2. MUSCLES CONNECTING UPPER LIMB TO
THORACIC WALL
1. Pectoralis major
2. Pectoralis minor
3. Subclavius
4. Serratus Anterior
3. In this lecture
Muscles connecting upper limb to thoracic wall
Muscles connecting upper limb to vertebral column
Muscles connecting scapula to humerus
4. Pectoralis major, Pectoralis minor and
Subclavius muscle are also known as
muscles of the pectoral region.
The pectoral region lies on front of the
chest. It consists of structures
connecting upper limb to anterolateral
chest wall.
5. PECTORALIS MAJOR
ORIGIN:
Anterior surface of medial half of clavicle
Anterior surface of manubrium and sternum
upto 6th costal cartilage
2nd to 6th costal cartilage
INSERTION:
Lateral lip of the bicipital groove
NERVE SUPPLY:
Medial and lateral pectoral nerves from
brachial plexus
NERVE ROOTS:
C5, C6, C7, C8 and T1
6. ACTION:
Acting as a whole the muscle causes Adduction and medial rotation of shoulder
Clavicular part causes flexion of arm
7. PECTORALIS MINOR
ORIGIN:
3,4,5 ribs
INSERTION:
coracoid process of scapula
NERVE SUPPLY:
Medial pectoral nerve
NERVE ROOT:
C6,C7,C8
ACTION:
Draws scapula forward (with serratus anterior)
Depresses point of shoulder
Helps in forced inspiration
If scapula fixed, it raises the ribs of origin
8. PATHOLOGY
Both the axillary artery and vein, as well as some
nerves of the brachial plexus run between the
pectoralis minor and the coracoid process
(coracopectoral space).
In cases of hypertrophy or stiffening, a compression
of the neurovascular bundle can often occur.
This is referred to as pectoralis minor syndrome
(PMS). Common complaints are tingling, numbness
up to pain in the affected arm (especially in the ring
and small finger) and a stiff shoulder.
9. SUBCLAVIUS
ORIGIN:
1st rib at costochondral junction
INSERTION:
Subclavian groove in middle one-
third of clavicle
NERVE SUPPLY:
Nerve to subclavius from upper
trunk of brachial plexus
NERVE ROOT:
C5, 6
ACTION:
Steadies and depresses the clavicle
during movement of shoulder
10. PATHOLOGY
The vessels and nerves running behind the
subclavius muscle can sometimes get
entrapped in the room between the clavicle
and the first rib (costoclavicular space). This is
referred to as the costoclavicular syndrome.
Typical symptoms are irritations of the
brachial plexus and circulatory disorders of
the arm.
11. SERRATUS ANTERIOR
ORIGIN:
Upper 8 ribs
INSERTION:
Medial border and inferior angle of scapula
NERVE SUPPLY:
Long thoracic nerve
NERVE ROOT:
C5,C6,C7
ACTION:
Scapular abduction and upward rotation
Along with the pectoralis minor muscle it pulls
the scapula forward to protract the upper limb
in pushing and punching movements.
12.
13. CLINICAL FEATURES
Paralysis of serratus anterior produces ‘winging of scapula’ in which the
inferior angle and the medial border of scapula are unduly prominent. The
patient is unable to do any pushing action, nor he can raise his arms above
head. Any attempt to do so makes the inferior angle of scapula more
prominent.
14. MUSCLES CONNECTING UPPER LIMB
TO THE VERETBRAL COLUMN
1. Trapezius
2. Latissimus dorsi
3. Levator scapulae
4. Rhomboid minor
5. Rhomboid major
15.
16. TRAPEZIUS
ORIGIN:
Medial one-third of superior nuchal line
External occipital protuberance
Ligamentum nuchae
C7 spine
T1-T12 spines
INSERTION:
UPPER FIBERS into posterior border of
lateral one-third of clavicle
MIDDLE FIBERS into acromion of scapula.
LOWER FIBERS into upper lip of spine of
scapula.
NERVE SUPPLY:
Spinal part of accessory nerve (motor)
17. ACTIONS:
UPPER FIBERS act with levator scapulae and elevate the scapula (shrugging)
MIDDLE FIBERS act with rhomboids and retract the scapula
LOWER FIBERS lower fibers pull medial border of scapula downward
18. LATISSMUS DORSI
ORIGIN:
Posterior one-third of outer lip of iliac crest
Lumbar fascia
Spines of T7-T12
Lower 4 ribs
Inferior angle of scapula
INSERTION:
The tendon is twisted and inserted into floor
of bicipital groove of humerus
NERVE SUPPLY:
Thoracodorsal nerve, or middle subscapular
nerve or the long subscapular nerve
19. ACTION:
Adduction, extension and medial rotation of shoulder.
Folding the arm behind the back and scratching opposite scapula
Hold inferior angle of scapula in place
20. LEVATOR SCAPULAE
ORIGIN:
Transverse processes of C1-C4
INSERTION:
Superiorly medial border of scapula.
NERVE SUPPLY:
Dorsal scapular nerve
C3, C4
ACTION:
Elevation of scapula
Steadies the scapula during movements of arm
21.
22. RHOMBOID MAJOR
ORIGIN:
Spines of T2 T3 T4 T5
INSERTION:
Middle of the Medial border of scapula.
NERVE SUPPLY:
Dorsal scapular nerve
ACTION:
Raises medial border of scapula
upward and medially
Retracts scapula
23. RHOMBOID MINOR
ORIGIN:
Spines of C7 and T1
INSERTION:
Medial border of scapula
NERVE SUPPLY:
Dorsal scapular nerve
ACTION:
Raises medial border of scapula upward
and medially
Retracts scapula
24. MUSCLES CONNECTING SCAPULA TO
HUMERUS
1. Deltoid
2. Supraspinatus
3. Infraspinatus
4. Teres major
5. Teres minor
6. Subscapularis
25. DELTOID
ORIGIN:
Anterior fibers into Lateral one-third of clavicle
Middle fibers into acromion of scapula
Posterior fibers into Lower lip of spine of
scapula
INSERTION:
Deltoid tuberosity of humerus
NERVE SUPPLY:
Axillary nerve
26. ACTION:
Anterior fibers are flexors and medial rotators of
arm
Middle fibers are powerful abductors of arm at
shoulder joint
Posterior fibers are extensors and lateral
rotators of arm
33. ROTATOR CUFF MUSCLES
The rotator cuff consists of the following muscles: supraspinatus muscle, infraspinatus muscle, teres
minor muscle and subscapularis muscle.
These muscles all originate from the scapula and insert in the humerus.
The main function of the rotator cuff is to stabilize and center the humeral head in the joint socket,
the glenoid cavity.
Certainly the rotator cuff – as the name suggests – plays a major role in the internal and external
rotation of the upper arm in the shoulder joint.