Origin and Insertion (Las)

The names imply that a muscle starts at "origin" and ends at "insertion". However, you may still confuse these two, so here is a general guideline I found to be helpful.

• The origin part usually does not move (or moves less than the insertion part) when the muscle is flexed. 
  
• The insertion part usually moves when the muscle is flexed.

Also note that origin and insertion areas always refer to tendons that connect a muscle and a bone. There are no muscles that connect directly to a bone.