Outcome measures are used in all areas of physiotherapy not only in research, but also in clinical practice. Therefore, reproducibility studies are needed to evaluate the repeatability or consistency of these measurements. The purpose of this experiment is to examine the repeatability of testing by a practitioner for an outcome measure in physical therapy. Seventeen subjects were recruited to participate in this experiment. Three separate readings were conducted for each topic each day on two separate occasions. The results showed excellent within-day and between-day repeatability with an intraclass correlation coefficient (ICC) of 0.98 and 0.92, respectively. The 95% confidence interval of the difference in value between -1.08 and 1.10 showed no difference within the subject score. Furthermore, the standard error measurement (SEM) was 1.78, which is considered an acceptable value in clinical practice. Bland and Altman's 95% limits of agreement (LOA) ranged from −2.7 to 4.7. In conclusion, although this outcome measure has demonstrated excellent retest reliability, the lack of an adequate sample size may reduce the reproducibility of this finding. Therefore, further research with an adequate sample size is needed to draw a definitive conclusion. Introduction The reliability of an outcome measurement reflects how reproducible or repeatable the measurement is under a given set of circumstances. For an outcome measure to be useful, it must provide stable or reproducible values ​​with small measurement errors when no variable influences the attribute that the measurement is quantifying (Rankin and Stoke 1998). In practice, the physiotherapist introduces a therapeutic intervention and then evaluates the effectiveness of the ...... middle of paper ......), the smaller the variation, the greater the reliability. Subsequently, the SEM value of 1.78 showed that there was little variation with repeated measurements. Bland and Altman's 95% limits of agreement predict that approximately 95% of the difference between two measurements falls between -2.7 and 4.7. Careful examination of the graph presented in Fig. 4 indicated no evidence of a learning effect and minimal outcome measurement error for the subjects. The decision whether this limit is clinically acceptable depends on the clinical judgment of the therapist (Portney and Watkins 2009). In conclusion, although this outcome measure has shown excellent reliability, the small sample size and missing data may have affected its reliability (Shoukri et al, 2004). Therefore, a further study with a larger sample is recommended to confirm the consistency of this outcome measure.