I do not associate this knob on the side of the trunk with any anatomical feature of a human body. Rather, to me, it symbolizes character. Everyone takes lumps and bumps in life; they record how we obtained character. The faces of older people--worn, discolored, lined, dried, scarred--show their character. Depending upon how we wear these features, how they hang on the inner spirit, determines whether character so shown has nobility or not.