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!

Food Chain, a la J

"If the plants die, then everything will die too: all the sharks, all the lions..."

Free Online Child Nutrition and Cooking Course

Stanford is offering a free online Child Nutrition and Cooking Course. Today was the first official day.

I decided at the last minute to join the class this morning. We are minimal cookers in our family. It's hard as two working parents to cook every night of the week. If you don't count sandwich and quesadilla nights, we have maybe 8-10 dishes we repeat over and over. We also eat out on weekends as our form of entertainment. I wanted to see if the course would offer at least some fresh ideas on how to eat in more.

After joining the class, I realized a big challenge in at least the first assignment. A veggie dish appetizer which is due on Saturday. We've been sick around here, we don't have any cookable veggies (my family has sensory/texture issues/preferences with cooked veggies), and we're going to be busy most of the week, including the days leading up to Saturday. If I was going to complete the assignment, I needed to do it today or tomorrow. If I waited till tomorrow, I'd have a great amount of anxiety. If it was something I cooked with veggies, my family wouldn't eat it.

Anyways, I decided not to cook but rather prepare the raw veggies in a fun display for my picky eaters. There's enough veggies in there to satisfy everyone. They don't have to eat the ones they don't like. There's also roasted garlic hummus for those who like to dip.

Based on my posts on Nerdy Science and now this one, can you tell we like vehicles in our house? Here's my bus scene. We have many different veggie people, zucchini as wheels, and bell pepper benches and greenery. The rainbow of colors is good, as each color contains different nutrients. I'm not sure if I'm supposed to share it, but I decided to make it instead of watching The Voice. It was that important to me. I also submitted for grading before posting this. The time stamps should be in my favor. I'm satisfied with it:

Assignments are peer reviewed, so I'm a little nervous that it's not cooked. After 6 years of being done, I forgot how anxious school makes me.

We'll see how J likes it tomorrow since he's the ultimate judge and who I'm doing this for. He may not eat it since he's still not feeling well. This stomach bug he's had since Friday just won't go away!

Biomechanics a la J

Super sleepy, sick J revelation: "See this?" [points to folds on palms of hands]

"It's so we can pick up things like our toys."

Recycling a la J

"When someone gives us something to recycle, we use it again, like I built a rocket ship out of a bottle."