Can the natural turf pitch affect injury risk and performance within elite football

Abstract

Abstract Historically, natural turf has been the pitch of choice within elite English football. However, its susceptibility to both climatic variation and footfall affecting its hardness, catalyzed the development of more robust, hybrid natural turf pitches. Despite such evolution, stakeholders continue to question the role hardness plays regarding injury on such natural turf. Unfortunately, the literature is scarce and lacks objective measures of pitch hardness providing no evidence to support or refute these concerns. Thus, the primary aim of this thesis was to question the role of natural turf hardness in both injury and performance in elite football. The first study (Chapter 3) established that 87% of stakeholders within football perceived pitch hardness to be a major injury risk. Relative risk to specific tissues was perceived to be dependent upon the surface namely hard pitches affecting joint/tendons whilst soft pitches increased risk of ligamentous and ligament strains. The second study (chapter 4) developed the necessary methodological procedures for the objective evaluation of pitch hardness. The study proposed the use of a portable and practical objective measure of hardness (Clegg Hammer 2.25kg), evaluated its reliability and formulated a protocol for its use. This new protocol was then used within the remaining chapters to evaluate the pitch hardness. Chapter 5 established the temporal and spatial variation of natural turf, over eight football seasons, showing pitches have become harder. Such was the variation in hardness that over 23% of pitch exposures fell outside of UEFA’s recommendations. It also established for the first time that the new hybrid natural turfs are significantly harder but less variable than native soil. The novel findings of chapter 6 showed that injury incidence, injury burden and even the type of tissue at risk may be related to the hardness of the natural turf pitch. It also demonstrated that the type of hybrid pitches carry their own injury profile. The final pitch hardness manipulation study (chapter 7), the first of its kind, provided insight into how such surface hardness affects external and internal loads experienced by players. In summary, this thesis has taken the first step towards exploring how the hardness of natural turf pitches could be viewed as a risk factor for injury within elite football. The novel design and methodology enabled detailed investigation of how natural turf pitches are changing and affecting both injury and performance. Profiles of injury, and technical and physical performance measures, were found to be dependent upon relative surface hardness. These findings provide clarity to those working within the applied setting enabling stakeholders to maximize player performance, whilst mitigating injury risk.