Inter- and intra-rater reliability of computerized photogrammetry and universal goniometer in the measurement of hip flexion and abduction

ABSTRACT The universal goniometer (UG) is the most frequently used tool for measuring range of motion (ROM), with demonstrated reliability. Computerized photogrammetry (CP) is widely used for postural assessment, but its role in the measurement of ROM of hip flexion and abduction has not yet been fully explored. This study aimed to test inter- and intra-rater reliability for measuring ROM of hip flexion and abduction using UG and CP, as well as the reliability between the instruments. Our sample consisted of 40 healthy volunteers (aged from 18 to 28 years). Measurements of ROM were conducted by two independent raters, 15 minutes apart, using UG and CP to assess inter-rater reliability. The procedures were repeated one week later by the first rater (intra-rater reliability). Using UG, inter-rater reliability was excellent for flexion and abduction (ICC=0.92 and 0.91, respectively); using CP, it was rated as very good (ICC=0.77 and 0.80, respectively). Intra-rater reliability using UG was excellent for flexion and abduction (ICC=0.95 and 0.92), and very good using CP (ICC= 0.81 and 0.89). The correlation between the instruments was excellent for flexion and very good for abduction (r=0.92 and r=0.82). Future investigations should seek a more diversified sample and symptomatic patients. Inter- and intra-rater reliability is high when measuring range of motion of hip flexion and abduction using both UG and CP, and the correlation between instruments is excellent for flexion and very good for abduction, meaning that both are valid