Using preoperative magnetic resonance imaging, the cross-sectional areas of the trapezius muscles at the C3–4, C4–5, C5–6, and C6–7 intervertebral levels were measured on T2-weighted axial images. a)Multifidus, b)semispinalis cervicis, c)semispinalis capitis, d)splenius capitis, and e)trapezius.