October 18, 2012 Strength: Max pullups in 2 minutes
400 m run 25 kb swings 53/35 25 situps
from crossfit verve:
The wonders of knee anatomy.
If you’ve been coming to Verve for any length of time, you’ve probably heard us express, in our own loving way, the need to drive your knees out while lifting. It’s probably a good idea to review why. Granted, I’m no doctor. Although I have saved a baby or two in my day, a human anatomy major I am not. So some of you A&P nerds out there may be able to better describe what I am about relate.
First off: If you take nothing else from this discussion, remember that your knees are in a healthier position if they are driven out. Period.
The knee is the body’s largest joint. It is sandwiched between the femur (the thigh bone), on top, and the tibia (the big calf bone), on the bottom. Protecting the innards of the knee is the patella (the knee cap). The knee sits on top of the meniscus cartilage, which acts as a firm shock absorber.
The sides of the knees are supported by ligaments. The LCL (Lateral Collateral Ligament), which lines the outside of the knee, and the MCL (Medial Collateral Ligament), which lines the inside of the knee. Both the LCL and MCL limit sideways movement for your knee. That being said, you don’t hear a lot about the LCL when it comes to injuries. Why? Number one, it is a more mobile ligament. Number two, it requires a severe blow from the inside of the knee to injure it. The inside of the knee is naturally protected by our body. The LCL also runs from the top/front part of your knee, down and back towards the bottom of the knee. Thus, when we externally rotate our leg and hip system, we simply add tension to a mobile ligament in a direction that it can handle. The MCL on the other hand, is purportedly the most injured knee ligament. It is injured when the knee is twisted to the inside repeatedly over time, or with excessive shock to the inside. The MCL is longer, and is less flexible than the LCL. So it’s easy to see why a knee twisting inwards repeatedly (say, while doing squats, dipping on push press or push jerks, or landing on box jumps) could cause excessive stress to this ligament. Hence, our potentially over-the-top concern about your knees. I care about your MCL. Not in weird way, either. In a totally platonic way.
The femur and tibia are also connected by two ligaments on the inside of the knee: The ACL (Anterior Cruciate Ligament), and the PCL (Posterior Cruciate Ligament). The two ligaments cross each other in an “X” pattern, and help keep the knee from moving too far forward or back. We’ll focus on the ACL. The ACL runs from the back of the knee down towards the inside anterior portion of the knee. When the knee bends in, you can visualize the ACL bending over onto itself. This, in technical terms, is what is referred to “in the biz” as an “oh dang” moment. As is in, “oh dang, that ACL is in trouble.” When you drive the knee out, the ACL is in a position of strength, due to the fact that the tibia and femur are still in line with each other. Hence, the continued focus on the driving of your knees out. Me and your ACL are tight. We hang on the weekends. I want the best for your ACL. Do you?
That’s the scoop. Externally rotate your leg “system”, as it were, and keep your joints in positions of strength, even throughout the day. If flexibility prevents you from moving your knees into healthy positions when WOD’ing, it’s time to address it.