For the treadmill press while standing on the treadmill, set it to one mile per hour or slower and carefully step off without changing direction (as though you were running on the belt), and set up in quadruped stance (i.e., on your hands and knees). Place the hand of your working arm on the moving belt toward the head end of the treadmill (where the control panel is). Your other hand can serve as support on the side of the treadmill, safely away from the moving belt.
Instructions
Begin with your shoulder flexed and your elbow at maximal extension (i.e., the top of the ROM), just as in the top of a shoulder press.
As you push the palm of your open hand into the belt, try to concentrically flex the shoulder and extend the elbow.
Allow your hand and arm to be forced backward, replicating an eccentric portion of a one-arm shoulder press.
When the desired ROM is complete, simply lift your hand from the belt.
Rest as long as necessary to perform the next rep with full focus, and then repeat.
