Varus and valgus refer to the angulation of the distal segment of the joint, so a bowlegged individual would have varus knees as the lower ends of the tibia angle inward. The term abduction refers to movement away from the anatomical midline. I frequently talk about abduction of the inside knee as a turn initiation mechanism executed at the neutral point of the turn. However, I was recently looking over an article concerning female athletes and their knee kinematics relative to ACL injury. In that article there was frequent reference to knee abduction, which put the knees into a valgus orientation, i.e., knock kneed. So you can see my confusion. I was saying "abduct the inside knee" thinking that this was a movement of the knee joint away from the midline toward the inside of the turn, whereas in this clinical article, abduction of the knee had the distal end of the tibia moving away from the center line, and the knee joint itself opening up on the medial side. So my question is, if this is the clinical definition of knee abduction, how would you phrase a description of movement of the entire knee joint away from the midline toward the inside of the turn (which can create a momentary varus knee look), and hopefully not confuse it with the clinical definition?
- 315 Posts. Joined 9/2004
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A varus or valgus orientation does refer to the distal end of the bone, except at the knee. It seems to be one of those rules like "i before e, except at the knee".
Tibial Varum means the distal tibia is oriented medially, the individual is bow-legged. Tibial valgum means the distal tibia is laterally oriented, and the individual is knock-kneed.
Genu-varum is used to indicate bow-legged, yet the term Genu refers to the knee and it is not oriented medially in the bow-legged individual.
I avoid using genu-varum and genu-valgum for this very reason and use tibial instead of genu.
Most of the time I just say bow-legged or knock-kneed, since that is what everyone else understands.
Well, I get that, but the question was, knee abduction in a clinical sense leads to a genu valgus stance. Do we still refer to a conscious movement of the knee toward the center of the turn as abduction of the knee?
- 5,434 Posts. Joined 9/2000
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I don't know if this will be useful here, but may I suggest one thought that may be a point of confusion? I submit that it is quite possible to move the inside knee into the turn (whatever words you prefer to use to describe it), without necessarily resulting in a bowlegged orientation (again, whatever you want to call it). In fact, your knees could actually get closer together, creating a knock-kneed "a-frame" arrangement, even as you vigorously pull your inside knee into the turn.
Does this sound like a paradox? Don't forget that your other knee can--and usually should--move at the same time as your inside knee. So as you move your inside knee into the turn (which I would certainly think fits the definition of abduction), there is no reason that your other knee cannot also move into the turn (adduction)--at the same or at a different rate. If the outside knee moves into the turn more quickly than the inside knee, your knees will move closer together, even as your intent is to pull your inside knee away from your outside knee.
PS--I think that much confusion about ski technique arises from a similar mistake. When we say, for instance, that our body, hips, or center of mass move "diagonally forward" in the transition of a turn, it is usually essentially true. But many skiers (and instructors) translate that truth into a directive to move their hips ahead of their feet to start a turn, as might occur in a standing broad jump, for example. What they may fail to consider is that in a standing broad jump, the feet stay planted in one spot as the "hips move forward," while in many ski turn transitions, the feet are actually moving faster than the body. So as the body does truly move forward, the feet move forward even faster--quite possibly getting well "ahead of" the hips as a result.
This paradox also explains how the identical principle movements of "parallel" (or even diverging) turns can actually produce wedge turns--causing unending confusion for many skiers and instructors. I am a big proponent of focusing on inside leg activity for offensive turns--meaning both tipping the inside ski and guiding its tip into the turn. I've probably said it here a thousand times: "right tip right to go right." It's a clear directive to pull your inside ski tip away from the outside ski tip, which you might expect to cause the skis to diverge. But if the left ski turns even more quickly into the new right turn, as it will tend to do at low speeds or low skill levels, even this clear "diverging thought" will result in converging (wedge) skis. It is the failure to understand or acknowledge this critical point that leads some to proclaim that wedge turns are necessarily the "opposite" of parallel turns--when in fact (done properly) they can entail entirely identical principles of technique and intent.
Other examples abound!
For what it's worth...sorry to interrupt.