Rhomboid muscles
（重定向自Rhomboideus）
The rhomboid muscles (/ˈrɒmbɔɪd/), often simply called the rhomboids, are rhombus-shaped muscles associated with the scapula and are chiefly responsible for its retraction. They are innervated by the dorsal scapular nerve. There are two rhomboid muscles on each side of the upper back: