Posts

4 Mistakes People Make When Rehabilitating Hamstring Strains

When it comes to hamstring strains, two things are certain:

  1. They are very common in athletes, with research showing almost 30% of all lower extremity injuries in sports are hamstring strains.
  2. The recurrence rate is high, with research showing up to a 30% recurrence rate for hamstring injuries.

Call me crazy but I feel like the recurrence rate is just way too high, showing that we either are rushing people back too soon, don’t have an adequate return to sport criteria, or simply are not rehabilitating these hamstring strains very well.

It’s likely a combination of the three. We can do better.

 

4 Mistakes People Make When Rehabilitating Hamstring Strains

In my experience, people often make 4 common mistakes with hamstring strain rehabilitation. By focusing on these 4 key areas, I think we can do a better job returning athletes to their sport following hamstring strains, and keep them out on the field without reinjuring their hamstrings.

 

Loading the Hamstring Too Early

The first mistake I often see is simple. People often load the hamstring tissue too early.

I think it’s obvious that contracting a strained hamstring causes pain, so this is often avoided, but for some reason people tend to want to stretch through this pain and discomfort, thinking that if they get looser it will feel better.

I don’t think this is true, and overstretching too early is just going to delay healing. In fact research has shown that too much stretching can actually delay the return to sport.

This can occur in the rehabilitation setting, but also from the athlete themselves as the constantly want to stretch or “test” the area throughout the day.

One of the easiest things you can do acutely after a hamstring strain is to avoid stretching. Don’t get me wrong. I want to start some gentle range of motion in the acute phase, but I don’t want to stretch the tissue that was essentially just damaged by an overstretch type of injury.

Trust me, take a step back in the acute phase and avoid stretching and you are putting the tissue in a position to succeed in the future phases on rehabilitation when we need to start applying more load.

 

Not Performing Eccentric Exercises

It has been theorized that hamstring strains are so common due to the large eccentric contractions observed during the swing phase of running as the hip flexes and the knee extends.

This seems to make sense.

So it also makes sense that hamstring strain rehabilitation and even prevention programs that incorporate eccentric hamstring exercises tend to have better results.

After a hamstring strain, it has been shown that eccentric hamstring strength is impaired.

The common theory is that there is a change in the force-length relationship of the hamstring after an injury, resulting in peak force at a shorter length. But, eccentric training shift this relationship and allow peak force at a longer length.

This makes is important to include eccentric exercises for the hamstring during rehabilitation. I also recommend you include eccentrics with exercises at various degrees of hip flexion, for example the Nordic hamstring exercise at 0 degrees, and a single leg RDL, which includes hip flexion.

 

Not Performing Dynamic Hamstring Exercises

While it’s important to include eccentric exercises, I’m actually surprised at how little I read about people recommending dynamic exercises.

It’s one thing to perform a slow eccentric contraction, and another to perform a dynamic and explosive contraction.

I often use lower body plyometrics for this, as it allows both a rapid eccentric contraction, followed by an explosive concentric contraction. That’s what happens in sports.

 

Returning to Sports Too Early

Several studies have been published showing that many athletes return to sport too early, showing signs of hamstring weakness and imbalances.

Part of the problem is that there is no validated criteria to determine return to sport. But, we are getting there.

It’s probably best to understand the factors that are associated with prolonged hamstring injuries, you can read a nice review of those in AJSM.

But we also may have a new clinical test that can be performed. The Askling test involves have the person rapidly perform an active straight leg raise to assess their ability to perform and pain.

It has been shown that the recurrence rate of hamstring strains that passed the Askling test was less than 4%, much lower than the normal rate.

 

How to Diagnose and Treat Hamstring Strains

For those that want to learn more about how I rehabilitation hamstring strains, including the postoperative rehabilitation follow hamstring repairs, I have an Inner Circle presentation on the Diagnosis and Treatment of Hamstring Strains that overviews my approach to these injuries. Click below to learn more:

 

 

How to Diagnose and Treat Hamstring Strains

The latest Inner Circle webinar recording on How to Diagnose and Treat Hamstring Strains is now available.


How to Diagnose and Treat Hamstring Strains

This month’s Inner Circle webinar is on How to Diagnose and Treat Hamstring Strains. In this presentation, I’m going to overview a simple 3 phase approach to rehabilitating hamstring strains. Hamstring strains can be tough, and have a really high recurrence rate. But luckily there are things you can do to assure we are helping the tissue remodel and accept load again.

This webinar will cover:

  • The anatomy and injury mechanics behind hamstring strains
  • The best way to diagnose and grade hamstring strains
  • A 3 phase rehabilitation progression to get back on the field
  • What to focus on to reduce recurrent strains in the future
  • The postoperative rehabilitation following hamstrings repair

To access this webinar:

6 Hip Mobility Drills Everyone Should Perform

Recently, I have seen dozens of social media posts with “advanced” hip mobility drills that made me stop and think…

Should we actually be seeking to perform these advanced variations?

I would argue most people still need the basics, and should incorporate just a handful of more simple drills as the foundation of their mobility drills.

The internet is famous for sensationalizing the drills that look “fancy” rather than the ones that are likely the most effective.  It’s probably another case of the Pareto Principle, where 80% of the drills seen online should only be performed 20% of the time, and conversely, 20% of the drills seen online should be performed 80% of the time!  Heck it may be even less than that when it comes to hip mobility.

To make matters worse, the more advanced hip mobility drills are probably inappropriate for most people.  In my experience, limitations in hip mobility seem to be more related to the individuals unique anatomy, boney adaptations, and alignment rather than simple soft tissue limitations.  So, forcing hip mobility drills through anatomical limitations is just going to cause more impingement and issues with the hips, rather than helping.

Sometimes less is more.

 

My Favorite Hip Mobility Drills

I wanted to share my favorite hip mobility that I use with most of my clients.  I think you should really focus on these hip mobility drills before proceeding to more advanced variations.  If these don’t do the trick, it’s probably best that you seek out a qualified movement specialist to assess the reason behind you hip mobility limitations, rather than forcing more drills.

 

Quadruped Rockbacks

The first drill is a quadruped rockback.  This is one of my favorite drills for the hips, and feels great to loosen up the adductors and hip joint into flexion.  Plus, I do these barefoot to get more dorsiflexion and great toe extension.

 

Adductor Quadruped Rockbacks

The adductor quadruped rockback is a variation of the rockback that involves straightening out one hip.  This takes away a little bit of the hip flexion benefit, but enhances the effect on the adductors.  Performing this on both sides is the best of both worlds.

 

True Hip Flexor Stretch

The true hip flexor stretch is probably the most fundamental hip mobility drill we should all be performing.  I started calling it the “true” hip flexor stretch because the more common versions of this do not lock in the posterior pelvic tilt and just end up torquing the anterior capsule.

 

Posterior Hip Stretch

The posterior hip stretch feels great on the glutes and hits the posterior hip area, which is often tight.  Many people feel like the can get into a hip hinge much better after this drill.

 

Figure 4 Stretch

The posterior hip is a complicated area of muscles, I often pair the figure 4 stretch with the posterior hip stretch above to get different areas.  For me, I simple go by the feedback from my client on what feels more effective for them.

 

Spiderman

The Spiderman hip mobility drill is likely the most advanced of this list, which is why I have it last.  This is something I don’t always perform right away, but is a goal of mine to integrate with everyone eventually.  This requires more hip mobility that the others, so acts as a nice progression to put these all together.

 

How to Get Started with Hip Mobility Drills?

So wondering how to get started?  Start with the quadruped rockbacks and hip flexor stretch.  Those two are very foundational and will be the most impactful for most people.  Once you get those down, progress to the posterior hip stretch and figure 4 to hit more of the posterior aspect of the hip.  Lastly, progress to the Spiderman drill.

I honestly don’t think you need much more than that, and if you seek to get too aggressive with hip mobility drills, you often make things worse.

 

 

Hip Variations and Why My Squat Isn’t Your Squat

Today’s article is an AMAZING guest post from my friend Dean Somerset.  I’ve been talking a lot lately about how hip anatomy should change your mechanics and why exercises like squats should be individualized based on each person, but Dean blows this topic out of the water with this article.  If you love this stuff as much as I, check out the link at the bottom for Dean and Tony Gentilcore’s new program, The Complete Shoulder & Hip Blueprint.  This is just the tip of the iceberg of what is covered in the program.

 

Hip Variations and Why My Squat Isn’t Your Squat

In a recent workshop, I had a group of 50 fit and active fitness professionals and asked them all to do their best bodyweight squat with a position that felt good, didn’t produce pain, and was as deep as they could manage. As you can imagine, looking around the room produced 50 different squats. Some were wide, narrow, deep, high, turned out feet or some variation all of the above.

Did these differences mean there was a standard everyone should aim for, and those who weren’t there had to try to improve their mobility or strength or balance in that position? Maybe, but there’s probably a bunch of other reasons as to why 50 people have 50 different squats.

A standard requirement for powerlifting is to squat to a depth that involves having the crease of the hips below the vertical position of the knee. That’s probably the only known requirement for squat depth out there. The universal recommendation of “ass to grass” depth being the best thing since sliced bread may sound nice on paper (or in Instagram videos or Youtube segments), but it might be something that’s relatively difficult for some people to achieve, and for others it could be downright impossible, regardless of how much mobility work or soft tissue attacks they go through. The benefits of a deep squat seem to only be reserved for those who have the ability to express those benefits by accessing that range of motion without some other compensatory issue.

Let’s just consider simple stuff like anthropometric differences between individuals. Someone who is taller will have a bigger range of motion to go through to hit a parallel position than someone who is shorter, and someone with longer femurs in relation to their torso length will have a harder time maintaining balance over their base of support compared to someone who has shorter femurs. A long femur could be any femur that comprises more than 26% of an individual’s’ total height. So someone who is tall and long femured will have trouble getting down to or below parallel due to simply having the limb lengths to allow the bar to stay over the base of support during the squat motion without losing balance one way or the other.

Not as commonly known is the degree of retroversion or anteversion the femoral necks can make. The shaft of the femur doesn’t just always go straight up and insert into the pelvis with a solid 90 degree alignment. On occasion the neck can be angled forward (femoral head is anterior to the shaft) in a position known as anteversion, or angled backward (femoral head is posterior to the shaft) in a position known as retroversion. Zalawadia et al (2010) showed the variances in femoral neck angles could be as much as 24 degrees between samples, which can be a huge difference when it comes to the ability to move a joint through a range of motion.

hip variations squat

The acetabulum could itself be in a position of anteversion or retroversion, and this difference itself could be more than 30 degrees. This means the same shaped acetabulum would give someone who has the most anteverted acetabulum 30 extra degrees of flexion than someone who had the most retroverted acetabulum, but would give them 30 degrees more extension than the anteverted hips.

There’s also the differences in centre-edge angles, or the angle made from the center of the femoral head through the vertical axis and the outer edge of the lateral acetabulum. Laborie et al (2012) measured this angle in 2038 19 year old Norwegians, and found that it ranged from 20.8 degrees to 45.0 degrees with a mean of 32 in males and 31 in females.

hip anatomy squat

Now to throw even another monkey wrench into the problem, there’s the simple fact that your left and right hips can be at different angles from each other! Zalawadia (same guy as before) showed that the angle of anteversion or retroversion of the femur could be significantly different from left to right, sometimes more than 20 degrees worth of difference.

squat anatomy

All of this can have a direct effect on their available range of motion. You can’t easily mobilize bone into bone and create a new range from that interaction, so if one person has hips where the bony alignment and shape doesn’t causes earlier contact in a specific direction compared to someone else who has a different shaped and aligned hip structure, it’s going to show in their overall mobility.

Elson and Aspinal (2008) showed that there can be a massive variation in both passive and active movements of the hip across age ranges and gender differences. They showed a true hip flexion range of between 80-140 degrees (mean of 25)with no lumbar rounding, a strict active straight leg raise with no lumbar rounding range of 30-90 degrees (mean of 70), and active leg raise with lumbar rounding of 50-90 degrees (mean of 86). This means someone in their sample managed to get 60 degrees more hip flexion than someone else in the sample. There was also a range of between 5-40 degrees of hip extension too, and across an age range from 19-89 years old, that’s a notable difference, especially if you work in general populations where everyone walks into the gym and over to the squat rack.

D’Lima et al (2000) found that hip flexion ROM could be as low as 75 degrees with 0 degrees of both acetabular anteversion or femoral anteversion, but as high as 155 degrees, with 30 degrees of both acetabular anteversion or femoral anteversion. An increase in femoral neck diameter of as little as 2mm was able to reduce hip flexion range by 1.5 – 8.5 degrees, depending on the direction of motion.

So essentially, your ability to achieve a specific range of motion is as much up to your unique articular geometry as it is to your strength and mobility. In many cases, it’s entirely independent of your strength and mobility, and no amount of stretching, mashing, crushing, or stripping will improve it. In many cases, trying to achieve that range of motion that’s outside of your joints ability to achieve will cause less desirable results, like bone to bone contact and irritation (potentially leading to things like femoroacetabular impingement), or compensatory movement from other joints like the SI joint or lumbar spine.

So with as much involved with the structure as I’ve presented here, and how impactful it can be to the end result of total motion of the hips during exercises, how can you determine whether it’s a limiting factor or not? If you happen to have X-ray vision you can do a good job of this, but you’d likely be charging a heck of a lot more money than you are right now for your services.

What we have available is a detailed assessment that focuses on a combination of features.

Involving a passive assessment to assume a theoretically available range of motion and shape of movement capability, an active assessment to see how they can use that range and whether there’s a difference between the two, and then determining strength or motor pattern aptitudes for the movements can be the best tools we have at our disposal, and then coaching the movement until their face sweats blood.

By using multiple approaches to assessing available and usable range of motion, you can get multiple views into a room that can paint a broader picture of what’s available. If the person has the ability to easily let their knee drop to their chest on your treatment table and squat to the floor, there’s obviously no restriction to their range of motion. If they have trouble breaking 90 degrees, even if they move wider through abduction and external rotation, their active range is limited through multiple tests, and their ability to show you a squat shows a lumbar flexion at around 90 degrees of hip flexion as well, the odds of you mobilizing that tissue to produce a significantly bigger range may be limited.

 

Passive Assessment of Hip Structure

 

Active Hip Flexion Capability Against Gravity

 

Active Rockback for Hip Flexion without Gravity Influence

 

Supported Squat Assessment


If all of these tests show a specific limitation to the range of motion consistently across all situations, it could be assumed that there would be a structural limitation versus passive insufficiency, weakness or other considerations. If active testing is limited but passive or supported assessments are fine, there could be a strength or motor pattern limitation holding the movement back.

Now sure, there’s a lot of brakes that could be restricting that range, from things like scar tissue to guarding and some soft tissue restrictions. Doing some work to help reduce that can help improve overall range of motion, but in some cases will be limited to just minimal gains. In some situations, trainers or therapists may work on improving range of motion for weeks or months and see no improvement, and in many cases the deck would be stacked against them seeing any improvement at all.

customized squat pattern

As mentioned earlier, there could also be an asymmetric structural element at play, which may necessitate an asymmetric setup for the movement where one foot is either turned out more, held slightly forward or back, or even turned into something like a one-heel elevated squat. The difference between this and a lunge is merely how far back that elevated foot is relative to the other foot, but again it’s taking advantage of potential asymmetries in structure and allowing an asymmetric set up to be more congruent with the individual.

Another way to think of it is if we have a potentially asymmetric structure yet force a symmetric set up on it, we may be creating an imbalance or compensative element in our training versus preventing it.

The Complete Hip and Shoulder Blueprint

complere shoulder and hip blueprintThese and many more elements are discussed in Complete Shoulder & Hip Blueprint, a new continuing education resource from Tony Gentilcore and Dean Somerset. This digital video product is 11 hours of lecture and hands on where they break down pertinent anatomy, considerations for program design, and delve into assessments, corrective options, and training considerations for these 2 highly involved complex structures.

The series is currently on a launch sale pricing, and the entire package is available for only $137 versus the regular pricing of $177. The sale is on from November 1 through 5, so act quickly to get your copy.  Click below to learn more or check out the below preview video!

large-learn-more

 

large-learn-more

Do Tight Hip Flexors Correlate to Glute Weakness?

Lower crossed syndrome, as originally described by Vladimir Janda several decades ago, is commonly sited to describe the muscle imbalances observed with anterior pelvic tilt posture.

Janda Assessment and Treatment of Muscle ImbalanceJanda described lower crossed syndrome to explain how certain muscle groups in the lumbopelvic area get tight, while the antagonists get weak or inhibited.  Or, as Phil Page describes in his book overviewing the Janda Approach, “Weakness from from muscle imbalances results from reciprocal inhibition of the tight antagonist.”  Assessment and Treatment of Muscle Imbalances: The Janda Approach is an excellent book that I recommend if you’re new to the concepts.

When you look at a drawing of this concept, you can see how it starts to make sense.  Tightness in the hip flexors and low back are associated with weakness of abdominals and glutes.

Lower Cross Syndrome

 

I realize this is a very two dimensional approach and probably not completely accurate in it’s presentation, however it not only seems to make biomechanical sense, it also correlates to what I see at Champion nearly daily.

Yet despite the common acceptance of these imbalance patterns, there really isn’t much research out there looking at these correlations.

 

Do Tight Hip Flexors Correlate to Glute Weakness?

Do Tight Hip Flexors Correlate to Glute WeaknessA recent study was publish in the International Journal of Sports Physical Therapy looking at the EMG activity between the two-hand and one-hand kettlebell swing.  While I enjoyed the article and comparision of the two KB swing variations, the authors had one other finding that peaked my interest even more.  And if you just read the title of the paper, you would have never seen it!

In the paper, the authors not only measured glute EMG activity during the kettlebell swing, but they also measure hip flexor mobility using a modified Thomas Test.  The authors found moderate correlations between hip flexor tightness and glute EMG activity.

The tighter your hip flexors, the less EMG was observed in the glutes during the kettlebell swing. [Click to Tweet]

While this has been theorized since Janda first described in the 1980’s, to my knowledge this is the first study that has shown this correlation during an exercise.

 

Implications

It’s often the little findings of study that help add to our body of knowledge.  This simple study showed us that there does appear to be a correlated between your hip flexor mobility and EMG activity of the glutes.  There are a few implications that you can take from this study:

  • Both two-hand and one-hand kettlebell swings are great exercises to strengthen the glutes
  • However, perhaps we need to assure people have adequate hip flexor mobility prior to starting.  I know at Champion we feel this way and spend time assuring people have the right mobility and ability to hip hinge before starting to train the kettlebell swing
  • If trying to strengthen the glutes, it appears that you may also want focus on hip flexor mobility, as is often recommended.  While a common recommendation, I bet many people skip this step.
  • This all makes your strategy to work with people with anterior pelvic tilt even more important.  Here is how I work with anterior pelvic tilt.

So yes, it does appear that hip flexor mobility correlates to glute activity and should be considering when designing programs.

 

A Simple and Easy Hip Mobility Drill for Low Back Pain

Low back pain continues to be one of the most common health complaints that limit people, especially as we age.  Rehabilitation of low back pain has transition from simply focusing on reducing the local pain to emphasizing a biomechanical approach of how other areas of the body, such as the hips, impact low back pain.

Essentially we have done a great job moving away from simply treating the symptoms and working towards finding the movement impairment leading to the low back pain.  Sure, using something like a TENS device may have a role to neuromodulate pain, but it is now common knowledge that the improvements seen are transient at best and not addressing the real dysfunction.

One area that has received a lot of attention, and rightfully so, is looking at limitations in hip mobility as a cause of low back pain.  Much of the research to date has focused on looking at the loss of hip external rotation and internal rotation mobility.  In fact, I have an older article on the correlation between hip mobility and low back pain.

I can say that my own ability to help people with low back pain has greatly improved as I’ve learned to focus on hip mobility over the years.

 

hip extension mobility low back painHip Mobility and Low Back Pain

A new study was recently published in the International Journal of Sports Physical Therapy that adds to our understanding of the influence of hip mobility on low back pain.  In the current study, the authors evaluated hip external rotation, internal rotation, and extension mobility in two groups of individuals, those with and without nonspecific low back pain.

While using a Thomas test to assess hip extension, the authors found the follow:

  • Hip extension in those with low back pain = -4.16 degrees
  • Hip extension in those without low back pain = 6.78 degrees

That’s a total loss of 10 degrees of hip extension in those with low back pain.

 

A Loss of Hip Extension Correlates to Low Back Pain

So now in addition to rotational loss of hip rotational mobility, it has been shown that a loss of hip extension correlates to low back pain.  To me, this has always been something I have focused on and makes perfect sense, especially as we age.

The vast majority of our society sits for the majority of the day and becomes less and less active as they age.  Among many things, this results in tight hip flexors and an anterior pelvic tilt posture.

Putting recreational activities like sports and running aside, this anterior pelvic tilt posture with tight hip flexors causes a loss of hip extension mobility and the low back tends to take the load but hyperextending.  This happens while simply walking and in a standing posture.

Think about the results above, people with low back pain have negative hip extension, meaning they can’t even extend to neutral!

As we all know, the human body is amazing and will compensate.  Hips don’t extend?  No problem, we’ll extend our spine more.

So a pretty easy step to take to reduce back pain is to work on hip extension mobility.

One drill that almost everyone that trains at Champion PT and Performance gets is what I named the “True Hip Flexor Stretch.”  I’ve talked about it at length in past articles, but I am a believer that most of our hip flexor stretches commonly performed in the fitness world are disadvantageous and not actually stretching what we want to stretch.

The True Hip Flexor Stretch is a great place to start to work on hip extension mobility:

As you can see (and feel), this gets a great stretch on your hip flexors without causing any compensatory low back extension.  And by focusing on posterior pelvic tilt, we gear this towards those with a lot of anterior pelvic tilt.

 

I really believe that the “True Hip Flexor Stretch” is one of the most important stretches you should be performing.  [Click to Tweet]

 

Next, Focus on Reducing Anterior Pelvic Tilt in People with Low Back Pain

Updated Strategies on Anterior Pelvic TiltI’m not a big believer that static posture is the most important thing we should all be focusing on when outline our treatment and fitness programs, but it’s a start.  Someone in an anterior pelvic tilt static posture isn’t always evil, and can be the result of many things such as poor core control, poor mobility, and even excessive weight.  I tend to care more about how well people move.

But based on the current evidence, it’s a great place to start.

Once you’ve started to gain some hip mobility, there is a ton more work to do.  We also have to work on glute and core control, among other things.  If you’re interested in learning more, I have a hugely popular Inner Circle webinar on my treatment strategies for anterior pelvic tilt that goes into detail on what I recommend:

 

In summary, we now have a nice study that shows people with low back pain have 10 degrees less hip extension that those without.  This makes sense, and focusing on hip extension should be one of the key components of any low back pain program.

 

 

Should We Stop Blaming the Glutes for Everything?

Today’s guest post comes from John Snyder, PT, DPT, CSCS.  John, who is a physical therapist in Pittsburgh, has a blog that has been honored as the “Best Student Blog” by Therapydia the past two years.  He’s a good writer and has many great thoughts on his website.  John discusses some of our common beliefs in regard to the role of the proximal hip on knee pain.  I’ll add some comments at the end as well, so be sure to read the whole article and my notes at the end.  Thanks John!

 

Should We Stop Blaming the Glutes for Everything?

should we stop blaming the glutes

Anterior cruciate ligament (ACL) rupture1,2 and patellofemoral pain syndrome (PFPS)3,4,5 are two of the most common lower extremity complaints that physicians or physical therapists will encounter. In addition to the high incidence of these pathologies, with regards to ACL injury, very high ipsilateral re-injury and contralateral injury have also been reported6,7,8.

With the importance of treating and/or preventing these injuries, several researchers have taken it upon themselves to determine what movement patterns predispose athletes to developing these conditions. This research indicates that greater knee abduction moments9,10, peak hip internal rotation11, and hip adduction motion12 are risk factors for PFPS development. Whereas, for ACL injury, Hewett and colleagues13 conducted a prospective cohort study identifying increased knee abduction angle at landing as predictive of injury status with 73% specificity and 78% sensitivity. Furthermore, as the risk factors for developing both disorders are eerily similar, Myer et al performed a similar prospective cohort study finding that athletes demonstrating >25 Nm of knee abduction load during landing are at increased risk for both PFPS and ACL injury14.

 

Does Weak Hip Strength Correlate to Knee Pain?

With a fairly robust amount of research supporting a hip etiology in the development of these injuries, it would make sense that weakness of the hip musculature would also be a risk factor, right?

A recent systematic review found very conflicting findings on the topic. With regards to cross-sectional research, the findings were very favorable with moderate level evidence indicating lower isometric hip abduction strength with a small and lower hip extension strength with a small effect size (ES)15. Additionally, there was a trend toward lower isometric hip external rotation and moderate evidence indicates lower eccentric hip external rotation strength with a medium ES in individuals with PFPS15. Unfortunately, the often more influential prospective evidence told a different story. Moderate-to-strong evidence from three high quality studies found no association between lower isometric strength of the hip abductors, extensors, external rotators, or internal rotators and the risk of developing PFPS15. The findings of this systematic review indicated hip weakness might be a potential consequence of PFPS, rather than the cause. This may be due to disuse or fear avoidance behaviors secondary to the presence of anterior knee pain.

 

Does Hip Strengthening Improve Hip Biomechanics?

Regardless of its place as a cause or consequence, hip strengthening has proved beneficial in patients with both PFPS16,17,18 and following ACL Reconstruction19, but does it actually help to change the faulty movement patterns?

Gluteal strengthening can cause several favorable outcomes, from improved quality of life to decreased pain, unfortunately however marked changes in biomechanics is not one of the benefits. Ferber and colleagues20 performed a cohort study analyzing the impact of proximal muscle strengthening on lower extremity biomechanics and found no significant effect on two dimensional peak knee abduction angle. In slight contrast however, Earl and Hoch21 found a reduction in peak internal knee abduction moment following a rehabilitation program including proximal strengthening, but no significant change in knee abduction range of motion was found. It should be noted that this study included strengthening of all proximal musculature and balance training, so it is hard to conclude that the results were due to the strengthening program and not the other components.

 

Does Glute Endurance Influence Hip Biomechanics?

All this being said, it is possible that gluteal endurance may be more influential than strength itself, so it would make sense that following isolated fatigue of this musculature, lower extremity movement patterns would deteriorate.

Once again, this belief is in contrast to the available evidence. While fatigue itself most definitely has an impact on lower extremity quality of movement, isolated fatigue of the gluteal musculature tells a different story. Following a hip abductor fatigue protocol, patients only demonstrated less than a one degree increase in hip-abduction angle at initial contact and knee-abduction angle at 60 milliseconds after contact during single-leg landings22. In agreement with these findings, Geiser and colleagues performed a similar hip abductor fatigue protocol and found very small alterations in frontal plane knee mechanics, which would likely have very little impact on injury risk23.

 

Can We Really Blame the Glutes?

The biomechanical explanation for why weakness or motor control deficits in the gluteal musculature SHOULD cause diminished movement quality makes complete sense, but unfortunately, the evidence at this time does not agree.

While the evidence itself does not allow the gluteal musculature to shoulder all of the blame, this does not mean we should abandon addressing these deficits in our patients. As previously stated, posterolateral hip strengthening has multiple benefits, but it is not the end-all-be-all for rehabilitation or injury prevention of lower extremity conditions. Proximal strength deficits should be assessed through validated functional testing in order to see its actual impact on lower extremity biomechanics on a patient-by-patient basis. Following this assessment, interventions should be focused on improving proximal stability, movement re-education, proprioception, fear avoidance beliefs, graded exposure, and the patient’s own values, beliefs, and expectations.

 

John SnyderJohn Snyder, PT, DPT, CSCS received his Doctor of Physical Therapy degree from the University of Pittsburgh in 2014. He created and frequently contributes to SnyderPhysicalTherapy.com (Formerly OrthopedicManualPT.com), which is a blog devoted to evidence-based management of orthopedic conditions.  

 

Mike’s Thoughts

John provides an excellent review of many common beliefs in regard to the influence of the hip on knee pain.  While it is easy to draw immediate conclusions from the result of one study or meta-analysis, one must be careful with how they interpret date.

I think “anterior knee pain,” or even PFPS, is just too broad of a term to design accurate research studies.  It’s going to be hard to find prospective correlations with such vague terminology.  Think of it as watering down the results.  Including a large sample of people, including men, women, and adolescents and attempting to correlate findings to “anterior knee pain” is a daunting task.

Imagine if we followed a group of adolescents from one school system for several years.  Variations in gender, sport participation, recreational activity, sedentary level, and many more factors would all have to be considered.  Imagine comparing the development of knee pain in a 13 year old sedentary female that decided she wanted to run cross country for the first time with an 18 year old male basketball player that is playing in 3 leagues simultaneously.  Two different types of subjects with different activities and injury mechanisms.  But, these two would be grouped together with “anterior knee pain.”

What do we currently know?  We know hip weakness is present in people with PFPS and strengthening the hips reduces symptoms.  As rehabilitation specialists, that is great, we have a plan.  I’m not sure we can definitely say that hip weakness will cause knee pain, but I’m also not sure we can say it won’t.  Designing a prospective study to determine may never happen, there are just too many variables to control.

John does a great job presenting studies that require us to keep an open mind.  I’m not sure we can make definitive statements from these results, but realize that there are likely many more variables involved with the development of knee pain.  Hip strength and biomechanics may just be some of them.  Thanks for sharing John and helping us to remember that it’s not always the glutes to blame!

 

 

Hip Rotator Cuff

Hip Rotator CuffThe latest Inner Circle webinar recording on the Hip Rotator Cuff is now available.

Hip Rotator Cuff

This month’s Inner Circle webinar on the rotator cuff of the hip was great.  We discussed how our knowledge of the hip has continued to increase over the last decade and has resulted in a much better understanding of how the hip is involved in the mechanics of the lower body and stabilization in multiple planes of motion.  We then broke down the hip musculature as either prime movers or prime stabilizers, and discussed how different positions and exercises impact both of these different muscles groups.

If this sounds familiar, it is, we use the analogy of the shoulder to show the similarities between the hip and the shoulder.

To access the webinar, please be sure you are logged in and are a member 0f the Inner Circle program.