Executive Summary

Not every study in this library confirms a favorable picture for synthetic turf, and this is one Act Global believes deserves a direct, unhedged review rather than a quiet skip. Published in 2019 in the American Journal of Sports Medicine, this Georgetown University / MedStar-led study analyzed a decade of NCAA football injury surveillance data — one of the largest datasets ever assembled on this question — to compare knee ligament injury rates on artificial turf versus natural grass.

The headline finding is not favorable to artificial turf for certain injury types, and we think field owners are better served by understanding it clearly, in context, than by not hearing about it at all.

Key Findings

Study scope: 3,009,205 athlete-exposures and 2,460 knee injuries across NCAA football, 2004–2005 through 2013–2014 seasons (10 seasons) — the largest surface-comparison dataset of its kind for this injury category.
PCL (posterior cruciate ligament) tears occurred at 2.94 times the rate on artificial turf compared to natural grass during competitions — a statistically significant difference (RR = 2.94; 95% CI 1.61–5.68).
Stratified by division: Division I athletes experienced PCL injuries at 2.99× the rate on turf during competitions. Division II/III athletes experienced ACL injuries at 1.63× the rate and PCL injuries at 3.13× the rate on turf compared to grass.
No statistically significant difference was found for MCL, medial meniscal, or lateral meniscal injuries between the two surfaces — the elevated risk was specific to cruciate ligament (ACL/PCL) injuries, not knee injuries broadly.
No significant differences were found in practice settings — the elevated injury rates were specific to competition play, a pattern consistent with other research in this library (see Howard et al. 2020) showing that game intensity and context matter as much as surface type.

Important Limitations

The study could not identify specific turf type, generation, or product. All synthetic surfaces were classified identically, regardless of fiber technology, infill system, shock pad presence, or installation age. This matters significantly: the data spans 2004–2014, meaning much of it reflects synthetic turf systems that are now 15–20+ years old and predate significant advances in fiber design, infill engineering, and shock-absorbing underlayment.
This is a surveillance dataset, not a controlled experiment. It cannot isolate surface type from other variables that may correlate with it, such as regional climate, field maintenance quality, or which programs and divisions historically installed turf versus grass.
Absolute injury counts for PCL tears were small (116 total across the full 10-year dataset), which produces wide confidence intervals, particularly in the Division II/III subgroup analysis (95% CI up to 10.69 for PCL).
The study does not report on overall injury rates across all injury types — it focuses specifically on knee ligament and meniscal injuries.

Why This Matters

This study is frequently cited in public debate about turf safety, and for good reason — a nearly threefold increase in PCL injury rate, drawn from three million athlete-exposures, is a real signal, not noise. Architects, athletic directors, and parents evaluating a field should take it seriously rather than dismiss it.

At the same time, the study’s own stated limitation — that it cannot distinguish between turf products or generations — is the single most important caveat for anyone using this data to make a purchasing decision today. A dataset built on turf installed between 2004 and 2014 is, by definition, evaluating systems that predate more than a decade of subsequent engineering changes in fiber technology, infill design, and shock pad specification. That doesn’t erase the finding. It does mean the finding tells us less about “artificial turf” as a single category and more about turf technology as it existed during that specific window.

Act Global Perspective

We’re publishing this review because Act Global’s approach to research transparency means including findings that don’t flatter the category, not just the ones that do. A synthetic turf manufacturer that only cites favorable studies isn’t building trust — it’s building a highlight reel.

What this study reinforces for us operationally is that rotational resistance and traction release — the mechanical properties most directly implicated in ACL/PCL injury mechanisms — are not properties that come standard just because a surface is labeled “synthetic turf.” They are specific, testable, engineerable characteristics that vary meaningfully between systems and generations. This is precisely why Act Global publishes independent rotational resistance test data for our current systems rather than asking field owners to take turf safety on faith across the category as a whole. We’d encourage any organization evaluating a field — new or existing — to ask for surface-specific traction and release testing data, not rely on turf-versus-grass generalizations from any single study, including this one.

Related Resources

Access the Original Study

This review is Act Global’s independent summary of publicly available peer-reviewed research, prepared for educational purposes. Act Global does not host or reproduce the original article. Read the full study directly from the publisher:

Loughran GJ, Vulpis CT, Murphy JP, Weiner DA, Svoboda SJ, Hinton RY, Milzman DP. “Incidence of Knee Injuries on Artificial Turf Versus Natural Grass in National Collegiate Athletic Association American Football: 2004-2005 Through 2013-2014 Seasons.” American Journal of Sports Medicine, 47(6):1294–1301, 2019. DOI: 10.1177/0363546519833925

This is an Act Global Research Review — an independent interpretation of publicly available peer-reviewed research prepared for educational purposes only. It does not constitute medical, legal, or engineering advice.

Vincent Garcia

NCAA Knee Injuries: Turf vs. Grass, 10-Season Data | Act Global