Education

Motion is Lotion. Like an engine not being used over the winter, our joints stiffen when we don’t use them. Unfortunately, when trying to increase motion through weight-bearing activities like walking, knee pain and swelling can increase. When walking, our full weight goes through the knees which may then irritate the meniscus and worsen bone bruising.

Moving your knees on a stationary bike decreases pain and swelling in knees. Using a stationary bike allows the knees to move in a full range of motion without putting your full weight through the knees. It also gently massages the knees which decreases inflammatory fluid (effusion) in the knees, which then decreases pain and improves range of motion.  

Begin using the bike set at 0 resistance, for 5 minutes three times a day, every day.  If your knee is sore, then still get on the bike. It is treatment, just like an injection or brace is treatment. If your knee is swollen then get on the bike to gently get the fluid out of the knee.You may think you can’t go on the bike because you irritated your knee or it hurts too much at the end of the day but using the bike at these times usually decreases your pain and you will improve faster.

You can increase resistance and bike once a day if you don't have any swelling and your quadriceps are functioning properly (see section on quadricep inhibition).

You can use a seated pedal exerciser instead of a stationary bike. This is a great option, especially if a stationary bike is too difficult for you to use or you want a smaller and more portable option.

When you are having pain in your knee, an indoor bike is better than biking outdoors as you can keep the resistance at 0 and you have less pain getting on and off the bike.

Legs can have a bend often referred to bow-legged or knock-kneed, which can be difficult to see without an x-ray. On x-ray, the space between the top and bottom bone of the knee is narrowed on either the inside or outside of the knee. This is called medial compartment or lateral compartment narrowing/osteoarthritis of the knee.  It similar to bending a green stick and the outside of the stick stretches and the inside compresses. When you stand on a leg with this bend, more weight goes through the narrowed side and can cause bone bruising on that side which causes the bone to be tender. When you pivot or twist, the meniscus on the narrowed side can tear which causes swelling of the knee and tenderness at the joint line.

There are braces, called unloader braces, which apply tension to the leg to bend it in the opposite direction to take weight off the narrowed area of the joint. If the knee pain is in the area of the narrowing then unloader bracing is often recommended, which allows the bone bruising and meniscus irritation to resolve and decreases pain.

When your brain senses pain or swelling in your knee, it sends a message to your quadriceps (four big muscles at the front of your upper leg) to not work. This is called quadricep inhibition. This is not helpful to you and happens to everyone with knee pain or swelling no matter age or athletic ability.  It does improve with time but often does not return to full function without specific exercises.

The goal of the exercises is to tell your quadriceps to contract and all four quadriceps contract fully. When you do the exercises you must be fully focussed on them. You can’t be watching tv, on your phone or mindlessly doing them at your desk. Your brain is the problem so your brain needs to be part of the solution.

You may notice that your upper leg is smaller or caved in on the affected limb. This occurs because the quadriceps have been inhibited (not working) and the muscles are smaller from disuse.

To begin, sit upright on the floor (or a bed/couch if floor is too difficult) with your legs straight in front of you. You may want to lean back on your hands. Look at your upper legs and tell the muscle on the front of one of your upper legs to contract and then let go. Repeat on the other side. Do this 10 times on each leg.  

If this is difficult to understand, put a small cloth under your knee and push your knee down on the cloth. This uses the same muscles and can help you understand the exercise. If you can’t straighten your legs because they are too tight or your knee doesn’t straighten, then put a towel under your knee. The size of the towel depends on how bent your knee is but it should be large enough that your knee is resting on it.

You may find the exercise difficult and not know if you are doing it correctly, but if I asked you to make a fist with your hand or bend your elbow you would just do it. I can’t explain how to do that, you just do it. This is more difficult because your brain has been telling it not to contract so you are re-learning how to use this muscle. Also, this isn’t a movement you would normally do so it is challenging. 

You will likely find it gets harder to do each contraction and by the tenth repetition you may not feel any contraction. You may feel like you are doing it wrong and it isn’t working.  Remember, we are trying to override the inhibition to this muscle by the brain. As long as you are telling it to contract and trying to do it ten times three times a day it will start to work again. Then you can work on making it stronger. 

This is why I suggest no resistance on the bike until your pain and swelling are gone. If you have quadricep inhibition, riding a bike with resistance often causes pain at the kneecap. The kneecap is held by the quadricep tendon at the end of the quadricep muscle. If the quadricep muscle is inhibited then the kneecap doesn’t track properly, and this causes pain at the kneecap with activities like biking with resistance, running, squatting and lunges. Once your quadricep is contracting properly then you can add these activities.