In Exercises

September 10, 2010

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Knees rolling in on squats and pulls? Bill Starr explains how you can fix the problem by working on your adductors, which will translate to more weight on the bar.

All strength improvement emanates from the center of the body—hips, glutes, upper leg—then radiates upward and downward. Those on a mission to get stronger recognize the importance of leg strength and know the back squat is the very best exercise for the job. In addition to heavy squats, many strength athletes also add in leg extensions and leg curls to ensure that they’re keeping their quads and hamstrings plenty strong. But few do anything specific for their adductors. They’re sort of the forgotten leg muscle.

Of all the athletes, both male and female, that I started on strength routines, at least a third of them displayed a weakness in their adductors right away. So they start in squatting with a slight handicap that needs to be corrected as soon as possible. Then there are those who are fine at the beginning, but after the poundages in the squat start to be considerable, weak adductors reveal themselves.

How? When an athlete’s knees turn inward when he’s squatting or pulling heavy weights, his adductors are relatively weaker than his quads and hams. It’s easy to spot once you know what you’re looking for, and the nice thing about working the adductors is that they respond to direct attention rather quickly.



22 Comments on “Keeping Your Adductors Strong ”


wrote …

For knee caving I would imagine you need to look at both the abductors as well as adductors for weakness or dysfunction. Many of the exercises suggested work those too yet there is no real reference to the abductors ever being the cause also.


wrote …

How would strengthening adductors prevent the knees from rolling inward? I think you'd have to strengthen abductors in this scenario.


wrote …

this article doesn't make any sense. if you LOOSEN up your adductors, you'll certainly get more knee abduction.......but I'm with the first two comments.....

obviously having strong adductors helps, but I don't think ol' Bill understands his anatomy


wrote …

One trick that I use to strengthen my inner and outer thighs is by attaching a theraband or tube to anything. each one has varied resistance. (or .com) is a good source of physical therapy home remedies.


wrote …

Weak hip ABDductors (gluteus medius/ minimus, TFL, etc) cause excessive valgus (knocked knees/ knee in) during a squat, not weak ADDuctors. If your ADDuctors were weak you would "knee out", but people will mostly have weak hip abductors, so we typically never see this, except with tight IT bands.

I agree with the first three posts.
Mike Dickey, ATC


wrote …

I agree with the above posts to an extent. However the "knee-in movement" can be seen as a compensatory motor pattern (ie strong quads compensating for weak adductors) and not necessary an unbalanced tension between opposing muscle groups.

Bill Starr, thanks for sharing insights from years of competing and coaching.


wrote …

Do you honestly think Bill Starr would write an article with such a critical error??! Do you think the CFJ would actually publish that?!

Re-read the article after googling the origin, insertion and function of the adductors.

You move your feet to put them in abducted position at the top, you don't actively undergo abduction during the squat. Knees staying over the toes is just maintaining that position, not undergoing more abduction.

Below is a paraphrased Rip quote:

Look at what the adductors do on the way up. They originate at some point on the medial pelvis, and they attach on the medial femur. If you understand this anatomy, the question then becomes, does that distance increase on the way down and decrease on the way up? If it does, then the muscle is contracting and the muscle is contributing to the movement out of the bottom.

The fact is that when you get down to the bottom position with your knees out, those adductors (just like the hamstrings) form part of the rebound platform that involves the pelvis and the femur out of the bottom of the squat.
Now, in the bottom of the squat, the adductors are supposed to help you come up. On the way down, the adductors get longer and on the way up they shorten, correct? So that means that these muscles are contributing to hip extension. Now if I let my knees cave in, I have just contracted my adductors, but I didn’t make them do anything if I haven’t raised anything with them! If I make my knees stay out, then I have to use my adductors. They have to get strong enough to contribute to the movement.

Strengthening the abductors is not the solution because they are not weak. Weak adductors are the problem. That’s what is so counterintuitive. You strengthen the adductors by keeping the knees out. When you keep the knees out, the adductors have to do their share of the work. Keeping them out is, partially I suppose, a function of the abductors. But it’s not that they are weak.

You can prove this to anybody who’s been squatting with their knees pointed forwards. Make them shove their knees out and make them squat with the knees out. Then ask them the next day, “What got sore?” No one will ever tell you that their abductors got sore. They will all say that their adductors were sore. That tells you all you need to know right there. Do the exercise perfectly correct and then see what gets sore. That will tell you what muscles are working and what you’ve been doing wrong.

If reading isn't your thing, watch him explain it on video


wrote …

How about knees in being due to tight or over active adductors? Caused by that
damn adductor machine!


Tom Seryak wrote …

Straight from Gray's Anatomy: "in consequence of the obliquity of their insertion into the linea aspera they rotate the thigh outward, assisting the external rotators" Someone correct me if I'm wrong, but my understanding is the adductor's main function is to adduct the hip in the frontal plane; however, in the transverse plane they assist in external rotation by decelerating internal rotation (i'm guessing this is an eccentric contraction).

My interpretation of the purpose of the article was to present a possible solution to internal rotation during squats that most of us are overlooking. the standard prescription to foam roll the adductors and strengthen the gluteals has never really worked that well in my experiences. so, wide stance box squats with toes straight ahead it is!


replied to comment from Matt Solomon

whenever we have someone with the whole knees in thing, we'll do some adductor releases on the spot, and magically, the problem is solved. without strengthening!

I'm no stranger to strengthening the adductors, but what Bill and Rip are saying doesn't make any sense.

Squeeze your the knees go out or in?


replied to comment from mike mallory

Here's why Bill and Rip's comment makes sense. If your adductors are weak your knees roll inward in the squat to give them slack and take them off tension. If you push your knees out, the adductors are stretched and forced into tension, so they contribute to the movement as you come out of the hole. That's it in a nutshell.

To take it a bit further, when you roll your knees in, the adductors come off tension and drop out as a major contributor to the movement. It's a basic compensatory motor pattern. The load shifts from the weak muscles (adductors) to the strong ones (quads) when the weak muscle can't balance the strong.

The problem this causes is twofold.

First, your squat will be weaker than it can be because you are ignoring a weak link and aren't using a significant contributor. The adductor contraction helps pull you out of the hole when it's involved. If you have both flexible and strong adductors, they will allow you to get into a deep squat with good form and they'll help bounce you out of that deep squat like a stretched rubber band. More flexible adductors that stay on tension are like streching a rubber band further. You get more energy out of a longer pre-stretch.

Second, and just as important, a knock kneed squat is bad bad bad movement mojo. Bad for your knee ligaments, and it's also a bad motor pattern that transfers the rotational torque from the hips where it belongs to the inside of your knee, where it doesn't. Keep your knees straight and let your hips handle the movement deviations.


mike, hip abduction/adduction occurs in the frontal plane. in the squat there is hip flexion and external rotation of the femur. the adductors in the tranverse plane assist in externally rotating the femur by eccentrically controlling internal rotation to keep the knees tracking in the proper position. there is no hip abduction or adduction of the hip in the squat position and certainly no knee adduction or abduction. the normal function of the knee is to flex and extend. i don't think Bill is the one that needs to brush up on his understanding of anatomy.


wrote …

Mike Mallory- you're making far more sense to me than what some people are saying. I think weakness of the adductors is being assumed a lot when I'm more with you, thinking its more likely tightness and poor range of movement in the adductors.
Super slow clam shells will give an indication of someone's abduction control. If its jerky rather than smooth you can see there's some work to do. Also if the abductors aren't stabilizing you as well in a squat the adductors are always going to stay short and tight. I don't think you can talk about one without the other when talking about knee valgus issues.


replied to comment from Matt Solomon

Well said. I agree.


mike, hip abduction/adduction occurs in the frontal plane. in the squat there is hip flexion and external rotation of the femur. the adductors in the tranverse plane assist in externally rotating the femur by eccentrically controlling internal rotation to keep the knees tracking in the proper position. there is no hip abduction or adduction of the hip in the squat position and certainly no knee adduction or abduction. the normal function of the knee is to flex and extend. i don't think Bill is the one that needs to brush up on his understanding of anatomy.


wrote …

Wow, this is great. I stopped reading after page two because I was in agreement with the first 3 posts and because it was a 10 page article about adductors... seriously?

I think there is merit to both sides; however, when I see this in my clinic it is "generally" a force couple issue and/or a lack of skill/knowledge from the patient's prospective on what they are trying to achieve. Typical solution - mobilize and lengthen restricted tissue, if any (ext rot's, hip flexors/extensors, adductors... anything functionally tight); retrain proper mechanics of box squat (organized core, proper alignment thru LE, proper sequencing of hip/knee/ankle flexion and extension); move back to free squat and done. The ace in the hole is usually resisted abduction during the squat to facilitate powerful hip extensors and tension adductors for force production efficiency (both, can that happen?).

Is there a protocol for knee in position? Hell no! So adductor/abductor, mobilize/strengthen, weak muscle/inhibited muscle, blah blah - what ever produces a kick ass squat is the answer.

In the immortal words of Happy Gilmore: "Gold Jacket, Green Jacket, Who gives a sh!t"... just use your continued training and previous experience to get the job done and stop being poindexter (sp? GJ, GJ, WGaS)

Love it!


replied to comment from Matthias Schwartz

To matthias, Tom, and others;

Muscles can functionally shorten to stay in their optimal force tension curve.....but you still want to TEST it in the athlete......and from my own experience, rarely is the issue a strength discrepancy. Are you testing adductor strength/length in your athletes? Are the mobility restrictions cleared?

in some cases I've found some real adductor atrophy in people with a misaligned pubic symphisys, but then there's other hurdles to overcome.

With athletes, nine times out of ten, you just do the proper release work and everythings happy.....

Sit down in a squat, and feel whats going on, see if you can use your adductors to pull the knees out. It just doesn't work that way. I get great results doing exactly the opposite.



wrote …

Somewhat related is Thomas Kurz's emphasis on adductor strength for developing the side splits. If the adductors are weak at their end range of motion, they are unable to relax. Instead, they tighten up to prevent perceived tendon/ligament damage. By strengthening the adductors, they are better able to operate at that extreme ROM and enter new ROMs.

I imagine the same principle is behind the adductor's role in the squat. Weak adductors don't allow the necessary eccentric lengthening to take place. Instead they tighten up, bow the knees in, and don't contribute to the concentric part of the lift.

Nonetheless, I fully agree that mobility plays a huge role in movement limitations and should receive a big priority in training.


Emilie Hester wrote …

I had a hard time wrapping my head around this at first, but kept thinking if HQ is posting it and someone like Bill Starr is strengthening the adductors and having success with his athletes keeping their knees out (empirical evidence), then there has to be something to it.

I realized I was thinking of adduction & abduction as a hinged, open chain, sagittal plane movement. But the squat is a closed chain, frontal plane movement and the hip is a ball & socket joint, not a simple hinge. So if I'm thinking of it correctly, the terms adduction & abduction kind of go out the window in this case and need to be replaced with internal & external rotation.

Also, in the squat, the adductors act as hip extensors. They're eccentrically helping to decelerate hip flexion as you lower into a squat and concentrically helping to activate hip extension as you come out of the hole. So if the adductors are weak you'd be losing medial support in both hip flexion & hip extension.

So if I'm thinking of it correctly, reasons for the knees caving in could be:
-lack of body awareness -weak adductors -weak external rotators -overly tight adductors -some kind of tissue or joint dysfunction that's limiting external rotation -foot pronation

Up to this point I've only focused on cueing for body awareness, strengthening the external rotators, mobilizing external rotation and restoring length to the adductors, but will now consider the adductors strength role as well.

Interesting stuff HQ & Bill.


**Accidentally typed it in reverse.

--adduction & abduction as a hinged, open chain, FRONTAL plane movement
--squat - closed chain, SAGITTAL plane movement


wrote …

And from Rippetoe's Active Hip article, director's cut found here

"The knees want to track more medially than this because of the tension on the inside of the femurs produced by the adductors – the groin muscles. These five muscles (the adductor magnus,adductor brevis, adductor longus, pectineus, and gracilis) attach at various points along the medial and posterior aspect of the femur, and on the ischium and pubis of the pelvis. Tension is produced between these two bones as you squat down and keep your knees out; this is an eccentric action for these muscles, since they lengthen as the femur maintains its position parallel to the feet. As you come up out of the squat, the distance between the inside of the femur and the medial pelvis shortens as the hip angle opens up; the concentric action of the adductor muscles thus produces hip extension."

And there is more good stuff there, too.


wrote …

After thinking about my own comment I may have came up with a theory that at least may make sense of this article in my head and may discredit what I said previously.

I think it is agreed that the adductors act as hip extensors out of the bottom of the squat. If the hip adductors act as extensors the length tension relationship, which basically says that a muscle is strongest somewhere in mid range and weaker at shortened and lengthened range (think of a chin up hard at the bottom, easy in the middle, hard at the top) may explain this article.
For example, if my adductors are short, and I squat with knees out, I have maximally lengthened the adductors placing them at less than optimal length. Sub consciously if my knees come in the muscle shortens and could perhaps be at a more advantageous muscle length allowing me to use the adductors as more efficient hip extensors. Im allowing my knees to come in to engage the adductors more efficientlly as hip extensors...the adductors themselves are not pulling the knees in.

I myself have trouble with my knees coming in on heavy squats and have seen several athletes I have coached have trouble with this. I only buy it if we are talking about the knees coming in on the way up out of the bottom. If the knees are coming in on the way down it is a coordination/tightness problem in my opinion. But out of the hole I guess I could see it.

Rip talks about the knees out position allowing you to maximally use the adductors, my argument would be that in a person with tight adductors they become too lengthened in this position.

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