We can sustain different types of injuries to a muscle tendon, and each one could change how you treat it. It is important to differentiate what is actually happening with each type. A strain signifies that someone has pulled their tendon too far, and some of its fibres have torn. A strain can be a 1st, 2nd, or 3rd degree tear. Generally, a 1st degree strain implies less than half the tendon is torn, a 2nd degree is over half torn, and a 3rd degree denotes full rupture. Tendinitis refers to inflammation occurring at the affected site, usually stemming from repetitive stress or loading of the tendon, over a long period of time. Subsequently, someone can suffer from a tendinosis. This is where the tendon has been put under stress for a much longer period of time with tendinitis, but now the tendon has less inflammation and has chronic degeneration.

Heath Vermette, CAT(C), SouthSherbrook.com