The One Thing You Must Do When Evaluating for an ACL Injury

Anterior cruciate ligament (ACL) injuries are common. When evaluating the ACL, special tests like a Lachman Test or Anterior Drawer have been shown to have great reliability and validity.

However, there is one main reason why you may get a false positive for an ACL injury of the knee that is often overlooked – you actually injured your posterior cruciate ligament (PCL)!

I know, it seems backwards, but watch this quick video for my explanation!

Learn How We Evaluate and Treat the Knee

Product template on multiple devices

For those interested in learning more about how Lenny and I evaluate and treat the knee, we have an amazingly comprehensive course that covers everything you need to know to master the knee.  Our detailed examination process, all our treatment progressions, and detailed information on nonoperative and postoperative treatment of ACL, patellofemoral, meniscus, articular cartilage, osteoarthritis injuries, and so much more.

Can PCL Injuries Be Successfully Treated Without Surgery?

Champion Physical Therapy and Performance

My latest article is now up on the new Champion Physical Therapy and Performance blog!  I discuss a recent research study that looked at the outcomes of subjects with PCL deficient knees that were followed for up to 21 years.

Pretty interesting stuff that shows the efficacy of our programs!  However, as you’ll read, we can do as much harm as good when designing exercises for people with PCL injuries.

Read the article here and be sure to sign up to receive all the updates from the Champion blog, there is plenty more coming from the Champion team!


I have also announced my latest Inner Circle webinar will overview my manual therapy system.  I’ve been really trying to create systems for all aspects of what I do as we build out Champion Physical Therapy and Performance.

Last month, I talked about how I design functional rehabilitation programs.  This month is devoted to manual therapy.  In this webinar I’ll discuss my system to performing manual therapy, including the specific order and techniques that I perform.  This system can be used for any issue depending on the needs of the patient.

I like to take a systematic approach for several reasons:

  1. Assures consistency between sessions
  2. Assures consistency between therapists
  3. Creates reliable and predictable results
Join me Wednesday August 27th at 8:00 PM EST for the live webinar or be sure to catch the recorded when it is posted.

Do ACL Hamstring Grafts Fail More than Patellar Tendon Grafts?

This month’s issue of the American Journal of Sports Medicine included two studies comparing the revision rates of ACL reconstruction between hamstring grafts and patellar tendon grafts of over 25,000 people.  The overall number of people studied between the two groups was really compelling to me as a sample size this big is certainly worth discussing.

In recent years the graft choice for ACL reconstruction has been slowly shifting towards favoring hamstring grafts rather than patellar tendon grafts.  Recent reports have noted 84% of ACL reconstructions in Denmark and Sweden use hamstring grafts, 60% in Norway, and now are even becoming more popular in the US with 44% of ACL reconstructions using a hamstring graft compared to 42% using a patellar tendon graft.

Many research papers have been published showing that both grafts result in very good stability of the knee with excellent subjective outcome scores.  The major complaint of patellar tendon grafts is the increased risk of issues after surgery, such as patellofemoral pain and loss of motion.  Despite the reports of good stability and subjective outcomes, revision surgery is probably a more important factor to consider.

Do ACL Hamstring Grafts Fail More than Patellar Tendon Grafts?

The first study reviewed the nationwide Danish Knee Ligament Reconstruction Registry, which included 13,647 people undergoing ACL reconstruction between 2005 and 2011.

The revision rates for hamstring tendon grafts were 0.65% at 1 year after surgery, and 4.45% at 5 years after surgery.  The revision rates for patellar tendon grafts were 0.16% at 1 year after surgery, and 3.03% at 5 years after surgery.

Essentially, hamstring grafts had a 4x greater risk of revision in year one and 1.5x at 5 years following ACL reconstruction.

ACL reconstruction revision rates

The second study reviewed the nationwide Norwegian Cruciate Ligament Registry, which included 12,643 people undergoing ACL reconstruction between 2004 and 2012.

The revision rates for hamstring tendon grafts were 5.1% at 5 years after surgery, and 2.1% for patellar tendon grafts.  This study also looked at different age groups and found this increased rate to be consistent across all age group.s  However, the younger group (age 15-19) had a 9.5 revision rate at 5 years using the hamstring graft in comparison to 3.5% using a patellar tendon graft.

Together, there was a 2x greater risk of revision overall when using the hamstring graft, but closer to 3x greater risk for younger people.

ACL hamstring patellar tendon graft

Both Grafts are Great Options for ACL Reconstruction

When we really assess the numbers, it is clear that both graft options are great choices with low revision rates.  Even though we are comparing the two, realistically the revision rates after ACL reconstruction are low for both hamstring grafts and patellar tendon grafts.  There are many factors that go into deciding which graft to use.  Also realize this does not apply to skeletally immature patients.  This revision information is just a piece of the puzzle.

The patellar tendon graft has less failure rate and has been reported to heal faster in animal models due to the bone-to-tendon interface.  While this is true there are also reports of increased anterior knee pain and loss of motion.  I have discussed this in the past, but I really do believe that many of the issues with patellar tendon grafts after surgery are minimized or eliminated with proper physical therapy (in addition to excellent patient compliance).  This is especially true if these factors are the primary emphasis of the early phases of ACL rehabilitation.

SEE ALSO: 6 Keys to the Early Phases of Rehabilitation Following ACL Reconstruction Surgery

That all being said, hamstring grafts have also been shown to result in less strength of the hamstrings after surgery.  Considering the role of the hamstring to assist the ACL in control anterior tibial translation, this has to be considered when reviewing the higher ACL reconstruction revision rate when using hamstring grafts.  Perhaps it really has nothing to do with the graft itself and more to do with the hamstring strength.

Regardless, the revision rate following ACL reconstruction is higher when using a hamstring graft than when using a patellar tendon graft.

Did We Really Discover a New Ligament in the Knee?

This week’s Stuff You Should Read is about the “new” discovery of the anterolateral ligament of the knee.

Inner Circle and Updates

My next live Inner Circle will be an evening live Q&A which is always fun, ask me anything!  This was a big hit last year so I expect it to be even better this year.  It will be Monday December 16th at 8:30 PM EST.  Looking forward to this one. has a bunch of awesome new webinars coming up over the next few months.  Michael Mullin had part 1 of a webinar on Integrating Postural Restoration Institute Concepts into Training, part is coming in January.  This was a great webinar and a great intro into the PRI concepts!  This month, David Weinstock, the developer of Neurokinetic Therapy, discusses some of the principles of NKT.


The Discovery of the “New” Knee Ligament – The Anterolateral Knee Ligament

anterolateral knee ligamentFor this week’s stuff you should read, I thought I would piece together a few articles that go over the press received over the “discovery” of the “new” anterolateral ligament of the knee.  Notice all my “quotes!”  Here is a link to one of the many sensationalized articles from the media on this new ligament:

Pretty exciting title, right?!  The media cracks me up.  Sensationalizing everything.  The news report is in reference to a paper published in the Journal of Anatomy regarding the anterolateral ligament.  Here is the abstract of the paper, which ironically, starts with the phrase “In 1879, the French surgeon Segond described the existence of a ‘pearly, resistant, fibrous band’ at the anterolateral aspect of the human knee.”

The website io9 did a good job highlighting these facts in their article:

But Dr. LaPrade from the Steadman Clinic did an even better job talking about everything you want to know about this “new” ligament!

Here is a video of the ligament:

So, nice articles and video, but no, not a new ligament.

6 Keys to the Early Phases of Rehabilitation Following ACL Reconstruction Surgery

Rehabilitation following ACL reconstruction surgery has evolved significantly over the last 25 years.  We have progressed from casting the knee to allowing immediate motion and weight bearing in just a short amount of time.  As our understanding of rehabilitation concepts continue to evolve, our focus has shifted towards functional exercise and rehabilitation progressions, which is integral to maximize results following ACL reconstruction surgery.

We are now seeing professional athletes absolutely dominate their postoperative rehabilitation.  Adrian Peterson is now going to be the poster-boy for return to sports after ACL surgery after tearing up the league and winning NFL MVP just months after having ACL reconstruction surgery.  While, AP is definitely the exception, not the rule, the postoperative rehabilitation is a huge factor in determining how well people recover from surgery.

While everyone wants to talk about advanced exercises and return to sport, it is probably infinitely more important to assure that the early phases of rehabilitation go well to avoid complications and allow more advanced drills down the road.  If the early phases of ACL rehab go poorly, you will surely be behind for the duration of your rehab.

On that note, I wanted to discuss the 6 keys to the early phases of rehabilitation following ACL reconstruction surgery.  Master these basics and the advanced phases get easy.

Diminish Pain and Inflammation

early rehabilitation following acl reconstruction surgeryThe first key to ACL Rehabilitation is simple, diminish the pain and inflammation associated with the surgery.  While this is a no-brainer, it is worth reviewing why this is so important.  Really, the following list of keys to ACL rehabilitation are all going to be difficult to achieve without addressing the pain and swelling.  Here are just handful of important things to consider:

  • Pain and swelling has been shown in numerous studies to essentially shut down your muscles around your knee, specifically your quadriceps.  Even a small amount of fluid in the joint has been shown to decrease your ability to contract your quad.
  • Without a quad, it is hard to function, and you tend to walk around with a bent and stiff knee.
  • Pain and swelling will limit your range of motion progression.

So, as simple as this concept may be, diminishing pain and inflammation should be an area of focus initially after surgery.  Compression wraps, ice, intermittent compression machines, elevation, ankle pumps, electrical stimulation, and not pushing through too much activity can all help.

My biggest advice to patients after surgery is that you can’t ice too much.

Restore Full Knee Extension Motion

Loss of knee extensionRestoring full knee extension range of motion could be the #1 key to rehabilitation following ACL reconstruction surgery, however I chose to list it second here because addressing pain and swelling has implications for everything discussed in this article.  Really, though, my focus is almost always directed towards restoring full knee extension as soon as possible.  One of the more common complications following ACL surgery is loss of motion, with loss of extension being more troublesome than flexion.

When pain and swelling is present, it is just more comfortable to hold your knee in a slightly bent position.  Keep it this way too long and you run the risk of developing scar tissue, or arthrofibrosis.  Restoring knee extension immediately after surgery is so important, because once it gets tight, it’s often hard to get your motion back.  I’d much rather focus on this initially and slowly restore motion than get too tight and then have to aggressively attempt to improve motion.  That is never preferred.

Loss of full knee extension does not allow the knee to function properly, even if just a small loss of motion.  Plus, studies have shown loss of motion to be one of the most important factors associated with the development of arthritis after ACL surgery.

Luckily, with proper rehabilitation, loss of motion can be avoided.

In addition to my range of motion, soft tissue mobilization, and manual therapy techniques, I always instruct patients to perform a lot of range of motion and stretching exercises at home, essentially once an hour.  I like to show them hamstring stretches and calf towel stretches.  I don’t perform these stretches to really enhance hamstring and calf flexibility.  I perform them and instruct the patient to also work on knee extension at the same time.  So the focus is essentially knee extension.

Knee Extension Stretch ACL Reconstruction

Towel Knee Extension Stretch ACL Surgery

If loss of motion starts to become a problem, I don’t hesitate to start to introduce low-load long-duration stretching.  My goal is full knee extension by 1 week after surgery.  Biomechanical studies have shown that the stress of the ACL graft when stretching into extension is below the forces seen during common functional activities, so there is no need to avoid this motion.

This is such an important concept, that you may want to review my past article dedicated to restoring knee extension range of motion.

Gradually Progress Knee Flexion Motion

Knee Flexion Range of Motion ACL RehabilitationAlthough loss of knee flexion doesn’t tend to be as common as knee extension, it does happen and you don’t want to neglect working on flexion.  There is often a see saw between flexion and extension.  The more you work on one, the more you tend to get stiff in the other direction.  This is reduced by working on frequent bouts of gentle but progressive range of motion.

I also like to empower the patient to also work on restoring knee flexion, both by stretching as well as through functional motions like mini-squats and eventually lunges.  When the patient can control their range of motion progression, their perceived threat is reduced and motion often comes back easier.

Knee flexion is restored more gradually, with about 90 degrees achieved at 1 week and full knee flexion gradually advanced and achieved by week 4-6.

Maintain Patellar Mobility

Patellar Mobilization ACL RehabSometimes one of the reasons that range of motion is reduced is because patellar mobility is lost.  Full patella mobility is required for knee flexion and extension.  As the knee is painful, swollen, and difficult to move, scar tissue can form and limit patella mobility.  This is especially true if a patellar tendon graft is used for the ACL reconstruction surgery.  If patellar mobility is neglected, the chances of loosing range of motion goes up significantly.

Soft tissue mobilization around the knee and patellar mobilization is performed immediately after surgery.  I also like to instruct patients on how to do this themselves and add it to their homework.

Restore Volitional Quad Control

NMES quad ACLAs previously mentioned, there is a reflexive inhibition of muscle control around the knee after surgery due to the pain, inflammation, and swelling.  In addition to address these factors, there are techniques that can be performed to help restore volitional control of the quadriceps muscle.

Lynn Snyder-Mackler, at the University of Delaware, has produced dozens of articles on the use of neuromuscular electrical stimulation (NMES) on the quad follow ACL surgery.  Essentially, NMES helps restore quad strength and function faster that just exercises without NMES.

Naturally NMES becomes an important component of the early phases of ACL rehabilitation.  I will superimpose most early quad exercises that we perform with NMES.  This includes quad sets, straight leg raises, and knee extension exercises.

An added benefit of all these quadriceps contractions is that this also helps restore knee extension range of motion.

Restore Independent Ambulation

Retrowalking ACL Rehabilitation

Now that we have addressed the pain and swelling, started to restore motion and patellar mobility, and can now turn on the quads, we put it all together to work on being able to walk without limitations or a limp.  If any of the previously mentioned areas of focus have not been addressed, independent ambulation is often going to be difficult, or at least impaired.

I usually have people weight bearing as tolerated around week 1, unless other structures were damaged or need to be protected.  We may continue to use the crutches for up to two weeks, however, I still want them to be able to walk and just use the crutches as assistance, rather than, well, a crutch…

I have found weight bearing exercises like weight shifts that focus on transferring your weight and locking out your knee can be helpful initially.  I also tend to use cone walking drills to help groove the pattern of shifting weight and transitioning to single leg stance.  I have also found backward walking while stepping over a cone to be helpful to rock the body back over the foot and assist with achieving knee extension.

Learn Exactly How We Evaluate and Treat the Knee

Those are my 6 keys to the early phases of rehabilitation following ACL reconstruction surgery.  I try to focus on each one of those keys during each session I have with a patient.  These 6 keys are so important, that I would rather increase my visits early in the rehab process to assure that these are all addressed, then try to conserve visits (per our insurance limitations).

Really, this is just the tip of the iceberg.

online knee seminarIn our online course at we discuss the many pathologies of the knee, including ACL reconstruction. We outline a progressive program that starts preoperative and goes until the athlete is ready to return to their sport.  If you are interested in learning are full approach, our course has a lot to offer. You’ll learning exactly how we evaluate and treat the knee and become an expert at knee rehabilitation.

Do Males and Females with Patellofemoral Pain Need to be Treated Differently?

Today’s guest post is an interesting topic by Heidi Mills from the Sports Injury Clinic in the UK, asking if we should be treating male and female patients with patellofemoral syndrome differently.  The basis of the post comes from a recent journal publication showing different running mechanics between gender.  I am a firm believer that each person should have an individualized program based on their specific biomechanics and examination, meaning that we WOULD treat them differently – not because of gender itself, but because of the biomechanical differences between the genders.

Are Mechanics Different between Male and Female Runners with Patellofemoral Pain

patellofemoral pain syndromeA recent article published recently in Medicine and Science in Sports and Exercise found that males with patellofemoral pain syndrome (PFPS) demonstrated different mechanics whilst running and performing a single leg squat, to females with the same pain condition. So this leads to the question “should we be treating men and women with the same condition, differently?”

The authors analysed the gait cycle and single leg squat movement in 18 female and 18 male runners with PFPS as well as 18 male runners without knee pain.  Results showed that men with PFPS ran and squatted with an increased knee adduction and external rotation than men without knee pain. Men with knee pain also demonstrated less hip adduction but more peak knee adduction that female runners with PFPS.

To simplify, in those men with knee pain, the knee joint falls in and rotates outwards more than in those without knee pain. In comparison with women who suffer knee pain, men’s thighs fell in less but the knee joint itself underwent more knee adduction (between the Tibia and Femur bones).

The authors concluded that these differences in mechanics between men and women warrant that PFPS treatments be gender specific.

Clinical Applications

Based on this information, should we be treating men and women differently?  Or is it more accurate to assess each individual as a separate entity regardless of their sex?

My personal opinion is that gender should not be a leading influence on treatment protocols. Each person should be evaluated independently to determine their specific movement patterns, muscle imbalances, injury history and sporting / training techniques and how these factors all combine to cause the pain in question. If this is all evaluated thoroughly then their gender is largely irrelevant. Treatment should focus on the findings of the assessment, not what research suggests may be causing the injury due to the patient’s sex alone.

Based on this study, it appears that there may be gender based biomechanical differences, but a proper evaluation must be performed for each patient.  We can use information like this to help streamline our diagnostic process.

Treatment Considerations

What can be taken from the results of this research is that hip adduction, knee adduction and knee external rotation may be contributing factors for patellofemoral pain sufferers. Treatment should be as individual as the patient and address their specific problems.

Hip clam exerciseThose with excess hip adduction on squats and other functional movement patterns should focus on strengthening the hip abductors such as gluteus medius. This can be achieved with a number of exercises, including the hip clam exercise.

Those with excess knee adduction and external rotation should be examined for overpronation at the sub-talar joint, which can result in these movements. Overpronation can be corrected with orthotics in day-to-day footwear and specialist running shoes.

Hamstring length tests should also be administered, as a tight Biceps Femoris muscle could increase external knee rotation. If this is the case then hamstring stretches and massage may be effective.

Other common factors include tight lateral Quads, IT bands and hip adductors which can be corrected with quad and groin stretches, self-myofascial release (using a foam roller, or similar) and sports massage.

A weakness or delayed firing of the vastus medialis oblique muscle can also be to blame as it fails to counteract the stronger pull of the tight lateral structures. Re-training of this muscle can be performed initially in a seated position (with 10° knee flexion) and progressed to a standing position.

These are all potential things that we could look at when evaluating and designing a program for someone with patellofemoral pain syndrome.

Learn more about patellofemoral pain syndrome from  Also, has a couple of great webinars on the Biomechanics of Patellofemoral Rehabilitation and Rehabilitation of Patellofemoral Pain.



About the Author

Heidi Mills BSc (Hons) GSR, is a Graduate Sports Rehabilitator, working in the UK for






Muscle Impairments in People with Knee Arthritis

Knee ArthritisA recent paper reviewing the muscle impairments associated with knee arthritis was published in Sports Health that I thought did a great job overviewing the current evidence on the subject.  Alnahdi, Zeni, and Snyder-Mackler discussed several factors associated with muscle impairments and knee arthritis.

I thought I would take this article and combine it with some of my thoughts and recommendations from the “The MOVE Consensus” published several years ago in Rheumatology.

There are a lot of muscle impairments associated with arthritis, proper knowledge of these impairments should allow us to develop more appropriate rehabilitation and fitness programs for individuals with knee arthritis.


Quadriceps Strength

Quadriceps weakness and muscle impairment is well documented in the literature.  Previously published papers report strength deficits of the quad ranging from 11-56% when compared to healthy controls.  Even more disparity exists when assessing eccentric strength, with deficits up to 76% in some reported publications.

This loss of strength, especially eccentrically, can have several implications on functional deficits.  Think about how many daily tasks involve concentric and eccentric control of the quad – standing from a chair, getting up off the ground, ascending and descending stairs – all of these activities (and more) become limited and contribute to overall dissatisfaction with arthritis patients.


Quadriceps Atrophy and Inhibition

There are two main factors associated with loss of quad strength in patients with knee arthritis – atrophy and muscle inhibition.  The quad has been shown to exhibit a 12% reduction in cross sectional area, representing atrophy, in patients with knee arthritis.  This atrophy obviously contributes to loss of strength, however inhibition of volitional control of the quadriceps has also been found.

Again, the exact mechanism is still unknown but some potential reasons that the altered ability to contract muscle probably relates to alterations in the afferent discharge of knee receptors.  This could be altered due to degenerative changes in joint structures, effusion, pain, inflammation, and laxity.


Other Lower Extremity Strength Deficits

The loss of quadriceps strength has been one of the most commonly cited impairments associated with knee arthritis.  Much emphasis has been placed on the quad, however impairment of other muscles have also been identified.  Several papers have been published that demonstrate that patients with knee arthritis also have a:

  • 4-38% reduction in hamstring strength
  • 16% reduction in hip extension strength
  • 26-40% reduction in hip flexion strength
  • 27-40% reduction in external rotation strength
  • 20-43% reduction in internal rotation strength
  • 22-24% reduction in abduction strength
  • 26% reduction in adduction strength

This are pretty big strength deficits that seem to occur in every plane of motion.  I would imagine this again represents a general level of deconditioning associated with the development of knee arthritis.  Muscular weakness and imbalances can have a significant impact on the ability to develop and withstand forces without compensatory movement patterns that increase force applied to the static joint structures.


Bilateral Deficits

Interestingly, strength deficits of the quad are not isolated to the involved leg.  The contralateral leg has also been shown to exhibit a 16-26% deficit in quad strength compared to healthy controls.  This deficit isn’t as severe as the involved side but shows that both extremities should be examined carefully.  Volitional control has also been shown to be reduced bilaterally, with greater inhibition on the involved knee.

The reason behind this contralateral deficit is not completely known, however it could again represent general weakness and deconditioning of the patient.


The Chicken or the Egg?

If strength and volitional control is so poor in several muscle groups bilaterally in patients with knee arthritis, the classic “which came first, the chicken or the egg” question comes to mind.  Does knee arthritis have such a dramatic impact on muscle impairments of the body or did these impairments precede, and potentially facilitate, the develop of knee arthritis?

There have some studies published that prospectively showed that weaker quadriceps strength was correlated to the development of knee arthritis.  This makes sense to me, as it certainly appears that several of the above factors could be related to general deconditioning of the patient.

Perhaps there is a reason that we see bilateral deficits with the involved knee showing greater impairments.   Maybe knee arthritis begins with a certain level of weakness, imbalances, and overall deconditioning.  Then overtime, this deconditioning is superimposed with inhibition from the natural consequences of knee arthritis, such as effusion, pain, and inflammation.


Clinical Implications

After reviewing this well written article, I think we can summarize the following:

  • Quadriceps strength is significantly impaired in subjects with knee arthritis
  • Both activation deficit and atrophy contribute to this weakness
  • Impairments also occur with the hamstrings and hip muscles
  • Strength and activation impairments are seen bilaterally, though the involved side shows greater impairments
  • Strength is a major determining factor for functional activities
  • Strength is predictive of the development of knee arthritis


The authors also included a summary of the recommendations from Roddy et al and The MOVE Consensus, which I would summarize as:

  • Both strengthening and aerobic exercise can reduce pain and improve function in patients with knee and hip osteoarthritis, with few contraindications, and are essential in the management of osteoarthritis.
  • Improvements in strength and proprioception gained from exercise may reduce the progression of osteoarthritis, although adherence is the principle predictor of long-term outcome from exercise.


In addition to these recommendations, I would suggest that we also include the following principles for the development of rehbailitation and fitness programs for people with arthritis:

  • Exercise and strengthening of the entire lower extremity, with emphasis on quadriceps strength and muscle imbalances, are an essential part of exercise programs for those with arthritis
  • Any deficits and imbalances of the hip should also be addressed
  • Exercise programs should be performed bilaterally, with emphasis on areas of greatest muscle impairment
  • Any exercise program should focus on strengthening, dynamic stabilization, and neuromuscular control of the lower extremities
  • Programs to should be developed to also enhance mobility in people with arthritis
  • Any deficits in muscle impairments should be correlated to altered movement dysfunctions
  • Programs should be developed that reduce specific muscle impairment, mobility concerns, and movement impairments


Hopefully we can all make a positive impact on people suffering from knee arthritis.   Understanding and improving some of the muscle impairments, strength deficits, and muscle imbalances associated with knee arthritis is imperative.  Keep these findings and recommendations in mind next time you are working with someone with knee arthritis, don’t just focus on pain control and quad strength, look at the bigger picture!





Assessing and Treating Loss of Knee Extension Range of Motion

Assessing and treating loss of knee extension range of motion is an important component of rehabilitation following any knee surgery.  We recently discussed how loss of knee extension range of motion may be one of the biggest factors associated with the development of osteoarthritis following ACL reconstruction.

The purpose of this article is to review some of the many methods of assessing and treating loss of knee extension range of motion to help maximize outcomes following knee surgery or injury while minimizing long term complications.

Assessing Loss of Knee Extension Range of Motion

There are many ways to treat loss of range of motion in the knee, however, proper assessment of range of motion is even more important.  A certain degree of hyperextension is normal, with studies citing a mean of 5 degrees of hyperextension in males and 6 degrees in females.  Simply restoring knee range of motion to an arbitrary 0 degrees is not advantageous.

The most important factor in assessing loss of knee extension range of motion is looking at the noninvolved knee.  As simple as this sounds, this can not be overlooked as you need to establish a baseline for what is “normal” in each patient or client.

The first thing I look at is simply grasping the 1st toe with one hand to lift the foot off the table.  My proximal hand can stabilize the distal femur.  This is a quick and dirty assessment but I always recommend quantifying the available range of motion.

To accurately measure knee extension range of motion, you will need to use a towel roll of various height to assure the knee is fully hyperextended before taking a goniometric measurement.

Knee Hyperextension

Other aspects of assessment that should be performed when dealing with loss of knee extension range of motion should include patellar mobility, tibiofemoral arthrokinematics, and soft tissue restrictions.  Patellar mobility is especially important after ACL reconstruction using a patellar tendon autograft.  Any restrictions in patellar mobility can have an obvious correlation with restricted knee extension.  Scarring of the patellar tendon can restrict superior glide of the patella and full knee extension.

These assessments will help guide our manual therapy approach to restoring normal arthrokinematics and range of motion of the knee.

Documenting Knee Range of Motion

I took a poll of a large group of students coming through my clinic in the past and found that there was great confusion regarding how we document hyperextension of the knee.   Is + or – when defining a numerical value?

Let’s say that someone has a contracture and is sitting in 10 degrees of flexion and is unable to straighten their knee.  That would be +10 degrees of flexion, thus has to be -10 degrees of extension.  They are on two ends of the spectrum.

Still, using a + or – can be potentially confusing, so I have long taught my students that we should document range of motion using the A-B-C method.  Other authors, such as Dr. Shelbourne, recommend this method as well.

  • If a person has 10 degrees of knee hyperextension and 130 degrees of knee flexion, it would be documented as 10-0-130.
  • If a person has a 10 degree contracture and loss of full knee extension with 130 degrees of knee flexion, it would be documented as 0-10-130.

Using the A-B-C method eliminates the potential for confusion while documenting.

Treating Loss of Knee Extension Range of Motion

There are several ways to improve knee extension range of motion, however, if a person is struggling with this motion I have found that self-stretches, low load long duration (LLLD) stretching, and range of motion devices can be superior to us cranking of a already cranky knee!  Allowing gentle, frequent, and progressive load to the knee is usually more tolerable for the person, especially those that are sore or guarded in their movements.

The intent of this article is to discuss some specific independent strategies to enhance knee extension range of motion.  Other skilled treatments should focus on patellar mobility, soft tissue mobility, and other aspects of manual therapy for the knee as needed.   However, patients will need to perform stretches at home to assure good outcomes.

Self Stretches for Knee Extension Range of Motion

Two of the first stretches that I give patients following surgery are simple self stretches for knee extension.  The basic version simple has the patient applying a stretch into extension by pushing their distal thigh.  The second and slightly more advanced version, has the patient press down on their distal thigh while using a towel around the foot to pull up and simultaneously stretch the hamstrings.

Knee Extension Stretch

Towel Knee Extension Stretch

Similar to how we assess knee extension range of motion, you will want to use some sort of wedge under the heel to assure that you are restoring full motion.

Low Load Long Duration Stretching for Knee Extension Range of Motion

For the person that is having a hard time achieving knee extension, my next line of defense is usually LLLD stretching.  Several research articles have been published showing the benefit of LLLD stretching in achieving range of motion gains.

I prefer performing LLLD stretching for knee extension in the supine position rather than prone knee hangs (follow the link to learn why).  This has always been a more comfortable and thus more beneficial position for me.  To perform this exercise, place a towel roll or similar item under the heel to allow full knee extension and then a comfortable weight over the distal thigh.

Low Load Long Duration Stretch Knee

The purpose of this exercise is to be gentle and to hold the stretch for several minutes.  I typically use anywhere from 6 to 12 pounds and hold the position for at least 10 minutes.  If the person is fighting against the weight, then it is too aggressive.  Lower the weight and you’ll see better results.

Don’t forget that you can apply moist heat to the knee simultaneously for even more benefit.

LLLD Knee Stretch with Heat

Devices for Knee Extension Range of Motion

I am also quick to prescribe a range of motion restoration device for people that may be struggling with range of motion or are not moving their knee enough throughout the day.  I have tried some of the dynamic splinting in the past but found that many people would rather control and hold a sustained stretch rather than have the brace apply a dynamic stretch.

The two devices I have used and enjoyed are from Joint Active System (JAS) and End Range of Motion Improvement (ERMI).

JAS Knee Brace        ERMI Knee Brace

Both devices allow the patient to apply their own tolerable LLLD stretch at home.  This is helpful as frequent movement throughout the day is always beneficial.

Personally my criteria to use these devices is usually when I perceive the person will self-limit themselves and avoid motion.  I will get a device in their hands early so that they can move their knee more at home and have a feeling that they are controlling the restoration of range of motion.  We probably resort to using these devices when it is too late and the patient is already too stiff.

These are just some of the many ways to assess and treat loss of knee extension range of motion.  Considering how important it is to restore full knee extension after knee surgery, properly assessing early signs of loss of motion and effectively treating the knee to avoid long term loss of motion is critical.

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online knee seminarIn our online course at we discuss the many pathologies of the knee, including ACL reconstruction. We outline a progressive program that starts preoperative and goes until the athlete is ready to return to their sport.  If you are interested in learning are full approach, our course has a lot to offer. You’ll learning exactly how we evaluate and treat the knee and become an expert at knee rehabilitation.

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