부산대학교 도서관

In this study, we measured the psoas major/paraspinal muscle mass and intramuscular fat mass in subjects based on sex and age （≥65 or ＜65 years） and made statistical comparisons to obtain basic data on exercise therapy. A total of 45 subjects including men and women were recruited in the study, and those who suffered from diseases that interfere with the activities of daily living were excluded. Using an image analysis software, three-dimensional models of the psoas major and paraspinal muscle were created for each subject from their continuous computerized tomography （CT） images. These models were then used to measure the muscle volume, intramuscular fat mass, and intramuscular fat ratio. The data were compared using statistical analyses. Given the age, the results revealed that subjects ≥ 65 years had significantly low psoas major volume and significantly high paraspinal muscle fat volume and fat ratio. Based on sex, men showed significantly higher volumes of psoas major and paraspinal muscle than by women. Based on sex and age, men and women in the elderly group, that is, those ≥65 years of age, had significantly low psoas major volume and significantly high paraspinal muscle fat volume. In terms of body mass index （BMI）, for the≥65 years group with a BMI ＜25, the psoas major volume was significantly low, whereas the paraspinal muscle fat volume and fat ratio was significantly higher than those in the＜65-year group. The above results suggest that aging induces quantitative changes in the psoas major muscle and qualitative changes in the paraspinal muscles. The psoas major and paraspinal muscles have evident differences in muscle properties and age-related changes.