Come on now, don't be shy...raise your hand! I know some of you who are reading this are currently having knee pain...and many of you have had knee pain in the past six months. There are various types of knee pain experienced by both athletes and non-athletes. One of the most common causes is patellar tendonitis or patellar tendonopathy. Patellar Tendonitis is one of the most prevalent overuse injuries in America, accounting for nearly 20% of injuries in the overall athletic population (North American Journal of Sports Physical Therapy).
Patellar tendonitis (PT) is also widely known as 'jumper's knee". This condition, however prevalent among jumping athletes, is not isolated to jumpers. Runners, cyclists, tennis players, hikers...you get the picture, right? If you are active, and especially if you are an aging athlete like me, well then... you stand a pretty good chance of suffering from some degree of good 'ol jumper's knee.
I'll try to keep this as short as possible, but to have a fair understanding of what is happening with PT, we need to do a quick review of human anatomy. Ok, here we go...
Starting from the ground up, Maestro, please...the foot bone's connected to the ankle bone. The ankle bone's connected to the shin bone. The shin bone's connected to knee bone. The knee bone's connected to the thigh bone...and we can actually stop right there. How simple was that?!
That's really all you need to know about the anatomy to understand what I am going to share with you about this common problem. The 'knee bone' or 'knee cap' is actually called the patella, and it essentially floats atop the joint created by the 'shin bone' and 'thigh bone'. It 'floats' by way of the patellar tendon and other tendinous attachments...which is why, when your leg is relaxed, you can easily push your kneecap from side to side - something that, as a kid, always fascinated me. Come to think of it...it still does!
So where in the world does the patellar tendon come from? Looking at the picture below (which I borrowed from the Mayo Clinic), you can see that the patellar tendon is a relatively small, tendinous attachment that extends from the patella to the top of the shin bone (Tibia). Those of you who have a bit of knowledge in this area might be saying to yourself "I thought ligaments attached bone to bone, and tendons attached muscle to bone." Brownie points and gold stars to those of you who were thinking that! The patellar tendon is actually an extension of the quadriceps tendon, as you can see in the second picture, which I also borrowed. I promise to give them back...really!
In the second picture, you can see that the patella is encased within the quadriceps tendon and the patellar tendon...which, as we just learned, is essentially the same thing...sort of. In my last post we learned the basics of human movement, and how force is transferred from muscle to bone, by way of muscle contraction. Based on that knowledge, we know that when we contract our quadriceps muscle(s)...which by the way, are our thigh muscles...we put tension on the quadriceps and patellar tendons, which results in the straightening of our leg...we also call this knee extension.
Now you know what the patellar tendon is - you know where it is located - so let's look at why it hurts.
I mentioned earlier that PT is an overuse injury, so let's define that term before moving on. An overuse injury can be defined as a sports- or occupation-related injury that involves repetitive
sub maximal loading of a particular musculoskeletal unit, resulting in
changes due to fatigue of tendons or inflammation of surrounding tissues. Big words huh? Basically, tendons, ligaments, muscle tissue, and even bone can become inflamed due to repetitive use and stress.
It is important to know that during these repetitive actions, small micro-tears occur in the tissues, which ultimately leads to an inflammatory response, and pain.
So what kinds of repetitive stress can cause PT?
Obviously, in light of the common term jumper's knee, those individuals who participate in sports or other activities that involve jumping are highly susceptible to knee pain, via PT. Like I mentioned earlier however, jumping athletes are not the only one's susceptible.
Let's take runners for instance. While, technically speaking, they are not jumping per se, they are bounding. Take a look at the photo below. You will notice that there is light visible under each foot. What does that mean? It means that they are airborne for moments at a time, and must land on a single leg/foot, stabilize those forces, and then create power to do it again...and again...and again.
Repetitive stress.
How about a tennis player? Take into consideration the repetitive acceleration and deceleration necessary to move about the court. The forces sustained by the knee, and specifically the PT, are enormous...especially with repetition. Looking at the photo below of Roger Federer, it is easy to understand how the sport of tennis can precipitate various forms of knee pain...often due to patellar tendonitis.
Well...I think that's enough for one day. I'll let your brain digest the large amount of information that it just took in before moving on.
In my next post I'll discuss some common reasons why patellar tendonitis occurs, and what you can do to reduce your chances of becoming yet another victim of PT!
Yours in Health and Performance
John
No comments:
Post a Comment