Difficult hip presentations. Coordination of deep hip muscle activity is often altered in symptomatic femoroacetabular impingement (FAI). If your clinic is anything like ours, you are regularly seeing failed therapy cases of hip pain walk into your clinic. Many of these cases have been diagnosed clinically or with imaging as FAI (femoral acetabular impingement (syndrome)). FAI can give all kinds of hip pain presentations around the front, side or back of the hip, groin and pelvis, even with referral into the knee. Lets make no mistake, these are difficult cases. The attached study suggests that these often difficult cases are fraught with undefined parameters. These cases can be difficult for us all, particularly if one do not have the clinical examination skills to tease out what muscles are not working, which ones are over working, what has happened to joint centration, how the client loads the hip, what the pelvis posturing attitude is and what motor stabilization strategies are being deployed. Lumbar, pelvis and hip posturing and stabilzation is key in understanding FAI and these often vague and frustrating cases. Determing how the client deploys stacking of the lower limb joints and how they then deploy these strategies in gait and running is paramount to your success in assisting these client cases. This is a deeply multifactorial problem and often why these issues do not get resolved.  Recently I just closed yet another case with a 21 year old female who had FAI and labral tear surgery 2 years ago. She had been told she would always have some pain and never run again. As many of these cases often proceed, after defining all of the issues above, it was clear she had many unaddressed components postoperatively. It appeared many components had not been addressed preoperatively, and had they been addressed, I suspect she may have not needed surgery. These multitudes of dysfunctional components can lead to FAI and labral damage. Many torn labrums do not need surgery, as evidenced by how many clients come out of surgery still having the same pre-operative pain as well as how many improve or resolve by a non-surgical approach to addressing all of the components above. This study, by Diamond et al compared coordination of deep hip muscles between people with and without symptomatic FAI using analysis of muscle synergies (i.e. patterns of activity of groups of muscles activated in synchrony) during gait. The study utilized intramuscular fine-wire and surface electrodes EMG activity of selected deep and superficial hip muscles.   This study found a significant correlation with the quadratus femoris muscle, one we have repeatedly found problematic over the years. This study was nice to read, it confirmed many of the issues we have found rooted in these often difficult cases. The study surmised that  “coordination of deep hip muscles in the synergy related to hip joint control during early swing differed between groups. This phase involves movement towards the impingement position, which has relevance for the interpretation of synergy differences and potential clinical importance. ” We strongly refer you back to our podcast #99 to look into the gluteus medius during swing phase. This is a key component to one’s deeper understanding of how complex the hip works, during both stance and swing. We all tend to get too caught up in stance phase mechanics because that is the one we can see and assess most clearly, however, if one does not understand how vital the gluteus medius is in swing phase limb targeting through the sagittal plane, one is likely missing a big piece of a client’s clinical puzzle. One can do all the dynamic and functional movement and stabilization therapy they wish, but if one does not understand the swing phase mechanics, and perhaps most importantly, if one does not reteach a client how to make the necessary adaptive gait changes to employ the therapeutic work the changes remain on the therapy table and never cross over into functionally using them. The clinician must address the client’s previously deeply rooted gait motor program. A client may have in their bank account the new functional abilities they have been taught, but they likely have not been taught how to deploy them in a new more appropriate gait strategy.  -Dr. Shawn Allen 1. Coordination of deep hip muscle activity is altered in symptomatic femoroacetabular impingement. Laura E Diamond, Wolbert Van den Hoom, Kim L Bennell, Tim V Wrigley, Rana S Hinman, John O’ Donnell, Paul Hodges 2. J Neurophysiol. 2014 Jul 15;112(2):374-83. doi: 10.1152/jn.00138.2014. Epub 2014 Apr 30. A neuromechanical strategy for mediolateral foot placement in walking humans.  Rankin BL 3. Podcast 99: How foot placement, the glutes and cross over gait all come together and make sense. 4. https://thegaitguys.tumblr.com/post/133206339519/podcast-99-how-foot-placement-the-glutes-and

Difficult hip presentations. Coordination of deep hip muscle activity is often altered in symptomatic femoroacetabular impingement (FAI).


If your clinic is anything like ours, you are regularly seeing failed therapy cases of hip pain walk into your clinic. Many of these cases have been diagnosed clinically or with imaging as FAI (femoral acetabular impingement (syndrome)). FAI can give all kinds of hip pain presentations around the front, side or back of the hip, groin and pelvis, even with referral into the knee. Lets make no mistake, these are difficult cases.
The attached study suggests that these often difficult cases are fraught with undefined parameters. These cases can be difficult for us all, particularly if one do not have the clinical examination skills to tease out what muscles are not working, which ones are over working, what has happened to joint centration, how the client loads the hip, what the pelvis posturing attitude is and what motor stabilization strategies are being deployed. Lumbar, pelvis and hip posturing and stabilzation is key in understanding FAI and these often vague and frustrating cases. Determing how the client deploys stacking of the lower limb joints and how they then deploy these strategies in gait and running is paramount to your success in assisting these client cases. This is a deeply multifactorial problem and often why these issues do not get resolved. 

Recently I just closed yet another case with a 21 year old female who had FAI and labral tear surgery 2 years ago. She had been told she would always have some pain and never run again. As many of these cases often proceed, after defining all of the issues above, it was clear she had many unaddressed components postoperatively. It appeared many components had not been addressed preoperatively, and had they been addressed, I suspect she may have not needed surgery. These multitudes of dysfunctional components can lead to FAI and labral damage. Many torn labrums do not need surgery, as evidenced by how many clients come out of surgery still having the same pre-operative pain as well as how many improve or resolve by a non-surgical approach to addressing all of the components above.

This study, by Diamond et al compared coordination of deep hip muscles between people with and without symptomatic FAI using analysis of muscle synergies (i.e. patterns of activity of groups of muscles activated in synchrony) during gait. The study utilized intramuscular fine-wire and surface electrodes EMG activity of selected deep and superficial hip muscles.  
This study found a significant correlation with the quadratus femoris muscle, one we have repeatedly found problematic over the years. This study was nice to read, it confirmed many of the issues we have found rooted in these often difficult cases. The study surmised that 

“coordination of deep hip muscles in the synergy related to hip joint control during early swing differed between groups. This phase involves movement towards the impingement position, which has relevance for the interpretation of synergy differences and potential clinical importance. ”

We strongly refer you back to our podcast #99 to look into the gluteus medius during swing phase. This is a key component to one’s deeper understanding of how complex the hip works, during both stance and swing. We all tend to get too caught up in stance phase mechanics because that is the one we can see and assess most clearly, however, if one does not understand how vital the gluteus medius is in swing phase limb targeting through the sagittal plane, one is likely missing a big piece of a client’s clinical puzzle. One can do all the dynamic and functional movement and stabilization therapy they wish, but if one does not understand the swing phase mechanics, and perhaps most importantly, if one does not reteach a client how to make the necessary adaptive gait changes to employ the therapeutic work the changes remain on the therapy table and never cross over into functionally using them. The clinician must address the client’s previously deeply rooted gait motor program. A client may have in their bank account the new functional abilities they have been taught, but they likely have not been taught how to deploy them in a new more appropriate gait strategy. 

-Dr. Shawn Allen


1. Coordination of deep hip muscle activity is altered in symptomatic femoroacetabular impingement.
Laura E Diamond, Wolbert Van den Hoom, Kim L Bennell, Tim V Wrigley, Rana S Hinman, John O’ Donnell, Paul Hodges

2. J Neurophysiol. 2014 Jul 15;112(2):374-83. doi: 10.1152/jn.00138.2014. Epub 2014 Apr 30. A neuromechanical strategy for mediolateral foot placement in walking humans.  Rankin BL

3. Podcast 99: How foot placement, the glutes and cross over gait all come together and make sense.

4. https://thegaitguys.tumblr.com/post/133206339519/podcast-99-how-foot-placement-the-glutes-and