Science Buddies: "Ask an Expert"

Hello,

I am trying to the Super Advanced portion of the Deep Knee Bends the one regarding the forces on the elbow. I am not worried about doing the physics, I am unsure as to how to proceed with the elbow model. I don't understand what to measure as in the deep knee bend you measured the spring which represented the quadricep muscle, what would be measured for the elbow model? Would it be the tricep or bicep muscle? Will there be two springs, one for the bicep and one for the tricep? Also in the deep knee model, the hip was the moving part that controlled the bend of the knee, what will be the moving part that will control the bend of the elbow? Will it simply be a hinge? Finally, how is it going to connect with elbow, will it be through a "tendon", which was previously the guitar string? How will the guitar string connect in this case to create a balanced model?
If someone could please guide me along how to make the model that would be greatly appreciated as I am pretty confident in the physic's portion however, I am struggling with creating a model. Any help would be greatly appreciated.

Thanks.


[Moderator note - project: https://www.sciencebuddies.org/science- ... ical-model ; variations for students wanting to do their own version are on the Make It More tab]

Hi msthg5000,

Sounds like you've chosen an interesting and challenging variation on the deep knee bends project.

The model for the Deep Knee Bends project was designed to study how strain on the knee changes with the angle of the knee. A great first step for your project is to decide on a motion or force acting on the elbow that you're interested in studying. You may want to consider 3 or 4 different elbow motions. And you'll want to research elbow anatomy and the mechanics of how your prospective motions work. Once you have an idea about the mechanics of the motion you want to model you can decide which muscles and joints you need to include.

I hope this helps. Please post again if you have more questions.

A. Norman