Sunday, April 10, 2011

On the Real Benefits of Stretching If You Have Knee Pain

I became a stretching skeptic partly because of my unusual history.

All my life, I've been tight-jointed (the kind of person who is usually advised to stretch). At the same time, as a youth, I loved sports: basketball, baseball, winter pickup games of touch football on frozen fields.

I never stretched beforehand. And I never got injured.

When I finally did have a serious injury, in my mid-forties -- cartilage damage in both knees -- at the advice of my physical therapist, I started stretching. Every day. I stretched and stretched and stretched (and did a number of exercises that he prescribed as well).

But I didn't get better. At some moment I began to wonder, "What does this stretching really do anyway? And what's the mechanism by which it fixes what's wrong with my joints?" It soon became clear that stretching didn't fix anything -- for me, and I suspect for many other knee pain sufferers as well.

Still, it can't be completely useless, right? Today we'll look at the question, "What's the best case to be made for the benefits of stretching?"

Here are some arguments that strike me as defensible reasons to stretch.

1. Stretching just makes me feel good.

If you happen to simply like the feeling after a good stretch -- of being loosened up, and relaxed, and ready to take on the world -- great! This seems like a valid reason to stretch.

2. I believe stretching is helping improve the condition of my knees.

Belief is a powerful force! In Saving My Knees I discuss the dietary supplement glucosamine. My doctors were vague and unhelpful on several fronts, but when it came time to prescribe something, on two occasions that something turned out to be glucosamine. Later I discovered the black joke: glucosamine has been shown not to work. Let me explain in brief:

* A number of scientific studies have emerged in the last decade indicating that it's not effective.

* Even if you don't believe these scientific trials that looked at pain relief and arthritis symptoms (after all, others claim a beneficial effect), at least two studies examined glucosamine on the level of molecular biology. They showed that the supplement, after being swallowed, is essentially ripped apart by the liver. The amount that ends up circulating in the blood is far lower than what's needed to have a salutary effect on your knee cartilage.

* If you're still skeptical, ponder this. People claim they need glucosamine to "feel better" and immediately notice when they skip taking a pill. Meanwhile, glucosamine is supposed to act on cartilage, a tissue that has no nerves and heals very slowly. So riddle me this: How is it that glucosamine takers get such immediate, snappy neural feedback in taking a pill that's supposed to improve the health of something that has no nerves and heals very slowly?

The glucosamine story is probably a placebo story. The stretching story may also be a placebo story, to some degree. But a placebo story doesn't have to be bad. Beating knee pain requires mental fortitude and a positive outlook. So if stretching lifts your spirits and you think it works, it can be somewhat irrelevant whether it actually does or not.

3. Stretching is necessary to preserve knee motion after surgery.

In Dr. Ronald Grelsamer's book What Your Doctor May Not Tell You About Knee Pain and Surgery, he says:
Following an injury or surgery, your knee will not want to straighten all the way. And it will not want to bend. Indeed, bending or straightening stretches the ligaments and tendons, which is painful. If you give in to the knee's reluctance to straighten and bend, two things may happen: Your knee pain may persist or worsen. Moreover, you might permanently lose knee motion.
Certainly, right after surgery there will be a period when you won't want to move much and will avoid bending or straightening your leg. However, you need to. Post-surgery, you're especially at risk of developing scar tissue (reducing range of motion and hindering function).

So, with the aid of a physical therapist at first, you need to bend your leg through as wide a range of motion as possible. This seems like an acceptable reason to stretch. But still, note that stretching isn't what's most important. You're not trying to achieve "range of stretching." It's range of MOTION -- and stretching the leg, to push it through the range, is what's required at that point.

Later, when the joint is capable of bearing weight and you're strong enough, regular motion and bending exercises can replace the stretching.


You may think I've overlooked a big reason to stretch: to redress issues of tightness or imbalance that cause unusual and harmful wear patterns in the joint. I think though that "tightness" and "imbalance" are often structuralist code words that don't get at the heart of the problem and don't offer a real, lasting solution (for more on structuralism, check out this earlier post).

I think the stretching-to-fix-tightness-or-imbalance doesn't make a whole bunch of sense. It's a way for doctors and PTs to avoid the real issue: you need to fix the joint (which most of them are still mystified about how to do). Most imbalances serious enough to cause your joints to degrade, it seems, couldn't be fixed by stretching alone. Surgery perhaps.

NEXT TIME: A meta look at the attraction of stretching: why, even if the heavens parted and God himself appeared and said stretching was useless, everybody would keep stretching. Why has this activity so thoroughly captured the imaginations of those in the physical therapy and medical community for so long?

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