Some people may have heard of Achilles tendinopathy in addition to Achilles tendon rupture and may not understand the difference between the two. Tendinopathy describes pain or stiffness of the tendon and can be acute or chronic. Acute pain normally occurs with athletes who suddenly increase their activity. A classic example is a runner who starts training for a marathon. The pain builds gradually over a period of days to weeks. Chronic pain can be caused by poor running form, poor footwear, or low but sustained mechanical stress. Pain typically improves with rest.
Achilles tendon rupture is different. It is a sudden event, typically associated with a sudden increase in force. For example, a sudden pivot or abrupt stop-and-go motion can cause the tendon to experience a rapid increase in force. If the force overwhelms the strength of the tendon, the tendon can rupture. Certain medications, like ciprofloxacin, can make people more prone to rupture. Patients who have experienced a ruptured Achilles tendon often complain of a “popping” sensation followed by sudden, severe pain.