It seems a bit counter-intuitive to think about fitness before your surgery.

However attention to optimising limb strength and range-of-motion now will help you greatly when it comes to your mobility once surgery is over.

You will also be better prepared for those days you might have to spend with a walking aid.




Physical fitness before surgery varies of course from person to person. In people who have been in chronic pain, like before a knee replacement, fitness levels may be very low and muscles may be considerably wasted. Inactivity may also result in weight gain.

Today’s challenge is to assess your own fitness, so that you can determine if you can improve things prior to your surgery.

Let’s calculate you body mass index, or BMI. The BMI is calculated from the formula kg/m2 - that is your weight in kilograms divided by your height squared. Commonly accepted BMI ranges are underweight: under 18.5, normal weight: 18.5 to 25, overweight: 25 to 30, obese: over 30. But of course age and weight should also be taken into consideration

If you can measure your height and weight, there is an online tool in the Resources list that does this easily for you - all you need to do is to fill in your age, sex, height and weight and you will be given an assessment of whether your weight is significantly too high or too low for your height.

The next part of the challenge is to determine if there is objective quads muscle wasting on the affected side. Take a pen, mark a point two inches (or five centimetres) above your kneecap, and measure the girth at that point. Compare this with the good side.

The final challenge is to compare the range-of-motion of the two sides. Lie on your back on a firm flat surface, and bend your knee, pulling your heel up towards your buttock. Ask a helper to measure the closest distance you can achieve for this heel-buttock measurement. Compare the two sides. This will give you an idea of any lack of flexion.

Rolling onto your stomach on a bed, and allowing both legs to hang over the edge will give you some idea of the extension that you can achieve, and you will be able to compare the two sides.



Checklist of fitness things to think about before surgery - to download and print

BMI Healthy Weight Calculator

Knee exercises for knee pain - Isometric Quads