It was in her girdle that lay the great strength of the heroine Brunhild as did that of Thor in the megin-giardar. Saxo Grammaticus preserves the story that king Hother having met three Nymphs (i. e. Norns) and complained of his lack of success in battle, obtained from them ‘a girdle of victory’
Onians argues that in Norse tradition the girdle is the literal seat of heroic and divine strength, given by fate-figures to confer victory, establishing the girdle as a concentrated vehicle of magical power rather than mere clothing.
, The origins of European thought about the body, the mind,, 1988thesis