Correction to: Is Pre-season Eccentric Strength Testing During the Nordic Hamstring Exercise Associated with Future Hamstring Strain Injury? A Systematic Review and Meta-analysis.

BACKGROUND Interventions utilising the Nordic hamstring exercise (NHE) have resulted in reductions in the incidence of hamstring strain injury (HSI). Subsequently, quantifying eccentric knee flexor strength during performance of the NHE to identify an association with the occurrence of future HSI has become increasingly common; however, the data to date are equivocal. OBJECTIVE To systematically review the association between pre-season eccentric knee flexor strength quantified during performance of the NHE and the occurrence of future HSI. DESIGN Systematic review and meta-analysis. DATA SOURCES CINAHL, Cochrane Library, Medline Complete, Embase, Web of Science and SPORTDiscus databases were searched from January 2013 to January 10, 2020. ELIGIBILITY CRITERIA FOR SELECTING STUDIES Prospective cohort studies which assessed the association between pre-season eccentric knee flexor strength quantified during performance of the NHE and the occurrence of future HSI. METHODS Following database search, article retrieval and title and abstract screening, articles were assessed for eligibility against pre-defined criteria then assessed for risk of bias. Meta-analysis was used to pool data across studies, with meta-regression utilised where possible. RESULTS A total of six articles were included in the meta-analysis, encompassing 1100 participants. Comparison of eccentric knee flexor strength during performance of the NHE in 156 injured participants and the 944 uninjured participants revealed no significant differences, regardless of whether strength was expressed as absolute (N), relative to body mass (N kg-1) or between-limb asymmetry (%). Meta-regression analysis revealed that the observed effect sizes were generally not moderated by age, mass, height, strength, or sport played. CONCLUSION Eccentric knee flexor strength quantified during performance of the NHE during pre-season provides limited information about the occurrence of a future HSI.