The Lowdown on Femoral Acetabular Impingement. Trust Me: Not as Geeky as It Sounds.

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When I first moved to Boston – roughly seven years ago – I was working at a swanky, fancy-pants commercial gym in the downtown area and I remember on one of my days off Eric Cressey and myself took a little road trip to Worcester, MA to take part in an impromptu and informal workshop that orthopedic surgeon, Dr. Chris Vinton, was doing at the College of the Holy Cross on Femoral Acetabular Impingement (FAI).

Like some of you seeing this for the first time and starring at the screen as if I were saying the alphabet in Klingon, at the time of Dr. Vinton’s talk I had a similar reaction:  Femoral Acetabular Say-What-Now???

Without beating around the bush, in laymen’s terms:  “FAI is a condition of too much friction in the hip joint.  Basically, the ball (femoral head) and socket (acetabulum) rub abnormally creating damage to the hip joint.  The damage can occur to the articular cartilage (smooth white surface of the ball or socket) or the labral cartilage (soft tissue bumper of the socket).”

Resultantly it sucks donkey balls.

Source: (except for that last sentence).

FAI comes in a few flavors.  You have your Cam form which manifests itself as a bony overgrowth on the femoral head itself, and you have your Pincer form which results from a bony overgrowth on the rim of the acetabulum itself. And lastly, for those unfortunate few who can’t seem to make up their mind, you can also have a Mixed form which is a bony overgrowth of the two.

Even then, seven years ago, as I was sitting through the presentation, FAI wasn’t that prevalent in the athletic or fitness community – or, so it seemed.  I couldn’t recall one case of a current or past client who I felt fell under this FAI tree.

Fast forward to today and it seems everyone has FAI.  Hockey players, baseball players, soccer players, the mailman, the woman who does your hair, Batman.  Everyone.

Of Note:  Eric was talking the other day about this and mentioned something about a recent study that came out which showed something like 90% plus of high school hockey players have some degree of FAI.

I’ll have to see if I can ask him to find the study.  Stay tuned……

UPDATE:  Kevin Neeld discusses it HERE.

I don’t feel it’s because of some new pandemic or anything – like we’ve somehow mutated into a bunch of hip impingement ninjas.  Nah – nothing like that.

Well, maybe a little bit.  If I were speak freely I do feel that athletes today – particularly young athletes – fall into two categories:

1. Those who specialize too early and play ONE sport year round without any breaks.  It’s not rocket science to see how someone who plays a rotational sport year round, and develops pattern overload, can run into problems.

2.  Those who make the Tin Man look agile. It’s sad to say, but kids (and adults) just don’t move around as much anymore.  Texting has taken the place of riding a bike.  Call of Duty has trumped pick-up baseball games.  Escalators > stairs.

So I think we have ourselves to blame… a degree.  When we take people who have joint restrictions and don’t move well, and then ask them to “do stuff” they aren’t prepared to do. Well…….

But too, I just feel we’ve gotten a heckuva lot better in recent years at screening for FAI and recognizing symptoms.

Before I go on I should state the obvious:  as a strength coach I’m not diagnosing anything.  I can use some rudimentary “screens” (like the one to follow) which will better help me ascertain the situation and provide information on how I’ll go about programming for someone.  But almost always, I’ll be referring someone out to a more qualified fitness professional who can do a more thorough exam and/or possibly order an MRI.

That said if I’m working with an athlete or general population client who’s complaining of consistent and chronic hip pain – especially if they participate in a rotational sport or when squatting, I can do a quick “screen” as follows.

Here, I lie the person on their back and make sure their lumbar spine is flush against the table.  Then I’ll bring the affected limb into flexion, adduction, and internal rotation.

If the person winces or punches you in the face, it’s fair to say that that lit them up, and they may be a candidate for FAI. You can tweak the test by having them brace their abs – which will encourage more posterior pelvic tilt – and if it feels better, you know that’s it’s more of an alignment issue and not a worse case scenario.

No need to send someone for an MRI when all they had to do was posteriorly tilt their pelvis.

But it stands to reason that even with their anterior core engaged, if that still causes discomfort, it’s time to refer out and get them to see a more qualified practitioner to dig a little deeper.  Only through a combination of screens, tests, and possibly an X-ray or MRI can FAI be truly diagnosed.

But What Can You Do In the Meantime?

A lot, actually.  But lets try not to get carried away in thinking we’re going to solve the issue.  This is more about working AROUND the issue and maintaining a training effect than anything else.

FAI is a condition, not a disease. But here’s some food for thought.

1.  Rule numero uno is to nix squatting.  You’re not going to last long as a strength coach or personal trainer if you’re throwing caution to the wind and squatting those who are candidates for FAI.

I will say, though, that I say that with a grain of salt because technically you could still squat someone – albeit NOT BELOW 90 DEGREES OF HIP FLEXION.

If you look at the pictures provided above of the Cam and Pincer lesions, you can see how if someone were to squat below 90 degrees, that that would be, well, dumb.

Depending on symptoms you could get away with staying above 90 degrees, but honestly my rule of thumb is to wait six months before playing with fire.

2.  The good news is that you can still hit the lower body fairly hard.  Things like rack pulls, trap bar deadlifts, or even conventional deadlifts would be fair game given that neither require significant hip flexion.  In addition barbell glute bridges would be a viable option as well.

3.  Surprisingly, single leg work is fair game.  Even things like Bulgarian split squats – as counterintuitive as it sounds given they require deep hip flexion – would be okay.

The thing with single leg work is that the trainee can sort of find his or her “groove” with regards to hip internal and external rotation and be able to find a pain free ROM.

To that end I wouldn’t be apprehensive to crush single-leg training with someone with FAI – although certain things like femoral glide syndrome should be on the radar and may lend itself to making appropriate modifications.

4.  Go read anything and everything by Kevin Neeld on the topic. THIS and THIS would be good starts.

And that’s about it really. I think as strength coaches and personal trainers it IS in our best interests to know when to refer out and understand scope of practice.  But just as equally (if not more) important is to have the ability to assess and screen clients for certain conditions and be able to still garner a training effect and not make them feel like a patient.

Of course there is still a lot that’s unknown about FAI (s0me doctors still fail to admit that it exists!), and this post isn’t meant to serve as a definitive path to address the issue.  If anything I just wanted to throw it out there and hopefully bring forth a little more awareness on the topic.

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Comments for This Entry

  • Sue G.

    Nice article. Unfortunately, I'm finding that there is still a serious lack of understanding of FAI among the medical community. Even one of the hip specialists I saw said to me "Since you were a 1st year physical therapy student, you probably know as much about FAI as I do." Obviously I am trying to find someone better but it's slow going.

    December 5, 2013 at 10:28 am | Reply to this comment

    • TonyGentilcore

      Yeah, it's a pretty "recent' phenomena for sure. But more and more people in the field - PTs, chiros, athletic trainers, etc - are starting to recognize that it's a growing issue. As strength coaches and personal trainers, however, it just makes it all the more crucial to develop solid networks so that we can defer out and point people in the right direction.

      December 8, 2013 at 10:05 am | Reply to this comment

  • Harlan Siegel

    Tony, Once it's diagnosed (by a professional), are there ways to fix the issue? Or is this a chronic condition that would affect someone for the rest of their life?

    December 5, 2013 at 11:43 am | Reply to this comment

    • KevinNeeld

      Harlan-FAI refers to a BONY overgrowth, either of the femoral head/neck offset or of the acetabular hood above. Either way, the only way to truly "fix" it, is to shave off the bone. This, as you can imagine, should be treated as an absolute last resort for the overwhelming majority of people.

      December 7, 2013 at 9:13 am | Reply to this comment

    • TonyGentilcore

      Tough to say. I've worked with several athletes and clients who have gone in and had hip surgery (either the femoral head or acetabulum or both are shaved) and recovered nicely. We still have to be cognizant of their past history and be aware that squatting (aggressively) probably isn't in their near or distant future. But all in all, you can definitely "fix" the just takes varying degrees.

      December 8, 2013 at 10:09 am | Reply to this comment

    • Svengali

      I have a labral tear due to this overgrowth. I would say that fixing this prior to making things worse is preferable and has a more promising outcome than just trying the physio route. As I have read, the physio routines applied to this problem have been ineffectual thus far.

      September 21, 2015 at 6:39 pm | Reply to this comment

  • Tim Mercer

    Thanks for this article Tony, as it's very informative and super timely for me! My GF, who I coach, was just diagnosed with this on Monday. She had seen two different PT's over the last two years, and still was not able to help alleviate her hip pain when squatting. Unfortunately, as her coach, I didn't know anything about this issue, and continued trying to address mobility and muscle imbalance issues. FAIL! I wish I would have read this blog a year ago so that I would have been able to get her help sooner, but I can only hope I never make that mistake again.

    December 5, 2013 at 12:24 pm | Reply to this comment

  • Elsbeth

    Good stuff. It's certainly an interesting topic and one that still has lots of uncertainty. In addition to professional experience with clients with FAI, I also have personal experience with it and ended up having surgery for it on my left hip because the conservative efforts I tried didn't cut it. Interestingly, I have FAI on my right hip but no pain. Which begs the eternal orthopedic question: is it really the problem noted in the imaging that's causing the pain? In fact there's a paper from a few years ago where they looked at possibly using a squat as a diagnostic tool (they found the FAI group had less ROM in body weight squats). What I found particularly interesting in that study is that they had to exclude 3 of the 16 people selected for the control group because radiographs showed they each had at least one aspherical femoral head.

    December 5, 2013 at 12:32 pm | Reply to this comment

    • TonyGentilcore

      Thanks for chiming in Elsbeth (nice article on T-Nation the other week by the way!). Couldn't agree more with you that there's still a bit of mystery behind FAI, but I think it's something that definitely gaining more interest and something that being diagnosed a lot earlier now. Which is a good thing.

      December 8, 2013 at 10:12 am | Reply to this comment

  • Cody Bartosh

    Thanks for the info Tony. I had similar symptoms many years ago when I first starting lifting. I am pain free now so it must not have been FAI, but for a while there I was worried as it is painful. Do you think FAI is genetic or a structural adaptation?

    December 5, 2013 at 3:30 pm | Reply to this comment

    • TonyGentilcore

      Well you can still have it and be asymptomatic (see Elsbeth's comment). I'm mot professional on the topic and you can take my opinion for what it's worth: but I feel it's more a structural/gradual adaptation that anything else. Take people who play rotational sports year round, don't address tissue quality, and don't train appropriately and sometimes bad things happen.

      December 8, 2013 at 10:14 am | Reply to this comment

  • Kyle

    I just had a hip arthroscopy to fix this issue 5 months ago. The biggest difficulty I now have is the scar tissue from the surgical wounds, it won't go away and is affecting my movement. Those who decide to go this route, be aware of this issue. Since then though I have not had any pain in my labrum ever since.

    December 5, 2013 at 9:30 pm | Reply to this comment

    • TonyGentilcore

      Great sage words Kyle. Surgery should absolutely be a last resort!!!! As I alluded to in the post, FAI isn't a disease and it can be worked around. There are plenty of people walking around with FAI who lead pain-free lives. They just know how to train smart and know what they should, and more importantly, shouldn't be doing.

      December 8, 2013 at 10:16 am | Reply to this comment

  • Random Thoughts | Bret Contreras

    […] HERE is an important article on femoral acetabular impingement (FAI) by Tony “The Tiger” Gentilcore. […]

    December 6, 2013 at 3:21 pm | Reply to this comment

  • Nick

    Tony, what would you suggest someone with FAI do then or if you had FAI, what would you do? I discovered I had FAI about 7years ago (diagnosed 2 years ago), basically I got a sharp pain when attempting to get out of the hole when squatting. Fast forward a ton of mobility work and an MRI and I have FAI in both hips, however it only impacts my right hip (mild labrum tear - movement compensation I'm guessing.) I luckily discovered Kevin Neeld's stuff recently and have begun to accept FAI for life and train around the problem (time will tell how that goes.) Anyway what do you think you would do put in a situation with FAI. Is there certain people you'd recommend talking to such as kevin to assess where in the spectrum you are and whether surgery is the only viable route? Great to see more writing about this, I really hope it continues

    December 8, 2013 at 11:31 am | Reply to this comment

    • TonyGentilcore

      I think if Kevin is nearby and not too much of a hike....going to see him would be an excellent idea. That said, there does come a bit of "accepting reality" when it comes to FAI. I mean, if you've been dealing with it for seven years and have managed to work around it without too much pain, and you're willing to accept the fact that you're not going to be setting any squat records anytime soon, I'd DEFINITELY not recommend surgery. That is an absolute LAST resort.

      December 8, 2013 at 4:32 pm | Reply to this comment

  • ScottE

    As someone who has had major Hip repair surgery as a result of fai I can also tell you to be aware of lower back problems as well, if the impingement is significant as you sink into a deep squat the impinging can result in pressure which can also create forces that will impact on your ability to maintain lumbar extension. The old " butt wink " in squatting is not necessarily just a result of muscular tightness. I found that front squats to be an option for me as they allow a more upright torso.

    December 9, 2013 at 4:32 am | Reply to this comment

  • Rob M

    Hey Tony, Do you have any experience training clients with a hip labrum tear? Would your training recommendations for FAI be similar for a labral tear?

    December 13, 2013 at 1:10 pm | Reply to this comment

  • Nick

    Hi Tony, really enjoyable article, thank you for writing it. May I ask what your opinion of yoga and similar activites is like in this situation? For example I've seen yoga referred to as essentially the devil and otherwise a hero in this situation

    December 18, 2013 at 2:12 pm | Reply to this comment

  • Alex

    I have been reading a lot recently about femoral anterior glide syndrome. The symptoms (anterior hip pain) seem similar. The causes and fixes however are pretty different. It was cool seeing how you try "diagnosing" FAI. Do you have a specific screen to see if a client is dealing with anterior glide syndrome?

    April 1, 2014 at 6:19 pm | Reply to this comment

    • TonyGentilcore

      Well, to clarify: I'm not diagnosing anything!!!! That's out of my scope of practice. I can use that screen to kinda get an idea of what's going on and then I'm referring out.

      April 3, 2014 at 8:14 am | Reply to this comment

  • THE femoral specimin

    How do i know for sure if i have FAI or gliding syndrome for sure? it seems like after strengthening my glutes the impingement has gone away 100% in my right hip, but in my left my glute is still extremely inactive and i still have the impingement.

    April 2, 2014 at 2:43 pm | Reply to this comment

  • Bruce P.

    This is a great article Tony. I wish I had found this earlier. I'm just self diagnosing but I definitely experience that pain with internal rotation and hip flexion below 90 degrees.The last 3 or 4 months I have been avoiding lower body work altogether and it has really had an effect on my overall quality of life and physical state. Nice to know that I can work start working around this problem finally and get back in shape doing some deadlifts and single leg work. Thanks again!

    October 27, 2014 at 1:13 pm | Reply to this comment

    • TonyGentilcore

      Oh, my pleasure Bruce! Glad I was able to shed some light on the topic for you. Start slow and see how you respond. Stands to reason if you stay above 90 degree of hip flexion, you're golden. And single leg work "should" be okay below that point. You'll just have to test the waters and see how things feel.

      October 27, 2014 at 8:53 pm | Reply to this comment

  • A story today about an old client of mine, Jack. - Personal Trainer Development Center

    […] Squat Differently – Ryan DeBell Butt Wink is Not About the Hamstrings – Dean Somerset The Lowdown on Femoral Acetabular Impingement – Tony […]

    January 5, 2015 at 5:34 pm | Reply to this comment

  • Shane Dowd

    Tony! Wassup from a former Boston boy! *CHEST BUMP!* I went through my own FAI struggles from 2011 – 2015 or so and I don’t know how I never came across this post. I was a soccer player and did Olympic weightlifting (which is like...the worst possible combination of sports to try to do together) until the FAI thing damn near ruined all that for me. My story is a little unique I guess because I become utterly obsessed with fixing my hip WITHOUT surgery and am grateful to say I was successful. I chronicled my story in this video if you care to check it out: “How FAI almost ruined my athletic career”

    August 10, 2015 at 6:51 pm | Reply to this comment

  • Nate Huyser

    Tony, Really enjoyed the article! I appreciate you adding to the literature on FAI, which is seriously lacking in understanding among the medical community. FAI is a condition that I have struggled with for over 7 years now and I am only 22... FAI greatly hindered my athletic performance and gave me chronic pain that made life a lot less enjoyable. One of the physical therapists I worked with said that I had the worst hips he has ever seen in an 18 year-old and that they were the equivalent to 90 year-old hips. After several misdiagnoses and several physical therapists giving up on me, I finally had x-ray images done which confirmed large pincer and CAM lesions in both hips. Like Shane Dowd of the FAI Fix commented, I too am obsessed with fixing my hips WITHOUT surgery. This condition has inspired me to go into the fitness/physical therapy world and I will be starting physical therapy school this summer. I have spent years experimenting on my hips and believe that it CAN be fixed without surgery. I tend to believe we just haven't developed the correct/most effective protocols yet. I have started a blog documenting my progress and the knowledge that I have accumulated. I want to add to the literature that says that it can be fixed without surgery (which have not been shown to be overly effective). My blog can be found at!

    February 22, 2016 at 4:59 pm | Reply to this comment

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