Hello everyone! This is Joao from Kenhub, and today, we’re going to do an overview of the bones of the hand. Now, keep in mind that I’m going to just do an overview on that topic, but later on, I’m going to post more videos where I’m going to discuss the different types or the different groups of bones that you find on your hand in a little bit more detail.
Now, let’s start by saying that this image here that you can see, that you’re looking at, this is the palmar view of your hand. Now, knowing that, let me start by saying that there are three main groups of bones that you find on the hand.
Now, the first one is here, highlighted in green, and this is known as the carpal bones. And the carpal bones are basically the wrist bones or the bones that you find on your wrist. Now, the second group is going to be highlighted in yellow, and these are the metacarpals. And the metacarpals are a bit tricky to see where they are because, if you look at the palm of your hand, you cannot see any definition of bone. Well, what that means is that these bones, these five bones, are actually covered in muscle, a lot of ligaments going on between them, and also fat, so it’s really hard to feel them on the palmar side of your hand. But if you turn your hand and to the back of your hand or also known as the dorsal side, and if you close your hand, then you can see a few bony definitions, and that’s clearly the metacarpals. Now, the other group of bones are known as the phalanges, and they’re here highlighted in red. And these are basically the bones of your fingers.
Now, the first group of bones that we’re going to start discussing is the carpal bones or the wrist bones. What you need to know is that these bones are articulating on the proximal side with the radius—so the scaphoid and the lunate here articulating with the radius. Now, keep in mind that the ulna here is not involved in any articulation with the wrist bones because if you notice here, there is some space here that is left for an articular disc that will prevent any articulation from happening between the ulna and the wrist bones. Now, on the distal side, on this area here, you can see that the carpal bones are articulating with the other group of bones known as the metacarpals.
One important thing to mention about the carpal bones is that these are divided into two rows, a proximal row and a proximal row that is comprised of four bones. And these bones are the scaphoid, the lunate, the triquetrum, and the pisiform. Now, there is another row, as I mentioned, and this is the distal row. And the distal row is comprised also of four bones. And these are trapezium, the trapezoid, the capitate, and finally, the hamate.
Now, the second group of bones that we’re going to briefly discuss are the metacarpals. And in terms of articulations, you can see here that, proximally, the metacarpals are articulating with the wrist bones. And on the distal portion, they are articulating with the next set of bones known as the phalanges. Now, important to mention that you number the metacarpals. So going from the one that is articulating with the thumb all the way to the little finger, we name number one, number two, number three, four, and five.
Now, let’s talk about the last group of bones that you find in your hands, and these are the phalanges. And these are the bones of the fingers, like I mentioned before. And what you need to know about the phalanges, first thing, is that “phalanges” is plural for “phalanx.” So every bone that you see here is one phalanx, and combined, they’re phalanges. Now, every finger has three, so you can see here on your index finger—one, two, and three phalanges, except your thumb. So this is your thumb, looking at the palmar view, still on the palmar view, and you can see that there are only two phalanges—one and two.
Now, we also further distinguish them because they’re in different positions going from proximal to a more distal position. For that matter, we will call this one here the proximal. The ones located here are known as the middle phalanges. And then the ones on the tip would be called then the distal phalanges. As you can see here that the thumb only has two, then we would call them the proximal and the distal phalanges.
Now, knowing that, we further distinguish them by locating them in terms of the number of the finger that we’re talking about. And as I mentioned before on the metacarpals, the thumb is located or said to be number one going all the way to number five as the little finger. So if I'm talking about here, this proximal phalanx on the index finger, then I would say this is the second proximal phalanx.