The enthesis (plural entheses) is the connective tissue which attaches tendons or ligaments to a bone.

[7][8][9][10][11][12][13][14][15] However, research has shown that, whichever recording method is used, entheseal changes occur more frequently in older individuals.

Experimental studies have demonstrated how loading history (physical activity) can increase the relative size of muscle attachment sites.

[21][22][23][24] "Enthesis" is rooted in the Ancient Greek word, "ἔνθεσις" or "énthesis," meaning “putting in," or "insertion."

Relatedly, in muscle terminology, the insertion is the site of attachment at the end with predominant movement or action (opposite of the origin).