Zur Bedeutung dieses Beinamens bietet die deutsche Wikipedia folgende zwei Erklärungen: 1949 veröffentlichte der Däne Knud Stakemann Seedorff eine Dissertation über die Osteogenesis imperfecta ([...] Glasknochenkrankheit [...]), [...] Seedorff weist darauf hin, dass über Ivar berichtet wird, seine Beine seien so schwach gewesen, dass er auf einem Schild getragen werden musste. [...] Rory McTurk weist im Zusammenhang mit dem Beinamen darauf hin, dass Ivars Beiname falsch assoziiert werde. „Knochenlos“ sei demnach in einigen norwegischen Erzählungen eine Bezeichnung für den Wind, sodass damit Ivars Fähigkeiten als Navigator gemeint sein können. Die englische Wikipedia ist ausführlicher : There is some disagreement as to the meaning of Ivar's epithet "the Boneless" (inn Beinlausi) in the sagas. Some have suggested it was a euphemism for impotence or even a snake metaphor (he had a brother named Snake-in-the-Eye). It may have referred to an incredible physical flexibility; Ivar was a renowned warrior, and perhaps this limberness gave rise to the popular notion that he was "boneless". The poem "Háttalykill inn forni" describes Ivar as being "without any bones at all". Alternatively, the English word "bone" is cognate with the German word "Bein", meaning "leg". Scandinavian sources mention Ivar the Boneless as being borne on a shield by his warriors. Some have speculated that this was because he could not walk and perhaps his epithet simply meant "legless"—perhaps literally or perhaps simply because he was lame. Other sources from this period, however, mention chieftains being carried on the shields of enemies after victory, not because of any infirmity. [...] Genetic disease Still another interpretation of the nickname involves Scandinavian sources as describing a condition that is sometimes understood as similar to a form of osteogenesis imperfecta. The disease is more commonly known as "brittle bone disease." In 1949, Danish researcher Knud Seedorf wrote: Of historical personages the author knows of only one of whom we have a vague suspicion that he suffered from osteogenesis imperfecta, namely Ivar Benløs, eldest son of the Danish legendary king Regnar Lodbrog. He is reported to have had legs as soft as cartilage ('he lacked bones'), so that he was unable to walk and had to be carried about on a shield. There are less extreme forms of this disease where the person afflicted lacks the use of his or her legs but is otherwise unaffected, as may have been the case for Ivar the Boneless. In 2003 Nabil Shaban, a disability rights advocate with osteogenesis imperfecta, made the documentary The Strangest Viking for Channel 4's Secret History, in which he explored the possibility that Ivar the Boneless may have had the same condition as himself. It also demonstrated that someone with the condition was quite capable of using a longbow, such that Ivar could have taken part in battle, as Viking society would have expected a leader to do. Mal abgesehen davon, was Nabil Shaban ausprobiert hat, so kann ich mir nicht recht vorstellen, dass jemand mit der Glasknochenkrankheit in diesen vormodernen Zeiten große Überlebenschancen hatte, schon mal gar nicht als Krieger oder gar als Heerführer, von dem mehr erwartet wurde, als nur einen Angriff oder eine Schlacht zu planen.