The tests that I use to determine a diagnosis were all created many years ago by physio legends. They are designed so that any physio can use them on a particular patient and come to the same conclusion. For example, if I perform the McMurray test (which assesses meniscus injuries) on Brad and it turns out positive, my coworker should get the same result using the same test. Folks, this is known as having high inter-rater reliability. And that’s a good thing! It should not matter who examined Brad – whether it is myself, my coworker, or another physio in another country – we should all come to the same diagnosis.
There is a whole gamut of measurements and exams that I need to perform on Brad to determine the cause of his signs and symptoms. Here is a brief list of the things I will typically check out when dealing with a knee injury:
- Gait, or more commonly known as walking pattern. Is Brad limping? If he is limping, is it because he can’t fully extend his knee or push off his toes or a combination of a bunch of factors?
- Stance and posture. Is Brad favouring his “good” leg? Does his leg appear to be “stuck” in a bent position?
- Range of motion. There are a couple components to range of motion. First, I want to find out how much Brad can move his own knee without pain. This is his active range of motion. Then I want to compare this to how much I can move his knee. This is his passive range of motion. Let’s say Brad can actively move his knee to 50% of his full flexion. If I cannot push Brad’s knee past this mark, then I might be dealing with something blocking his joint. But if I can push his knee past 50%, then perhaps it is his hamstrings that are the culprit and are not firing correctly. Also, at this point, it doesn’t hurt to glide Brad’s knee cap around to make sure it’s moving properly as well. After all, your patella plays a big role in your knee!
- Strength. Does Brad have enough strength to put full weight through his knee? Is there pain when I ask him to contract his quads or hamstrings?
- Swelling. Certain knee injuries are going to have a ton of swelling (and/or bruising) that is very obvious. And on the other hand, certain knee injuries have more subtle swelling (that I can detect through special testing). So, does Brad have any observable swelling or more subtle joint swelling?
- Tenderness with palpation. Palpation means to touch or press the body with your hands. In short, can I reproduce pain if I poke at this spot or prod at that one? Does Brad have any tender spots around his knee? Say he pulled his hamstrings while running, I would expect the problem area of his hamstrings to be sore if I’m pushing down on it.
- Ligaments. Now we are getting into the knitty gritty special tests that I mentioned before. I want to figure out if any of Brad’s ligaments are loose! Ligaments stop your knee from buckling underneath you when you put weight on your leg. If his knee is anything like Gumby’s, that’s not a good thing! You want your knee to be a stable joint, not a sloppy one.
- Meniscus. Again, to rule in a mensicus injury, special tests are required. Your meniscus act like shock absorbers. They sit between your femur (thigh bone) and tibia (shin bone) and take a lot of pounding throughout your day and even more when you’re running or playing sports. Does Brad have any damage to these poor little guys?
There are a ton of other tests that I can (and probably should) perform on Brad. It’s important to check the lower back, hips and ankles when examining knees because problems in these surrounding joints can definitely contribute to (or even cause) knee pain.
Okay everyone, let’s take a timeout here and look at Brad’s situation. From his history, we learned that:
- He is 50 years old and has 6 children. (Wait, did he tell me about his kids or am I just a huge creeper…)
- He hurt his knee because he started running again.
- His pain began a few months ago without any mechanism of injury.
Now we can piece together the rest of this puzzle using Brad’s objective stats. After I tested his knee, this is what I found:
- He is limping. He uses a cane to take pressure off his right knee.
- He appears to favour his good side in standing and cannot put full weight through his right knee.
- He has full range of motion in his knee. However, there is some clicking of his knee cap when I passively take him through knee flexion.
- There is pain in his knee when I ask him to contract his quads but no weakness.
- There is no observable or joint swelling.
- No areas cause him pain when I poke around his knee.
- All his ligaments and mensicus are tested and found to be normal.
Uhh… So Brad is faking it? He just wants to walk around with a cane to look cool? Not quite! My (educated) hunch is that Brad is dealing with something called patellofemoral pain syndrome or PFPS for short.
PFPS is a condition that is related to overuse injuries. It simply means that Brad has certain muscles that are working too hard and others that aren’t working at all. In other words, Brad has a muscular imbalance that is causing him pain! I know this sounds very vague, but here is where my years of schooling and working kick in and I start delving into his lower back, hip, and ankle a bit more to figure out where exactly is the imbalance. Maybe it’s tight lateral (outside) quads and weak medial (inside) quads. Or it might be poor glute strength paired with overworking hip flexors.
Congrats on solving the mystery of Brad’s knee pain! Don’t you feel like a detective now? The problem solving part of physio is the best. And now that we’ve generated a diagnosis, we can kick this rehab into gear!
Side bar: I should add that sometimes you can’t come up with a specific diagnosis for a specific injury. The fact is I don’t always see textbook injuries. Unfortunately, not everyone comes to me gift wrapped with a card attached that says “To: Chris, From: Knee pain courtesy of PFPS”. There are times when I have to treat someone based on their symptoms because all the special tests cause pain!
Whoa. That was heaps of information. Thanks for listening to me ramble on! Now you know the sort of things physios are looking for. Having said that, if you actually have knee pain that persists for more than a few days, please get it checked out by your local physio and don’t self-diagnose based on this truly awesome blog.
Well, reader, it’s now time to step into the treatment world. This one is big. Huge. Massive. Ginormous! And it’s a load of fun. Are you excited? I am! Feel my sweaty palms…