As a nation, we’re not very good at staying in shape, with 11.2 million, or 63.4 per cent of Aussie adults either overweight or obese in 2014-15. We also like to wear unsupportive footwear, and 44.5 per cent of us either don’t exercise enough, or at all. All this makes for two very sore and vitally important parts of our bodies; the knees.
Taking care of your knees is not something many of us think about, until pain or signs of complications begin to surface. The number of knee and hip replacements due to osteoarthritis have been on a steady incline, caused by several factors, including weight.
Trends in total knee and hip replacements for osteoarthritis, 2005–06 to 2014–15.
Note: Rates are age-standardised to the Australian population as at 30 June 2001. Source: AIHW National Hospital Morbidity Database (Data table)
It’s no surprise that the frequency of knee replacements has risen alongside our wider waistlines. “For every extra kilogram of weight that you put on, that’s four kilograms of force going through each knee,” according to Tracey Powell, a physiotherapist on Sydney’s North Shore. “So, if you’re 10 kilos overweight, that’s 40 kilos of extra pressure going through your knees.”
However, even if you do keep in shape and exercise frequently in supportive shoes, you may be damaging your knees at the other end of the spectrum – by applying too much pressure from playing high-impact sports or activities.
If it sounds like a ‘damned if you do, damned if you don’t’ situation, have hope. There are some achievable, affordable ways to give your knees the strength they need.
1. Keep your weight in check
It is notoriously difficult to keep your weight at a healthy level. Keeping in mind that 1kg of weight equals 4kg of pressure through the knees, it’s not hard to see why this is an essential step to keeping your knees in good shape.
If you’re not sure what you should weigh, you can calculate your Body Mass Index (BMI) here. You should aim for a BMI of 18.5 – 24.9 to be considered a healthy weight. If you’re having trouble cutting the calories and stepping up the exercise, a dietitian and personal trainer can be of great assistance.
2. Maintain a level of activity and stay flexible
More than half of us manage to fit a good amount of physical exercise in every week, which has immeasurable benefits to our overall wellbeing, not least of which is our knee health.
“You shouldn’t get to 50 and say ‘oh well, I can’t play any sport now’,” says Powell. “The stronger and fitter you are, the more supported and scaffolded your knees are.” Staying flexible plays a big role in this.
Most of our joints are synovial, meaning that they have oil in them. This oil needs to move around to nourish the whole joint, so that you can stay flexible for longer. Good exercises for this include daily squatting, as this will take the knee to its full range of movement.
Flexibility gets even more important as we age. “I see a lot of grandparents who have injured themselves while looking after grandchildren bending down to the floor,” Powell says. “To be able to play with your grandchildren when you get older, you need to keep activity levels up.”
3. Reduce high-impact activity
This being said, as we age minimising the amount of pressure you send through your knees during activity is important.
It doesn’t mean you can’t play your favourite sport anymore, but you may need to adjust your game. “If you’re having knee problems, then you need to look at playing with less intensity and less duration, or look at playing a different sport,” advises Powell.
Easy changes include swapping a centre court runner position in netball for a wing or end role, going from singles to doubles tennis matches or taking up cycling or swimming, both low-impact activities.
Low-impact activities such as cycling put minimal pressure on the knees
4. Think support over style when it comes to footwear
High heel shoes, thongs and ballet flats provide very little support to our feet, which has ripple effects on our knees. Women are much more likely to get osteoarthritis than men and part of the problem can be their footwear.
Wearing cushioned and supportive shoes, such as sandshoes, on the train or bus, then swapping them for heels when you reach the office is a great way to take care of your knees.
5. Start early
As a physiotherapist, Powell sees many patients who want to improve the state of their knees. However, “often they’ve left it too late to improve their knee strength and flexibility. What we need is to educate people when they’re younger … that’s where it has to start”.
There are good signs, however, with Powell saying, “we’re getting much better at it, because the message has finally gotten through that if you keep your general fitness up, you’ll guard against these sorts of things.”
Have you had problems with your knees? Share your stories below.