[TA] the group of deep back muscles that originate from transverse processes of the vertebrae and pass to spinous processes of higher vertebrae; they act as rotators and include the semispinalis (e.g., capitis, cervicis, thoracis), multifidus, and rotatores (e.g., cervicis, thoracis, lumborum) muscles. All are innervated by dorsal primary rami of spinal nerves. SYN: musculi transversospinales [TA], transversospinal muscle, transversospinales.