anteriorly, posteriorly, inferiorly, and also
a limited degree of superior movement.
Now let’s move over to another joint, the acromioclavicular
joint. The acromioclavicular joint is between
the acromion of the scapula to the clavicle.
We’ve got the acromioclavicular joint here.
And this is stabilized by a number of ligaments.
So the joint capsule, we can see the joint
capsule of the acromioclavicular joint here,
contains a small wedge-shaped articular
disc. And the acromioclavicular ligament reinforces
the joint superiorly. So here we can see the
acromioclavicular joint and we can see the
acromioclavicular ligament, and that is reinforcing
the joint. This acromioclavicular joint is
supported by the coracoacromial ligament.
And this prevents the acromion from passing
deep to the clavicle. So here we have the
clavicle here. And here we have the acromion.
And here, we have the coracoid process. And running
between the coracoid process to the acromion
is the coracoacromial ligament. And this prevents
the acromion here passing deep underneath
the clavicle. It helps to stabilize again
this acromioclavicular joint. We also have the
coracoclavicular ligament. And the coracoclavicular
ligament, as its name suggests, reinforces
this acromioclavicular joint again, but its
running from the coracoid process to the clavicle.
And there’s actually two parts of it, the coracoclavicular
ligament. It anchors the clavicle to the coracoid
process, and augments its supports the acromioclavicular
joint. The two parts to it are the conoid ligament.
We can see the conoid ligament passing
away here, passing medially from the coracoid
process, passing towards the clavicle.
And here, we’ve got the coracoclavicular ligament
again. We’ve got the trapezoid ligament.
We’ve got the second part of the coracoclavicular
ligament. And these two parts, the conoid
ligament, the trapezoid ligament, you should
remember their features on the inferior surface
of the clavicle that we pointed out. These
two parts, the conoid and trapezoid, help
to reinforce, help to augment the acromioclavicular
joint. Movements at these joints, we have
rotation on the acromial end of the clavicle,
and this is due to the contraction of the
thoracoappendicular muscles. Muscles that
are passing from the thorax to the appendicular
skeleton, this can move the upper limb at this
acromioclavicular joint, and we can have
rotation. So forward, backward, lateral
rotations are some of the movements that are
possible. So now, we’re going to look at the
glenohumeral joints or the shoulder joints