thanks to everyone who contributed so far, i would like to share my own case and (partial yet helpful) solutions, and failed solutions for that matter.
i happen to suffer from both numbness at predominately right feet and rarely n. at left feet, and a strain in my right back-calf, to the right side of the achilles tendon. Even though numbness and strain/aching do not always coexist, they mostly do and hence probably are related.
by the way i run about 60- 80 mins, keeping very slow (about 10 km/h ), feeling very comfortable in terms of heart beat throughout the run.
i have been to an orthopedist, and got several scans of my musculature, bones etc only to find out that nothing was noticeably wrong with bones/joints/circulation
i am 25, spent years up to age 20 playing lots of serious football, so i dismiss the possibility of having weak muscles for runnning,
what works for me:
-stretching/releasing exercises - your oldschool leg/knee achilles exercises work unbelievably, doing them for at least 3-4 minutes instead of my previous ignorant 30 secs worked -exponential- wonders!
- loosening the laces at the front foot area.
-taking slight breaks, even though i hate 'em.
-running with a higher stress on toes, avoiding excessive heel impact., as suggested by several posts so far.
what does not work, or works too slightly to take seriously:
-various brands of sorbothane running insoles purchased for around 25 pounds at ebay (though i havent tried scholl's yet)
-switching among different brands/models of r. shoes (tried various popular brands/models so far, being careful about my type of pronation etc.)
-visiting a specialist (even though it helped with my fears of having a serious condition which might prevent running for the rest of my life),
hope this helps, best