A team of British and Canadian researchers has concluded that injury incidence rates between synthetic turf, hybrid and grass pitches, do not significantly differ. However, they did notice differences in mean severity and mean burden of injuries sustained between playing surfaces.
Researchers of the Centre of Health and Injury and Illness Prevention in Sport of the University of Bath and the London School of Hygiene and Tropical Medicine in the UK, as well as the Sport Injury Prevention Research Centre of the University of Calgary and the O’Brien Institute of Public Health in Calgary in Canada base their analyses on injury match data of 15 professional, English men’s rugby teams for games in the domestic and European competitions during the seasons between 2013 and 2019. The researchers were supported by the English Rugby Football Union and the English Premiership Rugby.
The dataset included 3351 injuries from a combined European and domestic data set whereby the surfaces were separated in the categories synthetic turf and natural/hybrid surfaces, and 2675 injuries from a domestic only dataset whereby the surfaces were separated into three categories; artificial, hybrid, and natural surfaces.
No differences in incidence rates were noticed between surface types on combined European and domestic match data. However, with 3082 days/1000 h, 95% CI 2847-3337, injury burden was significantly greater on synthetic turf. For comparison, data obtained for natural/hybrid surfaces showed 2364 days/1000 h, 95% CI 2277–2454, p < 0.001.
Interestingly, when natural, hybrid, and synthetic turf surfaces were compared as three categories, there was no significant difference between hybrid surfaces and either natural grass or synthetic turf. The significant difference in the domestic only dataset came between synthetic turf and natural grass with synthetic surfaces producing the more severe injuries.
Higher hip/groin and foot/toe injuries
The differences were primarily driven by a significantly greater mean severity of hip/groin, and foot/toe injuries on synthetic turf surfaces. A good example is the Turf toe, a sprain of the ligaments around the big toe joint.
The reason for this increase has been hypothesized; greater torque and rotational stiffness experienced in lower limbs on such surfaces have been suggested as the rationale for this, particularly in certain surface/boot combinations with injury location and mechanism being discussed in multiple studies on National Football League (NFL).
The NFL has recently started to direct significant investigation into the influence of boot-surface interaction and on forces applied to athletes during match play. This relationship may have a key role to play in terms of dissipation of force along the lower limb kinetic chain and therefore could impact on the severity of injuries sustained. Without adequate force dissipation, greater rotational and shear forces may be applied to lower limb tissues. This greater force may exceed the capacity of those structures to a greater extent than on grass and therefore modify the subsequent severity of injuries sustained on artificial surfaces, although it should be acknowledged that there is wide variation in the properties of natural surfaces. A recent, mechanistic analysis of boot-surface interaction may offer some further support of this theory. The review suggested that on contact between the players’ footwear and artificial pitch surface, the pitch infill compresses and becomes denser. As a result, the player will experience an increase in peak forces and different loading rates compared with a natural grass surface.