according to my research, and this artisic rendering of early human...
... you will note early man has a club. presumably for bonking food on the head to kill it. he also appears to have a large upper body in comparison to his lower body. one would suspect this is an evolutionary developement to, infact, HELP with the bonking on the head. it seems he has developed into a short chase with a big swing kind of creature. had early man been a chaser, you would expect to see more of a lean body type over all, helping with endurance running.