The English Knee Self-Efficacy Scale is a valid and reliable measure for knee-specific self-efficacy in individuals with a sport-related knee injury in the past 5 years

Knee Surg Sports Traumatol Arthrosc. 2021 Feb;29(2):616-626. doi: 10.1007/s00167-020-05974-x. Epub 2020 Apr 17.


Purpose: To translate and cross-culturally adapt the Swedish Knee Self-Efficacy Scale (K-SES) into English and evaluate the measurement properties in a sample of individuals with previous knee injury.

Methods: Translation, cross-cultural adaptation, and evaluation followed the Beaton multi-step process and COSMIN guidelines. Participants (n = 125) aged 16-60 years with a sport-related intra-articular tibiofemoral or patellofemoral injury within the last 5 years completed the K-SES, Knee Injury and Osteoarthritis Outcome Score, Anterior Cruciate Ligament-Return to Sport After Injury Scale, Tegner Activity Level Scale, and Multi-dimensional Health Locus of Control. Confirmatory factor analysis (CFA) tested a-priori two-factor structure and model fit. Cronbach-alpha, intra-class correlation coefficient (ICC), and absolute reliability (Bland-Altman plots) were calculated. Construct validity was assessed by eight pre-defined hypotheses. A sub-group of participants (n = 42) completed the K-SES twice to assess intra-rater reliability.

Results: The cross-cultural adaptation generated an English K-SES with face and content validity. The original two-factor structure was rejected based on CFA and a revised solution informed by Exploratory Factor analysis resulted in an adequate fit. All construct validity hypotheses were confirmed. The K-SES showed good internal consistency [Factor (F1: α = 0.96; F2: α = 0.73)], intra-rater reliability (ICC = 0.92), and no systematic bias between repeated measurements.

Conclusion: The English K-SES is a valid and reliable measure for knee-specific self-efficacy in individuals who have sustained a sport-related intra-articular knee injury in the previous 5 years.

Level of evidence: IV.

Keywords: Cross-cultural adaption; Knee injury; Patient-reported outcome measure; Psychometrics; Self-efficacy.

MeSH terms

  • Adolescent
  • Adult
  • Athletic Injuries / psychology
  • Athletic Injuries / therapy*
  • Child
  • Female
  • Humans
  • Knee Injuries / psychology
  • Knee Injuries / therapy*
  • Lysholm Knee Score
  • Male
  • Middle Aged
  • Patient Reported Outcome Measures*
  • Psychometrics
  • Reproducibility of Results
  • Self Efficacy*
  • Sweden
  • Translations
  • Young Adult