Posts by Symptomsky

The supraspinatus muscle, this what you can see here is the scapula and this is the humerus.

They articulate here in the glenohumeral joint.

What is this illustration up here?

Well, that is basically the same region of the body with the same bones illustrated but with the acromion removed.

And also we can see muscles over here and specifically this muscle.

That is the supraspinatus muscle.

The supraspinatus muscle was cut and then inverted like this.

But normally it originates here in the supraspinatus fossa.

That’s why it’s called supraspinatus.

Now why spinatus?

Well, because this here is the spine of the scapula.

Those are the two joints of the shoulder.

The acromioclavicular joint and the glenohumeral joint.

But where does the pain usually happen?

Where does it start?

Well, besides these structures, there are many structures, nerves, muscles and arteries in the shoulder and this question cannot be answered easily.

There is something we can do easily that helps us identify which one of these structures causes the pain.

We can perform clinical examination tests and there are two examinations I would like to highlight.

So to test the supraspinatus muscle and its tendon, we can perform the empty can test.

And to test the infraspinatus muscle, we can perform the infraspinatus test.

In reality there are two joints in the shoulder. We can see here the acromioclavicular joint.

Now this bone over here is the clavicle but this weird looking bone is the scapula. This part of the scapula is called the acromion and it articulates with the clavicle. So therefore the joint is called acromioclavicular joint. Now in order to see that second joint in the shoulder we would have to look at these bones from the posterior view and this bone over here is the humerus whereas this bone is the scapula. The joint between the scapula and the humerus is called the glenohumeral joint.

Now, let’s remove all of these structures, so we can see the deep branch of the ulnar nerve.
And here we can see the deep branch of the ulnar nerve.
It innervates this muscle over here, the adductor pollicis.
And because of that muscle, the thumb can be adducted.

from the palmar view. And this over here is the ulnar nerve.

From this side we can also see the median nerve over here a little bit more laterally, but it is specifically this ulnar nerve that we are interested in. This nerve innervates the medial side of the hand and the little finger. It also innervates the medial side of the ring finger, but there is also the deep branch of the ulnar nerve and it goes underneath all of these structures over here.

This ligament is the transverse carpal ligament and underneath it is the median nerve with many tendons. Now let’s remove all of these structures so we can see the deep branch of the ulnar nerve. And here we can see the deep branch of the ulnar nerve. It innervates this muscle over here, the adductor pollicis.