the last of them is at the sternum from the core of the tendon. this has two heads one at the sternum but its core is nervous and the other at the collarbone and most of its core is fleshy. because of these two heads it is thought that it is not one muscle but rather two muscles one above the other. therefore it was said that the muscles that are inverted to the head alone are three muscles. the truth is that they are only two muscles since those that have two heads do not have origins. these two muscles are large because of the size of the moving organ with them and they are in the inclination of those who move their heads a lot or strengthen them such as wrestlers and the like. and god is the grantor of success.
وآخرها عند القص من جوهر الوتر وهذه يصير لها رأسان أحدهما عند القص ولكن جوهره عصبي والآخر عند الترقوة وأكثر جوهره لحمي، ولأجل هذين الرأسين يظن أنها ليست عضلة واحدة وإنها عضلتان إحداهما فوق الأخرى، ولذلك قيل أن العضل المنكسة للرأس وحده ثلاث عضلات. والحق أنه عضلتان فقط. إذ لم يوجد للتي لها رأسان مبدآن وهاتان العضلتان عظيمتان لكبر العضو المتحرك بهما، وهما في ميلان الذين يكثرون حركة رؤوسهم أو يقوونها أعظم، وذلك كالمصارعين ونحوهم. والله ولي التوفيق.