Fidélité et validité de la mesure clinique du déjettement du tronc auprès d’enfants et d’adolescents présentant une scoliose idiopathique
Measurement of trunk list is an important component of an evaluation of posture in idiopathic scoliosis.  However, there is little information regarding its measurement and  the associations between trunk list and other relevant indicators or factors.  The objectives of this study were to: 1) evaluate the validity and test-retest reliability of the plumbline to measure trunk list from C7 - S1 in persons with idiopathic scoliosis and 2) to explore the  association between trunk list and the following factors: pain, Cobb angle, type of scoliosis, mental health and self-image, in persons with idiopathic scoliosis.      We recruited 55 participants aged from 10 to 21 years old with idiopathic scoliosis (Cobb angle: 15º to 60º) from the scoliosis clinic at a tertiary care pediatric hospital.  Trunk list was measured directly on participants on two occasions by the same physiotherapist and also on radiographs taken that day. Two measurements were taken each time: with feet together (FT) and feet apart (FA). The participants answered the Scoliosis Research Society-22 patient questionnaire, which addresses pain, self-image and mental health. Type of scoliosis and Cobb angle were measured on radiographs taken that day. We used generalizability theory to calculate test-retest reliability for FT and FA, reporting Dependability Coefficients (f) and Standard Errors of Measurement (SEM).   Validity of the plumbline measurement was calculated by comparing to measurements taken directly on radiographs using the Pearson correlation coefficient. Pearson correlations were calculated between trunk list and pain, Cobb angle, self-image and mental health. Spearman correlations were calculated between trunk list and type of scoliosis.  We then used multiple linear regression models to determine associations between these variables.   Our results indicated that the plumbline measurements of trunk list correlated highly (r=0.87) with the measure obtained via radiograph. Plumbline measurements of  trunk list demonstrated excellent test-retest reliability (f: 0.98 for FT and 0.99 for FA) and SEMs were 2.0 mm for FT and 1.8mm for FA.  Trunk list was positively correlated with Cobb angle (r=0.32, p=0.02) but it was not correlated with pain, mental health, self-image,  or type of scoliosis.   The conclusions of our study were that the clinical measurement of trunk list using a plumbline is both reliable and valid and that trunk list was associated with Cobb angle.  A longitudinal study is needed to determine whether trunk list is a prognostic indicator of scoliosis progression.    Keywords: idiopathic scoliosis, trunk list, plumbline, posture, lateral trunk shift
posture idiopathic scoliosis trunk list plumbline posture lateral trunk shift