According to statistics from the World Health Organization (WHO), the illnesses of the musculoskeletal system rank second after the most common heart diseases. Thus, the risk of diseases of the spine, bones, and joints is not attributable to a specific group, regardless of age or gender. Difficulty in walking often causes problems in other organs, making diseases of the musculoskeletal system a serious problem.

One of the important methods of rehabilitation of the human musculoskeletal system is the use of special trainers intended for motion function rehabilitation. However, such systems are often expensive and associated with high costs. An alternative to these expensive technical aids would be to develop a cheaper rehabilitation trainer model, which can be acquired also by small medical centres. The objective of Sergei Žigailov's research was to develop such a trainer.

According to the supervisor of the thesis, Associate Professor Gennadi Arjassov, the thesis consisting of four parts includes description and analysis of the models for simulating human lower-limb motion, identification of the mechanical heel-pelvis system parameters and mathematical modelling and providing examples of the work of the algorithm for inertial measurement unit (IMU) signal processing for plate-pelvis plane motion. As a result, the laws of motion of a plate pelvis by axes were determined and, on the basis of the defined transfer functions, the differential equations of mechanical system motions were found.

Gennadi Arjassov said: "The doctoral thesis achieved its objective to model experimentally and analytically human pelvic motion. For this, we, by using the identification method, modelled and constructed a mechanical system for human heel-pelvis motion simulation that can be used in human lower-limb recovery in the near future."

The supervisors of the doctoral thesis were Associate Professor Gennadi Arjassov (TUT) and Professor Victor Musalimov (ITMO University, Russia).
The opponents were Professor Mati Pääsuke (University of Tartu) and Associate ProfessorJulius Griškevičius (Vilnius Gediminas Technical University, Lithuania).

The doctoral thesis has been published in the digital collection of TUT library http://digi.lib.ttu.ee/i/?6134

Kersti Vähi, Research Administration Office