Mechanical overload is considered the main cause of Achilles tendinopathy. In addition to tensile loads, it is believed that the Achilles tendon may also be exposed to compressive loads. However, data on intratendinous pressures are lacking, and consequently, their role in the pathophysiology of tendinopathy is still under debate.
Therefore, we aimed to evaluate the intratendinous pressure changes in the Achilles tendon during stretching and eccentric loading. Twelve pairs of human cadaveric legs were mounted in a testing rig, and a miniature pressure catheter was placed through ultrasound-guided insertion in four different regions of the Achilles tendon: the insertion superficial and deep layers , mid-portion, and proximal portion.
Intratendinous pressure was measured during three simulated loading conditions: a bent-knee calf stretch, a straight-knee calf stretch, and an eccentric heel-drop. These observations offer novel insights and support a role for compression in the pathophysiology of Achilles tendinopathy by demonstrating high intratendinous pressures at regions where Achilles tendinopathy typically occurs.
To what extent managing intratendinous pressure might be successful in patients with Achilles tendinopathy by, for example, avoiding excessive stretching, modifying exercise therapy, and offering heel lifts requires further investigation.
Keywords: Achilles tendon; compressive load; eccentric loading; intratendinous pressure; stretching; tendon biomechanics; tendon compression. Abstract Mechanical overload is considered the main cause of Achilles tendinopathy.
