[TA] muscles of the back innervated by the dorsal primary rami of spinal nerves; includes erector spinae, transversospinalis, interspinales, and anterior and lateral intertransversii muscles; excludes the superficial back muscles, which are appendicular and are innervated by ventral rami, and the trapezius, innervated by the spinal accessory nerve. SYN: musculi dorsi proprii [TA], deep muscles of back, true muscles of back.