Exercises to do whilst recovering from broken leg

I broke my fibula bone in two places at the beginning of the year, and now that the cast is off, I'm wanting to know what exercises would be best for me. I've been doing the exercises the physiotherapist gave, and I've been attending an exercise class which focuses on deep muscle exercises (and has really helped with stretching out the achilles tendon and other leg muscles which were feeling very weak and tight since the cast came off), along with going for lots of walks. Before the break, I would go to the gym 2/3 times a week and use the vibro plate 3 times a week for 20 minutes each time.
Is it safe to use the vibro plates so soon after having the cast off? I've been told by the physiotherapist not to go to the gym just yet, but he had never heard of the vibro plates. Any information would be helpful please. Thanks.