spinocostalis

spi·no·cos·ta·lis

(spī'nō-kos-tā'lis),
The superior and inferior serratus posterior muscles regarded as one.
[L.]

spinocostalis

(spī″nō-kŏs-tā′lĭs) [″ + costa, rib]
The combination of the superior and inferior serratus muscles.