makunouchi i am in training for forces and such have had a few leg problems and at first was told it was shin splints but later been told it wasnt, il try clear this up.
Shin splints are "micro fractures" in the bone mainly the tibia/shin
These fractures are caused when trumour is caused via inpact or pounding affect along the area. For example, football/rugby and other inpact sports where shins might come under damage though hitting or being hit hard repeatedly.
As these inpacts happen the bone gets trumour and micro fractures appear.
this is shin splints. to find if you got them a simple X-ray will surfice.
I personally didnt have them but i had scar tissue builing up along my shins/tibia whch caused pain along the bone, these scars are like "little clusters along the bone as you feel down it".
ultra sound helps with this, but doesnt cure the cause only the symptom.
In the end it was found i "pronated" inwards and such stretched the shin to much though runner fast on road.
solution was to have insoles in my shoes to help this, and am currently having some ultra sound to get rid of the scars that are left
hope this answeres your question, feel free to ask more stuff as i am finding out more about problem you get though running as i run more and offen.
p.s how fast can you run 3 milers and 5 miles?