ORIGIN INSERTION NERVE SUPPLY ACTION
1. Pectoralis Major
clavicular head
-
medial 2/3rd anterior
surface of clavicle.
Sternocostal head -
1/2of the sternum upto
6th costal cartilage.
Lateral lip of bicipital
groove
Medial and lateral
pectoral nerves
Adduction & medial
rotation of shoulder
joint.
2. Biceps Brachii
Short head
– Tip of
coracoid process
Long head –
Supraglenoid tubercle
of scapula
Posterior rough part of
radial tuberosity
Musculocutaneous
nerve
Flexor of arm and
Supination of forearm
3. Triceps Brachii
long head- Infraglenoid
tubercle of scapula
lateral head-posterior
surface of humerus
above the radial groove
medial head- Posterior
surface of humerus
below the radial groove
Superior surface of
olecranon process of
ulna
Radial nerve : Above
the radial groove , it
supplies long and
medial head of triceps
At the radial groove, it
supplies lateral and
medial head oftriceps
Extension of arm
4. Deltoid
- Lateral 1/3rd of
clavicle,
- lateral border of
acromion process,
- Lower lip of crest
spine of scapula.
Deltoid tuberosity of
humerus
Axillary nerve
Ac
r
om
i
a
l
f
i
b
r
e
s
–
Abduction of arm from
150 - 900 ;
Anterior fibres –
Flexion and medial
rotation of arm
Posterior fibres –
Extension and lateral
rotation of arm
Clinical importance: Intramuscular injections
