Validity and reliability of the KTT an isokinetic knee torque evaluation device

Purpose

The aim of this study is to assess the validity and reliability of a new and low-cost instrument for isokinetic knee torque test, the KTT device.

Methods

Twenty participants were assessed using a gold standard device and the new equipment for validation. In a second protocol, twenty participants repeated assessments with the new instrument to verify between-session and between-sessions reliability. Statistical analyses about peak torque values for isokinetic knee extension and flexion were performed using the intraclass correlation coefficient (ICC), 95 % confidence interval of difference (CI), standard error of measurement (SEM), Bland-Altman charts.

Results

The results indicated an excellent data correlation of the KTT with Biodex® to peak torque for both extensors and flexors (ICC 0.96 [0.93–0.98] and 0.76 [0.53–0.88], respectively). In the Bland-Altman analysis, results were distributed within the limits of agreement between the two devices. In the within-session and between-sessions analyses, the SEM for the new isokinetic device varied between 4.9 % and 11.3 %. The accuracy of the evaluation was 99.9 % within a single session.

Conclusion

The proposed new instrument proved to be valid and reliable, being a simple and low-cost alternative to quantify the peak torque of non-athlete woman. It is possible to infer that this instrument can be used for individuals with similar torque such as non-athletes of both genders elderly population.