The (appropriately) quantified self

A year after we moved to northern California I acquired a pair of shiny new titanium hip joints. There would be no more running for me. But I’m a lucky guy who gets to to bike and hike more than ever amidst spectacular scenery that no-one could fully explore in a lifetime.

Although the osteoarthritis was more advanced on the right side, we opted for bilateral replacement because the left side wasn’t far behind. Things hadn’t felt symmetrical in the years leading up to the surgery, and that didn’t change. There’s always a sense that something’s different about the right side.

We’re pretty sure it’s not the hardware. X-rays show that the implants remain firmly seated, and there’s no measurable asymmetry. Something about the software has changed, but there’s been no way to pin down what’s different about the muscles, tendons, and ligaments on that side, whether there’s a correction to be made, and if so, how.

Last month, poking around on my iPhone, I noticed that I’d never opened the Health app. That’s beause I’ve always been ambivalent about the quantified self movement. In college, when I left competive gymnastics and took up running, I avoided tracking time and distance. Even then, before the advent of fancy tech, I knew I was capable of obsessive data-gathering and analysis, and didn’t want to go there. It was enough to just run, enjoy the scenery, and feel the afterglow.

When I launched the Health app, I was surprised to see that it had been counting my steps since I became an iPhone user 18 months ago. Really? I don’t recall opting into that feature.

Still, it was (of course!) fascinating to see the data and trends. And one metric in particular grabbed my attention: Walking Asymmetry.

Walking asymmetry is the percent of time that your steps with one foot are faster or slower than the other foot.

An even or symmetrical walk is often an important physical therapy goal when recovering from injury.

Here’s my chart for the past year.

I first saw this in mid-December when the trend was at its peak. What caused it? Well, it’s been rainy here (thankfully!), so I’ve been riding less, maybe that was a factor?

Since then I haven’t biked more, though, and I’ve walked the usual mile or two most days, with longer hikes on weekends. Yet the data suggest that I’ve reversed the trend.

What’s going on here?

Maybe this form of biofeedback worked. Once aware of the asymmetry I subconsciously corrected it. But that doesn’t explain the November/December trend.

Maybe the metric is bogus. A phone in your pocket doesn’t seem like a great way to measure walking asymmetry. I’ve also noticed that my step count and distances vary, on days when I’m riding, in ways that are hard to explain.

I’d like to try some real gait analysis using wearable tech. I suspect that data recorded from a couple of bike rides, mountain hikes, and neighborhood walks could help me understand the forces at play, and that realtime feedback could help me balance those forces.

I wouldn’t want to wear it all the time, though. It’d be a diagnostic and therapeutic tool, not a lifestyle.

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10 thoughts on “The (appropriately) quantified self

  1. I’m impressed and glad for you to be able to do that much biking and hiking with the new hips.

    I’d like to think there are more accurate sensors too. I remember kicking in to a kickstarter a few years back for “Sole Power” that was trying to make shoe inserts that could generate enough power to charge your phone. It would seem possible to have something similar to measure your gait and other measures. But a bike computer too could do things like track cadence etc.

    I had a similar discovery about the health app in 2016- I had just adopted a dog and with more regular walking wanted to track weight change. There was an old tech called Your Flowing Data where you could DM any kind of self measure that would provide charts and data summary. But it was no longer supported so I thought about the health app, where lo and behold it had been tracking the increases in walking miles. I was ok with that, and even if not accurate it did show enough trends for me. But like you I was out there for the time outdoors, not the numbers.

  2. When I had my hip resurfaced 15 years ago, others noticed that I still had a slight asymmetric limp even 5 months after surgery. I was pain free, so I suspected the limp was a bad habit.

    I hired a local Santa Rosa Feldenkrais movement practitioner (now retired) to help me lose the limp. She suggested several exercises, and did some massage-like hands-on pressure body work. She worked with me for about 6 weeks, once a week for about an hour in my home.

    Her most effective exercise was to have me walk backwards in socks, having me pay attention to my movements, but only looking forward and not at my legs and feet.

    She also had me do several effective floor movement exercises, which helped lose habits I had adopted to compensate for the bad hip. Walking backwards was far and away the most helpful, and the limp was gone within a month or so. No drugs, machines, expensive treatments or long term commitment.

    I now play handball 3 days a week in Rohnert Park with a bunch of other 60-70 year olds and ride a bike whenever it isn’t raining or too cold. I still warm up with walking/running backwards.

    Good luck with your asymmetry! Hope this helps with possibilities.

  3. It turns out I was accidentally playing iphone chicken with AT&T — I had a 4s and wasn’t especially bothered that they were turning off their 3G network, not that anxious to talk to people immediately and by any means necessary, which kind of froke them out and they sent me a (free) new iphone XR, which stands for GIANT PHONE. It’s pretty giant. Had to put a strap on it. And it does track everything and hides the buttons away, so you literally have to go through everything if you want anything resembling the appearance of privacy.

    I’m still running, so my kid also persuaded me to put Nike’s running club app on there, so yes, more loss of privacy, but I notice something interesting in the accelerometer etc. use: on a well-calibrated treadmill, it assumes wrong things about the length of my stride, even though I’ve given it correct height info. It gets the strides per minute right, but it thinks I’m wearing seven-league boots, so it also gets my pace and distance wrong.

    The thing is, though, I don’t run like I used to. I run old now. And I was having real trouble figuring out how to do that, not having fun at all. The thing that’s fixing that isn’t a gadget or a metric at all: it’s Joan Benoit Samuelson, who’s one of the coaches on this run app. Lady reminded me what running is, and told me to go long and ease into it, slow, slow, slow. So I did, and I had my best runs in years, and now I guess I’ll have to replace my shoes. On to Shalane and Mo Farah.

    Oh, also, more metrics, personal-energy related rather than fitness: https://energybore.wordpress.com/2021/12/09/we-cannot-techbro-our-way-to-saving-the-climate/

    1. > I guess I’ll have to replace my shoes

      I concluded that shoes don’t matter, but running style does. You can do “barefoot running” with or without shoes, and it bought me a couple of years before I had to quit. If that had been a lifetime practice would I still be running? We’ll never know. For what it’s worth, my surgeon said: “Don’t beat yourself up about it, it was probably in the cards no matter what, it’s genetic roulette.”

  4. hahahaha, barefoot running shoes. My ex-husband had those toe glove things, btw, and he looked like a total dork, especially when he paired them with his cool new Gepetto cargo pants that cut off at mid-calf for no reason and his safety vest. (Yes, I married this man. I was on drugs at the time, that’s my story.) He too left the gloves behind.

    I used to work for Rodale, so I hung out with a lot of marathoners at the company gym (where they had these cool treadmills that could do negative inclines, also known as declines)(also, free sample shoes!). I have a wildly springy gait but also land very hard, because I am graceless, and I used to run in the morning next to Budd Coates, who’d be there laying down sub-sixes like nothing at all. And he’d look at me and just shake his head, told me it was no wonder I had knee trouble. The knee trouble actually came from a lipoma in the knee capsule (words you don’t want to hear from a surgeon who’s just cut you open, years after going in and getting handed a lot of “Q-angle” garbage because you’re a girl, meaning the problem’s had time to get disablingly bad: “What the hell is that?”), but still, yes, the spring’s a little much. It also creates some problems now, because several years ago I was on a course of quinolone antibiotic before the “this will snap your tendons” labeling showed up, and a few days in I was like “something’s wrong”, read up on the drug mechanism and said “oh crap” and had to fight with the nurse to get the drug changed. It’s taken a long time to recover from that, and I find it’s still pretty easy to aggravate the achilles if I overdo it.

    I do find that when I slow things down, I calm the bounce, and I can run longer and the achilles are still happy. Interestingly, that does shift things to a more heel-strikey gait, closer to walking, but my hams are a little confused about the whole business. Still feeling my way.

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