1. The clavicle, also known as the collar bone, supports the shoulder so the arm can swing freely and transmits the weight of the upper limb to the sternum. 2. It has two ends - the lateral end articulates with the acromion process to form the acromioclavicular joint, while the medial end articulates with the manubrium sterni to form the sternoclavicular joint. 3. The clavicle is the only long bone that lies horizontally and gives attachment and origin to several muscles including the deltoid, trapezius, pectoralis major, and sternocleidomastoid.

1. CLAVICLE
Dr. Sharlin. BPT, PgD in Biomechanics and kinesiology in sports

2. • Clavicle is also called collar bone / Beauty
bone
• Supports the shoulder so that the arm can
swing clearly away from the trunk.
• The clavicle transmits the weight of the limb to
the sternum.
Parts Of Clavicle
• Cylindrical part – shaft
• 2 ends – Medial end
- Lateral end

3. Side Determination :
1. The lateral end is flat, and the
medial end is large and
quadrilateral.
2. The shaft is slightly curved, so
that it is convexforwards in its
medial two-thirds, and
concaveforwards in its lateral
one-third.
3. The inferior surface is grooved
longitudinally in its middle one-
third.

4. Peculiarities of the Clavicle
1. It is the only long bone that lies
horizontally.
2. It is subcutaneous throughout.
3. It is the first bone to start
ossifying.(5 th – 6 th week of
gestation)
4. It is the only long bone which
ossifies in membrane.
5. It is the only long bone which has
two primary centres of
ossification.

5. 6. There is no medullary
cavity.
7. It is occasionally pierced by
the middle supraclavicular
nerve.
8. It receives weight of upper
limb via lateral one-third
through coracoclavicular
ligament and transmits
weight of upper limb to the
axial skeletal via medial two-
third part

6. OSTEOLOGY

7. SHAFT:
The shaft is divided into
1. Lateral one-third
2. Medial two-third
The lateral one-third
flattened from abovedownwards.
It has two borders :
Anterior – Concave forward
Posterior – Convex Backward
It has two surfaces :
Superior – Subcutaneous
Inferior – Conoid tubercle and
trapezoid ridge

8. Medial two-third:
Shaft is rounded
It has four surfaces:
Anterior surface - convex forwards.
Posterior surface - smooth.
Superior surface - rough in its medial part.
Inferior surface - rough oval impression at the medial end.
lateral half of this surface has a longitudinal
subclasubclavian groove.The nutrient foramen
lies at the lateral end of the groove.

9. Clavicle Ends:
1. Lateral or acromial (Greek peak
of shoulder) end
2. Medial or Sternal end
Lateral/Acromial end:
flattened from above downwards.
It bears a facet that articulates with the
acromion process of the scapula to form the
acromioclavicular joint.

10. Medial / Sternal end:
• It is quadrangular andarticulates
with the clavicular notch of the
manubrium sterni to form the
sternoclavicular joint.
• The articular surface extends to
the inferior aspect,for articulation
with the first costal cartilage.

11. MYOLOGY

12. • At the lateral end, the margin of the articular
surface for its acromioclavicular joint gives
attachment to
a. The joint capsule.
• At the medial end, the margin of the articular
surface for the sternum gives attachment to:
a. Fibrous capsule of sternoclavicular
joint all around
b. Articular disc postero-superiorly.
c. Interclavicular ligament superiorly.

13. Lateral one-third of shaft
a. The anterior border gives origin to
the deltoid
b. The posterior border provides
insertion to thetrapezius.
c. The conoid tubercle and trapezoid
ridge giveattachment to the
conoidandtrapezoid parts of
thecoracoclaaicular ligament

14. • Medial two-thirds of the shaft.
a. Most of the anterior surface gives
origin to the pectoralis major
b. Half of the rough superior surface
gives origin to theclavicular head
of the sternocleidomastoid.
c. The oval impression on the inferior
surface at the medial end gives
attachment to the costoclaaicularligament.

15. d. The subclavian groove gives
insertion to the subclavius muscle.
E. The margins of the groove give
attachment to the clavipectoral fascia
F. The posterior surface close to medial end
gives origin to sternohyoid muscle

16. G. The subclavian vessels and cords of
brachial plexus pass towards the axilla
lying between the inferiorsurface of the
clavicle and upper surface of firstrib.
Subclavius muscle acts as a cushion.The
nutrient foramen transmits a branch of
thesuprascapular artery.

17. Clinical Anatomy

18. • The clavicle is commonly fractured
by falling on the outstretched hand
(indirect violence). Themost common
site of fracture is the
junctionbetween the two curvatures
of the bone, which is the weakest
point. The lateral fragment is
displaced downwards by the weight
of the limbas trapezius muscle alone
is unable to support theweight of
upper limb

19. • The clavicles may be
congenitally absent, or
imperfectly developed in a
disease called cleidocranial
dysostosis. In this condition,
the shoulders droop, and can
be approximated anteriorly in
front of the chest