| Term 
 
        | Two groups of back muscles. |  | Definition 
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        | Term 
 
        | The superficial group of back muscles are known as the ______________. |  | Definition 
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        | Term 
 
        | The erector spinae are composed of ____ sets of muscles that run from the sacrum and ileum and attach to the vertebrae, ribs and skull. |  | Definition 
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        | Term 
 
        | Function of the erector spinae. |  | Definition 
 
        | To keep the back straight. |  | 
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        | Term 
 
        | The deep group of muscles are known as the _______________. |  | Definition 
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        | Term 
 
        | Function of the muscles of the transverso-spinalis. |  | Definition 
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