TSUCHIYA Yoshio
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Lumbar load, which causes chronic low back pain, varies depending on posture and external load. However, the timing to feel the lumbar burden varies from person to person. It is also known that tightening the pelvic belt against the lumbar burden improves posture and reduces the lumbar burden. For this reason, the tightening force of the pelvic belt is measured for the posture and the lumbar load, and the relationship between the sensation and the load is evaluated.
Low back pain is a serious problem in Japan, so analysis of lumber load is needed. The conventional analysis method is an invasive analysis, and a non-invasive and safe analysis method is required. The purpose of this study is to make a physical model of L4-L5 vertebral body from radiographs and to estimate the lumbar load from the model. Five X-ray images of the upper body angle, standing postures, and backward bending were taken for each subject, and a three-dimensional model of the L4-L5 vertebral body was created. FEM analysis was performed using the model created, and the load acting on the intervertebral disc during the photographed postures ware measured. The results were evaluated for each of the four subjects to measure individual differences. Based on these results, we approached the lumbar load analysis using a physical model, which is the goal of this study.
This research developed assist equipment that changes the tightening force depending on low back burden. The final aim of this research is to develop the control system to tighten optimally. This paper aims to reveal the response of the human body to the tightening. The low back burden is defined as the compression force on the intervertebrae disk. The first half of this paper verifies the effect of the tightening on pelvis. In the verification about the posture of anteflexion, the low back burden decreased in two subjects among three. Also about the motion of lifting up, all of three subjects was reduced the low back burden. In the second half, the influence on joint stiffness by tighteing was shown for four subjects. By the experiment to identify the inpedance, the increase of elasticity on joints was shown about the one of the subjects.
Anteflexion motion is absolutely necessary when we spend daily life which we carry, snow shoveling, farm work, etc. Because it can be expected to explore the cause of low back pain, it is necessary to measure the lumbar load noninvasively taking lumbosacral alignment and external load into consideration. In this research, we develop a wearable sensor system for estimating the lumbar load.
In this study, it was verified that tightening of the pelvic area reduces the lumber load. In addition, a control rule that linearly changes the tightening force with respect to the load is provisionally implemented and the effect is verified. In the verification, even with the same tightening force, there was a difference in the degree of effect obtained by subjects. Consider the tightening control rule according to the weight, height, and gender of the subject for the development of the tightening control rule that can obtain a higher burden reduction effect.
In recent years, the necessity of measuring the physical stress is increasing. The reaction force that the legs receive from the floor is useful information for estimating the physical stress. But measurement equipment for reaction force cannot be carried in most cases. It is difficult to measure at the environment that human act. Furthermore, that equipment is expensive, and measurement involves several constraints. We prototype a sensor which is low cost and can measure the reaction force even in any environment.
Anteflexion motion is absolutely necessary when we spend daily life which we carry, snow shoveling, farm work, etc. This study aims to develop of wearable sensor system, and propose an estimation method of lumbosacral alignment and lumbar load caused by changes in posture. Lumbar motion have anteflexion,rotation motion and lateral bending. However, it thing don't know that relationship between the upper body attitude angle and the attitude angle of the vertebral body in rotation motion and lateral bending. We construct that estimation method of rotation angle and lateral bending angle in the vertebral body.
This study aims to develop of wearable sensor system, and propose an estimation method of lumbosacral alignment and lumbar load caused by changes in posture. Need to use the hand load for lumbar load estimation. Therefore, the hand load estimation method is developed by using muscle hardness sensor. By using this method, the hand load can be estimated with enough accuracy.