RT Journal Article SR Electronic T1 7 Is absolute or relative knee flexor strength related to patient-reported outcomes in patients with ACL reconstruction with hamstring tendon autograft? JF BMJ Open Sport & Exercise Medicine JO BMJ OPEN SP EX MED FD BMJ Publishing Group Ltd SP A2 OP A2 DO 10.1136/bmjsem-2023-sportskongres2023.4 VO 9 IS Suppl 1 A1 Högberg, Johan A1 Piussi, Ramana A1 Simonson, Rebecca A1 Sundberg, Axel A1 Broman, Daniel A1 Samuelsson, Kristian A1 Thomeé, Roland A1 Senorski, Eric Hamrin YR 2023 UL http://bmjopensem.bmj.com/content/9/Suppl_1/A2.1.abstract AB Background There is a need for better understanding of how knee flexor strength influence patient-reported outcomes (PROs) after anterior cruciate ligament (ACL) reconstruction. Therefore, the aim was to investigate the relationship between the eccentric NordBord test and the seated concentric Biodex test, with PROs, during the first year of rehabilitation after ACL reconstruction with a hamstring tendon (HT) autograft.Methods Data of patients with an index ACL reconstruction with an HT-autograft participating in a rehabilitation registry were screened for inclusion. Outcomes of interest were the correlation between absolute (N/kg or Nm/kg) and relative (limb symmetry index) knee flexor strength measured in the NordBord and Biodex with the results of PROs. The significance level was set at p<0.05 and Pearson’s correlation coefficient was used.Results 137 patients were included (47% women) with a mean age of 24.8±8.4 years. There were non-significant and weak correlations between relative strength for all PROs. Significant and weak correlations between absolute strength in the Biodex with the K-SES18present at 4 and 8 months, and for the ACL-RSI at 12 months was observed, accounting for 8.4–15.7% of the variance. Significant and weak correlations between absolute strength in the Nordbord with the KOOS-Sports at 4 months, the K-SES18present and the ACL-RSI at 8 months were observed, accounting for 9.4–14.4% of the variance.Conclusion Absolute knee flexor strength relative to bodyweight for both the Biodex and NordBord test appeared to have a stronger relationship with perceived knee function than relative knee flexor strength, although the observed correlations were weak.