Exploring the inter-limb asymmetries of football players with coordination impairments: A practical approach for evidence-based classification

Classification is an essential component that tries to minimize the impact of the eligible impairment on the outcome of the competition by grouping athletes into specific classes based on sport-specific activity limitations. Cerebral palsy (CP) football is a team sport designed for individuals with eligible coordination impairments (i.e., hypertonia, ataxia, athetosis) affecting motor skills and resulting in abnormal patterns, including asymmetries. Notable inter-limb asymmetries have been a popular research topic that can have practical implications for the classification of footballers with CP. This study aims to 1) quantify interlimb asymmetries using change of direction and unilateral jump tests, and 2) examine the relationship between asymmetry variables and physical test performance outcomes. International male football players (N = 142) with eligible impairments participated. Participants completed two trials of the 10-m sprint, dribbling speed test, and the 505 change of direction test for both dominant and non-dominant legs, followed by single-leg vertical and horizontal jumps. Paired t-test analysis highlighted significant differences between dominant and non-dominant legs in 505 (p < .01), and horizontal jump (p < .01), but not in the countermovement jump (p > .05). Significant associations were found between horizontal jump asymmetries and sprint capacity (p < .01), dribbling with the ball (p < .05), and vertical jump (p < .01). Additionally, higher vertical jump asymmetry was associated with reduced dribbling speed (p < .05) and unilateral horizontal jump (p < .05). No significant associations were found between change of direction asymmetry and physical test performance outcomes. Larger asymmetries are associated with slower sprints, decreased dribbling speed, and reduced jump performance. Asymmetry variables can bring valuable data for classifiers employing these tests to assess the impact of impairments on specific activity limitation tests. Further studies should consider classes or impairment profiles of players with CP.