In my last post, I introduced you to a condition known as patellar tendonitis, also known as jumper's knee. Patellar tendonitis can cause a great deal of pain as well as limit our ability to participate or compete in our favorite sport or physical activity, and if you remember, it is not limited solely to those athletes who jump as a requirement of their chosen sport.
I mentioned that overuse causes micro tears in the tendon tissue, and that this trauma triggers the body's inflammatory response system. While I would like to be able to keep these posts relatively simple and easy to understand...it does become necessary to dive a little deeper to gain a complete understanding of one concept prior to moving on to the next.
So...grab yourself a shot of espresso, give yourself a couple of slaps on the face, and let's get to it!
One of the contributing factors in the development of patellar tendonitis is muscle imbalance. I introduced this concept a few posts back, and now it's time to dig into this concept a little deeper.
Patellar tendonitis is often the result of repetitive stress place on the knee joint. You see, during running and jumping, the body must decelerate and stabilize a great deal of energy...energy that is developed as a result of our body weight being accelerated upward and forward. Muscles contract eccentrically in an attempt to decelerate and stabilize our bodies when in motion.
Let's back up for a moment.
There are three types of muscle contractions that occur; concentric, eccentric, and isometric. A concentric contraction of muscle tissue is generally associated with the working phase of a given action. Let's take the biceps curl exercise for instance. During this exercise, the biceps muscle, concentrically contracts...which means it shortens in length...to create flexion, or bending of the elbow joint. During this action, the antagonist muscle (remember that term?) - the triceps - eccentrically contracts, which means it lengthens. The eccentric contraction is a type of braking mechanism, which helps to control both the rate and distance of the joint action - in this case, the bending or flexing of the elbow. An isometric contraction is one in which the agonist and antagonist muscles reach a state of contraction in which there is nearly equal shortening and lengthening. Confused? Try this...
Flex your biceps muscle...you know, the way you do in the mirror when you are getting ready in the morning. Oh, you don't do that? I do.
Anyway, flex that thing, and then reach over with your other hand and feel the tension within both the biceps and triceps muscles. Those are isometric contractions, and they are stabilizing the elbow joint. Now imagine that you are jumping down from a small ladder. Why would you do that? Good question. Let's say the ladder was breaking while you were standing on it, and in an attempt not to fall to the ground, you decided to leap from it, and land on your own two feet. Ok? Good. Let's move on.
Now think about what occurs within the muscles of your legs and hips when you land. That's right...eccentric contractions occur. Your quadriceps (thigh muscles) lengthen as you flex your knees to absorb the energy of the landing. Simultaneously, your hamstrings concentrically contract (shorten). Without thought, these muscle groups work synergistically to control the rate and distance that your body travels toward the ground, stabilizing the knee joint, and preventing you from crashing into the ground. That's a very simple explanation of what happens, but it's enough to understand the basic concept.
Alright, lets get back to the muscle imbalance issue.
A large number of people are what physical therapists refer to as quad-dominant. What this means is that their quadriceps muscles (thigh muscles) have taken over as the dominant muscle group during various functions such as walking, running, squatting, lunging, etc. Each of these tasks relies on the synergistic effect of multiple muscle groups to function together...hence the term synergistic. Unfortunately, our society spends significantly more time sitting than we do moving.
Over time, our muscles adapt to the length that they spend the most time in. Remember...our bodies are amazing at adapting. When we sit for prolonged periods of time, our hip flexor muscles (the quads are part of this group) become shortened, and overactive. Conversely, our hip extensor muscles (glutes) become lengthened and relatively weak. To make things even worse, our hamstrings have to take over for the weakened and lengthened glutes, and as a result, end up shortened and overactive as well.
Wow...there's a lot going on there. Are you still with me?
Now let's look at the basic function of squatting. I'm not talking about squatting with hundreds of pounds loaded onto a bar...nope, I'm simply referring to the functional movement pattern that occurs when we sit into a chair...or better yet, onto the toilet!
Alright, we're going to do a little experiment here...and I want everyone of you to post a comment with your results. If you have a full length mirror, I would like you to stand in front of it. Now, I want you to perform a squat and watch yourself in the mirror. Do a couple facing the mirror, then turn 90-degrees from the mirror so that you can look over and see yourself from the side. Perform a couple additional squats.
Make note of what you see when you squat. While facing the mirror, you may notice that your knees collapse inward, or that you bend over severely at the waist, which causes you to have to bend your neck, as if looking upward, just to see yourself in the mirror. While looking from the side, you may notice your heels rise off the ground, and your knees travel forward (resulting in your knees being out in front of your toes).
We wont tackle each of these issues today, but rest assured that we will eventually discuss each and every one of them!
Today we are just looking at your knees. Do you remember the picture below? I am using it again to show perfect squat mechanics. Take a look at this little guy's knees, and note their position in relation to his toes. His weight is back slightly on his heels, and his knees have not 'traveled' forward, out in front of his toes.
Now compare YOUR squat to this picture...specifically the position of the knees. If your knees are forward of the toes, and your weight is shifted forward rather than back and into your glutes...then you my friend, are quad dominant!
Quad dominance can result in greater than normal amounts of tension to be placed on the patellar tendon. Think about it this way...the quad muscles are in a constant state of contraction above and beyond normal. They are in this state 24-7-365. Wouldn't that be classified as overuse? Absolutely!
What is the result of this muscle imbalance? Knee pain. The kind of knee pain that most people write off as either genetic or age related, when in fact...it has noting to do with either. Possibly the best exercise known to man, is the squat. There is a caveat to that statement however. Anyone care to hazard a guess? You got it...proper squat mechanics.
Unfortunately, many people experience knee pain when they squat (I used to be one of those guys...which is why my legs are so small!) So what do they do? They don't squat. Those who still want to train their legs, usually end up on the leg extension machine, and work their overactive quads even more...compounding the problem!
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| Before you squat like this.... |
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| You should be able to squat like THIS! |
Once again, I have written to much for one post. I am sure you all want to know what we can do to fix this quad dominance, and how it can affect your overall performance...so you'll just have to check back for part three!
Yours in health and performance...
John
