Anatomy, Causes and Treatment of Jumper’s Knee (Patellar Tendinopathy) Part 2

So in part 1 we discussed the presentation, causes and anatomy of patellar tendinopathy.  In part 2 we’ll dive a little deeper into treatment options for patellar tendinopathy.  So without further delay…

What is Effective as Treatment for Jumper’s Knee (Patellar Tendinopathy)?

1. Knowledge About the Diagnosis and Pain
2. An Initial Period of Unloading and Modification
3. Direct Quadriceps Strengthening and Patellar Tendon Loading
4. Kinetic Chain and Sports Specific Strengthening (Hips, Calves, etc.)
5. Assessing for and Correcting Mobility Limitations
6. Modifying Jumping and Squatting Technique

So let’s go ahead and talk about these key principles then huh?

1: Knowledge About Diagnosis and Pain

In order to start the process of rehabilitation we need a bit of information about the condition itself, pain and some expectations during rehabilitation.  Lack of knowledge about this condition can set us up for things we call:

• Poor Beliefs
• Fear Avoidant Behaviors
• Catastrophizations
• Central Sensitivity and Chronic Pain

Essentially, lacking knowledge about this type of injury can cause us to have poor beliefs that don’t help us rehabilitate.  One poor belief may be:

“I don’t want to push this injury because every time I do it hurts.  Having pain means the area is not healed yet and I should rest until it stops hurting”

A belief like this leads to what’s called fear avoidant behavior.  If you’re fearful of causing more damage or delaying the healing process, you may avoid all exercise that stresses the area.

As we’ll talk about soon, exercise when dosed appropriately is the most beneficial thing we know of to help rehabilitate these injuries and completely avoiding any stress may prevent you from getting better (2).

A catastrophization is a belief that the situation you’re in is far worse then it really is (9).  This is another irrational belief that is certainly not helpful for getting out of pain.  Here’s an example:

“The stupid knee injury will never heal and I won’t be able to play basketball ever again”

In reality, patellar tendon injuries generally do improve over time (2) and there is a good chance you’ll get back to basketball.  You can see how irrational these beliefs are.  However, these beliefs are very common and need to be addressed in people who have them.

Geeky Side Note: We know that in people with chronic pain, these negative beliefs or catastrophizations are associated with poor function and worsening pain.  However, we aren’t sure yet whether this greater or prolonged pain led to worsening beliefs or the negative beliefs led to a prolonging and worsening symptoms. (9)  We do know that educating patients about pain decreases their pain, increases physical performance, decreases perceived disability and decreases catastrophization. (9)  Hopefully it also helps to change our behaviors in a positive way as well.

Lastly, mismanagement of this condition (coupled with poor beliefs like we spoke of above) can lead to prolonged pain that is sometimes out of  proportion to the actual damage present with the injury.  We call this central sensitivity (9).  Basically our nervous systems get extra sensitive, out of proportion to the actual state of the injury.

Pain Science Side Note: Central sensitization is not the same as an athlete continually training with too much volume, poor technique, poor movement and a lack of a solid rehabilitation program.  In this case our athlete is continuing to irritate the patellar tendon and reducing the ability to adapt and heal.  Central sensitivity is perpetuated pain (coming from increased sensitivity of the brain and spinal cord) in the absence of offending stress to further damage the tendon (9).

Lucky for us, we can avoid most of this with some good old advice and starting off on the right foot.

Now, after reading part 1, we already have a decent background on this condition, the anatomy as well as the risk factors that can bring about patellar tendinopathy.  What’s also important to understand is that this is a condition that does actually tend to get better with rehabilitation and won’t necessarily haunt you for the rest of your life (2).

That being said, tendon issues typically take a long period of time to get better.  In our medical literature, most successful rehabilitation programs last 8-12 weeks (2).  However, it is common for these issues to take 6 or more months to resolve (4).  A research study by Bahr and Bahr found that only 46% of people reported no pain and full return to sport training 1 year following a strength based rehabilitation program (4).

The take home point is that it’s normal for the process to take a long period of time to resolve.  They can resolve more quickly but be prepared for the long haul.

Another concern of athletes with patellar tendinopathy is the tendon rupturing (tearing completely).  Lucky for us, rupturing the patellar tendon is not common and with proper rehabilitation shouldn’t be a major concern (4).

The next topic to understand during rehabilitation is pain.  Pain is a protective mechanism and exists to keep you safe.  (Click HERE for a video to help understand this better)  That being said, once you have pain your body is trying to tell you not to do anything stupid to let this injury recover.  The other important concept to understand is that pain and injury are not completely correlated.  When you get an injury, the area gets sensitive (because your body is trying to protect you).  Therefore movement and loading may hurt, but if the loads are kept at the right dosage, no damage is caused. (10)

Side Note: In most of our patellar tendon rehabilitation research, pain is kept between a 1 and 5 out of 10 on a 0-10 pain scale during physical therapy exercises (2).  In some of the studies the criteria for advancing an exercise is when the exercise is no longer painful (2).  The idea here is that if we aren’t provoking atleast some pain, the exercise may not be hard enough to cause progress (2).  

The next thing to understand is that the stress of exercise and loading your painful tendon is actually what helps the tendon heal and get out of pain (2).

The last point to understand is that tendons generally respond well to heavy loads (4).  The majority of newer research coming out about tendon pain and physical therapy is showing that heavy loading is a beneficial treatment for these conditions (5).

Side Note: An over-reliance on passive treatments such as ultrasound, laser and manual therapies can also keep athletes from progressing over time.  Our research shows us that it’s loading we know to be most effective for this condition (4).  

That being said, exercise is good but the dosage is important.  If we apply too much stress to the tendon it can potentially make the situation worse.  We need some guidelines for how much stress is appropriate and how much is too much.  Check these charts below:

In the first example, our athlete is staying away from all painful activities (firing level).  This is generally not helpful for trying to get out of pain and back to high level training.  As you can see the athlete actually makes no progress at all over the course of time.

In the second example, our athlete is just blowing through their pain (firing level), throwing caution in the wind.  We know this style of dealing with pain can make the pain stick around or worsen (4, 8).

In the last example we have an athlete who is working with their pain.  They load their patellar tendon with just the right amount of exercise to cause improvements in pain.  As the pain improves with time and exercise, they progress the difficulty of training as well to continue making progress.  This is key to rehabilitation.  (Click HERE for a more thorough explanation of this phenomenon)

So how much pain is acceptable during rehabilitation?  As I said before, our research is a bit varied in this regard.  Some studies allow up to a 5/10 on a 0-10 pain scale during exercise (4).  Some are lower (4).  Some studies also recommend pain levels returning to baseline 24 hours following exercise (4).  With this research in mind my general recommendations are:

• Pain should be kept at or below a 3/10 during physical therapy exercises
• Pain should return to baseline levels 24 hours following a therapy session
• Pain or exercise tolerance should be improving from week to week and month to month

Keep in mind that these are not hard and fast rules.  Some people may be able to push into more pain and make progress.  Others may have to back off a bit more then others.  Lastly, keep in mind that pain is a dynamic process that changes day to day.  Trying to quantify your progress on a daily basis is just like looking at the scale every day to figure out if you’re losing weight.  It takes time and will fluctuate.  This is normal.

2: An Initial Period of Unloading and Modification

Now this may be a no-brainer for most people but it is a commonly missed step for rehabilitation of jumper’s knee.  We know from our medical literature that if we don’t modify our activities with patellar tendinopathy often times the pain can persist (4, 8).  We also have some research to indicate that if we try to simply apply a strength program to the tendon without modifying our current training or sports routine the outcomes are poor and can even lead to worsening of pain (4).

As we learned on the flip side of the coin, we also don’t want to fully unload the tendon.  We know this isn’t the best plan of attack to return to activities and can lead to weakening of the tendon (2).

However, we will have to decrease the stress of our activities enough to allow the area to calm down and become less painful.  In a case study by Silva et. al eliminating all activities that create more then a 2/10 during sports training in addition to adding a strengthening program along with some modification of jumping technique led to an improvement in pain (3).  Studies in similar knee conditions like patellofemoral pain syndrome show an initial period of unloading or modification to lead to better long term outcomes then no period of unloading (8).

So what does this mean for our training?  My general recommendations are to:

• Temporarily eliminate activities that produce pain >2/10
• Temporarily eliminate activities that cause pain to increase 24 hours following training
• Reduce total training volume and intensity enough to have pain levels return to baseline 24 hours following training

As the pain improves over the course of time we can slowly start leaking back in more training and movements that were previously too painful.  Just make sure that when we re-introduce previously offending movements they obey the guidelines outlined above.

3: Direct Quadriceps and Tendon Strengthening

As discussed earlier, a common mistake when attempting to rehabilitate from jumper’s knee is avoiding painful movements altogether.  It’s natural and acceptable to modify exercises that aggravate the patellar tendon like front squats to more hip dominant movements like barbell back squats.  This allows us to continue training without irritating the tendon.  As discussed above in concept 2, modifications like this can be beneficial when attempting to dose stress to the patellar tendon and heal.

The issue with this strategy is that we know that movements that directly stress the tendon (like a decline squat shown above) work better for rehabilitation than regular squats for rehabilitating patellar tendinopathy (2).  We also have research to show that during patellar tendinopathy individuals have substantial motor cortex inhibition of the quadriceps muscle group (4).  This is basically a fancy way of saying that the quadriceps muscle is not firing well.

People with long standing patellar tendinopathy can also have large amounts of atrophy (decreased muscle size) of the quadriceps muscle group (4).  It makes sense that if the muscle doesn’t fire well we need to ensure we get it firing well and restore strength.  We can’t do this if we substitute all quad dominant movements in the gym to hip dominant movements.

Shifting your entire exercise program to hip dominant movements (deadlifts, box squats, good mornings etc.) may allow you to train without pain but doesn’t do much for your weak, inhibited quads.  It also doesn’t stress the tendon to allow it to adapt either.  We’ll have to ensure we apply some direct tendon and quadriceps strengthening to fully rehabilitate.

The frequency of exercise for patellar tendinopathy is our medical literature is somewhere between twice per day and every other day (2). These exercise programs also tend to be progressive in nature.  As the tendon becomes more and more resilient, we apply progressively more challenging exercises (2).

Malliaras et. al have proposed a progressive 4 stage patellar tendinopathy rehabilitation plan (4):

• Stage 1 Isometrics: Isometric (no movement) knee extension (between 30-60 degrees of knee flexion) for 5 sets of 45 seconds at 70% of your maximum effort.  Performed 2-3 times per day
• Stage 2 Isotonics:  3-4 sets of 15 repetitions every 2nd day.  Repetitions decrease over time and load increases.
• Stage 3 Energy Storage Loading: Progressive (volume and intensity) jumping, sprinting, cutting activities specific to demands of the sport
• Stage 4 Return to Sport: Progressive exposure to sport specific training drills and competition

Basically if you have too much pain (described as more then minimal or >3/10) during isotonic (exercise with motion) exercises then you start with isometrics (pressing against an immovable object).  Once you can tolerate isotonics with minimal pain, you move there.

Once you’re showing symmetrical strength in isotonic exercises in stage 2, you can move onto stage 3.  (Keep in mind these energy storage exercises should also have minimal pain and your pain levels should return to baseline 24 hours after exercise.)  As your energy storage exercises progress to the point where they begin to replicate the sport specific demands of your sport, it’s time to progress to more sport specific training and competition.

Also keep in mind that each stage may last several weeks.  As stated before, rehabilitation often takes 6 months or more and progression shouldn’t be based solely on time but instead on how well the tendon is tolerating exercise.

For our average lifter trying to get back to training in the gym their program may look like this:

Phase 1: Isometric (started when isotonic exercises are too painful)

• Knee extensions against the wall @45 degrees
• 5 sets of 45 second holds at 70% of maximal perceived exertion
• 3x per day
• 1 week in duration

Phase 2: Isotonic (started as soon as tolerated with minimal pain)

• Decline single leg squats 3-4 x 15
• Machine quadriceps extension 3-4 x 15
• Performed every other day
• 6 weeks in duration
• Each week progressing to heavier and lower rep ranges (week 2 sets of 12, week 3 sets of 10 etc…)

Phase 3: Energy Storage Loading (started when tolerated with minimal pain)

• Box jumps 3 x 3
• Running – 15 minutes of 30 seconds on, 30 seconds off interval runs
• Performed 2-3 x per week
• Continue with isotonic exercises
• 4 weeks in duration

Phase 4: Return to Sport (started when energy storage exercises begin to mimic sport activities)

• Slow transition back to regular gym activities

Keep in mind that the exercises selected in phase 3 and 4 will vary greatly based on the person and what they want to return to.  For a basketball athlete it may consist of a large variations of jumping, cutting and acceleration drills.  For the olympic lifter it may be more explosive lifts like jerks, cleans and snatches.

Well, that’s it for part 2.  In the next article we’ll talk about strengthening the kinetic chain, mobility and technique for success.  Stay tuned…

Click HERE for Part 3:

Want more in depth information about patellar tendon injuries and how to rehabilitate them fully and get back to training?  Join my Insiders Online Mentoring Program to gain access to these webinars and a 12 week training program to get you out of pain and back to squatting and weight lifting.

My patellar tendon is centrally sensitive,

Dan Pope DPT, OCS, CSCS, CF L1

References:

1. Superior results with eccentric compared to concentric quadriceps training in patients with jumper’s knee: a prospective randomised study1 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1725058/pdf/v039p00847.pdf study2 https://nizagara-online.net
2. CURRENT CONCEPTS IN THE TREATMENT OF PATELLAR TENDINOPATHY IJSPT 2016 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5095939/#B83
3. Rehabilitation of Patellar Tendinopathy Using Hip Extensor Strengthening and Landing-Strategy Modification: Case Report With 6-Month Follow-up JOSPT 2015 https://www.jospt.org/doi/full/10.2519/jospt.2015.6242?code=jospt-site
4. Patellar Tendinopathy: Clinical Diagnosis, Load Management, and Advice for Challenging Case Presentations https://www.jospt.org/doi/pdf/10.2519/jospt.2015.5987?code=jospt-site
5. Cook JL, Purdam CR. Is tendon pathology a continuum? A pathology model to explain the clinical presentation of load-induced tendinopathy. Br J Sports Med 2009;43:409–16.
6. Neovascularisation and pain in jumper’s knee: a prospective clinical and sonographic study in elite junior volleyball players http://bjsm.bmj.com/content/39/7/423ijkey=a16cd5a3976373e3a7cb301804ef49f9f932f98a&keytype2=tf_ipsecsha
7. Physio Edge 075 Tendinopathy, imaging and diagnosis with Dr Sean Docking https://www.clinicaledge.co/podcast/physio-edge-podcast/75
8. Moving Beyond Exercises for Managing PFP, Patella Tendinopathy and Iliotibial Band Syndrome Sports Kongres https://youtu.be/VJIN-WT8N00
9. Mechanisms and Management of Pain for Physical Therapists by Kathleen Sluka IASP Wolters Kluver
10. Therapeutic Neuroscience Education – Adriaan Louw