Ball-and-Socket Joint: Mobility in Every Direction

Lesson Plan - Get It!

Audio:

From throwing a baseball to climbing up a tree to helping vacuum the house, your shoulders do a lot of moving around.

• Have you ever noticed how you can move your shoulder joints in almost any direction?

Go ahead, give it a try. Reach above your head, in front of you, to the sides, and even behind you. Your shoulders can twist and turn so that you can reach in almost any direction.

• Have you ever noticed that your hip joint works in the same way, too?

Your hip joints have the mobility to move you from standing up to doing a split.

• Do you think our shoulder and hip joints are similar to the hinge joint you learned about in the last Bones Related Lesson, found in the right-hand sidebar?

Let’s check in with Dr. Jo to find out!

• Can you imagine having a floppy elbow like Dr. Jo mentioned?

It would seem strange! But this is why humans have ball-and-socket joints for their shoulders and hips instead of their elbows! The end of one bone sits inside the “cupped” end of another bone, thereby creating a ball-and-socket joint!

• But did you know that your body is made up of about six different freely-moving joints?

And you have only learned about two so far! A ball-and-socket joint is only one of them!

Continue on to the Got It? section to have a ball looking for more joints!