#ReadyToplay: hamstring injuries in women’s football–a two-season prospective cohort study in the Norwegian women’s premier league

In this two-season prospective cohort study (2020–2021), we aimed to describe the characteristics, clinical findings and magnetic resonance imaging (MRI) findings of hamstring injuries in the Norwegian women’s premier league. Hamstring injuries were examined by team physiotherapists using a standardised clinical examination and injury form. Injury location and severity (modified Peetrons classification) were graded based on MRI by two independent radiologists. Fifty-three hamstring injuries were clinically examined, 31 of these with MRI. Hamstring injuries caused 8 days (median) lost from football (interquartile range: 3–15 days, range: 0–188 days), most were non-contact and occurred during sprinting. Gradual-onset (53%) and sudden-onset injuries (47%) were evenly distributed. The injuries examined with MRI were classified as grade 0 (52%), grade 1 (16%) or grade 2 (29%). One proximal tendinopathy case was not graded. Grade 2 injuries caused more time loss than grade 0 (19 ± 8 vs. 7 ± 7 days, p = 0.002). Of injuries with MRI changes, 60% were in the m. biceps femoris, mainly the muscle-tendon junction, and 40% in the m. semimembranosus, most in the proximal tendon. Compared to previous findings from men’s football, a higher proportion of hamstring injuries in women’s football had a gradual onset and involved the m. semimembranosus, particularly its proximal tendon.