Anatomy, Causes and Treatment of Jumper’s Knee (Patellar Tendinopathy) Part 3

So in part 1 we discussed the presentation, causes and anatomy of patellar tendinopathy.  In part 2 we spoke about education, unloading and then reloading.  make sure you go back and read those 2 if you haven’t already.  In part 3 we’ll conclude with the last 3 parts of patellar tendon rehab.  So as a refresher…

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

Go back and read part 2 if you haven’t yet for the first 3 points.  Now moving on…

4: Kinetic Chain and Sports Specific Strengthening

When you’ve got an injury it’s easy to focus all of your attention directly at the injured area.  Truth is, your entire body moves as a unit and multiple joints and muscles need to work together to complete movements like squats, deadlifts and olympic lifts.  

Think of it this way.  Let’s say you have a tug of war team with 3 team mates.  One is an NFL lineman, the second is  a professional soccer player and the third is a marathon runner.  

Let’s say your NFL lineman is slacking and not doing his job properly.  The soccer and marathon runner are going to have to pick up the slack.  Because of this they may get injured but not because they aren’t strong and capable, potentially it’s the opposite.  Maybe they wouldn’t have gotten hurt if the lineman did his job properly.  

Now let’s say the NFL lineman consist of the muscles around your hip.  Let’s say the soccer player consists of the muscles around the knee like the quads and hamstrings.  Lastly the marathon runner consists of the muscles around the ankle like the calves.  

All of these muscles need to be optimized to normalize the stress at the knee and patellar tendon.  Failing to address this whole chain can be a reason why your rehabilitation program fails (4).  

The other important piece to recognize is that your rehab program should start looking more and more like your typical training program over time.  This is known as sports specificity (2, 4).  

For an olympic lifter, heavy squats and olympic lifts may need to be eliminated from your program initially.  As the knee starts to improve you can start to slowly introduce deep squats back into your program.  As these are tolerated we can add in olympic lifts, starting with power variations and slowly progressing towards full squat variations.

For an athlete that performs a lot of jumping (sports like basketball and volleyball) they’ll probably  require an initial period of unloading from jumping activities.  As the tendon progresses over time you can start slowly leaking in jumping exercises.

 Jumping exercises should be progressive in nature, starting with double leg exercises and progressing to single leg.  Jumping should also start with less reactive variations and progress to more reactive jump variations.  Here are some progressive jump variations to help you design a program if you’re looking to get back to jumping:

You can see how the stress on the quadriceps tendon will advance as we progress towards more challenging jump variations.

5: Assess for and Correct Mobility Limitations

As discussed in the part 1 of this article series people with patellar tendinopathy can also present with hamstrings and quadriceps tightness (2).  We also have some medical literature that shows that if you add hamstrings and quadriceps stretching to a patellar tendinopathy strengthening program, the results are better (2).  

Use the assessments below to determine if you or your patient has a mobility limitation in their quads or hamstrings:

If you find you have a mobility limitation I recommend applying a combination of foam rolling and stretching to help reduce tightness:

Here’s a quick video to show you some basic stretches and foam rolling to help improve a limited thomas test:

Once you’ve got a plan to address quadriceps and hamstrings mobility, the next important thing to tackle is ankle dorsiflexion flexibility.  Now, if we’re lacking ankle dorsiflexion mobility, this can create what’s called “dynamic valgus” or “knee in” during squatting tasks (11).  Check the video below to see how:

So, tendons are very good at taking stress in alignment with the fibers they are made up of.  When we get dynamic valgus we expose the tendon to forces that rotate the tendon along with normal tensile loads.  Tendons are generally not as good at handling these rotary forces and the idea is that this can contribute to developing tendinopathy. 

Either way, dynamic valgus at the knee is generally a suboptimal way of moving and has been implicated in other knee issues such as ACL injury and patellofemoral pain syndrome.  It’s probably a good idea to minimize the amount of valgus during jumping, squatting and single leg strength training.

For these reasons it’s important that we assess for ankle mobility limitations and correct them if present.  Use the assessment below to see if you have an ankle mobility limitation into dorsiflexion.

If you’ve got a a restriction, here are some of my favorite stretches and mobilizations:

Mobilizations for these restricted areas obviously should be a regular part of your rehabilitation program.  

There is a lot of confusion out there currently for how often stretching and foam rolling exercises should be performed.  Here are some general guidelines for frequency and duration of mobility:

Stretching (12):

• 60 seconds stretching per muscle group
• 5-7 days per week (the sweet spot is 5-10 minutes of stretching per week)

Foam Rolling (13):

• 60 seconds foam rolling per muscle group
• 3x per week (dunno optimal dosage yet, literature shows longer term improvements with this recommendation)

Mobilizations:

• 10-15 reps performed after stretching and foam rolling

Side Note: Stretching and foam roll recommendations were taken from evidence based guidelines.  Check the articles in the works cited if you want to check them out.

6: Modifying Jump and Squatting Technique

One contributing factor to patellar tendinopathy may be how our athletes choose to move during sporting tasks like jumping, squatting and running (2, 4).  

The way we squat and jump affects the amount of stress on the patellar tendon.  A few things that increase stress on the patellar tendon (2):

• Increased knee flexion (increased squat depth)
• Increased load (i.e. added weight to the barbell) 
• Forward weight shift 
• Faster more explosive contractions that require the tendon to act as a spring 
• Dynamic valgus at the knee

Let’s explore each of these a little deeper.

1: Increased knee flexion

As we descend deeper  and deeper into a squat we simply place more and more stress onto the patellar tendon (2).  We can easily modify depth of squatting and other knee bending exercises to place more or less stress on the patellar tendon.

2: Increased load 

The more external load (weight on the bar) we use during a given movement, the more load on the patellar tendon (2).  This is partially due to the amount of quadriceps activity during a given exercise.  The harder the quad is forced to work, the more stress goes through the patellar tendon

3: Forward weight shift and knee displacement 

This point is subtle but important to understand.  The more shifted forward our bodyweight is during a squatting or landing task, the more stress on the patellar tendon.  In the image above we have someone landing with more forward weight shift (left image) and someone landing with more backwards weight shift (right image).  The cue of “hips back” during landing displaces the weight backwards and reduces stress on the patellar tendon (3):

The same goes for the squat, the more we sit back during a squat, the less stress on the tendon.  Jason and Lauren Pak from Achieve Fitness in Boston present an excellent IG post on this point.  As we sit back in the squat, we unload the patellar tendon.  If you’ve got a painful tendon, this tends to reduce pain.

View this post on Instagram

KNEE PAIN DURING SQUATS? – What’s up, Achievers?! @jasonlpak here with a quick tip for you if you’re experiencing knee pain while squatting. First off, if you have chronic knee pain, you definitely need to see a physical therapist to get to the root cause of the issue. If you have more of an acute knee pain issue during squatting, it could be because you might be descending a bit improperly. – While technically, most squatting variations are knee/quad dominant, you still want to initiate the movement with a hip shift back and THEN drop straight down. If you let the knees shift forward first, then you immediately place a lot of stress on them. By shifting your hips back, you’re able to distribute the stress much more evenly throughout your hips and legs and takes a lot of pressure off your knees. – I hope this post helped you out! Until next time, Peace, Love, and Muscles! ✌️???????? . . . #squat #squats #squatting #somervillema #kneepain #achievefitnessboston

A post shared by Achieve Fitness (@achievefitnessboston) on May 14, 2018 at 8:38am PDT

Lastly, utilizing a decline board during single leg squats also forces an anterior weight shift (anterior knee displacement as described in the article).  This decline also increases stress on the patellar tendon (2).

Side Note: It’s important to point out that once you acquire patellar tendinopathy, directly stressing the tendon with decline squats actually produces better results for rehabilitation than single leg squats without a decline (2).  This points to the importance of directly stressing the tendon for rehabilitation.

4: Faster more explosive contractions that require the tendon to act as a spring 

Stiffer landings with reduced ground contact time tend to stress tendons more then softer landings with more bending at the hip, knee and ankle joint (3).  This makes sense given that a really fast jump with less time for the muscles to help absorb force will stress the tendon to a greater degree.

Interestingly, athletes who perform better during jumping tasks tend to develop more patellar tendinopathy and pain (2).  These same athletes may be better able to harness the elastic nature of tendons and jump better as a result.  Unfortunately, the better you’re able to produce forces in tendons, the more likely you may be to develop tendon pain.

One case study from JOSPT found that retraining jump patterns was helpful in reducing patellar tendinopathy pain (3).   Some cues used in the study that may help athletes when returning to jumping after patellar tendinopathy are:

• Land “softly” to minimize landing impact
• Reduce sound during landings (also to reduce landing impact)
• Lean forward during landings (to encourage increased hip motion)
• Push hips back during landings (also to increase hip motion)

The thought here is that patients with patellar tendinopathy tend to have stiffer landings and don’t adequately utilize their hips (send the hips back, bend at the hip and lean the trunk forward) during landings and instead tend to utilize the knees more (more knee flexion and less hip flexion).

Correcting these issues reduces stress on the patellar tendon, may help decrease pain and improve rehabilitation outcomes (and potentially decrease future issues).  Although this is only one case study, it makes sense that modifying jump technique  may be helpful in reducing pain in people with patellar tendinopathy.

The same goes for the squat and single leg strengthening exercises like lunges and step-ups.  If we encourage more “hips back” and encourage more forward trunk lean we’re taking some of the stress off of the patellar tendon and onto the hips and spine instead.  This can be useful to modify stress through the patellar tendon throughout the rehabilitation process.

5: Dynamic valgus at the knee

As stated earlier, having dynamic valgus at the knee can increase stress through the patellar tendon.  Inadequate ankle dorsiflexion can lead to this but often this is purely a technical issue that can be corrected with the right cues from a coach or feedback by standing in front of a mirror.

You’ll want to ensure you have optimal alignment of the knee and toes during all of your chosen activities (squatting, lunging, step-ups, running, jumping, landing etc..).

So there you have it, probably more information then you’ve ever wanted about patellar tendinopathy.

Do you 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 more educational webinars and a 12 week training program to get you out of pain and back to squatting and weight lifting.

Finally finished with knee information (or am I?),

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 study https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1725058/pdf/v039p00847.pdf
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
11. The association of ankle dorsiflexion and dynamic knee valgus: A systematic review and meta-analysis. 2018 Physical Therapy and Sport https://www.ncbi.nlm.nih.gov/pubmed/28974358
12. The Relation Between Stretching Typology and Stretching Duration: The Effects on Range of Motion IJSM 2018
13. The Foam Roll as a Tool to Improve Hamstring Flexibility The Journal of Strength and Conditioning Research (Dec. 2015)
14. Common Running Injuries Evaluation and Management 2018 by the American Academy of Family Physicians https://www.aafp.org/afp/2018/0415/p510.html
15. O’Sullivan K, McAuliffe S, Deburca N. The effects of eccentric training on lower limb flexibility: a systematic review. Br J Sports Med 2012; 46: 838–845