially rotates the shoulder joint
 Lateral Head
 Abducts the arm
 Posterior Head
 Extends and laterally rotates the arm
 Coracobrachialis
 Acts as a flexor and adductor of the arm
 Teres Major
 Medial rotator, adductor and helps extends the humerus at the arm
 Pectoralis Major
 Internal rotation, adduction and flexion of the arm
Muscles that Move the Humerus – cont’d
Pectoralis minor
Serratus anterior
Motions of Muscles
 Pectoralis Minor
 Elevates the ribs and depresses and protracts the scapula
 Serratus Anterior
 Upward rotation, abduction or protraction of the scapula
Elbow Flexors / Extensors – Anterior
Biceps brachii
Pronator teres
Motions of Muscles
 Biceps Brachii
 Supinator in the forearm, acts to flex the elbow
 Brachialis
 Acts as an elbow flexor
 Brachioradialis
 Elbow flexor
Elbow Flexors / Extensors – Posterior
Triceps brachii
(short head)
Triceps brachii
(long head)
Motions of Muscles
 Triceps Brachii
 Main extensor of the forearm
 Has three heads
 Short, long and medial
Muscles of the Forearm – Anterior
Biceps brachii
Muscles of the Forearm – Posterior
Triceps brachii
(lateral head)
Extrinsic Hand Muscles – Anterior
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris
Flexor digitorum superficialis
Extrinsic Hand Muscles – Posterior
Extensor carpi radialis longus
Extensor digitorum
Extensor carpi ulnaris
Extensor carpi radialis brevis
Extensor digitorum minimis
Motions of Muscles
 Using the wrist as an example, deduce the muscles that are
responsible for the movements that happen around that joint.
 What are the movements around the wrist?
Flexes hand and wrist
Adducts and abducts wrist
Extends hand and wrist
Adducts and abducts wrist
Muscle Contractions
 What are the 3 types of muscle contractions?
 Concentric (___________)
 Ex. Bicep shortens when lifting an object
 Eccentric (____________)
 Ex. Bicep lengthens when putting same object down
 Isometric (________)
 When trying to lift an immovable object!
Back to the Questions:
 What are the three types of muscle contractions in the body?
 How can you remember which muscles move a specific joint?
 What happens to the muscles at a specific joint during each
type of muscle contraction?
Antagonist vs. Agonist Muscles
 How do muscles work together in the human body?
 One muscles (extensor) is required to move the bone in the
opposite direction and stretches opposite the muscle (flexor)
 The flexor and extensor in this case are described as
anatagonistic muscles
Antagonist vs. Agonist Muscles
 Agonist Muscle
 The muscle primarily responsible for movement of a body part
 Antagonist Muscle
 Muscle that contracts the agonist, lengthening when the agonist
muscle contracts
Antagonistic Pairs
 What are some example of Antagonist and Agonist muscles in
the upper limb?
 Biceps Brachii and Triceps Brachii
 When you Flex your Biceps, your triceps extends
 Deltoid and Latissimus Dorsi
 When you abduct your shoulder your deltoid flexes and your latissimus
dorsi extends

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