Well, what have you been doing to warm her up thus far? Are your current ways not working for some reason?
What sort of hind leg injury was it? Muscle? Tendon? Is she stiff starting out? Any warm up should ideally take much longer than most people do. Sounds like a nice easy 20 minutes is a good start for your gal. Spirals in and out and square corner turns are good for hq engagement. Easy walk/trot work to get her going sounds like the ticket.
We are not human beings having a spiritual experience. We are spiritual beings having a human experience. -Pierre Teilhard de Chardin