Ubwoko umunani bwo guterura umupira ni ikintu cyingirakamaro kandi cyingenzi mubikoresho bya kijyambere.Igikorwa cyacyo nyamukuru ni ugushyigikira imashini izunguruka, kugabanya ubwumvikane buke mugikorwa cyayo, kugirango bizenguruke neza.Ifite uruhare runini mu kongera ubuzima bwimashini.