Joints Help Us Move

Designed by: Kristin Reinfurt, Rosewood Elementary

Grade Level: Three       Subject: Science

Core Curriculum: Recognize that bones, joints, and muscles in the arms and legs of the human body are structural adaptations responsible for movement. (This lesson focuses on joints.) (Standard II Life Science A 2 b)

Overview: The students will learn that there are three main types of joints in your arms and legs which are responsible for movement. They will look at x-rays to see that joints look different. They will work with a group to examine an exercise to see that joints act differently and allow for different movements depending on the type of joint. Then they will work with a partner to find a magazine picture of someone moving and identify how each of the three types of joints is responsible for some part of their movement.

Focus Question: How do the joints in your body help you move?

Time Frame: Two one-hour class periods

Resources:

Three pieces of chart paper

Index cards

Tape

www.scar.rad.washington.edu/RadAnat

AverKeys (if available)

Old magazines for students to cut from (sports or kids magazines especially)

Construction paper

Glue

Scissors

Pencil and paper

Culminating Assessment: The students will work in pairs to find and cut out a picture of someone moving from a magazine. They will write an explanation of how each of the three types of joints that we discussed is responsible for some part of that person's movement. The teacher will assess the explanation using the following rubric:

Instructional Activities: **This activity should be done as part of a unit about the systems of the human body including the skeletal and muscular systems.**

Activity One: Begin by having the class stand up and do a few short exercises together like jumping jacks, toe touches, running in place, sit ups, and push ups. Discuss reasons why your body is able to move in all of those ways. Because you should already have been talking about bones and muscles, remind them about how they help you move. Introduce the idea that you also have connections in your body called joints which "join" bones together to help you move. Since bones do not bend, ask someone to explain/show what your body would be like if it could not bend. It would be impossible to move. Explain that you need to have bones, muscles, and joints to be able to move in all sorts of ways.

Give some examples of joints in your arm like the wrist, elbow, and shoulder. Encourage students to move each of these joints as you point it out. Ask if they think those joints in the arm all move in the same way. Ask them to observe their wrist and how it moves and then compare it to their elbow and shoulder. Discuss their observations. Explain that just like bones and muscles, all of your joints are not the same. They are different so they are able to do different motions/movements.

Using a TV screen and AverKeys (if available) or a computer monitor, show the web site www.scar.rad.washington.edu/RadAnat/ It shows x-rays of different joints in the body. There is a menu of different joints on the left. Click on one of the joints like the shoulder. A couple of small x-rays of the shoulder from different views will appear. To make the x-ray larger, click on one of the x-rays and then click on "Show me a labeled version." On the top of a piece of chart paper, write the word ball and socket. Point out how your upper arm bone "joins" your collar bone at your shoulder which is a ball and socket joint. Explain that it is similar to a socket that you plug a lamp into because your arm bone has a plug (ball) which plugs into the socket of your collar bone. Click on the x-ray of the pelvis to show that ball and socket joint at your hip. Discuss/demonstrate the type of movements that a ball and socket joint is adapted for you to perform.

Click on another joint like the elbow and discuss how it is different from the ball and socket because it is a hinge joint which is like a hinge of a door so it can only open and close/back and forth. Write the word hinge joint on the top of a second piece of chart paper. Click on the x-ray of the knee to show another hinge joint. Discuss/ demonstrate the type of movements that a hinge joint is adapted for you to do.

Last click on the wrist and discuss that it is a moveable joint which is where many bones come together. It is very clear from the x-ray that many bones come together at the wrist. Discuss why there could not be a ball and socket or hinge joint at your wrist. Write the word moveable joint at the top of a third piece of chart paper. Click also on the moveable joint at your ankle. Discuss/demonstrate the type of movements that a moveable joint is adapted for you to do.

Explain that there are other types of joints like the joints in your spine, but that we are going to focus on these three main types of joints in your arms and legs that help you move. Review each type of joint by having them point to it on their body as you ask questions like, "Point to a hinge joint."

Have the students get into five groups. Give them a small pile of index cards. Have some tape loops on the board to stick index cards to the three class charts with the names of a joint at the top of each. Assign each group one of the exercises that we did at the beginning of class. Ask them to have one of the group members perform the exercise slowly for the group so that they can observe which joints are being used and then see how the joints are moving. Then on the index cards they are to write down the movement that they saw by which joint. For example, when observing a sit up, I see the hip joint is being used because the legs are bent at that joint and they must move to be able to sit up. So, after my group had discussed it and agreed, I would write on one index card, "In a sit-up, you use your hip joint to bend your legs and to allow you to sit up." Then I would get a tape roll from the board and I would tape that index card to the "ball and socket joint" poster. Encourage each group to come with as many joints and movements as they can for their assigned exercise, but do not set a number for how many they have to write. After about 10 minutes, stop the groups and go over the posters and different movements that the different joints are able to perform. Discuss how they just classified different movements by the type of joint.

Activity Two: Review the three types of joints and some of the movements that each joint enables us to do. For the culminating assessment, have them find a partner. Each pair will need to find a picture in a magazine of someone moving. Obviously pictures are of a frozen moment and not motion, but they will infer movement from the picture. For example, if I find a picture of a boy by a set of monkey bars, I will infer that he is going to cross them which is movement. Sports magazines are especially good for this, but children's magazines will also have pictures of active children which will show movement. The pairs' job is to cut out a picture from a magazine of someone moving. Then they need to identify one way that a ball and socket joint is helping that person move, one way a hinge joint is helping, and one way that a moveable joint is helping.

Model an example of a gymnast by cutting out a picture of a gymnast and gluing it to the top of a piece of construction paper. The on a piece of notebook paper write: She needs the ball and socket joint in her shoulder to be able to do a cart wheel. She needs the hinge joint in her knee to be able to bend and do a summersault. She need the moveable joint in her wrist to be able to do a handstand. Then cut out the explanation and glue it to the construction paper below the picture. Explain that to get the full three points, they must correctly identify all three joints and explain a movement that each joint enables the person in the picture to do. Allow for extra credit if the pairs write about the other ball and socket joint, the hip, and how it helps her move in gymnastics or the other hinge or moveable joint.

Have each pair share their picture and explanation with another group or in front of the class if time allows. Collect the pictures/explanations and bind them into a class book called "Joints Help Me Move" or post them on a bulletin board.