'elbow-related' is a modern English compound formed from the noun 'elbow' + the participial/adjectival element 'related', meaning 'connected to the elbow'.

'elbow' comes from Old English 'eln-bōga' (or 'elnboga'), a compound of 'eln' (forearm/arm) + 'bōga' (bend), which through Middle English became 'elbow' and then combined in modern usage with 'related' to form 'elbow-related'.

Originally 'elbow' literally meant 'arm bend' (the bend of the forearm); over time it became the regular word for the anatomical joint and the surrounding region, and now 'elbow-related' means 'pertaining to that joint or region.'