Human Body Levers

The following is what we will be doing this week in my Human Anatomy Class. It is an introductory lesson about human body levers.  It includes all of the worksheets given out. Students, please give me two examples of levers that you are aware of. Leave them in the comment section. Parents, please leave any questions or comments you may have.

Topic: Biomechanics & Human Body Levers

Grade Level: 9-12

Inquiry Level: Low

Learning Outcome/Instructional Objectives:

Students will derive the attributes of a lever

Students will identify first, section and third class levers

Differentiate between first second and third class levers

Recognize the levers in the human body

Background Information: Students will have a basic understanding of physics, therefore they will understand how simple machines work. This will be the beginning of their exploration of the human body. We will still review physics before this.

 

Sequencing of the Lesson:

We will begin with an activity which is classifying different objects into two categories which are labeled yes and no. After this, we will ask the students 4 questions about levers which will transition into education of the three classes of levers in the human body system. Once this is complete we will review the different lever systems and then assess them.

Materials and Equipment: A kit that is labeled Human Lever Systems which contains a string, boards, and various hooks and U bolts that attach to a ring stand, a powerpoint projector, white board, markers, and a space to show the different human body levers.

Safety Equipment & Considerations: The only safety concern would be knowledge of how to use the human lever kit safely without breaking the string or putting tension on the string.

Instructional Activities

1. Anticipatory Set

“Make Work Easier!”-   I will give students a list of several different objects that include levers and non levers and ask them to differentiate between them.  That is, they should determine what all the “yes” examples have in common.  No one should call out or name the concept until told to do so.  Draw a T-chart labeled “Yes” and “No” on the board similar to the following example:

Yes	No

Concept: The Lever. I will ask the students the following questions in class.

§  What do all the yes examples have in common? (They are levers with rotation around an axis which make work easier.)

§  How do they make work easier? (They multiply the effort force and change the direction of your force.)

§  What are other levers that you can think of? (Cranes, dolleys, baseball bat, bottle opener)

§  What are some levers in the human body?  (Head, foot, arm)

2. What I will use as instruction
1. Guided Practice- Educate/review characteristics and components of a lever:

fulcrum, effort, and load. I will be using an example from kit to demonstrate that the lever is the bar that is free to pivot about a fixed point.  The fulcrum is the point around which the lever rotates i.e. the joint, point where human body touches the floor, wall, or chair.  The resistance force, or load being lifted by the lever, can be either an object we are moving or the human body itself.  The part of the lever that exerts the resistance force is called the resistance arm.  The effort force is provided by muscles or tendons.  The part of the lever on which the effort force is applied is called the effort arm.

2. Independent Practice

I plan on having students divide into groups and draw a rough diagram, one at a time, a 1^st, 2^nd, and 3^rd class lever of the human body. They will label the fulcrum, effort, and load.  Stop between each class of lever and have students, one from each group,  present their examples while discussing the drawings(differences, similarities, misunderstandings) with the class.

Hand out the x-ray example worksheets, discuss and confirm human levers.

3. Closure

To close I will take students through the pictures features below and they will correctly identify the classes of unlabeled lever diagrams as well as determine the position of each aspect of the lever.  If time allows, review PowerPoint examples and identify those as 1^st, 2^nd, or 3^rd class levers..

Real-life Application of Concept

Using the x-ray worksheets, students can see how levers actually work in a real life situation and see the details they learned of levers portrayed in an actual scenario.  They also discuss other levers they encounter in real life.

Resources

The Human Lever System: A Biological Inquiry packet by Science Kit was used for the lesson.