Original Editor Oyemi Sillo
Spinous processes of C2 to C5
Deep cervical artery
Acting bilaterally: extension of the cervical spine
Acting unilaterally: lateral flexion of the neck and rotation to the opposite side.
Maintains head posture.
It was found that during neck pain the deep cervical extensor muscle semispinalis cervicis has shown reduction in activation 
manual resistance done in extension over the vertebral arch of C1 and C4 emphasized the activation of the semispinalis cervicis muscle relative to the splenius capitis at the spinal level directly caudal to the site of resistance. 
- Gray, Henry. Anatomy of the Human Body. Philadelphia: Lea & Febiger, 1918; Bartleby.com, 2000. www.bartleby.com/107/.
- National Center for Biotechnology Information, Anatomy, Back, Muscles StatPearls [Internet]. available from: https://www.ncbi.nlm.nih.gov/books/NBK537074/ (24 july 2019)
- Wheeless`textbook of orthopedic, Semispinalis Cervicis, available from:http://www.wheelessonline.com/ortho/semispinalis_cervicis_1 (24july 2019 )
- J Schomacher, J Erlenwein, A Dieterich, F Petzke, F Petzkeb, D Falla. Can neck exercises enhance the activation of the semispinalis cervicis relative to the splenius capitis at specific spinal levels? Manual therapy, October 2015:20: 694-702.