title: Asymmetry of neck motion and activation of the cervical paraspinal muscles during prone neck extension in subjects with unilateral posterior neck pain.
abstract: BACKGROUND
  Although unilateral posterior neck pain (UPNP) is more prevalent than central neck pain, little is known about how UPNP affects neck motion and the muscle activation pattern during prone neck extension.
  
  
  OBJECTIVE
  To investigate whether deviation in neck motion and asymmetry of activation of the bilateral cervical paraspinal muscles occur during prone neck extension in subjects with UPNP compared to subjects without UPNP.
  
  
  METHODS
  This study recruited 20 subjects with UPNP and 20 age- and sex-matched control subjects without such pain. Neck motion and muscle onset time during prone neck extension were measured using a three-dimensional motion-analysis system and surface electromyography.
  
  
  RESULTS
  The deviation during prone neck extension was greater in the UPNP group than in the controls (p < 0.05). Compared with the controls, cervical extensor muscle activation in the UPNP group was significantly delayed on the painful side during prone neck extension (p < 0.05).
  
  
  CONCLUSIONS
  Subjects with UPNP showed greater asymmetry of neck motion and muscle activation during prone neck extension compared with the controls. This suggests that UPNP has specific effects on neck motion asymmetry and the functions of the cervical extensors, triggering a need for specific evaluation and exercises in the management of patients with UPNP.
authors.affiliation: Department of Physical Therapy, College of Medical Science, Jeonju University, Korea.
authors.forename: Kyue-Nam
authors.initials: KN
authors.lastname: Park
authors.affiliation: Laboratory of Kinetic Ergocise Based on Movement Analysis, Department of Physical Therapy, College of Health Science, Yonsei University, Wonju, Korea.
authors.forename: Oh-Yun
authors.initials: OY
authors.lastname: Kwon
authors.affiliation: KEMA Healing Center, Daejeon, Korea.
authors.forename: Su-Jung
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Physical Therapy, Yonsei University, Wonju, Korea.
authors.forename: Si-Hyun
authors.initials: SH
authors.lastname: Kim
mesh_terms: D016022:Case-Control Studies; D002574:Cervical Vertebrae / Q000503:physiopathology*; D004576:Electromyography; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D009333:Neck; D009334:Neck Muscles / Q000503:physiopathology*; D019547:Neck Pain / Q000503:physiopathology*; D064170:Paraspinal Muscles / Q000503:physiopathology*; D016684:Prone Position; D016059:Range of Motion, Articular; D055815:Young Adult
keywords: Asymmetry; neck motion; prone neck extension; surface EMG; unilateral posterior neck pain