What all runners need to know about joint health

Let’s be clear: running won’t ruin your knees. ‘Three large studies show long-term endurance running doesn’t seem to damage joint health,’ says Richard Willy, assistant professor of physical therapy at East Carolina University, US.

In fact, runners may have healthier joints than inactive people, says Max R Paquette, an assistant professor of biomechanics at the University of Memphis, US. Running strengthens bone and muscle, and it’s thought it may do the same for cartilage, which cushions joints. And strong muscles – built by running and strength-training – support joints, so they are less vulnerable to injury.

But there’s a condition called ‘runner’s knee’ for a reason. Patellofemoral pain (knee pain) is the most reported injury in the sport. Hip, ankle and foot injuries happen, too, not because someone is running – but because he or she is running with poor form or muscle imbalances (see Why does my knee ache? below). Taking steps to minimise the risk can keep you running into your golden years.

WHAT HURTS?

These common ailments can sideline runners of any experience level.

Hip, knee, ankle, foot

Osteoarthritis: The wear-and-tear condition that occurs when cartilage breaks down over time. Blame your genetics and your biochemical responses (not necessarily running).

Hip

Bursitis: This friction syndrome is caused by inflammation of the bursa – the small sac of fluid that lubricates the muscles and tendons that run around the hip joint.

Knee

Patellofemoral pain: (‘runner’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 like bumpers between the femur and tibia. As you age, it becomes thinner and more susceptible to damage.

Ankle

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.

Big toe

Bunion: Under repetitive pressure, the big toe joint can move out of place, swell and turn in, causing a painful, bony protrusion.

WHY DOES MY KNEE ACHE?

Form flaws

Willy says hip adduction – when the thigh moves inward from the hip midstride, causing a knock-kneed effect – is one of the most common sources of biomechanical-related knee pain. Overstriding is another.

Muscle imbalances

This is related to biomechanics, since muscle imbalances can cause poor biomechanics and, conversely, poor biomechanics can result in imbalanced muscle development. If you can’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, says Keith Spain, a sports medicine specialist.

Genetics

Spain says that arthritis has a genetic component. ‘If your parents had arthritis, you’re more likely to have it,’ he says. And while age is a factor, Spain says that getting old doesn't necessarily mean you’ll get arthritis.

Gender

Women are twice as likely to report knee pain as men, says Willy. But researchers aren’t sure why. ‘The hypothesis has been that women’s lower extremity alignment places the knee in a position where it’s more susceptible to injury,’ says Paquette. ‘I think there’s more to it than that.’ He points out that subtle differences in women’s connective-tissue makeup may also play a role.

Unknown factors

Pain is something researchers are still working to better understand, says Willy, adding that joint-related pain seems to be individual. ‘Two runners with the same biomechanics can go through the same training programme, and one gets injured but the other does not,’ he says. ‘We really don’t know exactly why that happens.’ He says that variables such as sleep quality, nutrition and even psychosocial factors – such as fear of getting injured – may contribute.

6 WAYS TO PROTECT YOUR JOINTS

Shorten your stride

‘An increase in stride rate by five to 10 per cent can reduce patellofemoral joint load by up to 20 per cent,’ says Willy. Stride rates are individual, but it’s recommended to aim for 160-190 steps per minute. Be careful not to change how your foot hits the ground. Shifting your foot strike can change the load on your Achilles tendon.

Check your mechanics

Willy says it’s a good idea to have your running form evaluated if you suffer from joint pain – or want to prevent it. A physio can detect issues such as hip adduction and overstriding – and instruct you on how to correct them. In a study, Willy found that runners with knee pain who did eight gait-retraining sessions had less knee pain when reevaluated months later.

Watch your weight

Runners often complain of more joint pains as they age and one reason is weight gain. Paul DeVita, director of the Biomechanics Laboratory at East Carolina University, US, has conducted research that links excess weight with increased knee load – and injury risk – in runners. ‘Many of us are too heavy for our joints,’ says Spain.

Replace worn shoes

The verdict is still out on which running shoes are best for reducing joint load. You need to find out what works best for you. When you get a new pair, it’s key to break them in with a few short runs before going long in them. ‘The exposure to a new shoe after being in an old one could be a risk factor for injury,’ says Paquette.

Mix it up

Changing where you run and how loads are placed on joints may keep injuries at bay. ‘Runners who do the same thing every day are more at risk,’ says Willy. ‘Change the surface, your route and tempo, and cross-train. The more variable your movements, the less you stress your tissues.’

Pop a pill?

Many people swear by glucosamine supplements, but study results are mixed. For a 2015 study published in the Annals of the Rheumatic Diseases, researchers gave 605 subjects with knee pain either glucosaminechondroitin or a placebo. After two years, both groups reported reductions in knee pain in equal levels – the glucosamine had worked no better than a sugar pill. A few studies have found that glucosamine could possibly slow arthritic changes.