👉 Achiillobursitis is a common pain in the back of the thigh caused by a tenderness and swelling in the area around the knee joint, which is caused by inflammation or irritation of the Achilles tendon. The condition can occur as a result of injury to the foot or leg, weakness or stiffness in the lower back or leg, or spasm. It may be managed with conservative therapy and medications such as nonsteroidal anti-inflammatory drugs (NSAIDs) for acute pain. Long-term management is focused on prevention of injury to the Achilles tendon or treatment of weakness or stiffness.