Published 5/1/2016
Peter Pollack

Fewer Concussions, More Leg Injuries?

NCAA targeting rule may be linked to increase in lower extremity injuries
Recent years have seen a tightening of National Collegiate Athletic Association (NCAA) regulations aimed at preventing concussion. Although it is generally agreed that the rules are necessary and effective, an unintended consequence of implementation may be an increase in lower extremity injuries. A paper presented at the 2016 Specialty Day meeting of the American Orthopaedic Society for Sports Medicine attempted to evaluate such an effect.

"We take care of many athletes here at the University of Iowa, and we see quite a few knee and ankle injuries," explained Robert W. Westermann, MD, coauthor of "Unintended Consequences of Concussion Prevention in NCAA Football: Increasing Lower Extremity Injuries Since Implementation of the 'Targeting' Rule."

"We wondered if there was any correlation between the implementation of the rules to prevent concussion and a potential rise in knee and ankle injuries," he explained.

In 2008, the NCAA implemented rules to penalize teams when players target and initiate contact against an opponent with the crown of their helmets, or target and initiate contact to the head or neck area of a defenseless opponent with the helmet, forearm, fist, elbow, or shoulder. In 2013, those rules were strengthened to allow the ejection of players who engage in such actions.

"We hypothesized that an increased focus on concussion prevention may have affected the way players tackle, block, and make contact, leading to an increase in other injuries," said Dr. Westermann.

Evaluating 6-year trends
Dr. Westermann and his colleagues drew data from the NCAA Injury Surveillance Program during a 6-year period (2009–2015). They looked at information supplied by 57 NCAA football programs during 153 team-seasons. During the study period, they found the incidence of all lower extremity injuries increased 15 percent, and the incidence of lower extremity injuries associated with loss of field time increased 19 percent. The incidence of concussions per 1,000 athletic exposures (AEs) actually increased 34 percent.

"It's important to note that policies for concussion identification and management have improved over time," said Dr. Westermann, "so we're not sure if the rise we've seen reflects an increase in incidence or simply better detection of concussion. Ultimately, I believe the rule changes have improved player safety, because if we're identifying more concussions and having people go through the correct protocols, we're performing a good service for our athletes. The observed rise in the concussion rate makes sense given the tracking policies that have been enacted. I would argue that they ultimately benefit the players."

The research team found a 19 percent overall increase in lower extremity injuries due to player contact, along with a simultaneous 4 percent decrease in noncontact and overuse injuries.

"In 2012," said Dr. Westermann, "the NCAA implemented rules to limit the number of kickoffs returned. Kickoffs are regarded as plays with very high injury rates. So even during a study period in which there were fewer kickoffs being returned, lower extremity injuries still rose. That suggests a genuine upward trend in contact-related knee and ankle injuries."

In the period studied, knee injuries per 1,000 AEs rose 16 percent, and ankle injuries rose 34 percent.

"We observed no rise in noncontact and overuse injuries to the knee and ankle," he explained, noting that the investigators only found increases in contact-related injuries to these areas. "The number of time loss injuries—in which a player had an injury and ended up missing practices or games—also increased over 6 years. However, that's a correlation, not a causation. I think we need to emphasize that.

"We need further research on an individual football team basis, and also need further studies of [data from] national databases to see if the trend holds true," continued Dr. Westermann. "Our work here should drive hypotheses for other studies, and I recommend we use it only to recognize that the topic needs further study."

Dr. Westermann's coauthors include Peter Wehr, MD, and Annunziato "Ned" Amendola, MD.

Peter Pollack is the electronic content specialist for AAOS Now. He can be reached at ppollack@aaos.org

Bottom Line

  • NCAA data suggest an increasing trend in lower extremity injuries linked to player contact.
  • A corresponding increase in concussions may be linked to improved data tracking.
  • Study findings need to be verified by additional research and should be considered hypothesis-driving.