All of the following are superficial muscles of the back, EXCEPT:

Trapezius, levator scapulae, rhomboid major, rhomboid minor, and latissimus dorsi constitute the superficial muscles of the back. Erector spinae, splenius, transversospinalis, and suboccipital muscles constitute the deep muscles of the back. Erector spinae muscle:Iliocostalis, longissimus, and the spinalis muscles together constitute the erector spinae muscle.When it acts bilaterally it helps in extending the veebral column.When acting unilaterally it laterally flex the veebral column and rotate it to the ipsilateral side.Ref: Moon D.A., Foreman K.B., Albeine K.H. (2011). Chapter 1.Back.