Power Doppler ultrasound in ‘overuse’ and ‘inflammatory’ tendon disorders. Sonographically it is often impossible to determine the cause of tendinopathy from Power Doppler signals. The top row of images are all of patients without underlying rheumatological diagnosis and in whom mechanical overload or injury was the cause of the tendinopathy (from left to right insertional Achilles tendinopathy, proximal patellar tendon pathology and mid-peroneal tendon pathology). The bottom row of images is of patients with a known inflammatory rheumatological diagnosis. From left to right tibialis posterior tendinopathy (in RA) and insertional Achilles tendinopathy in a patient with reactive arthritis (longitudinal and transverse sections).