Looking back at the criteria for designing their knee braces, fourth graders had to a chance to reflect upon many things.  First off, did their knee brace design meet the criteria for the challenge?  Was their design able to allow the injured model knee to move like a healthy knee?  Was their design able to be taken on and off in an allotted time?  And was it durable to withstand repeated use?  Their knee brace designs varied extensively, but optimizing their solution was key...did they meet the goal of the challenge?  Or could the goal be met even better with a redesign?

In a culminating reflection, fourth graders had a chance to really connect what they've been learning in science about the human body and the process they've used in engineering.  Check out these students' ideas regarding two exit-slip questions they were asked...

With their plans officially approved, fourth graders are off  creating their own knee brace designs.  With a wide-variety of materials, students are creating a knee brace according to the following criteria.

1.  The injured model knee with the knee brace attached must move with the same range of motion as a healthy knee.

2.  The knee brace must be usable.  That means it has to be put on and taken off in a specific period of time.  Room 306 agreed upon 45 seconds and Room 308 agreed upon a minute.

3.  The knee brace must be durable over time.  This means that the injured knee with the attached brace must perform the same way after multiple uses.  

Here are some shots of the knee brace creation in action!

Working in teams of three or four, fourth graders are planning their knee brace designs.  They are thinking about the injured knee's range of motion and the materials they have available.  Each group's plan had to be approved first.  Notice how each team's plan is unique.  This will give students an opportunity to think about how each design meets the criteria of the challenge, yet be designed differently.  Each brace must allow for the range of motion of a healthy knee, be able to be put on and taken off in under an minute, and be durable enough to wear again and again.  

Designing our knee braces is no easy feat!  Using a wide variety of materials, it is important to see how each material's properties can be useful (or not) in a knee brace.  Some materials are sticky, while others are not.  Some provide a great opportunity to stretch around the knee, while others are rigid and won't provide any movement.  While it is important to know the properties of different materials, it is also important to brainstorm how they can specifically be used in a design.  Will they be used as a strap to adjust for sizing purposes?  Can they be stretched to provide support?  Will they allow the person to take the knee brace off easily when they don't need it?  With extended use, will they return back to their original shape?  

In order to design a knee brace for an injured knee, it is important to know how a healthy knee moves.  Using a goniometer, fourth graders are taking measurements of their own knees to see just how they move.  Extending their legs in four different directions, the readings on the goniometer will influence their own knee brace designs. 

How might a biomedical engineer be involved in helping a shoe company design shoes?  How might they help collect data to design a shoe that will fit most people?  Is it realistic to design a shoe for all types of feet?

These are some of the questions fourth graders are asking as they make recommendations to a shoe company.  Looking at the structure of their own foot and comparing it to others' feet, fourth graders will help a shoe company decide how many types of shoes they should make based on the data they collect.  

Because biomedical engineers use data to inform their decision making, it is important to be able to represent the data they collect in the best possible way.  Here are just some of the graphs fourth graders made in teams to depict data they collected!

Since biomedical engineering develop and recommend technologies to the medical field, it is important they also learn best techniques at collecting, representing, and analyzing data that provide evidence to support the development of various technologies.  Fourth graders are spending time doing just that!  

Fourth graders have finished reading about Erik and how he used the Engineering Design Process to help his friend Matthias.  With limited supplies in the middle of the forest and a knee that  is hurt, Erik must use what he knows about engineering to help design a brace for Matthias.  By using the engineering design process, a successful brace was made and Matthias could get out of the woods safely! Fourth graders had the chance to create their own map of how the main character used the Engineering Design Process to complete his goal.  See the examples from some fourth graders' notebooks below.    

Meet Erik, a young skateboarder who is forced to go on an unforgiving camping trip.  Erik must deal with friends, being outside in nature, and the fact that his mama is a biomedical engineer.  

Forced to use what he knows about the human body (muscles, tendons, ligaments and joint), Erik becomes a biomedical engineer himself as he helps develop a solution for his friend that's gotten hurt.

Key vocabulary:  biomedical engineer, joints, bones, ligaments, tendons, brace, engineering design process, materials, and properties.