Executive Summary
This 2022 meta-analysis from Stanford University School of Medicine addresses a specific, important question that broader turf-versus-grass studies often average away: does ACL injury risk on artificial turf differ by sex? The researchers were motivated by prior biomechanical research showing that artificial turf can produce higher rotational friction (“traction”) at the shoe-surface interface than natural grass — a mechanical property directly implicated in non-contact ACL injury mechanisms, particularly during cutting and pivoting.
The meta-analysis pooled data from 7 studies meeting inclusion criteria, all of which evaluated third-generation artificial turf — meaning the findings reflect modern turf systems, not outdated technology.
Key Findings
- Female soccer players showed significantly higher ACL injury incidence on artificial turf during games — approximately 1.18 times the rate on natural grass. This finding was statistically significant.
- Male soccer players showed no significant difference in ACL injury rate between surfaces. The elevated risk identified in this meta-analysis is specific to female athletes, not a general turf-versus-grass effect.
- All included studies evaluated third-generation turf systems — long fibers with rubber or alternative infill — meaning this finding is directly relevant to the type of turf currently being installed, not a legacy-technology artifact.
- The proposed mechanism, per the underlying biomechanical literature the authors cite: higher rotational friction on turf may increase resistance to foot release during pivoting movements, a factor more frequently implicated in female non-contact ACL injury patterns.
Important Limitations
- Only 7 studies met inclusion criteria — a relatively small evidence base for a meta-analysis, which limits statistical power and the ability to explore why the effect appears in games but not consistently across all settings.
- The analysis is limited to professional and collegiate levels of play. It does not address youth or high school soccer, where field conditions, athlete conditioning, and turf specification often differ substantially.
- Data on practice settings was limited, so this finding is most robust for competitive match play specifically, not all turf exposure.
- As with all injury epidemiology research, this meta-analysis identifies an association, not a fully isolated causal mechanism — other correlated factors (playing style, competition intensity, athlete conditioning differences by sex) cannot be completely ruled out.
- The review does not break results down by specific turf brand, infill type, or fiber technology — “third-generation turf” as a category still spans considerable variation in system design.
Why This Matters
This is an important, sex-specific finding that broader “turf vs. grass” injury summaries can obscure by averaging male and female data together. For organizations managing women’s and girls’ soccer programs specifically, this research is directly relevant to field selection and cleat/traction guidance — and it is not resolved by pointing to turf-versus-grass studies that don’t disaggregate by sex.
It’s also a finding that points toward a specific, addressable mechanical property — rotational traction and release — rather than an unavoidable property of “artificial turf” as a category. That distinction matters for what field owners and manufacturers can actually do about it.
Act Global Perspective
We think this is one of the more actionable findings in our Research Library, because it points directly at a testable, engineerable system property: rotational resistance. If the proposed mechanism is correct — that turf’s traction characteristics can create excess resistance during pivoting — then rotational resistance testing, and system design choices like fiber structure and infill selection that influence release characteristics, are the concrete levers available to address it, rather than treating elevated risk as an unavoidable tradeoff of choosing turf.
We’d also encourage organizations running competitive women’s and girls’ soccer programs to ask directly for a system’s rotational resistance test results and to have a conversation with turf providers about cleat compatibility — this is a case where the research points to a specific mechanical variable worth discussing at the specification stage, not a general caution to be noted and set aside.
Related Resources
- Rotational Resistance Explained — Traction and Lower-Extremity Injury Risk
- ACL Injury Risk on Synthetic Turf vs. Natural Grass — Review of Howard et al. 2020
- Incidence of Football Injuries on Artificial Turf vs. Grass — Review of Kuitunen et al. 2023
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 (open access):
- Xiao M, Lemos JL, Hwang CE, Sherman SL, Safran MR, Abrams GD. “Increased Risk of ACL Injury for Female but Not Male Soccer Players on Artificial Turf Versus Natural Grass: A Systematic Review and Meta-Analysis.” Orthopaedic Journal of Sports Medicine, 10(8), 2022. DOI: 10.1177/23259671221114353
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.
