the aim of this study was to evaluate the effect of sway back abnormality on body segments follow- up changes. For this reason 70 female students age ranged 18- 26 years randomly were enrolled. Posture screen and plump line used for posture evaluation. In present study Goniometer were used for ankle, knee and hip angle evaluation, flexible ruler used for measuring the degree of lumbar lordosis and thoracic kyphosis and inclinometer used for measurement of pelvic inclination. T test and Pearson correlation coefficient were used for statistical analysis (α≤ 0.05). Results revealed that sway back abnormality is a prevalent abnormality in Iranian young girls (35%). Subjects with sway back abnormality have a greater thoracic kyphosis angle and pelvic anterior tilt rather than normal subjects. Also the Subjects with sway back abnormality have a greater extension in hip and knee joints. There was statistical meaningful correlation between pelvic inclination with knee(r=0.02) and hip (p=0.01) angle, but this correlation wasn't meaningful with regard to the ankle joint angle(r=0.06). We concluded that the prevalence of sway back abnormality in young girl's age ranged 18- 26 years old was very high. Also we concluded that thoracic kyphosis, neck and lumbar lordosis, knee and hip angle in subjects with sway back abnormality changed during the life spam.
