Most Things Biology

Anatomical illustration showing the anterior and posterior views of the right humerus bone. The anterior view, labeled as such, displays the front of the bone. The posterior view shows the back of the bone, highlighting key anatomical differences in shape and features between the front and back. — Anterior and posterior views of a right humerus bone.

Head
Greater tubercle
Lesser tubercle
Intertubercular sulcus
Trochlea
Capitulum
Medial epicondyle
Coronoid fossa
Olecranon fossa

Time To Read

4–6 minutes

Date Last Modified

November 15, 2025

Which way is up?

You must place the bone in front of you in the anatomical positionA standard reference position where the body stands upright, facing forward, with arms at the sides whenever you are viewing a bone. To do this though, you have to know just a little bit about the anatomyThe study of the structure of the human body. of the bone. You need enough knowledge to tell the front from the back. You should also be able to distinguish the medialToward the midline of the body from the lateralAway from the midline of the body.. Fortunately, we can apply our knowledge of the femurThigh bone; longest and strongest bone in the body; has a large round head and prominent trochanters to do this. Although there is no neckNarrow region just below the head; common fracture site. to the headRounded proximal end that fits into the acetabulum of the hip bone. of the humerusLong bone of the upper arm; articulates with scapula at shoulder and radius/ulna at elbow., the head is easily identifiable. It is the structure that fits into the socket of the shoulder for that ball and socket joint. Adding official wording to this we can say that the head is medial. But knowing medial alone is not enough to help us determine if this is a left or right humerus. We must understand a bit about the bone’s front and back. This is similar to what we did with the patellar surfaceSmooth anterior groove where the patella glides during knee movement. and the intercondylar fossaDeep notch on posterior distal femur between the condyles. of the femur. However here on the humerus it’s not so straightforward as the femur.

Anterior view illustration of a human humerus bone, labeled with key anatomical features. The bone appears light beige against a light gray background. Labels point to the head of the humerus, the greater and lesser tubercles, and the intertubercular sulcus. These labels are positioned to clearly indicate each respective part of the bone. — Labeled anterior view of the humerus bone, showing head, greater/lesser tubercles, and intertubercular sulcus.

Proximal Epiphysis

There are four features that can be found on the proximalCloser to the point of attachment or origin. end of the bone. We already know about the head. This is the large rounded portion that fits into the shoulder blade. It forms the shoulder joint. Whereas the femur had trochanters the humerus has tubercles. It has both the greater and lesser tubercles, the greater being larger and more superiorAbove or toward the upper part of the body. on the bone. Between these tubercles is a groove. It is a depression that resembles a trench rather than a hole. This groove is called the inter tubercular groove. Sometimes it can be called a sulcus and sometimes it’s called the bicipital groove. We will call it the intertubercular groove, its name meaning the groove that is between 2 tubercles.

Distal Epiphysis

The distal end of the humerus is difficult. Let’s approach it by looking at the posterior and then the anteriorThe front of the body or toward the front when standing in the anatomical position.. The deepAway from the surface of the body. depression on the posterior side of the distal part of the bone is a fossa. It is called the olecranon fossaLarge posterior depression for olecranon process when elbow extends.. This is the fossa that locks the lower arm bone called the ulnaMedial forearm bone (pinky side); forms the elbow hinge with humerus. into place. Just inferiorBelow or toward the lower part of the body. to the olecranon fossa, there is a structure. It can be seen on both the anterior and posterior sides of the bone. This feature is called the trochleaSpool-shaped medial condyle that articulates with ulna at the elbow.. This is a word that means pulley. I want you to extend your right arm out in front of you. Now, flex your bicep muscle, pulling your lower arm toward the upper arm. Your bicep is the hand applying force, your elbow is the pulley itself and the weight is your lower arm. And the structure on the bone that allows this pulley motion is the trochlea. Notice how you can see this pointy part of the trochlea? That is a great way to remember how to spot it.

Labeled posterior view of a humerus bone. The image shows the humerus extending vertically along the image at an angle from lower left to top right, with important anatomical features labeled. The head and greater tubercle are at the top. The olecranon fossa, and trochlea are at the distal end. — Posterior Right Humerus

Diagram of the anterior view of a human humerus bone clearly labeled with the following anatomical features: Head, Greater Tubercle, Lesser Tubercle, Intertubercular sulcus, Capitulum, Coronoid fossa, and Trochlea. This provides a clear understanding of the bone's structure and major components. — Anterior Right Humerus

Some pendulum-y looking stuff that was as close as I could get to a capitulum

We can see the trochlea on the anterior and posterior sides of the arm. There is also another rounded projection on the distal portion of the arm. It resembles the condyles of the femur. It is a condyle however it has its own specific name which is the capitulumRounded lateral condyle that articulates with head of radius.. Extend your arm out in front of you. Rotate your palm so that it faces down, then up. Next, face it down again, then up again. This rotating motion is caused by your lower arm bone called the radiusLateral forearm bone (thumb side); rotates around ulna during pronation/supination. rotating around the capitulum. The word capitulum might make you think of the word pendulum (if not, it does now!). A pendulum swings back and forth along only one plane of motion. It also rotates along an axisSecond cervical vertebra; has the odontoid process (dens) for pivoting head (“no” motion). during this movementA fundamental property of life involving motion of the body or its parts.. The word capitulum means “head of flowers.” That is not helpful.

There are 2 other features are on the anterior side of the humerus. The trochlea and the capitulum are 2 specialized condyles at the distal portion of the bone. However, there is another structure. It is not a condyle but is an epicondyle. We know that the prefix epi means on top of. Therefore, this structure will be on top of a rounded condyle at the end of the bone. The structure you need to know is the medial epicondyleProminent bump on distal medial side; attachment for forearm muscles (“funny bone”).. Using our logic from the femur, you can determine this structure’s location. It is on the same side of the bone as the head. This is at the proximal portion. Students get confused and often want to call this just the condyle. Another structure is on the anterior side of the humerus. It mirrors the olecranon fossa on the posterior side. Extend your arm out in front of you. Pull your lower arm toward your upper arm. It locks into place. The lower arm bone fits into this structure called the coronoid fossaSmall anterior depression above trochlea for coronoid process of ulna when elbow flexes.. It locks the arm into place in the flexed position. This is opposite to the olecranon fossa, which locks the arm into place in the extended position. When we cover the ulna, we will talk about projections that have the same names as these fossae. The relationship between these fossae and the projections on the ulna is crucial for understanding. It helps make sense of the anatomical structures. These structures belong to a very complicated articulation called the elbow.