Staging achilles tendinopathy using ultrasound imaging: the development and investigation of a new ultrasound imaging criteria based on the continuum model of tendon pathology.

Intra-rater and inter-rater reliability were 'substantial' to 'almost perfect' when utilising an USI-based criteria to diagnose Achilles tendinopathy. This is the first study to use the continuum model of tendon pathology to develop an USI-based criteria to diagnose tendinopathy.