Pain in foot while bending upwards, what could be wrong?

Limited motion: If you have pain upon dorsiflexion of the foot, ether are a numbers of possible reasons. Limited ankle joint range of motion is the first reason. Tight achilles tendon, and posterior muslcle group (gastroc-soleus) is another. Tight pantar fascia, or tight muscle groups within the foot (intrinsic). Stretching exercises can help tremendously try some yoga.