Femoroacetabular Impingement A.K.A. Pinchy Hips
Have you ever experienced pinching in your hips or groin? Most commonly happens with squatting, prolonged sitting and driving?
There may be a few things that contribute to this sensation, one of the most likely causes is something called femoroacetabular impingement (FAI). This condition often relates to differences in the anatomy of someones hip. Some of these causes are naturally occurring and some are caused by trauma or injury to the hip. In this post we will take a look at the anatomy of the hip as well as some of the causes of FAI and ways to manage it.
What is the Anatomy of the Hip?
The hip joint is made up 2 parts. The acetabulum and the femoral head and neck. The acetabulum is shaped like a bowl and is fairly deep and this forms the “hip socket.” The femoral head is a spherical shape and this fits into the acetabulum. Because these two bones are extremely congruent the hip joint itself is a very stable joint. The femoral neck connects the head of the femur to the femur. The orientation of this can play a role in how you squat and move.
What are the Types of Impingement?
There are 3 types of hip impingement based on anatomical variances within the hip joint.
Cam morphology
Occurs when the head of the femur is not as spherical as it should be. Instead it has a flattening or convexity where it meets with the femoral neck.
Pincer morphology
Occurs when the acetabulum may be deeper than it should be, resulting in what looks like extra bony growth on the socket part of the joint.
Mixed (combined) morphology
This is the most common type, both the cam and pincer morphologies can be seen, and is the most common type in symptomatic patients
Just because you have these types of variances in your hip joint DOES NOT mean that you will experience pain or hip impingement.
What Causes Hip Impingement?
When impingement occurs it causes the femur to make contact with the acetabulum in an improper way causing pinching of the labrum and cartilage of the hip, and may cause cartilage damage or tearing of the labrum. This can also lead to osteoarthritis of the hip.
The exact reason for FAI is unknown, however there is evidence that adolescents who participate in high-intensity sports are 10 times more likely to have a cam morphology and FAI. The theory that stress along the growth plate of the hip may lead to this morphology. There may also be a genetic component as well.
What are the Treatment Options for FAI?
Unfortunately, as physical therapists we cannot change your anatomy. However, treatments such as joint mobilizations can help improve how the hip joint moves within the socket to allow for improved range of motion. Specific strengthening exercises can also help to improve range of motion and strengthen the muscles surrounding the hip (as well as the core), to stabilize the hip joint to decrease the likelihood of impingement. When conservative treatment is unsuccessful, then surgery may be the best option.
Tips and Tricks
Sleeping position
If you are a side sleeper make sure to put a pillow between your knees. This will prevent your top leg from crossing the middle of your body, which may be causing the impingement in your hip.
Sitting posture
Sitting with your hips slightly open, rather than at 90 degrees, can take pressure off of the front of your hip.
When sitting, do not let your knees fall in towards one another (knock-kneed). This position will lead to impingement in your hip.
Squatting
Perform self mobilizations of your hip before squatting to improve range of motion and decrease impingement.
Place a box behind you to limit your depth to avoid impingement or pinching in your hip.
Closing thoughts
In summary, FAI occurs when the two bony surfaces that make up the hip joint press against one another. This usually occurs with squatting and prolonged sitting. There are activity modifications, self mobilizations, and exercises that can help manage your symptoms. Finally, choosing the medical team wisely around you will greatly help manage your hip pain.
Kelsey Hight, PT, DPT, COMT
