Models allow for estimating forces inside the body
Biomechanic methods are used in order to assess health-related effects of postures and sequences of movements at the workstation. With the help of digital human models, forces inside the body can be estimated as well.
© Uwe Völkner, FOX photo agency
Biomechanics analyses structures and functions of the musculoskeletal system and examines the movement of biological systems. For this, it combines the methods, findings, and procedures of technical mechanics, biology, and anatomy. The use of biomechanics in the organisation of the work is similar to the use in the sports sciences. The focus is on health-related effects and optimisations of postures and courses of movements with or without additional loads and forces applied from the outside. The essential measuring methods include movement analyses, anthropometry, derivations of muscular activities (electromyography), and measurements of the external forces.
Measuring the forces inside the body is only possible at all in exceptional cases and tolerable for ethical reasons. An innovative alternative for this is the use of digital human models in the field of biomechanics. State-of-the-art models are capable of estimating muscle forces and joint forces – taking into consideration detailed anatomic structures inside the body. Some applications in the sports or medical area integrate specifically interesting body structures, such as spinal column, knee, or hip, as finite elements sub-models. A specific challenge is to use material parameters of the biological structures that were obtained within the framework of in vitro examinations to predict risks for possible damage of such body structures. Such methods allow for taking into consideration individual parameters, such as the build and age.
Projects sponsored by the Federal Institute for Occupational Safety and Health have examined the basic principles for the risk assessment when forces inside the body are applied. In so doing, the dependencies regarding age, sex, direction of the application of force, and posture are of interest. Findings regarding the application of a finite elements model for estimating internal forces within the spinal column have been incorporated into the development of the national standard DIN SPEC 45697 and international standard ISO 2631-5.