From Ohr Avigdor Shaar Bechina by Rabbi Avigdor Miller
If you focus your attention on the construction of your hand, you will see it contains a large number of bones that are joined together in an intricate fashion. The bones are able to move without friction because of the lubrication in the joints. Every bone moves in a socket which gives it freedom of motion in some directions, while restricting movement in others.
As you study each organ you will see the wonders of its design
Some move up and down, some move sideways, and others rotate. Your wrist has a special kind of bone arrangement that allows it to rotate in both directions, whereas your elbow can only move up and down. There’s a purpose to all this. Since you need to be able to put a big load on your elbow, limiting the freedom of movements assures that it will not bend and drop the load.
In contrast, your wrist needs the freedom to rotate to give you the dexterity you need to perform tasks with your hands. And so it is with each organ of your body, as you study it you will see the wonders of its design and the more you study it,