Norm-Referenced and Criterion-Referenced Reliability and Validity of the Back-Saver Sit-and-Reach

Abstract

The purpose of the study was to examine the norm-referenced and criterion-referenced reliability and validity of the Back-Saver Sit-and-Reach Test (BSR; Single-Leg Sit-and-Reach; Cooper Institute for Aerobics Research [CIAR], 1999). One hundred seventy-nine elementary school children (87 boys and 92 girls), 6-12 years old participated, with 44 randomly selected participants retested on a second day. The BSR, Modified Schober (MSCH, Low Back Criterion Test), Passive Straight Leg Raise (PSLR, Hamstring Criterion Test), Active Knee Extension, True Lumbar Extension, True Lumbar Flexion, and Double-Leg Sit-And-Reach were administered in random order. Intraclass correlation coefficients (norm-referenced reliability) for the BSR were extremely high (.98-.99) for both boys and girls. Pa and Km (criterion-referenced test-retest reliability) for the right leg was .90 and .80, respectively, for boys; and .91 and .82 for girls, indicating the participants were classified consistently across days. Norm-referenced validity coefficients (Pearson product-moment correlations, r) of the BSR as a measure of hamstring flexibility were moderate for boys (.67 and .68, right and left legs, respectively) and moderately low for girls (.47 and .44, right and left legs). Correlation coefficients of the BSR as a measure of low back flexibility were extremely poor for boys and girls, with coefficients ranging from .003 to .06. Criterion-referenced validity of BSR for hamstring flexibility was low and unacceptable for right and left legs (Km: .48, .58, respectively), for both boys and girls (Km: .40, .22). The BSR appears to be similar to the Double-Leg Sit-and-Reach in that it is a test of hamstring flexibility but not low back. The criterion-referenced standards for both BSR and PSLR should be re-examined and adjusted to provide a better degree of classification agreement between the BSR and the criterion measure (PSLR).