Intra-rater reliability in measuring range of motion in infants with congenital muscular torticollis

The aim of this study was to test the intra-rater reliability of measures in rotation and lateral flexion of the head in infants with congenital muscular torticollis (CMT). Twenty-three infants with CMT, aged 1 5 months, were classified into two groups. Group I was measured twice without time interval and Group II was measured with an interval of 1 h. All infants were examined supine. A goniometer was used to measure rotation and a protractor for lateral flexion. Photos were taken simultaneously with the readings of range of motion. Repeated-measures analysis of variance (ANOVA) was used to determine any significant differences between test and retest. The intraclass correlation coefficient and the standard error of measurement were calculated to determine intra-rater reliability. Results show high intra-rater reliability regardless of time intervals between the two measures, measured movement directions and differences in the end-feel of the sternocleidomastoideus muscle. Least agreement was found when comparing measures on infants and on photos taken simultaneously. The high intra-rater reliability found in this study indicates that evaluation of treatment effects over time can be made with adequate reliability when the measures are performed by an experienced physiotherapist. The methods used could form a good basis for performing a larger inter-rater reliability study.