Pressure: Tightness in smooth tissues e.g. ligaments, muscles and tendons, is a common reason behind bone spurs in feet. The limited tissue pulls over the part of the bone that it is connected far too, creating abnormal rigidity and local inflammation e.g. tight calf muscles/Achilles tendon results in heel bone https://www.theorthopaedicandpainpractice.com/what-are-spurs-on-the-foot/