Femoroacetabular impingement (FAI) syndrome has become more widely recognized thanks to folks such as Kevin Neeld, Eric Cressey, Mike Reinold, and a plethora of other smart coaches.  FAI is a common* syndrome/injury in athletics and football kickers are especially susceptible due to the nature of the violent hip flexion during the kick off/punt.  At the end of the article I'll put some links for more information regarding testing for FAI, research regarding FAI, and other resources. The last two posts have been marathon length, so we'll keep today short and to the point. What is FAI?

FAI is essentially:

Femoroacetabular impingement or 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).

from www.hipfai.com.  Athletes that participate in activities that include repetitive hip flexion and internal rotation or folks who have super crappy mobility in their hips are at a higher risk of developing hip issues. Also, athletes who are constantly in a state of anterior pelvic tilt (aka: nearly every one of them) are also primed for some impingement.

Now, look at a football kick off. Check out the crazy hip flexion and internal rotation (when his leg crosses over the midline of his body around the :29-:31 mark).

Can you see how a kicker might develop a problem? Especially if they're not a physically STRONG kicker?

Just so you know, FAI comes in three flavors, none of which include chocolate or vanilla:

     CAM- bony overgrowth on the femoral head (ball)

     Pincer- body overgrown on the acetabulum (on the socket on the pelvic bone)

     Mixed- a lovely combination of both.

How do I spot FAI?

IMPORTANT: Remember, unless you're a doctor, you CANNOT DIAGNOSE. The following are merely indicators that something is amiss. A visit to the doctor and possibly the Wonder Machine (MRI) will be the only sure way to diagnose any pathology.

Now, as a coach/player it's important to be aware of FAI and be on the look out for the symptoms. FAI will most likely manifest on the kicking leg simply because it is subject to that the crazy-hip-flexion. Bilateral FAI is found more often in sports with bilateral hip flexion such as hockey or powerlifting. However, this doesn't mean that both sides can't be affected, so be on the vigilant!

There are two simple tests that you can do yourself (though I STRONGLY recommend you see a professional..cough, cough.)

One is the Faber Test.

The other is a supine hip flexion with internal rotation of the femur.

If this lights you up, and you're also experiencing the symptoms below, you should probably high tail it to a person with the initials, "M.D." after there name.

A few other symptoms that as either a coach or a player you should be on the watch for (and probably perform the aforementioned tests):

1. Pain with squatting below 90 degrees. Speaking from experience, it feels "pinchy" in the front of the hip, just a smidge medial (inside) of the pelvic bone.

2. Pain with internal rotation and hip flexion. For example, getting into a car leading with the affected leg (one has to flex the hip to sit and internally rotate the hip to slide into the car).

3. Another potential, but not always present, is a history of repeated sports hernias or groin pulls.

4. As a coach, if you're watching a player squat, if one hip seems to drop more than the other. The hip that DOESN'T go as low, will be the affected hip. The player will also weight shift towards the affected side as they stand up from the bottom of the squat.

Don't be stupid and keep training through this pain (again, I speak from experience). Some of the associated symptoms/pathologies of FAI include: cartilage damage, labral tears, (the labrum helps keep the hip stabilized. It's really important.) early on-set osteoarthritis of the hip, sports hernias, and low back pain.

Speaking as someone who has bilateral FAI (and the labral tears), it sucks. Don't be a hero, go to the doc if you're experiencing these symptoms.

What are the Implications of FAI?

An athlete the has impingement of their hip will have limited hip flexion range of motion (ROM) on the affected side. What does this mean for a football kicker?

- No more squatting. Think about it: 1) hip flexion ROM is going to be limited on one side. 2) If you're bilaterally loaded, as in a squat, one hip will drop lower than the other, and if the hips can't move independently, as they could in a lunge, you're going to impose some wonky forces on the spine. 4) Wonky forces on the spine eventually lead to injuries and pain.  Not the best game plan. (You could get away with squatting above 90 degrees, but no sense in playing with tigers if you don't have to.)

- There's a study found here that looked at hip flexor strength a group of people with diagnosed FAI. The study found that those with FAI had weaker hip flexors than the controls. (I can personally attest this is true.) Whether the people had FAI because their hip flexors were weak, or the hip flexors became weak with FAI onset, doesn't matter for this discussion. What does matter is that the HIP FLEXORS ARE WEAK! Now, in a football kicker, what's the main group of muscles used to kick? HIP FLEXORS! Do you see a problem? If a coach is oblivious to this, yelling at a kicker to kick harder isn't going to do much. Also, without proper training (perhaps some focused work for the hip flexors such as SL marches or hanging leg raises), other muscles are going to take over for the lack luster hip flexors and then you have a whole new set of problems.

- Hip dominant exercises (deadlifts, RDLs, glute bridges, and swings) and single leg work (split squats, step back lunge variations, step ups (as long as the hip stays >90 degrees), and single leg RDLs) must be the bulk of lower body work. All of these tend to keep the hip out of excessive hip flexion + internal rotation. They also hammer the glutes, which will help keep the femur from gliding forward in the socket and causing more ruckus in the pelvic region. Food for thought: I've personally found that walking lunges/forward lunges tend to make my hip ache as do back-and-feet elevate glute bridges.

- As far as corrective work goes, hammer hip stabilization and anterior core. Low level glute work such as double- and single leg glute bridges, monster walks, and bowler squats will challenge the smaller stabilizers of the hip. This in turn will keep the femoral head from gliding around and causing more damage. Anterior core is necessary to, hopefully, control anterior pelvic tilt (which most athletes sit in anyway) and even, possibly, pull the pelvis a little posteriorly. This will, again, keep those bony overgrowths from grinding on each other. Here's a great video by my better half on anterior core progressions.

Another note: I've found that single leg anterior core exercises (such as a single leg plank) bother my hips. Be mindful and if it hurts, don't do it.

Wow, so I broke my promise of writing a lengthy post. However, this is an EXTREMELY important issue that many kickers are faced with (we've had one walk through our doors, not to mention the other handful of other athletes from a range of sports).

*Just chew on this; a recent study of asymptomatic people found that  of the 215 male hips (108 patients) analyzed, a total of 30 hips (13.95%) were defined as pathological, 32 (14.88%) as borderline and 153 (71.16%) as normal. That means potentially 1 in every 3-4 males have some sort of underling hip "thing" going on. (thanks Kevin Neeld!) That's a lot.

As promised here are some links for more information:

Post on Mike Reinold's site with more in-depth diagnoses.

Kevin Neeld has a bunch: 1, 2, and 3 (and the one linked above)

And Tony Gentilcore, who does a fantastic job communicating a complex topic to the lay population, while adding some humor to boot.

Whew!