ARE MEASUREMENTS OF HIP EXTENSION AND ANTERIOR PELVIC TILT TAKEN FROM STATIC PHOTOGRAPGHS DURING A CONSTRAINED FORWARD LUNGE TEST VALID AND RELIABLE IN HEALTHY ADULT RUNNERS?

Abstract

The aim of this study was to determine the concurrent validity, test-retest intra-rater reliability, and test-retest inter-rater reliability of photographic measures of anterior pelvic tilt range of motion (APT ROM) and hip extension ROM range of motion (HE ROM) during a constrained forward lunge test (CFLT) in healthy adult runners. Measurements of start, end, and range of motion (ROM) variables for APT and HE motion were taken from an Optorak kinematic measurement system and from printed photographs extracted from digital video footage using a protractor. A total of 13 healthy adult male and female recreational runners participated in the study. Measures of APT ROM and HE ROM were found to be valid compared to Optorak measures, with intraclass correlation coefficients (ICC) of 0.94 and 0.99 respectively, and limits of agreement of -1.42 ± 1.99 degrees and 0.41 ± 2.13 degrees respectively. APT ROM and HE ROM demonstrated high between-day intra-rater reliability with ICCs ranging from 0.75 to 0.91 and within-day inter-rater reliability with ICCs ranging from 0.86-0.90. For between day intra-rater measurements smallest detectable differences (SDDs) ranged from 5.59 to 4.12 for APT ROM and from 9.08 to 11.08 for HE ROM. The present study suggests that photographic measurements of APT ROM and HE ROM during a CFLT are valid and reliable in healthy adult runners; however, these measurements display a low sensitivity with respect to detecting changes between trials.