Compound fracture of tibia & fibia - what exercise can help healing?

by Linda
(Ramsgate, Kent UK)

Nearly 3 months ago my son was involved in a car accident and suffered a compound fracture of both tibia and fibula. The consultant confirmed last week that there is no sign of healing at present and said to go back in 2 months time. I asked about rehab or physio as he has very bad blood circulation and the consultant simply said my son should do light excercise but he would not elaborate. My son is now going to the gym and using the cycles to exercise. What physio/exercise should he be doing?