Science: Guiding the Investigation
Part 1: Making a leg model
Material: 4 dowels with holes, 18 cm
2 craft sticks with holes, 11 cm
2 rubber tubes, no tubes
2 rubber tubes, with holes
6 rubber bands, larger
12 paper clips
Start with writing the “I can” statement on the board and have the students
write it down too. “learn that muscles contract when they work. Build an
operating model to demonstrate how muscles and tendons work together ro
move legs and feet.”
1. Review Jump Rope
Remind students of the jump rope activity they did and ask them to
recall the body movements they observed. Review bones that played a
role in jumping.
2. Discuss Moving Bones
After reviewing what the students remembered about the bones ask,
We know bones don’t move by themselves, so how do you suppose
they move?
What do we have in our bodies that provides the power to move
our bones?
Once they mention muscles, have them locate some muscles on their
body
3. Explain the role of Muscles
Tell and then write on the board, along with have the students write it on
the board.
Muscles are responsible for all movements of the body. Nothing
moves unless a muscle is working. When muscles work, they contract.
That means that when they work, muscles actually become shorter.
Contracted muscles feel tight and solid. If a muscle is attached to two
bones, they will be pulled toward each other when the muscle contracts.
4. Introduced the Muscle Transparency
Use a leg muscle transparency to hold up against white background.
Identify different parts and then ask a student to attach the muscle to
the leg bone image that was previously but on the board from an earlier
lesson. Tell them these moving muscles are called skeletal muscles and
they play a part in making the body move; there are over 650 skeletal
muscles.
5. Introduce Tendons
Point out the stringy areas on the transparency. Tell students those are
tendons which attach muscle to bone with their long ropelike tissue.
6. Introduce tissue
Have students write down and write on the board “muscles is an example
of one of the body’s tissues. Tissues are the different kinds of
bodybuilding materials, such as muscles, tendons, ligaments, bones, and
fat. All of your organs, like your heart and lungs, are made out of
different kinds of tissue.”
7. Find working Muscles
Ask students to find spots where they can tell their muscles are moving
on their body, they are able to feel the muscles tighten or become solid
Flex arm at elbow
Open and close hand
Jaw as if crewing
Shrugging shoulders
Knee up towards the waist
8. Leg model
Assign pairs for working to build a model leg. Identify partsdowels with holes, 18 cm –leg bones
craft sticks with holes, 11 cm- knee joints
rubber tubes, no tubes -ankle
rubber tubes, with holes –foot
challenge students to assemble the five pieces into a leg and foot model.
Once completed check model before moving on.
9. Muscle-up the Knee Joint
Challenge students to add one muscle to model leg that will bend the
knee. Tell them one rubber band is a muscle, and the paper clips is a
tendon. (muscle contraction is stimulated by bring the two ends of the
rubber band towards each other, making the muscle shorter)
10.
Muscle-up the Foot
Once knees are working call attention and model how the muscles are at
work, then challenges them to attach to more muscles that will make the
toe point up and down.
11.
Compare
Have the students compare the model leg to their real leg and see the
similarities in the actions that take place. Ask them to move their foot up
and down and identify which muscles are contracting
12.
Reflection
Once they are finish have them reflect on the lesson and journal
answering these questions: what do muscles do when they work? What
happens when muscles contract? How do the muscles attach to bones to
make movement possible?