First you should specify
Injury what type?
Site of injury?
Weather any nerve damage or bony component involved?
Weather knee joint or other joints involved?
Also how were you ambulating/walking for 1 month with help of stick/walker or were you completely bedridden?
Answering any queries without knowing the above history would be harmful to advise?
Feel free to write to me with the details.
By your question I'm assuming that your doctor didn't ask for any diagnostic test for the injury as he might have felt it as a minor injury. Always remember that exercises are always condition specific individually tailored & there are not always same exercises which help everyone in the same way. One thing I can strongly tell by your question is that you haven't used your leg for a month. Any muscle when not used for longer time goes into atrophy & adhesions. Muscle atrophy is shrikage & adhesions mean tightness. Before starting any exercise no matter how accurate it might be, you must clear our adhesions which usually limit ROM ( range of motion ).