It’s been a long month, and my overwhelmingly busy schedule won’t calm down until a week or two into December, so no new articles until then. In the mean time, I thought I’d everyone know what I’ve been up to.
I’ve been spending a lot of time at my university, working on finishing up one of the heaviest courses – ‘Kinesiology Technologies’. Essentially, it’s a course about the theory and application of commonly used lab equipment for studying human movement. EMG, VO2 testing, indirect calorimetry, force plates, kinematic analysis… all kinds of fun stuff. For example:
The photo above is myself performing an ITT (interpolated twitch technique) test. This test gives an indication of how much of your muscle (i.e. motor units) you are activating during a maximum voluntary contraction (MVC).
Basically, you sit on the bench with a strap around your foot (look at the picture) which measures how much force you are producing when you try to extend your leg as hard as you can (an MVC). Also, EMG electrodes are attached to my leg to observe muscle activity.
Then, halfway through my maximum contraction, I get an intense electrical stimulation to the quadriceps to activate any remaining motor units. If I’m not voluntarily activating all of my quads motor units, then the e-stim should cause a little jump on the force reading.
But check out my graph:
The top (blue) part is force, and middle (green) is EMG, and the bottom (pink)… ignore that. See the big spike in the EMG around the middle of the test? That’s the e-stim. Usually, after the e-stim you will see a little spike upwards in the blue line (right before the drop – I won’t explain the drop here) because it would cause me to contract my leg harder. It would look like this.
But there was no spike… which means I was already activating 100% of my motor units (hypothetically)! Which might mean that my nervous system is pretty darn good at activating what little muscle I have… but you knew that already, right? :D
Doing stuff like this in the lab is really fun, and makes all the research I read come alive. I understand what experiments are doing (and their limitations) much more clearly now.
But it’s not all fun and games… for every hour spent in the lab, there’s another three or four hours spent in front of a computer screen, looking at spreadsheets of lab data, doing analysis… here’s what my evenings look like after I get off work:
Nothing like learning how to build digital EMG filters in Microsoft Excel… fun!
Thankfully, this technologies course will be finished in a couple weeks… then I’ll be able to write for this website a little more regularly.
Big things planned, so stay tuned!
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