Tubercles
The greater tubercle (tuberculum majus; greater tuberosity) is situated lateral to the head and lesser tubercle, and just lateral to the anatomical neck. Its upper surface is rounded and marked by three flat impressions: the highest of these gives insertion to the supraspinatus muscle; the middle to the infraspinatus muscle; the lowest one, and the body of the bone for about 2.5 cm. below it, to the teres minor muscle. The lateral surface of the greater tubercle is convex, rough, and continuous with the lateral surface of the body.
The lesser tuberosity or lesser tubercle (tuberculum minus; lesser tuberosity), although smaller, is more prominent than the greater: it is situated in front, and is directed medialward and forward. Above and in front it presents an impression for the insertion of the tendon of the subscapularis muscle.
Read more about this topic: Upper Extremity Of Humerus