抄録
A bone fracture due to an elderly person's turning over is a big cause of the so-called bedridden state. The prevention of turning over is then an important subject for elderly people. In these days, a kinematical method has been introduced as a countermeasure to the act of turning over. Strengthening muscular groups of lower limbs, focusing on the quadriceps femoris has been done as a main kinematical method of preventing a fall. Recently, however, the relationship between psoas major muscle (a muscle connecting the thighbone with the backbone) and the act of turning over has attracted attention because it has become clear that the muscle greatly influences walking ability. This research aimed at explaining the characteristics of the change of the quantity of psoas major muscle due to aging by comparing changes of the cross-section of the muscle to that of quadriceps femoris muscle as a part of the research on the prevention of elderly people's turning over. Participants in this research included solely women because the danger of female bone fracture due to turning over is approximately 2.5 times greater than that of male one. A total of 210 women who lived in two neighboring cites in the same prefecture, from ages 20 to 79, were divided into 6 age-groups in 10-year increments.
