Letâ€™s get this out of the way: running wonâ€™t ruin your knees, no matter what your smug, sedentary co-worker says.
â€œThere are three large studies that show long-term endurance running doesnâ€™t seem to affect joint health,â€ says Dr Richard Willy, an assistant professor of physical therapy at East Carolina University in the US.
In fact, runners may have healthier joints than their inactive counterparts, says Dr Max R Paquette, an assistant professor of biomechanics at the University of Memphis.
Itâ€™s well known that weight-bearing exercises such as running strengthen bone and muscle, and itâ€™s believed that they might do the same for cartilage, the tissue that cushions joints. And strong muscles â€“ built by running and strength-training â€“ support joints so they are less vulnerable to injury.
Yet thereâ€™s a condition called â€œrunnerâ€™s kneeâ€ for a reason. Patellofemoral pain (knee pain) is the most reported injury in the sport. Hip, ankle and foot injuries happen too.
But not because someone is running â€“ itâ€™s because he or she is running with flawed form or muscle imbalances. So while you can rest assured that running is healthy for your entire body â€“ joints included â€“ itâ€™s important to learn what causes joint pain.
Taking steps to minimise the risk can help you keep running into your golden years.
Common ailments that sideline runners:
Hip, knee, ankle, foot
Osteoarthritis: The wear-and-tear condition that occurs when cartilage breaks down over time. Blame genetics and biochemical responses (not necessarily running).
Bursitis: This friction syndrome is caused by inflammation of the bursa â€“ the small sac of fluid that lubricates the muscles and tendons that run around the hip joint.
Patellofemoral pain (aka runnerâ€™s knee): Discomfort behind the kneecap (patella) caused by repetitive contact between the underside of your patella and your femur (thigh bone).
Patellar tendinopathy: Inflammation of the tendon that runs from the kneecap to the top of the tibia (one of two lower leg bones). The pain usually occurs at the bottom of the patella, especially when running downhill.
Torn meniscus: Cartilage on the inside and outside of the knee acts as bumpers between the femur and tibia. As you age, it becomes thinner and more susceptible to damage.
Achilles tendinopathy: One of the most common sources of ankle pain, caused by inflammation of the largest tendon in the ankle.
Ankle sprain: When the foot and ankle turn in or out suddenly, the ligaments that stabilise the ankle joint can become damaged.
Bunion: Under repetitive pressure, the big toe joint can move out of place, swell and turn inward, causing a painful, bony protrusion.
Why does my knee ache?
Probable causes of the pain:
Dr Willy says hip adduction â€“ when the thigh moves inward from the hip mid-stride, causing a knock-kneed effect â€“ is one of the most common sources of biomechanical-related knee pain. Over striding is another.
This is intricately related to biomechanics, since muscle imbalances can cause poor biomechanics â€“ and conversely, poor biomechanics can result in imbalanced muscle development. If you canâ€™t do a single-leg squat without wobbling or having your knee dive in or out at a steep angle, you may have some glute or hip weaknesses that need attention, says Dr Keith Spain, a sports-medicine specialist at the Orthopaedic Group.
While the link between running injuries and genetics is still unclear, Dr Spain says that arthritis has a genetic component. â€œIf your parents had arthritis, youâ€™re more likely to have it,â€ he says. And while of course age is a factor, Dr Spain says that getting old doesnâ€™t necessarily mean youâ€™ll get arthritis. â€œI see 80-year-olds without any arthritic changes and 50-year-olds with terrible arthritis.â€
Women are twice as likely to report knee pain as men, Dr Willy says. But researchers arenâ€™t entirely clear on why. â€œThe hypothesis has been that womenâ€™s lower-extremity alignment places the knee in a position where itâ€™s more susceptible to injury; I think thereâ€™s more to it than that, though,â€ says Dr Paquette, adding that subtle differences in womenâ€™s connective tissue make-up may also play a role. Pregnant women or women who have just given birth are also more susceptible to joint injuries, because ligaments relax to prepare for childbirth.
Pain is something researchers are still working to understand better, says Dr Willy, adding that joint-related pain seems to be individual. â€œTwo runners with the same biomechanics can go through the same training programme, and one gets injured but the other doesnâ€™t,â€ he says. â€œWe really donâ€™t know exactly why that happens.â€ He says that variables such as sleep quality, nutrition, and even psychosocial factors â€“ such as fear of getting injured â€“ may contribute.
5 ways to protect your joints
Reduce the load:
Shorten your stride
â€œAn increase in step rate of 5 to 10% can reduce patellofemoral joint load by up to 20%,â€ Dr Willy says. Garminâ€™s foot pod or the MilestonePod can help you monitor your step rate. Dr Willy says stride rates are highly individual, but itâ€™s generally recommended to aim for 160 to 190 steps per minute.
A word of warning: be careful not to accidentally change how your foot hits the ground. Shifting your foot-strike pattern can change the load on your Achilles tendon.
Check your mechanics
Although Dr Willy doesnâ€™t want you to change your foot strike, he does suggest having your running form evaluated if you suffer from joint pain â€“ or if youâ€™re really serious about preventing it.
A physical therapist who works with runners should be able to detect issues such as hip adduction and over striding â€“ and instruct you on how to correct them. In research he conducted in 2012, Dr Willy found that runners with knee pain who did eight gait-retraining sessions had less knee pain when re-evaluated months later.
Watch your weight
Runners often complain of more joint aches and pains as they age, and one contributing factor can be weight gain. Dr Paul DeVita, director of the BioÂmechanics Laboratory at East Carolina University in the US, has conducted research that links excess weight with increased knee load â€“ and possible injury risk â€“ in runners.
â€œMany of us are simply too heavy for our joints,â€ Dr Spain says.
Replace worn shoes
The verdict is still out on what footwear is best for reducing joint load. Both Dr Willy and Dr Paquette say you need to find out what works best for you. When you do get a new pair, itâ€™s key to break them in with a few short runs before going long in them.
â€œThe exposure to a new shoe after being in an old one could potentially be a risk factor for injury,â€ Dr Paquette says.
Mix it up
Changing where and how loads are placed on joints may keep injuries at bay.
â€œRunners who always do the same thing every day are more at risk,â€ Dr Willy says. â€œChange the surface, your route and your tempo, and cross-train. The more variable your movements, the less you stress your tissues.â€
Pop a pill?
Youâ€™ve undoubtedly seen the rows of glucosamine supplements at the chemist and wondered if they help. While youâ€™ll find plenty of people who swear by them, the data-driven answer seems to be mixed.
For a 2015 study published in the Annals of the Rheumatic Diseases, researchers gave 605 subjects with knee pain either glucosamine-chondroitin or a placebo.
After two years, both groups reported reductions in knee pain in equal levels â€“ meaning the glucosamine had worked no better than a sugar pill. This builds on previous research.
A few studies have found that glucosamine could possibly slow arthritic changes.
Still, most doctors will tell you to keep extra kilograms off, strength-train regularly and shorten your stride.. .