Femoroacetabular Impingement

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Marc Surdyka

Do you have hip pain from squatting, sitting, or playing sports? Check out this blog to learn everything you need to know about Femoroacetabular Impingement (FAI), including exercise progressions with exact sets and reps.

Looking to improve the strength, range of motion, and control of your hips to enhance your function and performance?  Check out our Hip Resilience program!

 
 

What is Femoroacetabular Impingement?

The word “femoroacetabular” refers to your hip joint. Therefore, you may hear femoroacetabular impingement also called hip impingement. For the remainder of this blog I’m going to call it FAI.

https://commons.wikimedia.org/wiki/File:Blausen_0488_HipAnatomy.png
 

FAI was defined by Griffin et al in 2016 as a “motion-related clinical disorder of the hip with a triad of symptoms, clinical signs, and imaging findings. It represents symptomatic premature contact between the proximal femur [your thigh bone] and the acetabulum [part of your pelvis].” 

Symptoms include pain in the hip or groin, and in some cases, also the back, butt, or thigh. Additionally, you may experience clicking, catching, locking, stiffness, or limited range of motion. Symptoms commonly occur at the end ranges of your available hip range of motion, such as during a deep squat, deadlift, certain yoga poses, sitting for long durations, and various sporting activities.

Clinical signs involve the tests and measures that your physical therapist or medical doctor will perform during their examination. The most useful maneuver is bringing your hip into flexion, adduction, and internal rotation (FADIR). If you do not experience symptoms, it is unlikely that you have FAI.

 

Flexion, abduction, and external rotation (FABER) may also be used to evaluate symptoms and differences in side-to-side range of motion.

 

Additionally, your hip range of motion will be independently assessed, with an emphasis placed on hip internal rotation when your hip is flexed to 90 degrees.

 

Along with your symptoms and clinical findings, imaging is necessary to diagnose FAI. X-rays and an MRI may be performed to assess changes in the shape of your hip bones. Cam morphology refers to changes of the femoral head, pincer morphology refers to changes of the acetabulum, and mixed morphology describes a combination of the two. Changes to the labrum and articular cartilage often coincide with these imaging findings. 

Imaging findings, clinical signs, AND symptoms are all required to make the diagnosis because it is common to have changes on imaging without symptoms. For example, studies in 2021 by Kaymakoglu et al and Morales-Avalos et al found that cam morphology is present in 27-30% of asymptomatic adolescents. A well-known systematic review by Mascarenhas et al in 2016 found that cam morphology is present in 22% of asymptomatic individuals.

Systematic reviews by Heerey et al in 2018 and 2019, and research by Vahedi et al in 2019 found that labral tears are present in 41-54% of asymptomatic individuals, and cartilage damage in 12-17%.

 

I want to make it clear that although imaging is necessary to definitively diagnose FAI, it is not required to initiate rehab.

Should You Get Surgery?

I can’t give you a “yes” or “no” answer, but I can provide you with information that you can take into consideration during that discussion with your medical doctor.

There are three randomized controlled trials by Griffin et al in 2018, Mansell et al in 2018, and Palmer et al in 2019 that compare arthroscopic hip surgery to physical therapy. A systematic review and meta-analysis by Kemp et al in 2020 pooled this data and reported that surgery had a small positive benefit compared to physical therapy at 8-12 months, but no significant difference at 2 years.

Research by Ishøi et al in 2021 and Thorborg et al in 2018 suggest that, after surgery, 60-70% of patients get better, 50% of patients feel good, and 20-30% return to normal function. This data is based on Patient-Reported Outcome Measures (PROMs).

For example, 1-2 years after surgery, patients were asked – “Taking into account your hip and groin function and pain and how it affects your daily life including your ability to participate in sport and social activities, do you consider that your current state is acceptable if it remained like that for the rest of your life?” A little over 50% of people said “no.”

A study by Ishøi et al in 2018 found that 57% of individuals went back to their preinjury sport at their preinjury level, but only 17% returned to their prior level of performance almost 3 years after surgery. A different study by Ishøi et al in 2019 found that sprinting, kicking, and skating were among the most difficult activities for those athletes with impaired sport performance.

Finally, for reasons not fully understood, Rhon et al in 2019 found that seven types of comorbidities, such as chronic pain and sleep disorders, significantly increased following surgery.

Surgery doesn’t guarantee a return to normalcy, the monetary cost is higher, and there are more associated risks, so my bias as a physical therapist is to trial 3-6 months of rehabilitation before considering surgical management in most cases.

Load Management & Activity Modifications for Femoroacetabular Impingement

Regardless if you take the surgical or non-surgical route, load management and activity modifications are two of the most important aspects of rehabilitation. You need to determine your baseline level of tolerable physical activity and gradually progress toward your goals.

It’s not always helpful to compare your current self to your previous self. I cannot emphasize this enough. You may need to accept where you’re at right now so you can implement the appropriate changes that’ll help you get back to doing what you want to do. I’ll give some specific examples.

If you’re a powerlifter, you need to squat and deadlift in competition. However, you might have to alter your training temporarily and sacrifice some short-term PRs.

For example, if back squats are painful, opt for a variation that requires less hip flexion range of motion, such as a box squat or a heel elevated squat where you can maintain a more upright torso. If all double limb squats are off the table because of symptoms, split squats, which I’ll discuss later, are a good alternative.

 

If sumo and conventional deadlifts are painful, block pulls, RDLs, and trap bar deadlifts typically require less hip flexion range of motion.

 

If you’re a bodybuilder or recreational gym-goer, there’s no exercise that you HAVE to do to build muscle. You could easily train your legs using machines, such as a seated leg extension and prone hamstring curl.

 

If you practice yoga, make sure that you’re feeling the stretches in the target muscles. If you’re just experiencing pain in your hip joint during a groin stretch, don’t force the position or movement. Modify or regress as needed.

If you’re an athlete who is unable to run or play their sport, you should try to maintain your fitness by walking, swimming, cycling, rowing, throwing medicine balls, or doing anything else you can think of.

This isn’t an exhaustive list, but hopefully gives you some ideas to get started.

Resistance Exercises for Femoroacetabular Impingement

A systematic review by Freke et al in 2016 concluded that “individuals with symptomatic FAI demonstrate impairments in hip muscle strength and dynamic single leg balance.” Ishøi et al in 2021 concluded that “higher muscle strength was positively associated with higher sports function and ability to participate in sport” after hip arthroscopy. Therefore, rehabilitation at any stage should emphasize hip strengthening 2-3 days per week for at least 3 months.

Hip flexion range of motion may also be beneficial and will be tied in with the first resistance exercise. For all of the exercises, stay within your tolerance which is often recommended as a 2/10 pain or less.

Exercise Progression #1 (Split Squat)

The split squat is an excellent way to train simultaneous hip and knee extension while providing you with more control of your torso position, so you can stay upright and reduce the degree of hip flexion if needed.

 

Like all of the exercises I’m going to present, it’s also useful for targeting side-to-side differences in strength and range of motion since it’s unilateral in nature.

Level 1 – Split Squat Isometric. Start in a stride stance and lower yourself straight down so that your back knee is hovering over an egg that you don’t want to crack. Shorten the range of motion if it’s too difficult.

Level 2 – Rear Foot Elevated Split Squat Isometric. The overall technique of the movement and position of your torso should be similar, so use an object to elevate your back foot that isn’t too high. The majority of your weight should be through the lead leg.

Level 3 – Deficit Rear Foot Elevated Split Squat Isometric. You’re going to elevate the front leg using a 2-4” object to start. Over time, you can progress the height. The purpose of this exercise is to gradually expose and strengthen your hip to increasing degrees of hip flexion. This will be reinforced with exercise #6.

Level 4 – Deficit Rear Foot Elevated Split Squat w/ Weight. Aim for 3 sets of 6-12 slow and controlled repetitions.

To progress to level 4, aim for 3 sets of 60 seconds on levels 1-3.

Exercise Progression #2 (Hamstrings)

Assuming you aren’t able to train your hamstrings in a hip flexed position like a deadlift, most people with FAI will be able to comfortably train their hamstrings in a hip extended position. 

Level 1 – Double Leg Eccentric Slider. Bridge up, keep your glutes squeezed, slowly slide your legs out, drop down, bring your feet back to the starting position, and repeat. If you can work up to 3 sets of 12 reps, progress to the next level.

 

Level 2 – Nordic hamstring Curl or Single Leg Eccentric Slider. Aim for 3 sets of 4-8 reps.

Exercise Progression #3 (Adductors)

Level 1 – Lie on your back and squeeze a ball between your knees or ankles as hard as you comfortably can.

Level 2 – Short Copenhagen Plank Isometric. Keep your trunk in a straight line and thighs together.

Level 3 – Long Copenhagen Plank Isometric. Same as the previous exercise, but you’re going to keep the knee straight.

Level 4 – Long Copenhagen Plank. Aim for 3 sets of 8-12 slow and controlled repetitions.

To progress to level 4, aim for 3 sets of 60 seconds on levels 1-3.

Exercise Progression #4 (Extensors)

Level 1 – Double Limb Bridge Isometric. Lie on your back, bridge up, squeeze your glutes, and hold this position.

Level 2 – Single Limb Bridge Isometric.

Level 3 – Single Limb Hip Thrust Isometric.

Level 4 – Single Limb Hip Thrust w/ Weight. Aim for 3 sets of 10-15 slow and controlled repetitions.

To progress to level 4, aim for 3 sets of 60 seconds on levels 1-3.

Exercise Progression #5 (Abductors)

Level 1 – Short Side Plank. Start on your forearm and knees while keeping your trunk in a straight line. Hold this position.

Level 2 – Side Plank. Straighten your legs, stack your feet, and keep yourself in a straight line, both from a front view and top view.

Level 3 – Side Plank Hip Abduction. Position yourself in the same way as the previous exercise, but slowly move that top leg up and down with good control. 

Aim for 3 sets of 60 seconds as you work through each exercise.

Exercise Progression #6 (Flexors)

Level 1 – Incline Hip Flexion Isometric. Lean against a wall or object, lift your thigh up to 90 degrees, and hold this position. If you aren’t able to achieve 90 degrees, just lift your thigh to whatever height is comfortable. 

Level 2 – Standing Hip Flexion Isometric. Stand upright, lift your thigh up to 90 degrees, and maintain this position.

Level 3 – Banded Standing Hip Flexion Isometric. Exactly the same as level 2, but you’re going to place a loop band around your feet. You can also use a weight if that’s available to you. 

Level 4 – Banded Marching. Aim for 3 sets of 10-15 slow and controlled repetitions.

To progress to level 4, aim for 3 sets of 60 seconds on levels 1-3.

Guidelines, Not Rules

As always, the recommended exercises are based on guidelines, not hard and fast rules. The process needs to be individualized. Some people may benefit from partially progressing 1-2 exercises while others may benefit from fully progressing all of the exercises. You might also progress through the exercises at different rates, choose to split them up over multiple days due to time constraints, or swap out a movement for something else that you prefer that elicits similar adaptations. Additionally, the isometrics and different levels of exercises aren’t mandatory, but they can be a helpful starting point and framework.

Plyometric and Sport-Specific Exercises for Femoroacetabular Impingement

I also can’t include every possible exercise in this blog, but it’s important to understand that if your goal is to return to a sport that requires sprinting, jumping, cutting, kicking, or pivoting, you need to gradually incorporate plyometric and sport-specific exercises into your training. If you don’t prepare for it, you won’t be ready for it. Although they’re not specific to FAI, we have videos with a 4 stage plyometric progression and a 4 stage running progression that I recommend checking out. 

Banded Mobilizations and Stretching for Femoroacetabular Impingement

I didn’t include banded hip joint mobilizations and stretching in this blog, but I want to make a comment about each.

 

You can use banded mobilizations if they provide you with relief and help you train, but I’ve seen them recommended as a quick fix and unfortunately there is no quick fix for FAI.

 

And if you’re going to stretch, just make sure you’re not exacerbating your symptoms by forcing your hip into positions that cause you significant discomfort. Sometimes range of motion improves simply because pain decreases, so it’s okay to back off and let things calm down.

Femoroacetabular Impingement Summary

In summary, FAI is a motion-related clinical disorder of the hip with a triad of symptoms, clinical signs, and imaging findings. Rehabilitation is often the first-line recommendation with an emphasis on load management and activity modifications. Hip strengthening exercises should be performed at least 2-3 days per week for a minimum of 3 months.

If you want to learn more about Femoroacetabular Impingement, I highly recommend checking out our podcast episode with Mike Reiman:

Don’t forget to check out our Hip Resilience Program!

Want to learn more? Check out some of our other similar blogs:

Snapping Hip Syndrome

Total Hip Replacement

Gluteal Tendinopathy

Thanks for reading. Check out the video and please leave any questions or comments below.

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