Achilles tendon ruptures seem to be on the rise this NFL season. No new Achilles injuries occurred in week 9, but week 8 had 3. So far this season, including summer work outs and pre-season, there have been a total of 15 Achilles ruptures. Is it bad luck or is there a higher incidence this season?
Previous research studies show an Achilles rupture rate of 4-10 per season in the NFL. We are a little more than half way through the 2015-16 season and we’ve already exceeded the published injury rates. Do Achilles injuries fluctuate just like anything else or is there a rise in these injuries in the NFL?
A quick Google search shows sports articles from 2013 and 2014 discussing how Achilles injuries are “plaguing” the NFL season. Recent research articles do show a rise of Achilles tendon ruptures in the NFL. But, we are also seeing a rise in ACL injuries as well. Some thought is that with a decrease in voluntary off-season workouts and mini-camps, athletes may be less prepared for the rigors of pre-season and a 17 game NFL season (Myer et al, JOSPT, 2011). However, there are many theories behind achilles tendon ruptures with no specific mechanism reported to be the primary cause of these injuries.
There are many factors considered to be potential causes of Achilles injuries. These include underlying tendonosis, use of corticosteroids, use of specific antibiotics (fluoroquinolones), as well as biomechanical mechanisms such as rapid lengthening of the tendon. After watching videos of many of this season’s injuries, I saw a common mechanism for most of them. The athlete takes some kind of back step and as he pushes off, his knee extends at the same time. Arian Foster’s injury in the fourth quarter is a perfect example of this. This combination of eccentric loading of the Achilles followed by forceful plantar flexion and knee extension may overload the tendon causing rupture. There is some thought that the knee extension may be due to fatigue, and in Arian Foster’s case his injury did occur toward the end of the 4th quarter.
Return from sports following Achilles tendon ruptures can be difficult. A study by Parekh et from 2009 showed that 30% of NFL players did not return to play. That’s a pretty significant number of career ending injuries. And unlike ACL injuries, there are no prevention programs that have been shown to be successful in reducing the risk of injury. We will see how many more Achilles rupture occur in the second half of this season and we will continue to track injury rates across season to see if this year is an anomaly or if there is an increasing incidence of Achilles tendon ruptures in the NFL.