When I was a young PT, I started noticing a lot of hockey players dealing with hip impingement, or FAI.
This led me to dig deeper into the issue itself, but also why it was so common in hockey players. Most of the stuff I read was about how the skating stride caused bony contact in the hip joint. In theory, it made sense. Repetitive contact between two bones led to the body creating stronger bone. But as a hockey player, one thing didn’t make sense to me.
Players don’t reach end range hip flexion and IR in skating
The more I dug, the more this impingement theory didn’t make sense. I read cadaver studies (here) that showed bone contact happened at much deeper ranges than hockey players reach in skating. Other cadaver studies (here, here) showed that acetabular version had a larger influence on hip impingement than cam morphology. Now, I know you’re probably thinking “but Matt, these are cadavers. They aren’t living, moving humans”. But I think that’s what makes these studies so valuable. These studies suggested 2 things:
- Skating does not the cause true bony contact between the femoral head and the acetabulum
AND
- When you remove muscle and tissue, cam morphologies are not a factor in bony hip impingement*
(* Although larger cam morphologies (alpha angles >75 degrees) have been shown to limit range of motion from early bony contact)
Take a minute to catch your breath after that one.
Now, the next logical question is: then why do so many hockey players deal with FAI symptoms?
Here are my 3 theories. These theories of hip impingement are based on other theories of impingement and my experiences.
#1) Anterior femoral glide syndrome
I’ve modified legendary PT Shirley Sahrmann’s theory to fit hockey players hips. Her original explanation was that weak glutes and hip flexors cause the hamstrings to create a bowing effect. This would lead to greater forward gliding of the femoral head.
In addition to having weak glutes and hip flexors, hockey players get can tight adductor magnus and deep hip rotators from skating. If you think of the hip like a circle, tight muscle in the back will push the femoral head forward. This will also result in anterior femoral glide and impingement symptoms.
#2) Dynamic anterior pelvic tilt
Some players I see move the lumbopelvic-hip complex as one. Rather than producing all propulsion power with their legs, they will finish their push off with their back. Some do this because they lack the hip mobility. Others do it because they aren’t aware of the difference between hip and back movement.
This leads to anterior tilting of the pelvis during skating. When this happens, the acetabulum will move to a more retroverted global position. Previous research has shown that retroverted acetabulum can lead to hip impingement. This can lead to impingement on the stance leg during the skating stride.
#3) Tight rectus femoris
Hockey players are known for having tight hip flexors and quads. The rectus femoris is a part of both muscle groups. Interestingly, this muscle has a small secondary head near the hip joint. It blends with the anterior hip capsule to move it out of the way when the hip is flexed to avoid impingement. When the rectus gets tight, the reflected head can’t do it’s job and players feel a pinch in their hip.
In my experience, making changes to these three areas can have a huge impact on players hips. Even those who have FAI.