I can't. Because of my back issues when I do shoulder presses, be it Bb or Db, I have to have my back supported. Between my back and shoulders there are postures and movements I just can't do. I'm going to work a few of the ones I don't normally do into this cycle at low weight to start but there are some that are just not possible and standing presses are one of those. I wish I could because it's a great movement. Much like squats and deads, it's a whole body movement. Unfortunately without my lower back supported I can't push much weight above my head like that.
Let this log and other mature members like OGH be a testament to the fact that as you get older you can work around your physical shortcomings and still make progress as long as you possess the desire and the will to kill it. Everyone here has that or you wouldn't be here.