Abstract
We confirmed in our former study the advantage of the rucksack by way of testing the burden of load-carrying using two methods, one bearing the load on the back and the other holding it by hand, with young women as carriers. In this study we conducted further research into the rucksack to ascertain its utility for aged women, again by using the two testing methods.
Twenty women ranging from 54 to 84 years of age took part in the tests prepared with two types of rucksacks, A and B (usual type). While wearing either type A or type B rucksack on their back, the women walked a fixed course to undergo examination of their walking posture, how they felt while carrying the load, and their physiological changes throughout the testing. In addition, measurements were taken to determine the effects of the burden on the center and back portions of the shoulders, the lumbar area and the side of the chest.
As a result, larger numerical values of burden upon the center of the shoulders and the side of the chest were observed in the B-type rucksack-bearing walk, indicating that the smaller the Rohrer index, the greater the pressure imposed on the center of the shoulders as shown by the figure χ 279g/cm2. In the case of the A-type rucksack, the load imposed more pressure upon the back of the carriers' shoulders as the loads rested flat on their backs. Blood pressure after the testing rose in proportion to the degree of load pressure on the side of their chests, suggesting how they are vulnerable to the burden. The type-difference of the rucksacks caused a difference in their walking posture. As a whole, an irregular walking style peculiar to aged people was seen in their walk, such as an insufficiency in tiptoe lifting resulting in a tendency to drag their feet as they walked, and falling. This fact suggests the advantage of on-the-back carrying also for aged women, as their hands would be freed to protect them against falls. The necessity for designing a rucksack to fit the physical form and living style of aged people came to light.
