Why Achilles tendon injuries resist treatment

For people with pain in the Achilles tendon, the band of tissue connecting the calf muscles to the heel, recovery can be slow and unpredictable. Even with the best available therapy, many continue to struggle with recurring pain that can linger for years.

Achilles tendinopathy refers to injuries that result in pain and stiffness in the tendon, causing difficulty with movement. The condition can arise when the tendon is strained from repeated overuse during physical activity and is associated with factors like aging, metabolic disorders or obesity.

The gold-standard treatment for Achilles tendinopathy is a progressive series of calf-strengthening exercises. Yet even with this therapy, up to 60% of patients still report pain five years after diagnosis.

"The complex anatomy of the Achilles tendon varies across individuals, which may contribute to the inconsistent results of the current one-size-fits-all treatment approach," said Stephanie Cone, assistant professor at the University of Delaware's College of Engineering. "We seek to better understand how anatomy relates to Achilles tendinopathy injuries so we can develop more effective treatments in the future."