Monday, January 12, 2009

Femoral IR?

Gender Differences in Rotation of the Shank During Single-Legged Drop Landing and Its Relation to Rotational Muscle Strength of the Knee-AJSM Jan. '08
This study looked at femoral rotation during a 20cm single leg drop landing. The study showed the female subject's femurs internally rotated faster & further than the male subjects. The authors suggested female athletes strength train the hip external rotators as a method of ACL prevention. I would like your opinion on these questions:
1. What do you think was (or wasn't) going on in the other two planes at the hip?
2. What foot/ankle dysfunctions might exacerbate the effect at the knee joint?
3. Assuming a weak butt is the culprit in the excessive IR, what methods might you use to block that IR in rehab?

9 comments:

KP said...

It will be interesting to see what, if any comments you get on this topic.

I asked some of our athletic training students #2 the other day to see if I could get them to think a bit.

This could really turn into a chicken or the egg discussion: did the decreased function at the ankle due to numerous ankles sprains cause the problem at the hip or did the problem at the hip predispose them to the numerous ankle sprains.

Or I could be totally full of it.

bk said...

I'll take a stab at the last question, since I don't have the expertise for the first two.

Perhaps the athlete could hold the other knee and hip flexed at 90 degrees, and externally rotated, while completing a series of hops. This should change the balance and encourage the supporting leg to use the hip better.

Another option might be to put a light weight (3 lbs) in an outstretched hand (arm in the frontal plane, 90 degree angle with the floor). I think it's appropriate to put the weight on the same side as the supporting leg. But I'm not sure if I am visualizing the system properly.

Bonnie

JH said...

1. I think the pelvis is going from superior to inferior in the frontal plane and possibly anterior tilting in the sag plane.

2. The foot/ankle may be pes planus, or have an arch that drops upon weightbearing. many times an arch may seem acceptable until you get them weightbearing on 1 foot. Perhaps also a forefoot valgus(?)

3. I wouldn't try to block it per se, I would try to teach the leg/hip/ankle to work together in function by using either the arms or teh opposite leg as drivers. Gotta get the knee bent too. Different drivers work for some but noth others. It's really an art to figure out what works best for each person.

JH said...

KP,
One of the questions i wouold use as an interview question when hiring was, "Name 1 transverse plane exercise for the quadriceps?"

It really got them thinking.

Jonathan

Kev said...

JH you got me searching my grey mater .... what is a good transverse plane quad exercise??

JH said...

Joe,

Would you mind posing this question on your blog? "Name a transverse plane quad exercise?"

Thanks for considering.

bk said...

How about the l-sit as a transverse plane exercise for the quads? Does the entire movement have to be in the transverse plane for it to count? What about lunges in all directions?

atcref said...

Joe-

Thought provoking stuff - as usual.

In answer to the second question, a cavus foot or someone who over pronates is probably going to exacerbate this situation. Also potentially hypermobility in ankle dorsiflexion.

Great stuff.

Bill

JH said...

BK,

That's the question isn't it? Does the body part have to be moving in the transverse plane to be considered a transverse plane exercise OR can the forces acting on the body part be transverse in nature? In this case the body part is the quad or thigh.
What about a SL Half Moon? or a SL Wide rotations with a med ball?