Injuries are an unfortunate aspect of sports that can potentially derail an athlete’s career, future earnings, and team success. Injuries vary depending on the sport being played. For example, the knee and ankle joints are the are the two most common injuries football players [6]. Several factors may predispose players to joint injuries including age, position played, time of sport season, footwear, and inadequate recovery in the offseason [6]. Recently, the discussion of playing surface and injury has become a hot topic by NFL players, specifically increased injury prevalence on artificial turf, also known as synthetic turf, compared to grass. This article will briefly touch on the history of turf fields and why they may predispose athletes to injury.
Synthetic turf fields have been used regularly since the 1960s. These structures involve a matrix of superficial artificial fibers interspersed with rubber or sand and various layers of ground rock and cushioning underneath for stability, drainage, weed barriers, and contact absorption. Adoption of turf fields has been increasing over several decades due to many benefits of these fields. The lifespan of turf fields are about 10 years and require very little maintenance. Fields can also be placed locations independent natural resources due to no requirements for water, sunlight, or altitude [1]. The primary drawback of synthetic turf fields is the steep up-front cost, which can be upwards of over $1 million. Compared to the lifetime natural grass fields, though, maintenance costs over the life of the field can be tens of thousands of dollars cheaper than a grass field, making synthetic turf a cheaper option [2]. Additionally, synthetic turf fields may harbor bacteria, contribute to environmental pollution, and may contribute to sports injuries.
Synthetic turf may be a boon to those planning for field development due to the costs. Those who use the fields may have different opinions. NFL players frequently discuss their concerns and frustrations with career-altering injuries when playing on synthetic turf. Beyond the cost and durability of synthetic vs natural turf surfaces, the forces interacting between the ground and the foot of the athlete vary depending on the material. A primary concern when dealing with the cleated foot on an impact surface is the release point of the cleat from the ground. Due to natural grass and topsoil normally being destroyed by the athlete’s foot during motion, this serves as its own rate-limiting step and reduces the number of linear and rotational forces acting on the player [3]. Synthetic turf has a much slower cleat release rate. This is due to the combination of turf fiber material, size and thickness of rubber chunks mixed with fiber, depth of the combined materials, and inability of the material to tear during athlete movement, which may ultimately contribute to injury. Most athletes may not discuss specific movements on turf being felt. Rather, they discuss feeling more injured in general after playing on synthetic turf [4]. Increased injury prevalence has been a concern on synthetic fields, with the surface even gaining name recognition with “turf toe”, or hyperextension injury of the big toe.
Most NFL players and current evidence suggests synthetic turf has a higher incidence of non-contact lower body injuries [4]. Injuries vary in severity and duration, with ankle and knee injuries being the most common region affected. Several other factors played a role in injury prevalence, including age of player, style of cleat used, and time of season [5,6]. As previously mentioned, one probable issue is the contact between the cleat and the ground causing inappropriate joint and soft tissue mechanics, which may ultimately result in injury. Changes to the turf overtime, including damage to the synthetic fibers and loss of rubber filling, may also play a role in lower body injury.
The type of surface athletes use for their sports may continue to be a polarizing topic. Synthetic fields offer access to a playing surface in areas that may otherwise not be able to sustain an alternative grass field, though it appears to pose a higher risk for injury. This may be avoided by using specific footwear depending on the surface played on may be beneficial, as will the groundskeeper managing normal wear-and-tear on the field. Unfortunately, due to the complex nature and interactions between professional athletes and the field surfaces they play on, injuries will always be a reality of professional sports. The responsibility of the medical staff and leaders of professional sports is athlete success and competing minimal fear of injury. If current evidence suggests synthetic turf increases injury, it may be time to return to grass until new surfaces can reduce injury.
References:
1. Fleming, P. Artificial Turf Systems for Sport Surfaces: Current Knowledge and Research Needs, Journal of Sports Engineering and Technology, 3 Feb. 2011, citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=5ccf06ee5526de9e9.
2. Claudio, Luz. “Synthetic Turf: Health Debatetakes Root - Environmental Health Perspectives.” Environews, Environmental Health Perspective, Mar. 2008, ehp.niehs.nih.gov/doi/full/10.1289/ehp.116-a116.
3. Jastifer, James R, et al. “The Development of Mandatory Practices for the Testing and Maintenance of Synthetic Turf Fields in the National Football League.” International Turfgrass Society Research Journal, Wiley Online Library, 21 Sept. 2021, onlinelibrary.wiley.com/doi/full/10.1002/aenm.202103022.
4. Contributors, Multiple. “Inside the NFL Turf Debate: Injuries, Safety Measures, Problems.” ESPN, ESPN Internet Ventures, 11 Oct. 2023, www.espn.com/nfl/story/_/id/38624943/injuries-safety-measures-more.
5. Winson, Daniel MG, et al. “Foot Injuries, Playing Surface and Shoe Design: Should We Be Thinking More about Injury Prevention.” Foot and Ankle Surgery, Elsevier, Aug. 2020, www.sciencedirect.com/science/article/abs/pii/S1268773118304417.
6. Ready LV, Li NY, Worobey SJ, Lemme NJ, Yang J, Owens BD. Misconceptions in NFL Injuries: A Study on the Achilles. Foot & Ankle Orthopaedics. 2019;4(4). doi:10.1177/2473011419S00352