the movement you are describing actually makes sense, to the point that i am suprised more people dont have a similar complaint. for the same reason so many rsd patients experience dystonia involuntary movement seems plausible. in addition to the muscle atrophy, the nerves also show signs of injury. the messages that are supposed to go from an area of the body into the associated area of the brain. the simple path the messages used to follow have experienced an unexpected obstacle. just think of a train cruising along the tracks until someone throws the lever that switches the track. the train either bounces off the rails and crashes or it proceeds in a different direction. as a result the envisioned motions that normally would have remained in the mind until another image replaced it instead resulted in the actual behavior being played out. there is no filter so we act when others simply pondered the possibility.