Clinical Anatomy: Muscles and Nerves of the Upper Limb

Clinical Anatomy: Upper Limb Overview

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Clinical Anatomy
Lecture 7: Upper Limb Anatomy 2
Dr. Karyn Lumsden BSc, M.Ed., DC
Assistant Professor
Karyn.Lumsden@medready.org
Practice Questions are posted on Canvas

Lecture Objectives

1. Identify the muscles of the upper limb and their anatomical
   location within the limb
2. Understand the major compartments of the upper limb with
   respect to innervation and muscles located within each
3. Describe the main action of individual muscles with respect to
   upper limb joints
4. Identify which muscles work together to perform movement of
   the upper limb joints
5. Compare the common flexor origin (medial epicondyle) and
   common extensor origin (lateral epicondyle)
6. Explain the pattern of motor innervation to the arm
7. Understand the arc of abduction at the glenohumeral joint and
   which muscles would be involvedHow do muscles create
   movement of joints?

· The action of a muscle pulling on a bone often works like
a type of simple machine called a lever.
. The lever is the bone
· The axis of rotation (movement) is the joint
. The force pulling on the lever is the muscle
. Any force applied to the lever is called the effort.
. The contraction of the muscles creates movement of
the joint
. The muscle must cross the joint to exert force on it
. The shape of the articular surfaces ( the
classification) dictates the type of movement that is
allowed
. Review L6 for the upper limb joint classifications
and movements!
Force
Resistance
Force
Resistance

Anatomy of the Upper Extremity

Pectoral Girdle and Bones

Recall: Anatomy of the Upper Extremity
· Pectoral Girdle
· Scapula
· Clavicle
· Bones of upper extremity
· Humerus - proximal
· "Arm"
· Radius - lateral
· Ulna - medial
· "Forearm"
· Carpals
· "Wrist"
· Metacarpals
· "Palm"
· Phalanges
· "Fingers"

Joints of the Upper Extremity

· Joints of the upper extremity
· Glenohumeral (shoulder)
· Humeroulnar (elbow)
· Radioulnar (forearm)
· Radiocarpal (wrist)
· Metacarpophalangeal (fingers)
· Interphalangeal (fingers)
Pectoral
girdle
ARM/
BRACHIUM
FOREARM/
ANTEBRACHIUM
CARPUS/WRIST
Metacarpals
and Phalanges
Anterior
Posterior

Muscles and Nerves of the Upper Limb

Muscles of the Scapula and Shoulder

Muscles of the Upper Limb
· Muscles of the Scapula
· Long Thoracic nerve
· Muscles of the Shoulder
· Axillary nerve
· Suprascapular nerve

Muscles of the Arm and Forearm

. Muscles of the Anterior arm
· Musculocutaneous nerve
. Muscles of the Posterior arm
· Radial nerve
. Muscles of the Posterior forearm
· Radial nerve
. Muscles of the Anterior forearm
· Median and Ulnar nerve

Muscles of the Hand and Fingers

. Muscles of the hand and fingers
· Median and Ulnar nerve
Dorsal scapular
nerve
C5
Upper trunk
Subclavius
nerve
C7
Middle trunk
C8
Lateral
pectoral
nerve
Musculocutaneous nerve
T1
Medial cord
Long thoracic nerve
Medial pectoral nerve
Axillary nerve
Radial nerve
Median nerve
Ulnar nerve
Upper subscapular nerve
Thoracodorsal nerve
Lower subscapular nerve
Medial cutaneous nerve of forearm
Medial cutaneous nerve of arm
BRACHIAL
PLEXUS
Suprascapular
nerve
C6
Lateral cord
Posterior cord
Lower trunkLateral view

Muscles of the Scapula: Serratus Anterior

Muscles of the Upper Limb
Muscles of the Scapula:
· Serratus Anterior
LOCATION:
Medial/anterior border of scapula to
lateral surface of ribcage (ribs 1-10)
PRIMARY
ACTIONS:
· Stabilizes scapula against ribcage
· Protraction of GH joint
· Abduction of GH joint from 90-
180º
NERVE
INNERVATION:
Long Thoracic Nerve (C5, C6, C7)
Protraction of scapula:Anterior, Right

Muscles and Nerves of the Upper Limb Overview

Scapula and Shoulder Nerves

Muscles and Nerves of the Upper Limb
. Muscles of the Scapula
. Long Thoracic nerve
· Muscles of the Shoulder
· Axillary nerve
· Suprascapular nerve

Arm and Forearm Nerves

. Muscles of the Anterior arm
· Musculocutaneous nerve
. Muscles of the Posterior arm
· Radial nerve
· Muscles of the Posterior forearm
· Radial nerve
. Muscles of the Anterior forearm
· Median and Ulnar nerve

Hand and Fingers Nerves

· Muscles of the hand and fingers
· Median and Ulnar nerve
Dorsal scapular
nerve
Suprascapular
nerve
C5
C6
Upper trunk
Subclavius
nerve
C7
Middle trunk
Lateral cord
C8
Lateral
pectoral
nerve
Lower trunk
T1
Medial cord
Long thoracic nerve
Medial pectoral nerve
Axillary nerve
Radial nerve
Median nerve
Upper subscapular nerve
Thoracodorsal nerve
Ulnar nerve
Medial cutaneous nerve of forearm
Medial cutaneous nerve of arm
Lower subscapular nerve
Musculocutaneous nerve
Posterior cord

Muscles of the Shoulder: Deltoid

Muscles and Nerves of the Upper Limb
MUSCLES OF THE SHOULDER:
· Deltoid
LOCATION:
Superficial, lateral aspect of shoulder
to lateral shaft of humerus
PRIMARY
ACTION:
Abduction of GH joint from 15 to 90
degrees
NERVE
INNERVATION:
Axillary Nerve (C5, C6)
Lateral view
Abduction of GH Joint:
gifs.comLateral view,
Deltoid
removed

Muscles of the Shoulder: The Rotator Cuff

Muscles and Nerves of the Upper Limb
MUSCLES OF THE SHOULDER:
. The Rotator Cuff
. Group of 4 muscles located deep
to deltoid on lateral aspect of
shoulder
· Attach from scapula to humerus
· Tendons of individual muscles fuse
to form a 'cuff'
· Aka "SITS" muscles
· Supraspinatus
· Infraspinatus
· Teres Minor
· Subscapularis
Clavicle
Supraspinatus
Coracoacromial
Ligament
Acromion
Coracoid
Infraspinatus
Subscapularis
Long Head of
Biceps Tendon
Teres
Minor

Muscles of the Shoulder: Supraspinatus

Muscles and Nerves of the Upper Limb
MUSCLES OF THE SHOULDER:
· Supraspinatus
LOCATION:
Deep to deltoid, superior to shoulder
joint
Runs from posterior/superior scapula
to superior head of humerus
PRIMARY
ACTION:
Abduction of GH joint from 0 to 15
degrees
NERVE
INNERVATION:
Suprascapular Nerve (C5, C6)
Posterior view, Right side
Clavicle
Supraspinatus
Coracoacromial
Ligament
Acromion
Coracoid
Suprascapular Nerve
Infraspinatus
Subscapularis
Long Head of
Biceps Tendon
Teres
Minor
@ PAUL B. ROACHE, MD 2009
Abduction of GH Joint:

Muscles and Nerves of the Upper Limb: Abduction Movement

Muscles and Nerves of the Upper Limb
Muscles that perform Abduction:
180
180°
180°
1
90°
- 90°
0
0-15° = Supraspinatus
Suprascapular nerve
15-90° Deltoid
90-180° = Serratus Anterior
Axillary nerve
Long Thoracic nerve

Muscles of the Shoulder: Infraspinatus and Teres Minor

Muscles and Nerves of the Upper Limb
MUSCLES OF THE SHOULDER:
· Infraspinatus and Teres Minor
LOCATION:
Deep to deltoid, posterior to
shoulder joint
Runs from posterior scapula to
posterior head of humerus
PRIMARY
ACTION:
External rotation of the GH joint
NERVE
INNERVATION:
Infraspinatus: Suprascapular
Nerve (C5, C6)
Teres Minor: Axillary nerve (C5/6)
Clavicle
Supraspinatus
Coracoacromial
Ligament
Acromion
Coracoid
Infraspinatus
Subscapularis
Long Head of
Biceps Tendon
Teres
Minor
PAUL B. ROACHE, MD 2009
External rotation of GH Joint:
e www.kenhuo.com
Posterior view, Right side

Muscles of the Shoulder: Subscapularis

Muscles and Nerves of the Upper Limb
MUSCLES OF THE SHOULDER:
· Subscapularis
LOCATION:
Deep to deltoid, anterior surface
of the shoulder
Runs from anterior scapula to
anterior head of humerus
PRIMARY
ACTION:
Internal rotation of GH joint
Adduction of GH joint
NERVE
INNERVATION:
Upper and lower Subscapular
nerves
Adduction of GH Joint:
Anterior left :
Internal rotation of GH Joint:
1
MOTION"
SPECIFIC
RELEASE
? ?
1
N
ELEAnterior view, Left side

Clinical Correlation: Rotator Cuff Tear

Causes and Symptoms of Rotator Cuff Tear

Clinical Correlation: Rotator Cuff Tear
Supraspinatus muscle
Acromion process
Humeral head
Glenoid
fossa/cavity
. Common shoulder injury as we age
. Supraspinatus is the most common of the SITS muscles to
be involved
· Main causes:
· Shoulder Injury (heavy lifting, shoulder dislocation)
. Degeneration (wearing down of tendon in dominant arm over
time) aggravated by repetitive overhead activities/sports
· Tennis
· Volleyball
· Golf
.
Primary symptoms:
· Pain over superior aspect of shoulder
· Unable to sleep on affected shoulder
. Pain with Abduction OR inability to abduct
. Often described as difficulty with raising arm
above head
· Crepitus/clicking in shoulder
· General weakness of shoulder muscles
NORMAL MRI
RC TEAR
SSTPOLLING QUESTION 1:
We have examined 3 different muscles with the primary action of
abduction of the glenohumeral joint. Which of the following statements
is CORRECT?
A. Deltoid initiates abduction
B. Supraspinatus assists with abduction beyond 90 degrees
C. Serratus anterior helps with the beginning of abduction
D. Deltoid abducts 15-90 degrees
E. Supraspinatus abducts 90+ degrees

Muscles and Nerves of the Upper Limb: Brachial Plexus

Nerves of the Scapula and Shoulder

Muscles and Nerves of the Upper Limb
. Muscles of the Scapula
· Long Thoracic nerve
· Muscles of the Shoulder
· Axillary nerve
· Suprascapular nerve

Nerves of the Arm and Forearm

. Muscles of the Anterior arm
· Musculocutaneous nerve
. Muscles of the Posterior arm
· Radial nerve
· Muscles of the Posterior forearm
· Radial nerve
. Muscles of the Anterior forearm
· Median and Ulnar nerve

Nerves of the Hand and Fingers

· Muscles of the hand and fingers
· Median and Ulnar nerve
Dorsal scapular
nerve
Suprascapular
nerve
C5
C6
Upper trunk
C7
Middle trunk
Lateral cord
C8
Lateral
pectoral
nerve
Musculocutaneous nerve
T1
Medial cord
Long thoracic nerve
Medial pectoral nerve
Axillary nerve
Radial nerve
Median nerve
Upper subscapular nerve
Thoracodorsal nerve
Ulnar nerve
Lower subscapular nerve
Medial cutaneous nerve of forearm
Medial cutaneous nerve of arm
Subclavius
nerve
Lower trunk
Posterior cordAnterior, Right side

Muscles of the Anterior Arm: Biceps Brachii

Muscles and Nerves of the Upper Limb
MUSCLES OF THE ANTERIOR ARM:
· Biceps Brachii
LOCATION:
Superficial muscle of arm
2 heads, both attach to scapula
Crosses elbow joint to attach to radius
PRIMARY
ACTION:
Flexion of the GH joint (long head
only)
Flexion of the elbow joint (in
supinated position)
Supination of the forearm at the
elbow
NERVE
INNERVATION:
Musculocutaneous Nerve (C5, C6, C7)
Long head
Short head
Flexion in a supinated position:
Biceps brachii muscle
Biceps brachii tendonAnterior, Right side

Muscles of the Anterior Arm: Coracobrachialis and Brachialis

Muscles and Nerves of the Upper Limb
MUSCLES OF THE ANTERIOR ARM:
· Coracobrachialis
· Deep to biceps, proximal arm
· Action: Flexion of shoulder
·
Brachialis
· Deep to biceps, distal arm
· Action: Flexion of elbow
(in all positions)
Coracobrachialis
Flexion of elbow:
Biceps
Removed
MakeAGIF.com
· Nerve innervation: Musculocutaneous nerve
Brachialis

Muscles and Nerves of the Upper Limb: Brachial Plexus Review

Nerves of the Scapula and Shoulder

Muscles and Nerves of the Upper Limb
. Muscles of the Scapula
. Long Thoracic nerve
· Muscles of the Shoulder
· Axillary nerve
· Suprascapular nerve

Nerves of the Arm and Forearm

. Muscles of the Anterior arm
· Musculocutaneous nerve
. Muscles of the Posterior arm
· Radial nerve
. Muscles of the Posterior forearm
· Radial nerve
. Muscles of the Anterior forearm
· Median and Ulnar nerve

Nerves of the Hand and Fingers

. Muscles of the hand and fingers
· Median and Ulnar nerve
Dorsal scapular
nerve
Suprascapular
nerve
C5
C6
Upper trunk
Subclavius
nerve
C7
Middle trunk
C8
Musculocutaneous nerve
T1
Medial cord
Long thoracic nerve
Medial pectoral nerve
Axillary nerve
Radial nerve
Median nerve
Ulnar nerve
Medial cutaneous nerve of forearm
Medial cutaneous nerve of arm
Upper subscapular nerve
Thoracodorsal nerve
Lower subscapular nerve
Lateral cord
Lateral
pectoral
nerve
Posterior cord
Lower trunk