Stability Analysis of Muscular and Skeletal System of Human’s leg segments (Thigh and Shank)

Abstract

Muscular and Skeleton systems are the key elements for strength, support and locomotion of human system. Shank, a part of the human leg, not only supports body weight but provide locomotion at the time of walking and running. This part may be considered as an assembly of several mechanical springs, mass and damping elements. The mode of vibration and stability will depend upon the spring stiffness, damping coefficient and their arrangements in muscular and skeletal system. The modeling and analysis of this system has assumed that there are four stages of growth to tackle stability. The first stage (0-1 years) is formation stage where the bone forms from the cartilage to gain stiffness and damping. The second stage (1-20 years) when the system is getting stabilized and considered more stable, because of balance between stiffness and damping of the muscles and bone. The value for damping starts decreasing in the third stage (20 to 65 years) leaving stiffness alone to stand the locomotion at later years. The fourth stage (65 to 90 + years) relates to old age, in which both the damping coefficient and stiffness start deteriorating, causing considerable instability. The stability analysis is carried out with the mean values taken in these four stages to show how the system changed from one stage to another. A linear model is considered for simple analysis that shows that stiffness rate increases and damping decreases with the increasing age. This often takes place after the second stage. The Simulation Program with integrated Circuit Simulation Program with Integrated Circuit Examples (SPICE) is used for discussion of these results.