Incidence of football injuries sustained on artificial turf compared to grass and other playing surfaces: a systematic review and meta-analysis

Imaging and Surgical Procedures After Surface-Related Collegiate Football Injuries on Artificial Turf Versus Natural Grass: Prevalence and Trends Over 15 Seasons

Background

Few longitudinal studies exist comparing medical procedures after football injuries on artificial and natural grass surfaces.

Purpose/Hypothesis

The purpose of this study was to specifically compare imaging and surgical procedures after surface-related collegiate football injuries on artificial turf versus natural grass. It was hypothesized that there would be no difference in the incidence of imaging and surgical procedures, combined medical procedures, or combined substantial and severe injuries over time between these surfaces.

Study Design

Cohort study; Level of evidence, 2.

Methods

A total of 39 universities across all Football Bowl Subdivision conferences were evaluated over 15 seasons (2006-2020). Playing surfaces evaluated were either a heavyweight artificial turf infill system (≥9.0 lb infill/ft2) or natural grass. Outcomes of interest included medical procedures across injury category, primary injury type, injury location, and specific procedures. Data involved multivariate analyses of variance (MANOVA) and Wilks λ criteria using general linear model procedures and were expressed as medical procedure incidence rates (IRs) per 10-game season.

Results

Overall, 2224 games were documented: 1106 (49.7%) on artificial turf and 1118 (50.3%) on natural grass. Of the 9137 total injuries reported, 4010 (44%) were surface-related cases. MANOVA indicated significant main effects between surfaces according to imaging procedure (F 2,1738 = 4.718; P = .009), surgical procedure (F 1,539 = 5.974; P = .003), and medical diagnosis (F 2,456 = 2.643; P = .040). Post hoc analyses indicated significantly lower (P < .05) incidences on artificial turf versus natural grass, respectively, for the following outcomes: imaging procedures ordered after player-to-surface impact trauma (IR [95% CI], 1.5 [1.3-1.8] vs 2.1 [1.9-2.4]), shoe-to-surface trauma during physical contact (4.4 [4.1-4.7] vs 5.2 [4.9-5.5]), foot injuries (0.6 [0.5-0.7] vs 1.1 [0.9-1.2]), ligament sprains/tears (4.6 [4.3-4.9] vs 5.3 [5.0-5.6]), muscle strains/tears (0.2 [0.2-0.3] vs 0.7 [0.6-0.9]), surgeries performed after shoe-to-surface trauma during physical contact (1.1 [0.9-1.3] vs 1.6 [1.4-1.8]), lower body surgeries (1.8 [1.6-2.0] vs 2.3 [2.1-2.6]), and surgeries involving ligament tears (1.0 [0.9-1.2] vs 1.5 [1.3-1.7]), as well as fewer diagnoses of syndesmosis sprains/tears (0.7 [0.5-0.8] vs 1.0 [0.8-1.2]) and Lisfranc trauma (0.3 [0.2-0.4] vs 0.5 [0.4-0.7]). Trends over the 15 seasons indicated a significant rise in combined medical procedures (P = .005) and combined substantial and severe injuries (P = .0007) irrespective of surface.

Conclusion

Results indicated that collegiate football competition on heavyweight artificial turf resulted in lower incidences of imaging and surgical procedures and medical diagnoses compared with natural grass.

Evaluation of surface type and time of day on agility course performance

Introduction

Canine agility competitions are performed on a variety of surfaces. In the equine and human literature, surface type has been associated with speed, performance, and injury risk. The aim of this study was to evaluate the effect of general surface type and time of day on calculated speed (yards per second over a measured course distance) and course performance during the UKI Agility International (UKI) U.S. Open. We hypothesized that surface type would affect calculated speed, with sand being the slowest.

Materials and methods

Data on course performance from the 2021 and 2022 events were obtained directly from UKI. The officiating judge measured course length, automatic timers recorded dogs' course times, and speeds were calculated from these values. Three surfaces (dirt, grass, and sand) were compared across three categories of courses (jumpers, standard, and speedstakes). Differences in calculated speeds and qualifying rates were estimated using generalized estimating equations (GEE) to account for multiple runs by the same handler.

Results

Among jumpers courses, those run on sand in 2021 were markedly slower than those run on dirt. Grass and dirt were more similar in terms of average calculated speed, though some courses run on grass were significantly faster than courses run on dirt and vice versa. Time of day effects observed were inconsistent, with more variability observed for dirt and sand than for grass.

Discussion

There was a notable variation in calculate speed based on surface with sand being slowest, likely due to the increased energy cost required to run on sand due to its high compliance. Calculated speeds on grass and dirt appeared generally similar, but there was substantial variability of calculated speed among various courses, making comparison of surface effects challenging. Variables within the surface itself (such as compaction level and moisture content) likely play a role in the effects of surface on speed and performance. This study provides insight into the complexity of surface effects on performance in agility dogs and highlights the need for canine-specific surface studies on the effect of surface variables and how these relate to risk of development of musculoskeletal injuries.