Demystifying knee pain with our two-part examination process
We love treating knee pain here at EVOLVE Flagstaff. Knee pain is common, can be debilitating, and is often surrounded by uncertainty or mystique. Too often we hear people say things like, “I just have bad knees,” “I’m a runner, of course my knees hurt,” or, “Yeah, my knees are shot, I’ll definitely need a replacement.” Or, patients who have had knee surgery in the past continue to have issues years after their last operation. Too many people think knee pain is something they’ll just have to live with.
However, when diagnosed and treated appropriately, we can be incredibly effective at resolving knee pain and getting you back to doing what you love, without surgery or expensive imaging tests.
I want to break down our approach to diagnosing and treating knee pain. The knee is a nuanced and complex joint, but that doesn’t mean that we can’t simplify it to give you some clarity into how we systematically address issues. Your knees don’t have to hurt, even if you’ve had multiple injuries or surgeries in the past.
I’m the perfect case study. I had recurrent patella dislocations throughout high school and into college. My entire immediate and extended family all have knee injuries as well. Some even claim a genetic basis for our family’s knee issues (note: there is NO real scientific evidence for this). I got a major knee surgery in college (for those keeping score at home, it was called a tibial osteotomy), and struggled through a long rehabilitation. I was OK for a while, but never fully trusted my knee, and had a return of dislocations and pain just as I was starting physical therapy school. I struggled with it for years afterward, but as I began practicing physical therapy and diving deeper into my study of the knee, I was able to make progress. I followed the process that I’ll outline below, and I’m happy to say that my knees are now strong and pain-free. They feel better after years of issues than they ever have before.
Today’s post will delve into our knee examination process.
The first step in thinking about knee pain is to consider all of the possible pain generator. I use the term “pain generator” to refer to any tissue, be it a muscle, ligament, tendon, or something else, that has the potential to cause pain. When it comes to the knee, there are multiple pain generators to consider:
- Pain referral from the hip joint: In some cases, an injured hip joint can cause pain all the way down at your knee.
- The knee joint or intracapsular structures: This includes the joint itself and other specialized structures inside the joint capsule, such as the meniscus.
- Ligamentous injury: There are several large ligaments in and around the knee joint that you’ve probably heard of, such as the ACL, PCL, LCL, MCL. These are the “collateral” and "cruciate" ligaments, meaning that they are ligaments that cross the knee joint to help provide stability. The four big ones are the anterior and posterior cruciate ligaments, and medial and lateral collateral ligaments, although there are others that need to be considered as well.
- Muscle / tendon injury: Over a dozen muscles begin and end around the knee, and each could be causing issues.
- Bone: In the knee, bony involvement is almost exclusively seen in traumas, but should be considered.
Furthermore, we must consider the possible causes of a knee injury. We can simplify these into two broad categories:
- Overuse, usually with altered movement mechanics: An example of this would be a runner who lands with excessive knee extension. This can drive increased force through the knee joint, potentially causing pain with high running volumes.
- Trauma, often precipitated by high risk movement habits: An example would be a soccer player who habitually runs, jumps and lands with a knee valgus moment, and then suffers an ACL injury after an uncontrolled, high-speed knee valgus and rotation moment.
Are you struggling with knee pain? Click the button below to schedule to talk about your issues for free with a Doctor of Physical Therapy. We'll develop a strategy together to resolve your knee pain, for good.
So, if these are the main general factors contributing to knee pain, then our examination process should consider each one, right? Right. Too often we see patients who have had knee pain for a long time, after seeing multiple providers, simply because steps were skipped, and one of these factors was missed.
Our knee joint examination has two parts: The joint-specific examination to diagnose pain generators, and a functional examination to identify the root cause of the injury.
The joint specific examination includes:
- Hip screen: Rule out hip joint contributions to your knee pain
- Range of motion: How well does the joint move? Is there a motion limitation? Does it hurt at end-range? Reduced range of motion is a key indicator that the joint itself could be involved
- Stability testing: We test each one of the ligaments identified above (and others) for both pain and laxity
- Resistive testing: To identify painful muscles/tendons.
- Palpation: This is the last step in our exam, and often only serves to confirm our though process. Palpation of painful areas can occasionally be unreliable in the knee. However, it can be helpful in confirming a pain generator, such as a patella tendonopathy, or raising suspicion of a fracture (rare).
At this point, I want to note that too often, patients get far too "attached" to diagnoses. They cling on to a diagnosis of arthritis, or a meniscal tear, or patellofemoral syndrome. While these labels can occassionally be relevant, that's not what the joint-specific examination is about. We're simply concerned about determining what hurts, and then taking steps to reduce the pain and allow healing. No diagnosis is a life sentence, and there are few, if any, knee conditions that can't be positively affected by a combination of targeted hands-on manual therapy and focused exercise.
After the joint specific examination, we then must consider factors that lead to the injury in the first place. This takes us further out from the knee joint and pain generator to look at your entire system, kinetic chain, and movement patterns. Our functional exam is less standardized that our joint-specific examination, because it is dependent on you: your injury history, activities, and goals. It also depends on your pain levels. If you have a painful, swollen, and restricted knee, we might defer aggressive functional testing for a week or two until we can calm it down. However, there are some common elements:
- Lower extremity strength testing: Almost always includes testing of hip muscles, as the hip muscles play a HUGE role in knee mechanics. We often go to the lower leg as well.
- Flexibility/range of motion: Flexibility issues are less common than strength deficits, but muscle or joint restrictions can definitely contribute to knee pain, so if they are present, we want to identify and address them.
- Motor control, proprioception, and balance: This includes coordination, single leg balance, muscle inhibition, and control of movement throughout your available range of motion, in a variety of positions and loading patterns. A common test for this is called the eccentric step down tests. This aspect is absolutely crucial for those with knee injuries. Another key area is neuromuscular inhibition. Many runners may test strong on hip manual muscle testing, but after running for a few minutes, will test weak. This is not true muscle weakness or fatigue, but a different process called inhibition.
- Movement mechanics: How do you run, jump, land, cut, pivot, squat, lunge? Do your patterns change with fatigue or with heavy loading? Are these movement strategies contributing to your pain? This analysis is dependent on your activity of choice. Regardless, it is important for us to understand how you habitually move, and your capacity for changing or altering your movement patterns.
After considering all of these factors from the joint-specific and functional examinations, we can then arrive at a comprehensive treatment plan.
If all of the above seemed daunting, here’s some great news: We have fairly reliable tests and conservative, non-surgical treatment strategies for almost all of the issues outlined above. The key is in breaking down and understanding each of the components involved in knee pain. This allows us to diagnose and treat the vast majority of knee problems, and get you back to doing what you love to do.
The next post in this seres focuses on treatment of knee pain, including the three broad phases of knee injury treatment and rehabilitation that I use. Check it out!
Are you struggling with knee pain? Click the button below to schedule to talk about your issues for free with a Doctor of Physical Therapy. We'll develop a strategy together to resolve your knee pain, for good.