Foot Injury..

Hi,
Approx 14 months ago I hurt my foot while motorcycle riding.
Something punctured the top left side of my foot and it required 5 stitches.
Nothing was broken.
For sometime after that incident my foot was severeally swollen and the left side of my foot (where it arches) was very numb.
Over a year has gone by and although the numbness is mostly gone there is still some there.
I find that by running on a daily basis the numbness literally all goes away, but its not gone totally.
I have no pain in the foot, other than this ackward feeling at times.
Where they gave me stitches it is still slightly red and slowly getting better.
Did I damage nerves that are causing my foot to behave this way, or it simply the depth of the puncture in the foot that is taking so long as to heal ?
Your help would be greatly appreciated.