In ancient Egyptian belief, the spirit or life-force of an individual that lives on after death.  The hieroglyph for the ka was shoulders and arms, with the arms bent upwards at the elbow, similar to the touchdown signal in American football. Web resource here.

Statue of King Hor, with ka symbol on his head. Wood, stucco, rock crystal and quartz. Ca. 1750 BCE. Egyptian Museum, Cairo.