Studies That Probably Didn’t Need to Be Done: Knee Pain Causes Activity Avoidance

Today, we’re on the lighter side.

This just in, from the annals of Captain Obvious:

Patients with early symptomatic osteoarthritis (OA) of the knee avoid performing normal daily physical activities because they are experiencing pain, findings of a large, longitudinal study suggest.

I found this amusing and will bite back on my natural inclination toward sarcasm. I do find rather intuitive the concept that if someone has been banged in the kneecaps with a lead pipe his appetite to weed the flowerbed or climb a set of stairs will rapidly diminish.

There were 828 subjects in the study aged 45 to 65 years (yes, it is somewhat of a shame that this huge sample size went to waste.)

You might say the study helps confirm the vicious cycle that when your knees hurt, you move them less and so your muscles weaken, which leads to your knees hurting more, so you move them even less and etc. You get the picture.

I will say, in this study’s defense, that one admirable thing about scientists is that they don’t take accepted wisdom for truth. Some studies reveal curious, unlikely things, but others simply look at something that we think should be true and confirm it.

In this case:

“The results support the validity of the avoidance model in persons with early symptomatic knee OA,” said study author Jasmijn Holla, from the Amsterdam Rehabilitation Research Center in Reade, the Netherlands.

True. But I’m just not convinced we needed a full-blown study to tell us that.

Comment Corner: ‘To Heal My Knees, How Often Should I Increase Light Activity?’

We get mail. (Well, sort of.)

Recently someone left this comment:

I have been scrolling through your entire blog for the day and reading all of your posts. I even bought your book! I'm a 20 year old female who led a VERY active life. I underwent a bilateral knee athroscopy to obtain a final diagnosis of my knee problems AND fix any issues that are able to be fixed.

The surgeon removed a medial plica, a piece of cartilage the size of a pinkie nail that was floating around the knee joint and another piece of cartilage that was flapping around inside the knee joint from my left knee. However, I was diagnosed with softening of the articular cartilage behind my RIGHT kneecap (chondromalacia patella).

My father (who is a GP) told me it will get better if I do light exercise (e.g. walking to the toilet) at regular intervals throughout the day (e.g. every 30 minutes). I had also undergone physio for several months but this exacerbated the problem. After reading your blog, it has given me new hope in healing the cartilage in my right knee.

The only thing that I'm unsure of, is how do you know when and how much to increase light activity. I understand there is no magic answer, everyone is different. But did you increase your activity slightly when the pain had remained relatively stable or did you slightly increase your activity when the pain had improved slightly? After you had increased your activity slightly, would there be a few days where you experienced a little more pain than usual and persisted for a few days before determining whether to decrease or maintain the new level of activity.

First, note that physical therapy made her knee worse. No surprise there. When misguided physical therapy (strengthen muscles! strengthen muscles!) meets very weak knees, it’s about what should be expected. I know that all too well from my own experience.

Now on to the questions. And they’re the hard questions, make no mistake about it. If they were easy, I daresay there would be many fewer cases of knee pain. I've already tried to answer such questions before (based on my experience), but they’re well worth revisiting.

First, she’s right of course. There is no magic answer. I wish it were as easy as saying, “Do x repetitions of exercise y for 2 weeks, then add 5 repetitions every week.” But you have to figure out exactly what works best for your knees.

However, here are three guidelines that worked for me:

(1) If possible, try to enlarge pain-free, or relatively pain-free, windows. So try to find a place of no pain/little pain, and go from there. This may require a radical readjustment: your knees may be too weak to do much more than walk around your apartment (or house) for short bursts at regular intervals. That then becomes your baseline.

Between the choice of (a) “increase activity when pain was stable” and (b) “increase activity when pain had improved slightly,” I guess -- if I had to choose -- I’d take (b) in most cases, as that’s the least-pain route.

(2) I had success operating on a weekly schedule. Each week I decided on my plan for the following week (based on how the current week had gone). And I tried to stick to the same regimen for at least one week.

Why weekly, not daily?

For me, it reinforced my belief that I had to go slow and get on cartilage time, where progress would be measured in weeks and months, not days. Also though, I found it easier to isolate cause and effect, when troubleshooting little issues with my knees, when I kept my program fairly constant.

(3) Err on the “go slow” side.

Say you’ve spent four weeks doing 2 one-mile walks each day. Your knees feel a little better, but not much, and could the “improvement” be just your imagination? Now you’re thinking: “Week 5. Time to step it up (so to speak)! I need to dial up the intensity. So I’ll start walking 1 1/2 miles twice a day!”

Time out. There’s no rush. If in doubt on increasing activity, I would give that stage of the program (assuming you are active, which is important), another week or two, or month even.

My hunch is that, while you’re going slow and thinking “I really ought to be doing more,” you’re actually building a nice “motion groove” for your knee that will help ensure success when you do step up to the next level.

(Oh, the commenter also asked if, after I increased the level of activity, were there a few days of increased pain? Honestly: not really. I tried to stay at a given level long enough, and increase intensity so gradually, that the transition was fairly uneventful.)