Differences in the technical performance of heading between men and women football players during FIFA World Cup 2022 and FIFA Women's World Cup 2023 matches.

Objectives: To compare the incidence of headers, attempted headers, and other head impacts, and the difference in heading descriptors, including technical performance, between men and women in a purposive sample of FIFA World Cup 2022 (FWC22) and FIFA Women's World Cup (FWWC23) matches. Methods: Video analysis of all observed headers, attempted headers and other head impacts during eight FWC matches (FWC22 (n=4); FWWC23 (n=4)) where the same national teams competed. Heading descriptors (including ball delivery method, purpose of the header and involvement of other players) and technical performance of each header (including controlled or uncontrolled header, use of upper body, point of head contact) were analysed using negative binomial regression analyses with men as the reference group (reported as incidence rate ratios (IRR)). Timing of eye closure was analysed using a t-test; α-error, p=<0.05. Results: From 973 head impacts, 845 (87%) were headers (FWC22 mean 5.0 headers/player/match, FWWC23 mean 4.6 headers/player/match), 93 (10%) were attempted headers and 35 (4%) were unintentional head impacts. When compared with men, women were less likely to perform controlled headers (73% vs 83%, IRR 1.20, p=0.01), use their foreheads (IRR 2.36, p=<0.001) and their upper body during the header (80% vs 88%, IRR 1.29, p=0.005). Women also closed their eyes earlier before the header (1.91 vs 1.56 frames, d=0.41, p=0.002). Conclusion: There were significant differences in heading technique between women and men, which could be important to address in training to improve heading performance and potentially reduce short-term and long-term burden of heading.