Intra- and interrater reliability of the Ergo-Kit functional capacity evaluation method in adults without musculoskeletal complaints.

Abstract

To evaluate the intra- and interrater reliability of tests from the Ergo-Kit (EK) functional capacity evaluation method in adults without musculoskeletal complaints. Within-subjects design. Academic medical center in The Netherlands. Twenty-seven subjects without musculoskeletal complaints (15 men, 12 women). Not applicable. Seven EK tests (2 isometric, 3 dynamic lifting, 2 manipulation tests) were each assessed 3 times (over 4 days), twice by 1 rater (R1) and once by another rater (R2). Intrarater reliability was calculated using the EK test scores assessed by R1. Interrater reliability was calculated using the EK test scores assessed by both raters. Counterbalancing the rater order made possible the calculation of 2 interrater reliability levels (at time intervals of 4 and 8d). All reliability levels were expressed as intraclass correlation coefficients (ICCs). Intrarater and interrater reliability (8-d time interval) was high (ICC, >.80) for the isometric lifting tests, moderate (ICC range, .50-.80) for the dynamic lifting tests, and low (ICC, <.50) for the manipulation tests. The interrater reliability of the isometric and dynamic lifting tests (4-d time interval) was high (ICC, >.80), and it was moderate (ICC range, .50-.80) for both manipulation tests. The isometric and dynamic lifting tests of the EK have a moderate to high level of reliability; the manipulation tests have a low level of reliability.