Biomechanical understanding of English Premier League players
As part of the visit of Leeds United for their pre-season testing in 2021 and 2022, academics from the Carnegie School of Sport (CSS) collaborated with club staff to undertake research that improves our biomechanical understanding of English Premier League players.
The team underwent physical performance tests at the high-tech Carnegie School of Sport building at our Headingley Campus. High-speed video cameras, force platforms and an isokinetic dynamometer were used to conduct jumping and change-of-direction assessments, as well as for evaluation of running gait and muscle strength.
Our novel research investigation examined the preferred running style of the first team squad and is the first analysis of its kind in the English Premier League. Not only is the English Premier League one of the most physically intensive leagues in Europe, but the findings are also hugely insightful as the analysis was conducted when Marcelo Bielsa was manager. Leeds United at this time were renowned for their physical fitness, distances covered and aggressive pressing style. Animal metaphors are used greatly in gait research, and the research team found it useful to describe players as “gazelles” or “grizzly bears” based on the way these animals run.
The “gazelle-style” players had a spring-like vertical bouncing manner and might be more economical in their running style, potentially making them suited to continuous box-to-box running. By contrast, the “grizzly-style” players had a more grounded, horizontal gait and are potentially more suited to short sprints and fast changes in direction. The identification of individual players’ running styles is an attractive proposition for coaches and support staff, especially when interpreted alongside in-game data obtained from global-positioning systems (GPS). Running style preferences could have implications for the running capabilities and recovery needs of players, which are key considerations in the modern game where aggressive pressing tactics continue to be adopted and coaches have the capacity to use up to five substitutes.
Another new research investigation examined the interlimb asymmetries (i.e., right versus left leg imbalances) of the first team squad and interpreted this relative to players’ dominant kicking legs. The preferred kicking leg did not display clear dominance in a range of running, jumping and change-of-direction activities. However, the preferred kicking leg did have a notable influence on muscle strength in the lower limb, with players having stronger hamstring muscles in the kicking leg but stronger quadriceps (thigh) muscles in the non-preferred leg. These strength differences raise important considerations for injury-reduction strategies, particularly for players who display pronounced preferences. The findings of this research are expected to inform the future monitoring practices of football medical teams with potential applications to all levels of the game.
The research further strengthens the firm relationships that exist between the Carnegie School of Sport and club staff, and is testament to the forward-thinking approach of the Leeds United sports science and medical team who are committed to ensuring that the team’s training and injury prevention strategies remain up to date with the latest developments. Students on the School of Sport’s undergraduate, postgraduate and research programmes now benefit from this research, which further enhances the expertise within the Centre for Human Performance at the University.
The research is available here and is free to download.
Gareth Nicholson is a Course Director for the Postgraduate Suite of Sports Science courses and a Senior Lecturer in Sport and Exercise Biomechanics within the School of Sport.