achilles injury?

i just noticed when i point my right foot as far down as it will go theres some pain where the achilles inserts at the bottom. theres no pain when i just move the foot down with my hands. any idea what this is? i last trained on thursday (3 x 100 fairly slowly as im coming back from injury) and have been doing literally nothing since then. any ideas about what this is?

edit: my friend says this also happens to him but in both legs. he said maybe youre just not supposed to do that (pointing ur foot down)

How did you feel one day after training. Did you have soreness in that region the next day?

could be a joint alignment/mobility issue in there. could be something very simple like that. go see a mechanic - preferably a chiropractor and get both your feet manipulated first before working on soft tissue options. Something like even a jammed talus bone joint could put muscles, ligaments and tendons on stretch.