a thornlike bony excrescence on the lower surface of the calcaneal bones where the foot ligaments or Achilles tendon are attached; a type of osteophyte. Calcaneal spurs occur most frequently as a result of metabolic disorders or overtaxation of the foot ligaments in flatfootedness. Although a spur can cause severe pain, it is not visible externally. Detection is by means of a foot X ray. Treatment includes physical therapy, the use of special orthopedic inner soles and shoes, and—in cases of persistent severe pain—roentgenotherapy and surgery.