Low Range of Ankle Dorsiflexion Predisposes for Patellar Tendinopathy in Junior Elite Basketball Players: A 1-Year Prospective Study.
Backman LJ, Danielson P. Am J Sports Med. 2011 Sep 14. [Epub ahead of print]
Patellar tendinopathy is one of the most common causes of knee pain in sports; especially those involving rapid jumping like volleyball and basketball. Unfortunately, the causes of patellar tendinopathy remain unclear. Many factors have been hypothesized to increase the risk of developing patellar tendinopathy: intensity of training, training surface, strength, flexibility, poor landing technique, etc. A recent study demonstrated that athletes with patellar tendinopathy had less ankle dorsiflexion but it was unclear if limited dorsiflexion causes patellar tendinopathy or if it was a consequence of the patellar tendinopathy. To determine if limited ankle dorsiflexion contributed to the onset of patellar tendinopathy, Backman et al conducted a 1-year prospective study to examine if reduced ankle dorsiflexion range of motion increases the risk of developing patellar tendinopathy among 75 Swedish junior elite basketball players. The included basketball players had no history of anterior cruciate ligament reconstruction, Osgood-Schlatter disease, femoropatellar cartilage injury, and no signs of anterior knee pain at baseline. Ankle dorsiflexion range of motion was measured with an inclinometer on the tibia during a standardized weight-bearing lunge following a warm-up at both baseline, and at 1-year follow-up. Athletes that developed knee symptoms during the year were evaluated using a standardized clinical definition for patellar tendinopathy. At one year, no athletes developed bilateral patellar tendinopathy, and 12 athletes had developed unilateral patellar tendinopathy. Those 12 athletes with patellar tendinopathy at follow-up, had significantly less dorsiflexion at baseline compared to the athletes that did not develop patellar tendinopathy. Athletes with dorsiflexion less than 36.5 degrees had a 18.5 to 29.4% risk of developing patellar tendinopathy compared to a 1.8 to 2.1% risk for athletes with dorsiflexion greater than 36.5 degrees.
This study provides further evidence that limited dorsiflexion is a risk factor for developing patellar tendinopathy. While the authors proposed a cutoff of 36.5 degrees of dorsiflexion during a lunge, based on statistical analyses, it is important for this cutoff to be confirmed in another cohort. Limited dorsiflexion may be important because it is impairing the athletes’ ability to dissipate forces causing the patellar tendon to experience greater loads. Injuries can occur with a single high-force impact or, as in patellar tendinopathy, a highly repetitive low-force exposure with inadequate time for the tissue to recover. This study complements two other studies that showed that increases tightness of the hamstrings and quadriceps also contributes to development of patellar tendinopathy and anterior knee pain. An important next step would be to see if we can reduce the risk of developing patellar tendinopathy by increasing dorsiflexion and decreasing tightness of the hamstring as well as quadriceps. Regardless, stretching and range of motion exercises are relatively low risk, have other benefits, and may be worth incorporating into our injury prevention programs while we wait for further verification of their benefit at reducing the risk of patellar tendinopathy.
Written by: Jeffrey B Driban
Reviewed by: Kyle Harris
Backman LJ, & Danielson P (2011). Low Range of Ankle Dorsiflexion Predisposes for Patellar Tendinopathy in Junior Elite Basketball Players: A 1-Year Prospective Study. The American journal of sports medicine PMID: 21917610
Workplace repetitive motion injuries in the U.S. are very complicated as they increase mainly by some frequent sources. The other terms of repetitive motion injuries are repetitive injuries or collective distress chaos. It happens by doing the same work constantly for a long era. Take for example, if a job requires a vigorous physical exertion in an itchy or abnormal pose, and if it is a customary part of doing the job, it can escort to these kinds of injuries. There are two kinds of repetitive motion injuries, they are known as tendinitis and bursitis. Away from these two mentioned types of repetitive motion injuries, there are other ordinary problems such as, muscle stiffness problems, back pain problems and hernias.
I think this is important to consider from the perspective of ankle injury as well. There is a high incidence of ankle sprains in basketball, and one of the potential complications associated with ankle sprains and too early return to play is decreased dorsiflexion. I think it would be interesting to see what the causes of the decreased dorsiflexion were and if previous injury could be contributing to problems like patellar tendonitis further up the kinetic chain.
Hi Abby: Thanks, that's a great point. I'm not sure if anyone has looked at that. Possibly, another reason to take the time to properly recover before returning to play 🙂
Have you noticed if any of your patients reflect this? Do you find that the individual who wants to rush things with their ankle rehab sometimes develops an overuse condition somewhere else in the lower extremity?
I think this article does a great job of building upon the previous literature in this area. As I was reading through this article the effects that bracing, especially lace-up, has on ankle dorsiflexion came to mind. Ankle bracing is incredibly common among this population due to the high incidence of ankle injuries and is utilized prophylactically for both injured and uninjured participants. It has been shown time and time again that ankle bracing during static and dynamic measures seems to have an effect on ankle plantarflexion and inversion but a component that is often swept to the side is the dorsiflexion deficits that accompany. Based on McGuine’s latest articles on lower extremity injury rates in braced and no brace conditions which showed similar injury rates in all areas except ankle injuries, the pieces don’t quite seem to line up. What are your thoughts on this?
That's a great point. I hope others will chime in. You're right that the recent ankle bracing research seems to indicate that injury rates are no different between those with ankle braces or without.
One possibility, and it's speculation, is that some people with limited dorsiflexion MAY have different tissue mechanics (e.g., tendon stiffness) and those tissue issues may predispose them to other tendinopathies. In that situation, a person with limited dorsiflexion could have an increased risk for patellar tendinopathies, but a person without those tissue properties but wearing an ankle brace won't. This emphasizes the role of intrinsic limits on dorsiflexion versus the extrinsic influences on dorsiflexion (e.g., braces).
Perhaps Steve can respond since he does some shoulder tendon research 🙂
This is a great point that Greg and Jeff bring up. Where recent research shows no differences between ankle injury incidence, my question would be geared more towards ankle injury severity. Those with a history of chronic ankle instability seem to often times be braced prophylactically, however, athletes with chronic ankle instabilities often times demonstrate arthrokinematic deficits in dorsiflexion to begin with. I clinically use bracing in those with a history of ankle pathology and demonstrated laxity. However my goal is more geared towards lessening the severity of injury if/when a mechanism were to occur. DOes anyone else have thoughts on this notion?
Jeff- That is a great point, I definitely think it is more of a "tissue issue". When the authors use the term "range of motion" it makes me think "joint" and joint related restrictions. I think a term that may be more appropriate is "flexibility". I would imagine these individuals likely have excessive tightness in their triceps surae which could relate to decreased dorsiflexion as well as decreased knee extension. A deficit in knee extension could increase pressure at the patellofemoral joint and increased stress on the patellar tendon. Like you mentioned, maybe they simply have a different tissue make up, are predisposed to these tendinopathies, and dorsiflexion is one of the places it shakes out.
Nicole- I think McGuine's articles showed decreased ankle injury incidence rates with ankle bracing in both those with previous injury and no history, no change in ankle sprain severity, and no increased injury rates proximally.
That lace-up bracing seems to show an ability to decrease injury rates but not severity, is extremely interesting. In my mind it is because these braces are not able to truly limit as much range of motion (specifically plantarflexion and inversion) as previous research states. I would argue ankle bracing helps to decrease injury by one or more of the following factors: improvement to the sensorimotor system through increased sensory feedback, it places the foot/ankle complex in more everted position through swing phase and/or changes foot loading patterns through stance phase. Changes to these factors would most likely have little effect on the severity of the injury. Thoughts?
Thank you both for your responses!
Greg, I agree that the braces are probably providing additional feedback to the sensorimotor system. That may help reduce the overall rate of injury. Severity of injuries might not be decreased because sometimes the ankle is going to suffer a sprain no matter what based on the mechanics of the event(for example, landing on someone else's foot).