What are Possible Meanings of Ivar "Boneless" Ragnarsson?

If you have become a Viking enthusiast, you may find out that Ragnar Lothbrok was a great leader. This is not to mention he also fathered many great sons who later became kings. Among them is Ivar the Boneless who later invaded Northumbria with his brothers. 

Some of the nicknames in the Viking are quite easy to comprehend. They might be related to some personal physical traits or personal achievement in battles. For example, Sigurd Snake-in-the-Eye refers to the physical traits in his eye. Or Erik the Red had his nickname coined because he had firing red beard and hair. 

But what about the Ivar the Boneless? What does this Boneless actually refer to? There have been a lot of heated debates around the meaning of "Boneless". Below are some of the possible explanations for this. 

Cripple?

The most common meaning of the Boneless is that Ivar was a cripple. He was said to have a disease inside which is called osteogenesis imperfecta. This kind of disease refers to the imperfect bone formation. Some of the legends said that Ivar was carried by his people when he joined the battle. 

However, the point is, this kind of disease would never let a human survive without modern medicine and medical care. Hardly could anyone make it through their infancy if they were subject to OI disease, not to say that he could come and fight like warriors. 

The other thing is that the Vikings never allowed anyone that was born cripple in their family. Back in their time, if an infant was born with physical disabilities, the parents would abandon them. Because they thought having a disabled child in the family was a bad luck. 

Although this meaning of "Boneless" is quite common, it is not really historically appropriate. 

Impotent?

Back in the Viking Age, the Vikings also used something crude and ridiculous to call others. So the meaning of being impotent is also a possible meaning. One thing is that there were no children's names in the family tree of Ivar the Boneless. He might have never fathered any child in his time. 

Cunning?

Boneless can be interpreted as having a flexible battle mindset. Ivar's legends had it that Ivar once invaded many parts of Anglo-Saxon, especially Northumbria whose king put an end to the life of Ragnar Lothbrok. 

To be able to lead an army to invade many parts of Anglo-Saxon, the leader had to be a very excellent.