are the key to elastic energy storage which evolved allowing humans to kill effectively from a distance.

Read these and see if you didn't already know this as principles from TCMA.

http://cashp.gwu.edu/ntroach/the-evolution-of-throwing/

http://www.nature.com/nature/journal...67.html#access

http://www.geeksaresexy.net/2013/07/...n-of-throwing/