The tendons of the rotator
cuff are the next layer in the shoulder joint. Tendons
are much like ligaments, except that tendons attach muscles
to bone. Muscles move the bones by pulling on the tendons.
One important tendon that travels through the shoulder
joint is the biceps tendon. The biceps tendon actually
begins at the top of the shoulder socket (the glenoid)
and then passes across the front of the shoulder to connect
to the biceps muscle. (The biceps is the muscle that weightlifters
are always showing off).
The rotator cuff tendons are a group of four tendons that
connect the deepest layer of muscles to the humerus. They
are the tendons of the rotator cuff muscles (left)
Tendons of the shoulder from front to back:
Subscapularis
Biceps Tendon
Supraspinatus
Infraspinatus
Teres Minor
The Acromio-claviculaire Joint
The Acromio-claviculaire Joint (ACJ) is formed by the
lateral end of the clavicle articulating with the medial
aspect of the anterior acromium.
The ACJ is important in transmitting forces through the
upper limb and shoulder to the axial skeleton. The ACJ
has minimal mobility due to its supporting ligaments:
Acromio-claviculaire Ligament which is composed
of strong superior (top) and inferior (bottom) ligaments,
and weak anterior (front) and posterior (back) ligaments
restricting anterior-posterior (forwards and backwards)
movement of the clavicle on the acromion
Coracoclavicular Ligament is composed of the Conoid
and Trapezoid ligaments. It forms a strong heavy band
to prevent vertical movement.
