Biomechanical mechanisms impacting the injury potential of positioning roles during football striking

Abstract

The mechanisms of knee injury, despite an abundance of research remain vague, especially within football. Therefore, the aim of this study was to investigate how differentiating striking patterns and trunk angles impacted loading at the knee across field positional roles. Eleven Caucasian male football players of similar age (20 ± 1 years), height (183 ± 6 cm) and mass (79 ± 7 kg) who currently represented a university first team were utilised for the study. Each joint centre was marked using active CODAMotion markers (200 Hz) and performed two striking methods; a lofted strike and a driven strike, on a forceplate (9287B, Kistler, Winterthur, Switzerland) (1000 Hz) embedded within a Mondo surface. Inverse dynamics was utilised as a method of estimating internal joint loads acting at the lower extremity joints, with particular emphasis on the knee joint. Internal joint force (IJF) data were normalised to body weight and muscle moment (MM) data to the segment mass divided by its length. There were deemed to be significant differences (P < 0.05) between trunk angles across striking methods and significantly larger (P < 0.05) IJF of 3.3 body weights at the knee joint during lofted striking. Goalkeepers and defenders were deemed the most ‘at risk’ position of sustaining injury to the knee joint, with attackers deemed the least ‘at risk’. Therefore, extended trunk angles, as seen in lofted striking are deemed to increase internal loading at the knee and flexed trunk angles seen to reduce loading at the knee. While this study suggests that while no position predisposes an individual to knee injury, due to the mechanics of their typical striking methods, defensive players are at higher risk.