Abstract
Study Design.A repeated measures single group design.
Objectives.To investigate test-retest reliability of Progressive Isoinertial Lifting Evaluation on patients with long lasting musculoskeletal problems related to the lumbar spine.
Summary of Background Data.Test-retest reliability has been satisfactory in healthy men. Test-retest reliability for clinical populations has not been reported.
Methods.A total of 31 patients (17 women and 14 men) with long lasting low back pain participated in the study. The patients were tested twice at an interval of 2 days and at the same time of the day. The heaviest load that the patient could lift 4 times was used as outcome measure.
Results.The error of measurement indicates that the true result in 95% of cases will be within ±4.5 kg from the measured value, while the difference between 2 measurements in 95% of cases will be less than 6.4 kg. Intra-class correlation (1,1) was 0.91.
Conclusions.Relative test-retest reliability was high assessed by intra-class correlation, but absolute measurement variability reported as the smallest detectable difference has relevance for the interpretation of clinical test results and should also be considered.