A method for characterizing high acceleration movements in small-sided football

Small sided football is the most popular area of adult football in the UK, with an estimated 1.5m adults playing every week. Matches are played on smaller pitches using different rules to the 11-a-side game; this results in less stoppage time and a higher volume of ball activity per player. Despite these established differences in playing style and the increase in participation, the types and frequencies of movements performed are not fully understood due to the time consuming nature of current notational analysis methods. Understanding movements is of particular interest to researchers and developers seeking task representative protocols and products for small sided football. The importance of movement type, specifically those with high horizontal plane accelerations, has been demonstrated by recent findings linking traction and shoe stiffness to injury and performance in a number of team sports. In this paper we introduce a new motion analysis technique that uses a combination of inertial sensors and manual notational analysis to describe high acceleration movements in a repeatable and more time effective manner than previously published. A recreational 5-a-side team (mean ± SD: age 17.8 ± 0.26 years, body height 1.77 ± 0.05 m, body mass 74.23 ± 16.25 kg) were observed during one season at a commercial football centre. Player mounted sensors were used to identify 1824 high acceleration movements from three players in seven matches. These movements were then classified using operational definitions adapted from notational analysis literature. This paper outlines a high acceleration movement analysis technique, provides normative high acceleration movement profiles for three individual 5-a-side players, and suggests comparisons to published 11-a-side data. These movement profiles provide a foundation for footwear researchers and product designers to re-align their current practice or products from the 11-a-side game to this more popular style of football.