going to throw
in my unsolicited random thoughts.
first, the push model with arms straight out or bend. shoulders are the weakest points for force conduction, so locked you arms straight out, would put stress on the shoulders beyond its physical design. bending arms, especially, the elbows touching the body, would distribute the forces to the body and lessen the stress at the shoulder joints. it's a sound biomechanical/physics model.
there is nothing wrong to go with both theory and applied. one approach is to trying things first then come up with theory to explain/model it. the other approach is to come up with the theory, then experiment to either prove or disprove or improve the theory. some folks like the experiment first; other folks, theory first.
me, i liked to do both, at the same time. left hand for theory, right hand for applied. waving left hand and said watch this hand, then kick with the right foot. oh wait! there supposes to be a throw somewhere in here. hey, if you kick hard enough, the other person might throw
last i checked, newtonian physics still applied on earth. i was reminded this morning in the shower, what goes up, must comes down. damn cold water!