How many thousands of miles can your knees take? As the years go by and the miles pile up, it’s a question I’ve been thinking about with increasing regularity. Achy knees are one of the most common ailments hikers face, especially as time and adventures wear down these crucial joints.
To maximize the longevity of your knees—and reduce existing aches, pains, and soreness—a few simple gear changes can make a world of difference.
First, some quick background. Anytime you walk, your knees compress as your feet strike the ground and your weight settles. The resulting forces are amplified when going downhill, explains Erin Futrell, an orthopedic certified specialist with Joint Ventures Physical Therapy and Fitness in Boston. “People fear walking uphill, but it’s actually more difficult to walk downhill,” she explains. “It puts a lot more force on your knees.”
Wearing footwear with minimal shock absorption or carrying excess weight on your back (or body) also increases the pressure on your knees. Over time, these factors wear out your knees’ natural shock absorbers, including the meniscus, a specialized layer of cartilage that sits at the top of your shin bones, and the cartilage located at the bottom end of your femur.
The key to reducing knee pain is to minimize the amount of force they absorb in the first place.
Solution #1: Use Trekking Poles
Studies have shown that using trekking poles significantly reduces the amount of compressive force on the knees, especially on downhill sections. (Shock-absorbing poles may help even more, however the trade-off is that they are counterproductive on uphills unless switched to a locked position.) One oft-cited study in the Journal of Sports Sciences found that using poles on a 25-degree downhill grade decreases the compressive force on the knees by 12 to 25 percent. Another study found that poles reduce knee stress on level ground by approximately 5 percent.
To maximize the benefits of your trekking poles, make sure they are adjusted to the right length. When the pole is planted in front of you, your elbow should form a 90-degree angle. On downhill sections, this means you’ll need to extend the length of your poles accordingly. Also make sure you’re using the wrist straps correctly to transfer weight effectively to your upper body.
Solution #2: Upgrade Your Insoles
Your shoes can absorb some of the forces that otherwise would go straight to your knees. Most hiking boots, however, offer far less shock absorption than other athletic footwear, such as running shoes.
Offset this cushion deficit by upgrading your hiking insoles. “Squishy” insoles work (think Dr. Scholl’s) but only until they become permanently compressed, which can happen relatively quickly on the trails. A better option are designs like those from Superfeet, which position the meaty part of your heel underfoot to provide natural shock absorption; they easily last for years. When shopping for insoles, look for styles that feature stiff arch support and that closely match your foot shape (which varies extravagantly from person to person).
Solution #3: Carry Less Weight
Lightening your load benefits more than just your muscles. It also reduces pressure on your knees. Losing several pounds from your pack can be easier than you might think, especially if you focus on cutting weight from your shelter, backpack, or sleep system (sleeping bag and pad). Carrying excess pounds on your body doesn’t help either; consider dropping a few if it’s appropriate.
Solution #4: Tread Lightly
Beyond gear solutions, Futrell recommends one other simple technique on the trail. “When you’re hiking, listen to how hard your feet hit the ground,” she says. “Listening to your footsteps can help you recognize when you’re pounding your knees. Try instead to literally tread lightly. This forces you to use your muscles more and reduces the pressure on your knees.”
The knee is a complex joint and prone to a variety of injuries beyond simple wear and tear, including damage to the many ligaments and tendons that surround the joint. While it’s common to experience sore knees for a day or two immediately after a strenuous hike, long-term pain is a red flag. “If the pain doesn’t go away after two or three days, seek advice from a medical professional,” Futrell advises.
You can strengthen your knees further with two simple exercises. Get details in Stronger Knees, Please.