An undersized running back who is hard to tackle due to his lack of height, low center of gravity, stocky build and extremely thick lower body.
1) Damn! Maurice Jones-Drew just ripped my fantasy team defense for 174 yards and two touchdowns! That dude is a muscle-ball, you just can't tackle him!
2) That runningback is a damn muscle ball! We couldn't tackle him in a phone booth!muscle jones-drew football