The primary purpose of this bachelor thesis is to investigate the effects of technical and functional characteristics of external fixator along with procedures that comprise its application on conditional stability of design and bone defect site. In order to do so, it is essential to include the default field of orthopaedic surgery and outline significant data, structured and selectively with regard to available literature. The aim was achieved consecutively by defining medical terminology, historical facts, principles and (contra)indications of external fixation, classification of fixators and emphasizing their features and materials along with conducted comparison of models and selection of optimal design according to existing literature. Finally, an ergonomic analysis was conducted by dividing it on analysis of design factors and analysis of human factor or processes that the application of fixator includes. Evaluation of the method demonstrated that the source of frequent complications is pin-bone interface despite the fact that the available literature mostly did not include information on the causes of negative outcomes. Furthermore, it was concluded that imperfection of the design regarding any of the presented factors, from pins and configuration to bone drilling and wire tensioning, will not satisfy stability conditioned by the process of healing even though pins are considered as crucial structural elements. According to that, and other premises, it is recommended that when designing a fixator, in order to improve this method of bone fractures treatment, vital design requirements are set upon pins and their material that will provide a convenient biological environment for bone and be an adequate mechanical properties carrier along with eventual suggestion of reprocessing and reuse.