Forward flexed posture: reliability and determinants of tragus-to-wall measurement

Introduction Forward flexed posture is an impairment in body structure commonly seen among older adults and those with pathologies such as ankylosing spondylitis and osteoporosis. Accurate measurement of forward flexed posture is important as it is related to pain, mobility limitations, and falls. Our purpose was to examine the reliability and determinants of forward flexed posture as indicated by tragus-to-wall (TTW) distance Methods Twenty healthy younger and 20 healthy older adults were included in this secondary analysis of data from a neck strength study. Measurements included the linear distance of TTW standing naturally and with neck retraction, age, gender, body mass index (BMI), and neck retraction strength. Measurements were performed initially by 2 investigators and by the primary investigator 1 week later. Intraclass correlation coefficients (ICCs) (model 3,1) described relative reliability and Bland-Altman plots characterized absolute reliability. A mixed general linear model examined the determinants for TTW distance Results Good inter-rater (ICC = 0.811-0.878) and test-retest reliability (ICC = 0.853-0.862) were found in both positions. Bland-Altman plots showed that absolute limits of agreement ranged from - 1.9 to +3.8 cm for inter-rater reliability and -2.4 to +2.6 cm for test-retest reliability. Analysis of TTW determinants demonstrated significant differences between neck positions, dichotomous age groups, and BMI groups (p <= 0.001). There was no significant difference based on neck strength. Conclusions Our results indicate that TTW distance, measured using a standardized procedure, is a reliable method of quantifying forward flexed posture. TTW distance is greater in relaxed standing, older individuals, and those with greater BMI.