To learn more about the hand and wrist, let's build a model and see how the ligaments in your hand work!

Before you get started, think about:

1. What tasks and movements can be done by the human hand?

2. Examine your own hand. Pay attention to how and where it moves.

3. What structures are found in the human hand?

4. How do the parts of the human hand work together to complete a task?

Materials Needed:

• Tape

• Scissors

• Cardboard paper or cardstock paper

• Standard drinking straws

• Smoothie straw or bigger diameter straw

• Yarn or twine

Procedure:

1. Trace your hand on a cardboard or cardstock paper.

2. Cut the traced hand out (cutting it a little bigger than the actual tracing).

3. Mark your finger joints on the cutout by drawing straight or curved lines across each finger. Look at your own hand to see where the joints should be drawn on your model.

4. Fold the fingers at the lines.

5. Cut smaller straws to size (leave a little gap between the lines to facilitate in threading the yarn).

6. Tape straw pieces to the hand.

7. Thread yarn through the straw pieces. Each finger will have a length of yarn of its own. (Hint: if you have trouble threading the yarn through the straws, you can wrap tape around the end of the yarn to make it easier - similar to the plastic tip of a shoelace.)

8. Thread all five pieces of yarn through the bigger straw.

9. Now experiment by pulling on one or multiple strings to cause the hand to close. Compare your model to your own hand. How are they similar and how are they different? In a human hand, the brain sends signals to muscles and tendons which contract to move the fingers. In your model, the string represents the tendons and, when pulled, cause the fingers to move.

10. Now try to do every day tasks with your bionic hand. Can you pick up a pencil with the bionic hand? Creating a robot that can function like a human with the same amount of dexterity is very challenging!

Discussion:

Compare your model to your actual hand. Can you see similar reactions occur with the ligaments/strings? What would happen if a ligament was injured?

The floor is Lava! Today you can use pillows, tiles, chairs, tiles from inside or outside use whatever you find (with parents/guardian's permission) to keep off the ground because...the floor is LAVA! This is a great way to think creatively on how to come up with a unique path, a skill that is very useful for ninjas running through the course.

Procedure

Call out, "The floor is lava!" and the goal is to not touch the actual ground till the time is up. Start with 2 minutes and see if you can work your way up to 5 minutes! You also cannot stay in the same place for more than 10 seconds of you sink into the lava!