Revelation the first: 4mph on the treadmills at the gym != 4mph on the treadmill at home. Whether the motors on the ones at the gym being in constant use has made them slower than they should be, or ours is faster than it should be, or some combination thereof, I don't know. Short of an exact camera timer with a mark on the belt, done for each one, to determine the actual speeds, it's not likely I'll ever know. All I know is, if I set our treadmill to 4mph I'd have an incredibly hard time keeping up and still walking, but on the one at the gym I'd have to set it to about 4.5mph—I can manage 4.4, but it's a wee bit much and I was more comfortable at 4.2.
Revelation the second: I never paid much mind to how I walked, i.e. what motion my legs moved in, and I think maybe I've been doing it wrong. Sounds dumb, right? After all, I've been doing it for over 25 years, I should bloody well know how to walk. It's nothing like being bowlegged, or turning my toes inwards as compared to my heels. It's just... at least for walking fast, the way I've been doing it probably isn't the best for my knees. I'm considering asking on FO (either in one of the existing exercise advice threads or in a new one) if what I've noticed makes any sense.
How I realized I may've been walking wrong, and theories as to whether changing to do it to what I perceive is right will lessen my chances for injuries in the future:
I walked 2 miles yesterday in a few seconds over a half hour (well, I did a really, really slow careful log for about a minute or so just to test the waters, and decided that while it didn't exactly hurt, I probably shouldn't do it again during the session). In that time, I wanted to make damn sure I could keep walking without pain, because I didn't want to have to quit. So, I had lots of time to pay really close attention to how I put each foot down. I started as just paying attention to feel: did my foot come down perfectly "square" rather than to one side, did it come down with no pressure to either side of my knee, did it come down properly on the heel—not too hard but a roll from heel to toe, did my foot roll evenly from heel to toe without angling off badly too far to the inside or outside of the foot? All those were going through my head, though not in so many words, every single time I took a step with either foot.
Then, after I'd kinda gotten the hang of perfecting each step (though still concentrating, mind you; apparently if I don't my body likes to be a bit careless with its motion), I started watching my feet. I know that they say it's a sign of fatigue plus likely to increase said fatigue by looking down rather than up, but I didn't care about that; I wasn't fatigued in spite of going fast enough that I was dripping sweat. Oh no; I was specifically watching the motion of my feet that went along with the properly aligned steps I was taking. I was a bit surprised.
First off, I should note that if I paid a whole lot of attention at all to my feet and legs, I generally could've told anyone that I generally walk with my legs making basically two parallel line motions forward and back, with kind of a wide "stance" if you will. None of this silly "one foot directly in front of the other" ladylike catwalk crap. Just straightforward, let's geterdone "I mean business" walk. That wasn't the pattern my legs were taking last night. I wasn't walking toe-heel like a balance beam (good thing, I probably would've fallen on my face if I'd purposely tried keeping that up) but the path of one foot did overlap the path of the other. So basically instead of two straight lines in parallel, the paths for my feet were more like very, very narrow ovals slightly tilted inward (once the foot is actually down it's gonna go straight back till it's picked up again).
I thought about this, and I wonder if it's to do with something my dad mentioned when I was discussing leg sleds with him, and his suggestion to use knee braces or wraps to do so. He suggested this because, due to a woman having wider hips, if you take an x-ray of most women's legs, the thigh bone is not in perfect parallel with the shin bone. The thigh bones angle slightly inward from hips to knees. Looking at mine, I'm certainly not an exception. I sit down with my legs out into a V for stretching, and it's clear looking at each leg separately that my thigh and shin are not one long perfectly straight line. So I put that in with what I'd noticed, and it appears that a more even way for me to walk actually involves bringing the whole leg inwards rather than close to directly below the hip to minimize strain to the inside of my knee, but of course since the hip joint swings the way it does I'm not going to just be making perfectly straight path lines when I do so that just angle inward towards each other, but more that oval thing with perhaps a flat side to it while the foot is going from heel to toe.
Obviously my "doing it wrong" isn't solely responsible for the current issue with my left knee; otherwise both knees would be fucked. However, I do wonder if it contributes. Of course, I also second guess my conclusions a bit, wondering if I might end up causing myself hip problems instead of knee problems by changing how I walk, but my hips didn't hurt last night and they don't hurt now, so I'm tentatively going to ignore that particular voice. Hence the possible FO thread question for the fitness gurus. What it comes down to is, I never took biology, and I've never studied anatomy in any way, so I don't really know in depth how the musculoskeletal structure all works together, male or female, and I just can't say with 100% certainty whether my conclusions are correct.
Even if I am correct, all of it changes when discussing jogging rather than walking. For starters, I don't know if I can pay quite that much attention and make it work while jogging since it's faster. Simply put, I'm afraid all the concentration might just serve to make me trip over my own damn feet. Plus, I have no clue whether the basic lines my feet take should stay the same for jogging as for walking.
Regardless, I do need to strengthen my knees, especially the inside and outside. I found out they do still indeed make what my dad referred to as wobble boards; they're simply called balance or rocker boards now. My class instructor, who works as a PT assistant, gave me a website to go to in order to check, and I did indeed find 'em. And, I'm so definitely not buying one but rather improvising. All I need is various widths of PVC and a scrap piece of plywood (a shelf from my desk was suggested since it was intended for use inside the tower compartment, but my tower's far too big so it's spare; I'd rather not scratch it all up in case I ever have a smaller tower to put in it and want the shelf). The absolute cheapest one I saw was $70. They had one that was $175, and several in between, though most were $80-100. Fuck. That. Considering the cost of, say, 6 different pieces of PVC a foot long of varying diameters an a 3-4'x1' piece of plywood would probably cost around the price to fill up my gas tank once at most, why buy one?