AMC Outdoors, October 2005
The trails of the Northeast punish your knees. Unyielding rock slabs, plummeting descents, and thudding drops over refrigerator-sized boulders combine to induce Richter-scale compression on this precious joint. Aftershocks of soreness, stiffness, and downright pain can linger for days. Over time, this abuse can wear down your knees, paving the way for the development of arthritis.
There’s no getting around these features of our backcountry landscape, but there are things you can do to mitigate their effects. A few easy techniques can help protect the cartilage in your knees for a lifetime of hiking adventure.
Your knees act as natural shock absorbers. With age, they slowly lose some of their spring, a process accelerated by regular compressive abuse. Consequently, anything you can do to reduce the pressure on your knees will help increase their longevity, and reduce the accompanying pain and soreness. Knees are difficult and painful to rebuild (see sidebar), so before you consider any radical solutions focus first on a few simple techniques.
First, carry less weight, especially if you’re backpacking. Downward force on your knees can reach eight times the weight applied, which means that shaving five pounds off your packweight will spare your knees up to 40 pounds of pressure. As any dedicated backpacker will tell you, ounces matter. By extension, staying fit and keeping extraneous body fat to a minimum have the same positive effect.
Second, use trekking poles, which have been shown to reduce the compressive forces on your knees by as much as 25 percent (see Tools, April). Remember that both poles are necessary to be effective. Using a single pole can actually increase stress on the unaided knee.
Third, wear properly fitting shoes and invest in some quality insoles—the inserts that come with most footwear offer little to no help when it comes to shock absorption. Dozens of squishy, cushy inserts line the shelves in both pharmacies and outdoor gear shops, but are usually not built for hiking abuse. They will initially absorb shock, but will also rapidly flatten out and lose their cushioning effect with prolonged hiking.
Look instead for more rigid models, such as Superfeet, which cup the fleshy pad under your heel bone and take advantage of the body’s natural shock absorbing capabilities. Made of plastic and dense foam, they can last for months and hundreds of miles of use.
The view from the inside
OK, so you’ve tried all that and your knees are still buzzing hives of discomfort. So let’s go a little deeper.
Inside your knee there are two types of cartilage. Hyaline, or articular, cartilage lines the ends of your bones. Fibrocartilage composes the menisci, two small disk-like pieces that nestle between the femur and tibia in your knee. Though both types have shock-absorbing capabilities, articular cartilage tends to take the brunt of compressive forces. The viscoelastic properties of synovial fluid—which lubricates your knee like the motor oil in your car—aid in the process.
If articular cartilage is damaged, either traumatically or through simple wear and tear, the bones in your knee can start to rub directly against each other, causing pain and stiffness. This is the condition known as arthritis, which can cause potentially debilitating symptoms. But several over-the-counter items may be able to help.
Non-steroidal anti-inflammatory medications such as aspirin and ibuprofen provide temporary relief for arthritis-induced swelling and pain, and can offer a short-term solution. But over the long-term, the dietary supplements of glucosamine and chondroitin may actually prevent cartilage breakdown, as well as stimulate the production of new cartilage.
Glucosamine is a raw material that your body uses to help build cartilage. Chondroitin, specifically chondroitin sulfate, is a major component of cartilage and its ability to attract water helps to lubricate joints. Both are made naturally by the body, but in decreasing amounts as we age.
More than 30 medical studies have been conducted on the effects of glucosamine and chondroitin, and most indicate that they are better than placebos in reducing joint pain caused by arthritis. Nevertheless, the studies have come under scrutiny due to small sample size, short duration, and the fact that many were supported or performed by supplement manufacturers. Additionallly, the Food and Drug Administration classifies glucosamine and chondroitin as dietary supplements, and consequently has not made them the subject of its rigorous drug-testing standards.
In part as a response to these concerns, the National Institute of Health has undertaken a comprehensive five-year study on the effects of glucosamine and chondrotin. Results are expected to be realeased by the end of this year.
A variety of invasive techniques are also available to address chronic and debilitating knee pain caused by arthritis, from injecting steroids directly into the joint to inserting new cartilage harvested from elsewhere in the patient’s body. These are generally serious procedures, and carry with them increased risk, rehabilitation time, and expense—ask your doctor.
—Matt Heid is senior editor of AMC Outdoors.