Artificial turf increases the risk of several types of injuries compared to natural grass, particularly non-contact injuries to the knees, ankles, and feet. NFL injury data collected from 2012 to 2018 showed players had a 28% higher rate of non-contact lower extremity injuries on turf. The reasons go beyond just injury rates, touching on surface heat, chemical exposure, and how these fields change as they age.
Higher Rates of Non-Contact Injuries
The biggest concern with artificial turf is what it does to joints during cutting, pivoting, and planting movements. In college football, the rate of ACL injuries on artificial surfaces is 1.39 times higher than on grass. Non-contact injuries, where no other player is involved, account for 44% of injuries on turf compared to 36% on grass. That gap points to the surface itself as the problem, not the collisions happening on it.
The NFL Players Association has been especially vocal about this. Their data shows a 32% higher rate of non-contact knee injuries on turf and a 69% higher rate of non-contact foot and ankle injuries. The NFLPA is now advocating for all teams to convert their practice and game fields to natural grass, stating plainly that “playing on turf is not in the best interest of our players.”
How the Surface Grips Too Much
Natural grass gives way when a cleat digs in. Blades bend, roots shift slightly, and the soil beneath has some forgiveness. Artificial turf doesn’t behave the same way. When a cleat catches in synthetic fibers and rubber infill, the surface resists rotation more aggressively, especially in the first few degrees of foot movement. Biomechanical testing shows that longer studs increase both the stiffness and the peak torque the surface produces, meaning your foot locks in place while your knee or ankle keeps turning.
This initial resistance, that first moment when your cleat catches and holds, is likely the mechanism behind the higher ACL and ankle sprain rates. Athletes don’t typically rotate their feet far enough to reach the point where the surface finally releases. Instead, the force transfers up through the ankle and knee before the foot can free itself.
Extreme Surface Temperatures
Artificial turf gets dramatically hotter than grass in direct sunlight. Research from the University of Kansas measured surface temperatures on turf reaching as high as 136°F, while grass fields topped out around 91°F. On average, turf surfaces ran about 95°F compared to 75°F for grass, a 20-degree difference.
That said, the heat story is more nuanced than it first appears. When researchers measured overall heat stress at chest height (about four feet off the ground), the readings were nearly identical between turf and grass. There are no confirmed reports of higher heat illness rates among athletes on turf compared to grass. The surface is genuinely hot to the touch, which matters for skin contact and ground-level heat, but the air around you isn’t drastically worse. For athletes who spend time on the ground, like football linemen or soccer goalkeepers, the surface heat is more relevant than for those who stay upright.
Turf Burns and Infection Risk
Sliding or falling on artificial turf causes friction burns that natural grass rarely produces. These abrasions strip away skin and create open wounds that are vulnerable to bacterial infection. MRSA, a drug-resistant staph infection, has become more prevalent among athletes, and turf burns provide an easy entry point for the bacteria.
The turf itself doesn’t harbor bacteria for long. Penn State research found that staph bacteria applied to synthetic turf in sunlight dropped to less than 1% survival within two hours. The real risk comes from the wound, not the field. A turf burn that isn’t properly cleaned and covered can pick up bacteria from shared equipment, skin-to-skin contact, or locker room surfaces in the hours and days that follow.
Chemical Concerns in Crumb Rubber Infill
Most artificial turf fields use crumb rubber made from recycled tires as infill. This material contains heavy metals, with zinc being the most abundant at concentrations between 2,989 and 5,246 milligrams per kilogram. In many samples, zinc and lead levels exceed the safety limits set in European standards for soil and children’s toy materials.
Athletes are exposed to these chemicals through three routes: inhaling dust and volatile compounds released from heated infill, absorbing chemicals through skin contact, and accidentally ingesting small particles. The backing of turf systems can also contain PFAS, a class of industrial chemicals that persist in the body and the environment. While the concentrations found in individual turf samples are generally low, the exposure is cumulative and repeated for athletes who train on these surfaces daily. Basic precautions like washing hands after play and showering promptly reduce exposure, but they don’t eliminate it.
Fields Get Harder With Age and Use
Artificial turf isn’t static. Over time, the infill compacts, the synthetic fibers break down, and the surface loses its ability to absorb impact. ASTM International sets a maximum allowable hardness rating (called G-max) of 200 for synthetic fields. As a field ages, its G-max value climbs with heavy use, compaction, and infill settling. A harder surface means more force transmitted to the body during falls, tackles, and landings.
This degradation is particularly concerning for facilities that don’t test or maintain their fields regularly. A well-maintained turf field in its first few years performs very differently from a neglected one approaching the end of its lifespan. Many youth and recreational fields don’t receive the same attention that professional venues do, which means the athletes most likely to play on degraded surfaces are the ones with the fewest resources to address injuries when they happen.
Why the Debate Continues
Artificial turf exists because it solves real problems. It handles heavy use without turning to mud, requires no watering or mowing, and stays playable year-round in climates where natural grass struggles. For schools and municipalities with limited budgets, it can be more practical than maintaining a high-quality grass field.
But the trade-offs are real. A 28% increase in non-contact lower extremity injuries isn’t a rounding error. Surface temperatures that reach 136°F create genuine discomfort and risk for athletes close to the ground. Heavy metals in infill exceed established safety thresholds. And the surface gets worse, not better, with time. For athletes who train and compete on turf daily, these factors compound in ways that occasional recreational players may never notice.