November 2016

How foot and ankle injury trends reflect today’s NFL

Michael Crabtree. (Photo courtesy of miamisportsgeneration.com)

Michael Crabtree. (Photo courtesy of miamisportsgeneration.com)

Professional football players are enduring higher levels of force than ever, and foot and ankle injury rates are increasing as a result. Advances in surgery and rehabili­tation have helped get players back on the field more quickly, but injury prevention remains a significant challenge.

By Will Carroll

There are two injury-related trends that are noticeable right now in the National Football League (NFL). The number of foot and ankle injuries⎯Achilles tendon tears, ankle sprains, and various maladies of the foot, especially the midfoot⎯have increased greatly over the last decade. And the amount of research the NFL is putting into solving this problem remains troublingly flat.

As with most sports, the NFL players themselves have gotten bigger, stronger, and faster, in combination rather than isolation. A bigger man running faster has greater forces that he must dissipate. Even as the muscles higher up the kinetic chain are getting bigger, feet and ankles are essentially left with the anatomic gifts of a player’s genetics. And, while advances in the design of shoes and cleats have led to exponentially better performance, it’s clear that one thing the expensive shoes aren’t doing is reducing foot and ankle injury rates.

Achilles tears

One of the highest-profile injuries in the NFL is the Achilles tendon tear, due in part to the length of time required for recovery and for the player to return to pre-injury performance levels. One of the highest-profile studies on NFL performance after Achilles tear was done in 2009,1 led by Selene Parekh, MD, MBA, who is now an associate professor of orthopaedic surgery at Duke Health in Durham, NC. The study looked at a relatively small number (31) of Achilles ruptures in NFL players between 1998 and 2002. About two-thirds of injured players (64%) returned to NFL play after an average of about 11 months, and their performance in the three years after their return tended to be significantly lower than preinjury levels.

Foot and ankle injury trends suggest an opportunity for customization within the framework of existing shoe designs, such as orthotic devices, to help reduce risk.

That study is limited not only by the number of athletes studied, but as surgical and rehabilitation techniques have advanced, the study’s relevance to today’s NFL has also changed. New surgical methods and tools have helped improve player outcomes, but a change in rehab protocols appears to have made even more of a difference.

One current NFL team physician (NFL medical personnel are not authorized to speak on the record to the media) says quicker weightbearing and an emphasis on active mobilization after surgical Achilles repair (see “Battles of Achilles II: How the debate is informing clinical practice,” November 2015, page 20) have increased success rates while simultaneously reducing return times.

“Terrell Suggs is the one that stands out,” the physician explained, noting a speedy linebacker from the Baltimore Ravens who returned from a 2012 Achilles rupture in just six months. “When [the Ravens] announced that he was playing, I thought he was just a decoy. Instead, he was quick. There was a play where he was pushing his blocker, stopped, and made a quick jump to bat down a pass. That was an athletic play that showed complete confidence in his leg.”

Suggs, now 33, tore his contralateral Achilles tendon in September 2015 and returned to start the 2016 season after a more conventional recovery period. But other players have been posting shorter recovery times: After San Francisco 49ers wide receiver Michael Crabtree tore his Achilles in 2013, for example, he made headlines, not just for returning to play in six months but also for racking up more than 100 receiving yards in two of his first six postinjury games.

David Chao, MD, a former NFL team physician in practice in San Diego, believes the changes in foot and ankle injury patterns—both positive and negative—are inherent in the player, not the surgery or rehab.

“People have gotten braver, more willing to be aggressive in rehab, but the technique remains the same for the repair,” Chao explained. “Twenty years ago, Dan Marino came back from [an Achilles tear] and he was pretty immobile. Today, they come back and are back to explosive movements.”

In the National Basketball Association (NBA), the oft-cited Achilles case is Kobe Bryant. The future Hall of Famer ruptured his Achilles in 2013, near the end of his career, but after a repair, had no issues for the next two seasons. While he did have other injuries and Father Time was making his presence known, the Achilles held up, despite reports of extensive workouts to keep Bryant competitive. Indeed, analysis from SportVu, the tracking system used by the NBA, shows no real change to Bryant’s in-game speed from year to year in his final three seasons (unfortunately the only seasons for which these data are available).

A 2016 study of return rates after various orthopedic procedures in the NFL offers a partial snapshot of the positive Achilles rehab trend.2 The study found Achilles tendon repair, along with other procedures, was associated with a decrease in number of games played and decreased performance in the first year after surgery, but not the second or third years.

Accelerated rehab

Bryant. (Photo courtesy of Wikimedia Commons.)

Dez Bryant. (Photo courtesy of Wikimedia Commons.)

Almost every physician and physical therapist I spoke with pointed to one technique that has altered recovery most: earlier rehab, largely driven by antigravity treadmill use. The ability to get rehabbing athletes back on their feet and into motion with some weightbearing early in rehab is seeing huge gains in terms of results. Several physicians and therapists I spoke with also pointed to techniques such as platelet-rich plasma and stem cell injections as positives.

Adam Bitterman, DO, an orthopedic surgeon with Northwell Partners in Huntington, NY, who specializes in Achilles reconstructions, noted that minimally invasive surgical techniques have helped make accelerated rehab possible.

“Because of advances in surgical technique, wounds are smaller and the procedures are less invasive, thereby allowing patients to begin physical therapy and weightbearing exercises at an earlier time frame then in the past,” Bitterman said.

Lenny Macrina, MSPT, SCS, CSCS, the director of physical therapy at Champions Physical Therapy in Boston, said new and advanced rehab techniques include low-level laser therapy to help with tissue recovery and healing, dry needling to potentially prevent excessive tightness in the muscle belly and maintain a proper length-tension relationship, and blood flow restriction training (BFR; see “Blood flow restriction training: The slow flow movement is fast becoming rehab’s hottest trend,” July 2016, page 20) in the acutely injured or postsurgical patient.

“BFR seems to help aid in gaining muscle mass back quicker than any modality out there, but we still need further research on all of these to figure out the exact mechanisms and long-term ramifications,” Macrina said. “Good old-fashioned strengthening and manual therapy will always be the mainstay in treatment, but these modalities offer promise for future treatments.”

Improvements in both the treatment and the rehabilitation for athletes with Achilles damage have made the return both faster and better, but there’s been little progress on prevention or reducing injury severity. And, given the increased forces associated with elite-level sports today, that lack of progress seems likely to continue. The balance is clearly off.

Ken Jung, MD, of the Kerlan-Jobe Orthopedic Clinic in Los Angeles and the team physician for the Los Angeles Lakers and other teams, is seeing a rapid increase in incidence among athletes—and not just those one would expect.

“It used to be a middle-aged couch potato injury,” Jung said, “but now it’s elite players. It’s young, in-shape college guys, pros, and everyone.”

Jung believes part of the reason behind the increase is a lack of rest.

“Players are year-round now, especially the younger ones,” he said. “Even with cross-training, I don’t think that there’s enough rest time for tissue to heal.”

Foot injuries

Beyond Achilles ruptures, sports is also seeing a major increase in midfoot sprains and dislocations. The Lisfranc fracture is now a common part of the fan’s lexicon, just a few years after it was an absolute unknown. The anatomical complexity of the area only increases the issue, but it is also poorly understood by strength and conditioning. As with most sports, there’s more of a focus on narrow improvements rather than holistic and systemic factors.

“It’s hard to fix feet in the weight room,” explained one NFL athletic trainer I spoke with.

Among NFL medical staff, there are a number of theories about what is leading to the increase in incidence of foot and ankle injuries. The focus is on the increased forces or the “bigger-stronger-faster factor.” With shoes getting lighter (and often less stable) while experiencing higher levels of traction and friction thanks to evolutions in playing surface technology, the forces acting on the foot and ankle complex are simply too high to survive, both on a traumatic and a chronic basis.

One injury in which this is apparent is Jones fractures. Several star NFL players, including three named Jones, have had this specific kind of fracture. The injury has happened almost exclusively to receivers and to defensive backs, which indicates it’s an issue of function. The hard cuts necessary to the positions are generating too much force for the fifth metatarsal to hold up. Again, this likely has a chronic component with repetitive stress from these maneuvers, followed by a straw-that-broke-the-camel’s-back trauma forcing the fracture.

In addition, there is a significant re-injury risk with Jones fractures. Even after surgery to install an intermedullary screw, many have needed a revision of this operation or a secondary operation to use a bone graft to further stabilize the bone. Changes in the treatment, such as going immediately to the bone graft, have not shown a decrease in the incidence of setbacks.

While Jones fractures are still relatively rare, it does appear the incidence rate is increasing at all levels. The increase in incidence at elite levels indicates strongly that the “bigger-stronger-faster” is a key component in this; NFL athletes are usually all three, while equipment and physical demands are roughly the same at every level from high school up.

In fact, the size-speed combination appears to be predictive. Elite receivers like Julio Jones and Dez Bryant—both of whom have suffered Jones fractures—combine height, size, and speed, which translates into force on the hard cuts. In most situations (but not all), the players have artificial turf in their home fields and almost all of them were playing on them when injured.

Researchers from OrthoCarolina Foot & Ankle Institute in Charlotte, NC, performed a recent study analyzing 34 Jones fractures in the NFL between 2004 and 2014.3 The return rate was high and predictable (all returned to play, and 80% were still playing when the study was published), but first author Craig Lareau, MD, who is now a foot and ankle surgeon with New England Orthopedic Surgeons in Springfield, MA, said the recurrence rate is the biggest issue. Twelve percent of athletes needed a repeat of the surgical procedure, the study found, which raises questions about the efficacy of current techniques in high-level, high-impact athletes.

Chao questioned the use of the surgical screw itself and wonders whether its shape could be improved.

“I’ve altered the technique slightly and seen results in a small sample,” he said.

There is very little in the way of research on Jones fractures or even related conditions in American football players. But, if we look across the ocean at the wealth of research on European soccer players, there’s a lot that can translate, despite the differing physical demands of the two sports. For example, a 2013 Swedish study4 of fifth metatarsal fractures in 64 elite European soccer teams found—as Lareau’s NFL study did—that the injury was particularly common in the youngest players. Interestingly, the Swedish study also found that 45% of injuries were associated with a prodromal period, which suggests an opportunity for early intervention that NFL teams might find worth exploring.

Opportunities

The climate of acceptance of scientific research and sports science is significantly higher in European soccer than it is in American football. Even the less-popular Major League Soccer (MLS) league is demonstrating more acceptance of both sports medicine and sports science than the NFL, including an emphasis on injury prevention. For the MLS, the relative youth of the league and the relatively high average age of its star players has created a need for quick results, so we haven’t seen a major increase in published research, but I’ve heard that inside the clubs there’s been quite a bit of work, as well as collaboration with larger clubs in Europe.

However, the specifics of the foot and ankle complex injuries involve unique issues that could affect injury prevention efforts. It’s impossible to upgrade the basic human anatomy, and it would be difficult to make wholesale changes to currently popular footwear designs. But that would suggest an opportunity for customization within the framework of the shoe, such as orthotic devices and other interventions that augment what is available.

There are great opportunities for advancement, but only if the right studies and experiments are done, then transferred to practice. The NFL, and American professional sports organizations in general, tend to be well behind the curve in research. And, when individual leagues or teams do their own research, there is little sharing, which increases the risk that any findings will be applied inconsistently or inappropriately.

The crisis of Achilles and other foot/ankle complex injuries is not being addressed from a preventive basis by stakeholders like the NFL. A clear opportunity exists for further research that is both focused and funded.

Will Carroll is a writer in Indianapolis who specializes in covering injuries in professional sports.

REFERENCES
  1. Parekh SG, Wray WH 3rd, Brimmo O, et al. Epidemiology and outcomes of Achilles tendon ruptures in the National Football League. Foot Ankle Spec 2009;2(6):283-286.
  1. Mai HT, Alvarez AP, Freshman RD, et al. The NFL Orthopaedic Surgery Outcomes Database (NO-SOD): The effect of common orthopaedic procedures on football careers. Am J Sports Med 2016;44(9):2255-2262.
  1. Lareau CR, Hsu AR, Anderson RB. Return to play in National Football League players after operative Jones fracture treatment. Foot Ankle Int 2016;37(1):8-16.
  1. Ekstrand J, Van Dyjk CN. Fifth metatarsal fractures among male professional footballers: a potential career-ending disease. Br J Sports Med 2013;47(12):754-758.
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One Response to How foot and ankle injury trends reflect today’s NFL

  1. teri green says:

    Foot and ankle injuries are increasing in high school football programs. They can be decreased in my opinion with education of foot and ankle injuries. They can be helped with heat mold orthotics, foot pads and heel lifts. In my experience, a good podiatrist can educate these athletes on proper foot care. For example, in turf toe, a steel plate insole can make a huge difference. In some cases, orthotics, change of shoe gear, foot pads can help. Great article, thanks,

    Teri Green
    Atlas Biomechanics

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