Match Exposure and Estimated Travel Before ACL Injury in Professional Women’s Football: An Exploratory Within-Player Case-Crossover Study

Anterior cruciate ligament (ACL) injuries are a substantial concern in professional women’s football and involve a complex interplay of intrinsic and extrinsic factors. Pre-injury match exposure and match-related travel may represent relevant contextual factors; however, their relationship with ACL injury occurrence remains unclear. To quantify and compare pre-injury match exposure and estimated travel distance between ACL injury seasons and matched preceding-season periods using a within-player design. This retrospective, within-player case-crossover study included professional women’s football players (Tier 3–5) with publicly reported ACL injuries between 2022 and 2024. For each player, match exposure and estimated travel distance before injury were compared with the corresponding calendar window 365 days earlier. Match minutes, appearances, and matches started were assessed across 30-, 60- and 90-day pre-injury windows, whilst estimated travel distance was assessed over 30 days. Paired tests and Cohen’s d quantified the differences. Mixed-effects logistic regression models examined whether exposure variables differentiated injury-season from control-season observations, and Spearman’s correlations assessed associations between the corresponding between-season differences in match exposure and estimated travel distance. Data from 375 players were analysed. Match minutes, appearances and matches started were greater during injury seasons across all observation windows, with small effect sizes ( d = 0.21–0.37). Estimated travel distance during the 30 days preceding injury was significantly greater in injury seasons (2724 ± 4821 km vs 2194 ± 4625 km, p < 0.001), though variability was substantial and the effect size was negligible ( d = 0.106). In both mixed-effects logistic regression models, no travel was associated with lower odds that an observation belonged to the injury-season period (OR = 0.43–0.53, p ≤ 0.024). Match exposure was moderately correlated with travel distance ( ρ = 0.399–0.556, p < 0.001); this was most evident amongst players transitioning from Tier 3 to Tier 4 or competing at Tier 5. Injury season periods were characterised by slightly greater match exposure and estimated travel distance than matched control periods from the preceding year. However, effect sizes were small and between-player variability was substantial. These exploratory findings do not establish causality but identify contextual exposure patterns that warrant further prospective investigation.