Ariko kandi tumenye ko habaho n’ubushobozi buke bw’inyama z’umubiri biturutse ku gucika kw’imitsi ikomeye cyane itarimo umwenge ifatisha inyama z’umubiri ku magufwa, utwo dutsi twacika urugingo ntirwihine (ni two bita « tendons »), hakabaho kutihina neza kw’ingingo z’umubiri (ankylose des articulations), ariko kandi iyo byatewe no guterwa ikinya cyangwa kujya muri koma (kurwara cyangwa kugira impanuka kugeza ubwo umera nk’uwapfuye), ibyo ntibishyirwa muri urwo rwego rw’uburwayi bwo kugagara ingingo.