My Dad tries walking to a rhythm or to a beat. It bypasses some circuitry in his brain and gets him out of the freeze. Doorways and turns are especially tricky for him. His physical therapist taught him to say/think "Inside the box" (his walker), "Stand up straight," and "Focal point." This helps him to "reset" and try again when he gets stuck. He has been improving with this strategy. We also say "Prancing Pony" to make him laugh and remind him to take big steps. Hope this helps.

Try music. Put some of his favourite tracks on MP3 and when he freezes tell him to put on the head phones and play the music. I have heard of cases where the person may even start to dance.

Try actually counting out loud too ("one, two, three, four" on beat), that sometimes helps my Dad get unstuck. :)

Have you tried listening to your favourite music. This works with some not all people. Who knows you may start dancing