Knee-Self Efficacy Scale

K-SES Questionnaire



International Knee Documentation Committee (IKDC)


The Knee-Self Efficacy Scale (K-SES) is a self-report questionnaire that measures patients’ perceived self-efficacy of knee function after ACL injury (Thomée et al. 2006).


Validity and Reliability

The K-SES has been shown to have good reliability, validity, and responsiveness during rehabilitation for patients’ perceived self-efficacy of knee function. The K-SES has been found to have good internal consistency, with a Cronbach’s alpha of 0.84. The K-SES has also been positively correlated with measures of optimism and life satisfaction, indicating good construct validity (Thomée et al. 2008).

Since it has been devised in Swedish, English and Dutch translations of the questionnaire have been found to be valid and reliable to determine knee self-efficacy in patients with sports-related knee injury (Ezzat et al. 2021, van Lankveld et al. 2019).

Beischer et al. (2021) validated an 18-item version of the K-SES based on feedback from patients who completed the original 22-item version and found acceptable reliability and validity to assess knee self-efficacy in patients up to 18 months after ACL injury and reconstruction.


Scoring and Interpretation

The K-SES questionnaire consists of 22 items subdivided into 4 categories: daily activities (A), sports and leisure activities (B), physical activities (C), and future knee function (D).  Each item is rated on a 11-point Likert scale, ranging from 0 (not at all certain) to 10 (very certain).  To score the K-SES questionnaire, the scores for each item are summed, with higher scores indicating higher levels of hope. For injured patients, who have not undergone an ACL-reconstruction, item 22 is excluded.

The authors of the questionnaire recommend to calculate and interpret two scores:

  • 1. K-SESpresent to evaluate the self-efficacy at present (item categories A, B, C)
  • 2. K-SESfuture to evaluate the self-efficacy in the future (item category D)


K-SES PDF Download



K-SES Online Calculator






Thomeé P, Währborg P, Börjesson M, Thomeé R, Eriksson BI, Karlsson J. A new instrument for measuring self-efficacy in patients with an anterior cruciate ligament injury. Scand J Med Sci Sports. 2006;16(3):181-187. doi:10.1111/j.1600-0838.2005.00472.x

Thomeé P, Währborg P, Börjesson M, Thomeé R, Eriksson BI, Karlsson J. Self-efficacy of knee function as a pre-operative predictor of outcome 1 year after anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2008;16(2):118-127. doi:10.1007/s00167-007-0433-6

van Lankveld W, van Melick N, Habets B, Pronk Y, Staal JB, van Cingel R. Cross-cultural adaptation and measurement properties of the Dutch knee self efficacy scale (K-SES). BMC Sports Sci Med Rehabil. 2019;11:3. Published 2019 Mar 7. doi:10.1186/s13102-019-0115-y

Beischer S, Hamrin Senorski E, Thomeé P, Thomeé R. Validation of an 18-item version of the Swedish Knee Self-Efficacy Scale for patients after ACL injury and ACL reconstruction. J Exp Orthop. 2021;8(1):96. Published 2021 Oct 25. doi:10.1186/s40634-021-00414-2

Ezzat AM, Whittaker JL, Brussoni M, Mâsse LC, Emery CA. 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;29(2):616-626. doi:10.1007/s00167-020-05974-x

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