It is shin splint pain happens on fast walking .
Start with stretching of calf hams and tibialis anterior muscle I. e muscle just next to your shin bone . Hold the stretch for 30 sec 10 rep 3 times a day and before starting to walk.
No need of any medicine .
Next Steps
learn stretching and streathening exercises for the same from a good physio.
Health Tips
drink lots of water each day helps in maintaining flexibility of muscles.