Hip Abductors

[HarveyD]

In view of the excellent recent discussions about the hip adductors, I wondered about the role of the abductors. There isn't much about them in the Instructor's Manual. In Expert 2 there is a discussion of counteracting movement and I thought they may play a role there. I know that the opposite hip abductors can cause a rise in the hip. Does this help with lightening and tipping? If so. should we consciously be trying to contract these muscles to initiate tipping and how does their action blend with that of the abductors?

[dewdman42]

Funny you should mention this. I had posted a question about abductors and adductors on another thread a few days ago and haven't heard anything so I literally just now logged in with the intention to create a new thread, but you already did it for me Harvey. We're both thinking about the same thing!

Anyway, my question is even further than that. Since I am ignorant when it comes to human anatomy names, I was hoping someone could give my right brained mind some help in understanding what exactly abduction and/or adduction is....as opposed to say "rotation". In a recent thread Harald drew a distinction between rotation and adduction.. But since I don't really understand what adduction or abduction is..(the actions), or which muscles are considered the activating muscles for such actions...I didn't really know for sure exactly what he meant.. But I would really like to understand this better...

[Hobbit]

A quick Google on "adduction abduction" brings this Page as a first hit.
It even has animations. Hope this helps.

[dewdman42]

Great link. Thanks for finding it. So now to hear about how those movements or muscle forces relate to skiing ?? If there are no rotational movements happening..then it seems to me if we are skiing with predominantly narrow stance between our legs..there would not be much adduction or abduction "movements". Perhaps some resistive forces though. Anyway, I'm speculating. I'd like to hear from Harald or experts on this..

I read the other post Harald made about adduction again..seems like he's saying that as we inclinate and angulate more we're somehow using the adduction related muscles..but I know when I ski I am not really thinking too much about trying to press my leg down into the snow adduct-ly. I'm thinking more about just angulating, countering, standing on my stance ski.. but perhaps I am subconciously activating those adduct related muscles. I want to go skiing now to try some things...

[Lisamarie]

In a rush but I want to shed some light on this. The adductors are a crucial muscle group for protecting the MCL. Any ski technique that engages them has to be good. The adductors also work in conjunction with the deep core stabilizers, which is a good thing. More later!

[Harald]

Adduction in skiing:
Let?s be clear about the understanding of adduction of the leg with the femur adductors. First Adduction of the leg, in an open kinetic chain movement is very different from adduction in a closed chain. There is a huge difference between open chain and closed (keeping it simple and understandable) chain adduction. Closed chain is when the foot (distal end) is locked to the ground, as in skiing, when the ski is on edge. When the foot is free, like when you pick up the ski or boot from the ground, this is open kinetic chain.

The major adductor muscles are the:
Adductor longus
Brevis
Magnus
Pectineus
Gracilius

They are attached and originate in the lower pelvis or groin and connect to the medial side along the femur, above the knee.

Of these muscles only the Graclius bridges the knee on the medial side, and it is thinnest and weakest of the adductors; therefore adductors are not good knee stabilizers.

The good knee stabilizers are the hamstring muscles, which do bridge the knee on the posterior, medial side, therefore they help to stabilize the medial collateral ligament, but only when they are contracted: the muscles involved are the:
Sartorus, Semi tendinousus and Gracilus


The best way to keep the knee stable is to keep the joint in co-contraction, which means stand centered and use equal hamstring and quad contraction.


Previous post:

Adduction is different, adduction of the leg when the foot is pressured, as in skiing, when the ski is on edge, produces different results. Adduction is not a rotary movement and rotary movements of the femur, leg or ski, are not the goal of adduction.

So when the ski is on edge and you want more big toe edge grip, tip the ankle and foot of the stance foot further on edge. When you initiate this movement the recruited muscles higher in the chain are the adductors. Adduction moves the leg closer to the middle of the body, but with the ski boot and ski attached to the leg, that action creates a strong angulation movement. The action helps to bring the upper body laterally toward the stance ski side. This allows you to relax and drop the hip closer to the center or inside the arc and therefore creates more dropped inside hip, to the inside of the turn.

Not all skiers are aware of muscles recruited higher up in the body, by movements at the base of the kinetic chain.

[Harald]

DHarvey, abductors of the femur are the Gluteus medius and Minimus, with the help of the six external rotators (these include the Obturators, Genelli and the Piriformus) they rotate and abduct the femur, which is an external rotation of the femur. In PMTS skiing, this movement originates with foot tipping of the releasing stance foot, toward the little toe edge. The abductors and external rotators are recruited to help with tipping and moving the leg (knee mass, femur) toward the inside of the turn. When tipping to the little toe edge the goal is to increase angles of the skis and body, so flexion of the inside leg must accompany tipping to achieve high ski angles and carving.

Hip countering action is created during release, by additional adduction and foot tipping of the new stance leg.

These movements we are discussing in this thread are not only different from the muscles used in steering and rotary actions, but they actually are counter to rotary and steering actions.

[milesb]

See, stuff like this is why we drink the Kool-Aid!

[HarveyD]

Thanks for the great information Harald. Just to clarify a bit, is it correct that the opposite (outside) femur abductors would work on the inside leg?

[HarveyD]

I guess that I can answer my own question, since I looked it up in Gray's Anatomy. The gluteus medius/minimus can raise the opposite side of the pelvis when the foot is raised. The body weight can otherwise make the pelvis sag downwards on the unsupported side. Apparently the muscles are active when the feet are placed parallel and close together. All of this information looks like it fits right in with PMTS.