Anyone who reads my book (to be available the first week in January, it appears) will see me, in chapter eight, engaging in a bit of "medical study deconstruction" -- namely, taking apart a large study that was done about the effect of physical exercise on knees and showing how it comes up short in a number of ways.
It was a fun and illuminating exercise (fun because, to my wife's dismay, I spend a lot of time with my brow furrowed, thinking about things). To those who wonder what insight a layman could possibly have into a formal medical study, well, you might be surprised. The application of basic logic will get you far in analyzing complex subjects, even without specialized knowledge. For instance, judging the truth of the statement "the green disarticulation contours were green" doesn't require an understanding of what disarticulation contours are, why they are drawn, how they are drawn, whether they should or should not have been drawn in this specific instance. To recognize the sentence is true, you just need to identify an identity: "green equals green."
Okay, that example may seem a bit trite, but my advice is not to let the "experts" scare you away from examining their work, cloaked in all its jargon and statistical raiments. At the very least, after a thoughtful examination, you'll be in a position to ask some good questions.
And one question I asked, regarding this study, was "What were somebody's knees doing the other 98 percent of the time?"
Let me explain: The study looked at people who exercised, to see if they were less likely to develop osteoarthritis of the knee later in life. One category of exercise, fittingly enough, was walking. They were asked if they walked for exercise, and if they did, if they went less than, or more than, six miles a week.
Through how the categories were constructed, the researchers made it sound as though six miles a week was a lot of walking. So I decided to do a little math.
Let's say Joe Smith walks six miles a week for exercise. How long does it take to walk a mile? Well, I've walked one in 13 minutes before, but the average is probably closer to 20 minutes. So that equals two hours a week total. How many hours is Joe awake each week? Let's say Joe gets a full eight hours of sleep a night -- an optimistic assumption, but we'll go with it. That means Joe is awake 112 hours (16 hours x 7 days).
Divide 2 by 112 and you get 1.8 percent: That's right, Joe spends less than 2 percent of his waking hours on walking for exercise. Why does that matter? I hope you can see now where I'm going with this. What's happening with his knees the other 98 percent of the time? That's HUGE. (And the study in question makes no mention of this as a potential issue.) After all, his knees don't just magically detach from his body whenever he happens not to be exercising.
One of my complaints about physical therapy stems from this 2/98 problem. My therapist laid out a program of exercises and stretches that took me ... about two hours total, each week. Yet he didn't seem concerned about what my knees were doing the rest of the time! He never asked me questions that I would ask any knee patient, knowing what I know now. (Do you lug things to work? Do you often carry a loaded backpack? If so, about how much does it weigh? Do you often carry a child around the house? If so, how big is the child? Do you navigate a lot of steps during a typical day? Do you run for a bus? Do you run at all during a typical day? If so, for what distance and how often? Do you squat a lot at work? Do you stand a lot at work? Etc., etc.)
These questions are important because they are the other 98 percent! If your PT isn't asking about the other 98 percent, I believe you need to do the asking and thinking yourself. Because your job/house/lifestyle/whatever greatly affects how you use your knees. And how you use your knees -- over 100 percent of your waking hours, not just 2 percent -- is a big determinant of how your knees feel (and heal), I learned during my recovery.