When you have knee pain, it can seem like everything hurts. Knee pain can affect walking, going up and down stairs, picking your child’s toys up off the floor, and making a quick turn to catch a pot of water on the stove before it boils over. The knee can be tricky to treat because it is usually not the knee that is causing the problem.

Yes, you read that right. The knee is usually not the problem. See, the knee is a hinge joint. It opens and closes. There is a little bit of rotation at the knee as well, but for the most part its primary job is to straighten and bend. Think about a hinge on a door. It moves back and forth. One direction. How often does something go wrong with a hinge on a door? Not that often, right? Apply this same principle to the knee and suddenly it makes a bit more sense why the knee is usually not the issue.

So if the knee is not the issue, what is? Typically, multiple other body parts are involved. The hip, ankle, foot, balance, and coordination of your leg are key in whether or not knee pain develops. Typically, when we see people for knee pain, we treat all these areas as well as treating the knee. We treat the knee to decrease pain and then we treat the other areas to prevent the pain from coming back.

This article will go through a few self-tests that you can do on your own to determine what is contributing to your knee pain. This is not an all-encompassing list of factors that can lead to knee pain. Rather, this is a list of things that we often see as major contributors in whether or not knee pain will develop. The factors we will talk about are knee mobility (if your bends enough), knee stability (the entire leg and how it works together) as well as knee strength (the overall strength of your leg).

 

Knee pain – is it due to limited mobility?

We are going to start with knee mobility. To start, kneel down and then sit your bottom back on your heels. If you cannot get your bottom to your heels without discomfort in your knees, knee mobility is contributing to your knee pain. If you cannot get your bottom to your heels due to ankle pain, sit on a surface like a box or table with your toes off the side so that your ankle mobility is not limiting your ability to test your knee mobility.  

 

Knee pain – is it due to limited stability?

Next, we will turn our focus to stability. This is assessing the stability of the entire lower limb – hip, ankle, feet, balance, and coordination – not just knee stability.

Find a stable surface to stand on with one leg and the other leg off the side. A stair typically works well for this. Then, with your hands on your hips, you will squat down using the foot that is standing on the box, lowering yourself towards the floor. When your other heel touches the floor (do not put weight through it), push through the heel of the foot that is on the box or step and return to the starting position.

If you cannot do this without having your knee move side to side, front to back, or without losing your balance, stability is likely contributing to your knee pain. Stability is typically what we find limits most individuals. Similar to the way your hands control where the opposite end of a baseball bat goes, your ankles, feet, and hips control how your knee moves. If you lack stability, it places abnormal forces on the knee joint and these abnormal forces overtime can lead to pain.

If you are a visual learner and would prefer to watch a demonstration of this test, check out this video!

Knee pain – is it due to limited strength?


Last but not least, we are going to examine strength. This test examines knee strength as it tests the quadriceps, which is the major knee muscle that is located on the front of your thigh. In addition, this test also looks at strength of the hamstrings (the muscle on the back of your thigh) and your glutes (your buttocks). The combination of these muscles working together is necessary for proper function of the knee.

For this test, you will start sitting down in a chair, on a box, or other surface of a similar height. The lower the surface, the more challenging this test is. If you are fairly athletic, you will want to use a low surface. If you do not typically exercise, choose a surface that is a bit higher, closer to a kitchen chair.

From the starting position, you will press through the heel of one foot and stand up. You will then slowly lower back down to the starting position. From here, you will repeat this test until your leg fatigues. This can take up to 20, 30, or more repetitions for more athletic individuals, which is why we suggest athletes use a lower surface.

The key for this test is completing it on BOTH sides. If your painful knee can only complete 20 repetitions while your non-painful knee can do 30+ before fatigue, odds are that strength is a contributing factor to your knee pain. However, if your knee pain becomes exacerbated with this test and you stop due to pain and not fatigue, strength may not necessarily be your limiting factor. In that case, this test is too aggressive to determine the cause of your knee pain and it will be more important to focus on decreasing the pain so that an accurate test can be performed.

There are two important things to note for this test. First, if you are not pushing through your heel, it is possible to increase your knee pain with this test. Increased pain with this test makes the results invalid. You may need to play around with your foot position to find an angle that does not cause increased pain when performing this.

Secondly, this is not a balance test. If you find yourself wobbling, place the heel of the other foot lightly on the ground for a balance assist. Ensure you do not put weight through it, but make sure you are testing strength, not stability here.

Wrapping it up!

There you have it – a guide on how to self-diagnose whether or not knee mobility, stability, or strength are contributing to your knee pain. You may find yourself thinking, Where do I go now? I know what is contributing to my pain, but how do I fix it? A great starting point is each of these tests that you just did. The tests themselves are mobility, stability, and strength drills that we often give to our clients. For example, say you were limited in knee stability – you would want to perform the corresponding ‘test’ regularly as an exercise to improve your stability.

One last key point that we want to make before we leave you to start improving your knee pain – typically we find that it is not just one factor that causes pain, but a combination of different factors. It is not uncommon to find more than one test positive and have to address more than one limitation in order to resolve the discomfort. And, furthermore, it is not just physical factors that contribute to pain. Sleep, stress, mental health, and recent major life changes are just a few non-physical factors that can contribute to pain in a big way. So, if you pass all the tests with flying colors, take a look at your lifestyle and see if you can find any patterns between that and your pain levels.

running with knee pain
dad after rotator cuff rehab