Injury mechanism and return to play duration in non-contact muscle injuries in elite football players: a case series

A retrospective case series was conducted to compare return to play (RTP) duration in elite football players from a first-division team with lower-limb non-contact muscle injuries (NCMIs). Cases were compared according to symptom timing onset and the presence (typical) or absence (atypical) of a typical injury mechanism, such as a specific movement or identifiable moment during which the injury occurred. During the study period, 43 NCMIs were recorded in 28 football players, including 37 with typical mechanism and six without. RTP duration was substantially shorter following atypical than typical injuries (median 2.5 days [IQR 0.5–3.0] vs 12.0 days [IQR 8.0–24.0], respectively; Mann–Whitney U = 221.0, p < 0.001; Cliff’s δ = 0.991, player-cluster bootstrap 95% CI 0.958–1.000). No injury recurrences were observed among the atypical injuries for at least nine months after RTP. Given the limited number of participants, cases and the exploratory nature of the study, these preliminary findings should be interpreted cautiously.