Since cloning of humans is still not a done thing, you have leeway to play a bit. You could invent a way to use electrical stimulation of muscle groups to assist in the proper development of the adult clone. Since you’ve already said the clone will possess full awareness from the original, they will have the experience of walking in their brain already, and should have the proper neural pathways established. So, it becomes a question of readying the muscles. Perhaps there’d be some initial unsteadiness, but the memories are there, and if the muscles are not atrophied, and have been kept limber and healthy, it should pass as quickly as a couple of days.