Dr. Jaclyn Kissel: “Trending Injury in Tennis… Jumper’s Knee”

Written by: Dr. Jaclyn Kissel BSc, DC, FRCCSS


***After completing her bachelor of sciences degree from the University of McMaster, Dr. Kissel enrolled in the Canadian Memorial Chiropractic College (CMCC) graduating with her doctor of chiropractic degree. Following this degree Dr. Kissel completed the two year post graduate residency program in Sports Sciences at CMCC, giving her the designation of Chiropractic Sports Science Specialist. This program provided her with extra training in the management of sport injuries and research. Dr. Kissel has also worked with many teams. She worked as the team doctor for the Over The Top track club from 2008-2010. She was also the team doctor for the Canadian Junior Taekwondo team at the 2009 Junior PanAm Games in El Salvador and was also part of the core medical team for the Canadian Track and Field Championships 2010, the Canadian National Beach Volleyball Championships in 2010 and the Canadian National Under- 16 Soccer Championship 2011. Dr. Kissel also travelled to the Dominican Republic with Chiropractors Without Borders in 2009, which was a life changing experience.***


A successful tennis player requires extreme power, precision and agility.  The physical demands placed on the modern tennis player to push the envelope in each of these domains inevitably results in some aches, pains and injuries along the way.

An injury receiving increased attention in tennis media is patellar tendinopathy (PT), otherwise known as jumper’s knee.  This injury has plagued past world number 1 Rafael Nadal throughout his career.  The new world number 1 Novak Djokovic won the Wimbledon title while battling PT, with the pain causing him to pull out of the Queen’s Club tournament just 1 month prior to his victory at The All England Club.

So what is Jumper’s Knee?

The term ‘Jumper’s Knee’ is considered by many to be of little use as the condition affects athlete’s in all types of sports.  Common terms for the condition include patellar tendonitis, patellar tendonosis, and patellar tendinopathy, all of which describe an overuse injury. The chronic repetitive loading (like those required in tennis), does not allow the tendon to adapt fast enough to the continuous stress and begins to respond by breaking down through microtears and degeneration.  To compound this degenerative cycle, the tendon has poor regeneration ability because of a meagre blood supply which means it receives poor oxygenation and nutrition.  The tendon that is involved in PT is the patellar tendon which is formed by your thigh muscles (quadriceps) and extends over your kneecap (patella) to insert onto your shin bone (tibia).  Signs that you may have PT include pain with activity at the bottom of your knee cap and just below it.  This pain is present with activities that load the tendon (think running, jumping, depth squats, cutting).

Does anyone know what causes PT?

PT is still a poorly understood condition.  In fact, with chronic tendon pain, research indicates it is not even an inflammatory condition!  Because of this imperfect understanding, Prevention is extremely important. A recent systematic review of risk factors for PT found 40 risk factors that have been studied and concluded there is some evidence for only 9, and no strong or even moderate evidence for any one factor.  The take home point suggested addressing dysfunctions in the entire pelvis, knee and lower leg as essential for this condition.  A sports specialist chiropractor is optimally suited for this role.

How do I treat PT?

The most important facet of appropriate treatment for PT is diagnosis by a qualified health professional.  The knee is very complex and a delayed or missed diagnosis can turn a relatively harmless injury into a potential season ending one.  Dependent upon which therapist you see, treatment may consist of any or all of rest, ice, electrotherapy, exercise, massage, taping, anti-inflammatory medications, injections, shock wave therapy, sclerosing agents, and even surgery!  Although therapists will typically claim their approach is the best, the research is poor when comparing treatment approaches.  Also, what works for one athlete cannot be assumed to work for Every athlete in every sport.  There are 2 approaches to treatment that deserve further attention: one because it has fairly good research supporting it (eccentric training), and another because it is appearing all over the news recently (platelet-rich plasma or PRP).

Eccentric Training as a Treatment Approach

Eccentric training for the treatment of tendonopathy’s has been in clinical use since 1984.  A recent review analyzed 7 articles on the clinical effects of eccentric training specifically on PT and concluded that it does have an important role in treatment.  The authors found that even if results are interpreted with caution, the effect of the therapy could be estimated to give a patient a 50-70% chance of improvement of knee function and in pain.  These results are highly significant for a conservative treatment!

The major issue that was identified was a lack of continuity in exercise prescription and execution – essentially stating it is hard to compare research because everyone is doing the exercises differently!  A sports specialist chiropractor plays an essential role in exercise instruction because if not performed properly it can actually make your symptoms worse!

The most commonly described execution involves using a decline board on a 25 degree incline for the affected knee.  Squats on a 25 degree incline board has been shown to maximize the load on the patellar tendon.  Keep your trunk upright to minimize the use of your hip extensors (bum muscles).  From upright, use just your injured leg to lower yourself down to a 90 degree knee angle.  Then use the other leg to straighten yourself back up and repeat.  Typically, but not in all of the research, the athlete performs this exercise into pain.  In fact, if there is no pain, it is suggested you wear a backpack filled with weight until pain is felt.  Typical exercise prescription involves 3 sets of 15 twice daily for 12 consecutive weeks. This protocol may seem extensive, however considering the average duration of substantial pain and reduced function due to PT is nearly 3 years, , this 12 week commitment is well worth it.

Platelet-rich Plasma (PRP)

Tiger Woods, Kobe Bryant, Rafael Nadal……this is a short list of athletes who have allegedly utilized PRP for athletic injuries to their knees in the past year.  PRP is a very complex procedure that is only performed by sports medical physicians, and is not covered under the provincial health plan.  PRP is a multistep process using an athlete’s own blood.  A Physician withdraws your blood and performs a process called centrifuging that separates certain components of your blood (red and white blood cells, plasma, and platelets).  Following this, it is again centrifuged, this time to increase the concentration of just platelets and something called growth factors (an important substance for repair) by 3 to 5 fold.  In the final step, a substance is added to the concentrated platelets that is meant to make them more active.  Following all of this, the mixture is injected into the site of injury.  These injected platelets appear to increase the concentration of certain proteins that may help regenerate tissue.  Overall, the benefit is meant to be two-fold: first to help repair tissue, and second to inhibit certain pro-inflammatory substances that disrupt the healing process.  A very recent review of PRP effectiveness concluded 8 of 13 human trials had favourable outcomes, however numerous weaknesses were pointed out.  In this article, just 1 study was on PT which included 20 athletes and it had very favourable outcomes.  So what can we conclude about PRP?  Not much at this stage, except with the increasing popularity and use in high profile athletes, it is likely here to stay!


As you can see, something as simple as a seemingly minor knee pain with tennis can result in a substantial problem with numerous proposed treatment approaches.  The best thing you can do to help yourself is visit a qualified sports specialist to both diagnose the injury, and provide advice based on sound research to employ the optimal treatment method to suit your case.

Please visit Absolute Endurance Training and Therapy to find a chiropractor to help with your injuries.  We are always accepting new patients.

115 Merton St, Toronto, On. M4S 1A7

(416) 483-2388



Alfredson H. The chronic painful achilles and patellar tendon: research on basic biology and treatment.  Scandinavian Journal of Medicine and Science in Sports. 2005; 15: 252-259.

Visnes H and Bahr R. The evolution of eccentric  as a treatment for patellar tendinopathy (jumper’s knee): a critical review of exercise programmes. British Journal of Sports Medicine. 2007; 41: 217-223

Filando G, Kon E, Della Villa S et al. Use of platelet-rich plasma for treatment of refractory jumper’s knee.  International Orthopaedic. 2010; 34: 909-915.

van der Worp H, van Ark M, Roerink S et al. Risk factors for patellar tendinopathy: a systematic review of the literature. British Journal of Sports Medicine. 2011; 45: 446-452.

Taylor D, Petrera M, Hendry M et al. A systematic review of the use of platelet-rich plasma in sports medicine as a new treatment for tendon and ligament injuries. Clinical Journal of Sports Medicine.  2011; 0: 0.

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