BioX Kids Day 2013 - Elbows revisited

I was asked to help with Stanford BioX's Kids Day this year, which happened today!

I met lots of fun families. Thanks to all who stopped by to learn about how your arm works!

Here are some old posts for your reference if your elbow breaks (ouch!) or if you want to do it all by yourself. It's very easy and a wonderful way to learn how muscles move the bones in your body.

Elbow Booth Recap, BioX Kids Day 2012.

Elbow Lesson for High Schoolers (with a little kid adaptation).

Science Saturday Elbow Lesson (intro with moving a rock towards me by pushing on a string).

I love learning about how my body works. I hope you did too.

J visits the gait lab

My poor baby, J, was sick for his fourth birthday last week. It started the day before his bday party and lasted through the weekend until Wednesday of last week. Wednesday, he was still banned from school but feeling good enough to be compliant while I got some work done at the office. For fun, I thought I'd show him what I do.

I manage a motion capture laboratory where we use special cameras to analyze the forces and moments on knees through gait analysis. Gait is a fancy term for walking. Ultimately, we want to find out where knee osteoarthritis starts before symptoms appear in order to develop interventions to slow or even prevent the progression of osteoarthritis (the degeneration of the cartilage - that slippery material that helps your knee move without friction/creaking). Currently, osteoarthritis is diagnosed once you feel pain, and you can only treat the symptoms.

Well, my little guy doesn't know the particulars of my job except that I have access to some cool science equipment. We decided to do a quick collection with J. We stuck reflective markers on our subject. The markers are plastic balls covered in reflective material, like what's on running shoes. The special cameras then send out infrared light to detect the x, y, z position of each marker during each frame of the collection period (typically 120 capture points/second - aka 120 Hz sampling rate). We have force plates (sensors) embedded in the floor too.

J with the motion capture markers

J insisted on the forehead marker

Then instead of walking, I had him dance around. Here's what was reconstructed in the computer (looped twice). The red arrow is the force J is exerting on the floor.

John just showed it to him for the first time, and J was able to point out his feet, legs, and arms. He loved it.

Then just a fun picture of J and the floor plunger (technical term "floor panel lifter"). It's just not working:

I actually got work done too! Win win!

M&M Math Supplementals

Yes, this is how we spent our Saturday night (don't judge).

We started with sorting...well, eating. J was super excited for this lesson. So excited, that he wouldn't focus and kept eating our lesson. John snuck a few too...

Counting or eating?

"Seven" (note the multi-colored lips)

Daddy helps

Our sorted cup of M&Ms

Our resulting Pie Chart:

Next was the rolling of the M&Ms.  We got 10 M&Ms in a cup like this...

Shook it up and tossed it on the floor like this...

and counted the M's (3 in the picture below)...

We repeated 36 more times and ended up with a cool bar graph (histogram) like this...

J liked the rolling of the M&Ms more than picking and sorting the colors.  Well, J liked eating our experiment more than the experiment itself.  Sigh.  John wanted me to make sure to recommend rolling the M&Ms more than 37 times and plotting the results as you go.  The plot should be more normal looking (bell-shaped) the more you roll.  However, with our 37, I'm seeing a bell-shaped trend.  What do you think?

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3/23/12 - edited to remove Pepsi Refresh voting tag - voting period is over.  We won!  Thanks for your support



P.S. I love you guys. Thanks for all of your support!