<s>[INST] My girlfriend has been having horrible shooting pain in both of the arches and heals everyday for the past few months now, it brings her to tears. tonight I was rubbing her foot and noticed a hard bump between the heal and the joint of big toe on both feet, I do not have this on my foot, thought this could be the root of the problem, researched and saw about navicular syndrome, what do you think [/INST] Hello, There are several syn Chat Doctor.  X-ray or ultrasound or even MRI can be the first step.  BUT frankly, cannot say in your particular case, but generally, irritated/scarred tendons form lumps in the bottom center of the foot. Local injection by a podiatrist mostly works.  Since the needle goes right to a spot you can feel and is about 1/2 inch under the surface, it is hard to miss and hard to have side effects. Basically, it's a pretty simple injection. Hope I have answered your query. Let me know if I can assist you further. Take care  </s>