For the evaluation of physical function in the population with knee osteoarthritis (KOA), one of the tests recommended by the Osteoarthritis Research Society International (OARSI) is the Stair Climb Test, so it is important to investigate which factors can influence performance in the test.

To investigate whether sex, age, BMI, and pain intensity interfere with the performance of the population with KOA in the Stair Climb Test.

The present study is an observational cross-sectional study. Participants over 45 years of age, of both sexes, with clinical diagnosis of KOA, according to the American College of Rheumatology (ACR) criteria, and pain intensity greater than 4, evaluated by the Numeric Rating Scale (NRS), were recruited. Anthropometric data were collected through an initial anamnesis, followed by the application of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire. Subsequently, participants were submitted to the Stair Climb Test. Participants were instructed to climb and descend a flight of 11 stairs, each 20 cm in height, quickly but safely. The sum of the times for climbing and descending was recorded by the evaluator. The Statistical Package for Social Sciences, version 21.0, was used for the multiple linear regression analysis, and the significance level was set at 5%.

100 participants were included, 52% of whom were female, with a mean age of 60 years. The mean BMI of the participants was 29.64 with a mean pain intensity of 9.5 by the specific domain of the WOMAC questionnaire and Stair Climb Test performance of 22.79 seconds. The final regression model (Table 1) indicated that sex (p = 0.029), age (p = 0.001), BMI (0.004), and pain by the specific domain of the WOMAC (p = 0.003) may explain 42% of the variability in Stair Climb Test performance.

The present study demonstrates that there is an association between sex, age, BMI, and painful symptoms in the performance of the Stair Climb Test, which may be potential factors that interfere with the performance of subjects with KOA.

Understanding the influence of such factors helps in the interpretation of the performance of patients with knee osteoarthritis in the stair climb test.