Why does the entire bottom of my foot feel deeply bruised or severely sore, but without a specific injury?

That deep, sore feeling across the bottom of your foot is often caused by fat pad atrophy, which means the natural cushioning under your heel and ball of the foot has worn thin. This can happen with age, from high-impact activities, or from wearing shoes that don’t provide enough support. Without that padding, your bones and tissues take more impact, causing the bruised, aching feeling. To feel better, you need extra cushioning. Specialized insoles with deep heel cups and dense padding can help spread out pressure and protect your feet. Upstep makes custom orthotics designed to provide this kind of support and cushions, and they deliver them right to your door without a specialist visit needed.