Interrater reliability of the active-knee-extension test for hamstring length in school-aged children.

Purpose: The purpose of this study was to determine the interrater reliability of the active knee-extension test (AKET) using a stabilizing apparatus to measure hamstring length.

Methods: One hundred one subjects (53 girls, 48 boys) ranging in age from 10 to 13 years with no known neuromuscular problems participated. The AKET was performed with subjects lying supine with the hip flexed to 90 degrees with a stabilization device attached to a plinth. Next, subjects were instructed to actively extend the knee until the rater detected myoclonus. Then, the rater flexed the knee until myoclonus subsided and the knee angle was measured with a blinded goniometer. This procedure was repeated by each of three raters.

Results: Data were analyzed using ICC (2,1) demonstrating good interrater reliability of 0.79.

Conclusion: Our results suggest that the AKET, when used with the stabilizing apparatus, demonstrates good interrater reliability for children aged 10 to 13 years.