The Achilles tendon is attached to the large calf muscle behind your lower leg. The tendon attaches or inserts (thus the word insertional) to the heel bone (calcaneus) in your foot. Tendinopathy usually means a tear or some other type of damage to the tendon.
Noninsertional tendinopathy is a tear or injury to the Achilles tendon. This occurs somewhere between where it attaches or inserts to the bone and where it becomes muscle. It’s not right at the point of insertion.
Technically a tendinopathy is not the same as tendonitis. Some say it’s on a continuum or line. Tendonitis is at the beginning of the line and tendinopathy is at the other end. That’s because chronic overuse of a tendon leads to inflammation and microtears
(tendonitis). Tendonitis can later become a tendinopathy. The tendinopathy tear is large enough to show up on ultrasound imaging; tendonitis is not seen.
Both conditions have pain, but there’s often a tender bump or nodule above the insertion point with a tendinopathy.