title: Acuity of goal-directed arm movements to visible targets in chronic neck pain.
abstract: OBJECTIVE
  To evaluate end-point acuity in goal-directed arm movements in subjects with chronic neck pain, while taking the trade-off between speed and accuracy into account, and to evaluate associations between reduced acuity and self-rated characteristics.
  
  
  METHODS
  Single-blinded, controlled, comparative group study.
  
  
  METHODS
  Forty-five subjects with chronic non-traumatic, non-specific neck pain (n = 24) and whiplash-associated disorders (n = 21). Healthy subjects served as controls (n = 22). The groups were age- and sex-matched.
  
  
  METHODS
  Subjects performed fast and accurate pointing movements to a visual target. Group differences in end-point variability, controlled for peak velocity, were evaluated. Associations between end-point variability and self-rated symptoms, functioning, self-efficacy and kinesiophobia were analysed.
  
  
  RESULTS
  End-point acuity, controlled for peak velocity, was reduced for both neck-pain groups. Similar spatial error patterns across all groups indicated no direction-specific reduction. For both neck-pain groups, associations were found between end-point acuity and neck movement deficits, physical functioning and, in whiplash, also balance and pain.
  
  
  CONCLUSIONS
  Acuity of goal-directed arm movements can be reduced in chronic neck pain. Associations between acuity and self-rated characteristics support the clinical validity of the results and indicate that impaired neck function contributes to reduced end-point acuity. The results can be of importance for characterization and rehabilitation of neck disorders.
authors.affiliation: Centre for Musculoskeletal Research, University of Gävle, Gävle, Sweden.
authors.forename: Jonas
authors.initials: J
authors.lastname: Sandlund
authors.forename: Ulrik
authors.initials: U
authors.lastname: Röijezon
authors.forename: Martin
authors.initials: M
authors.lastname: Björklund
authors.forename: Mats
authors.initials: M
authors.lastname: Djupsjöbacka
mesh_terms: D000328:Adult; D001132:Arm / Q000503:physiopathology*; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D009068:Movement / Q000502:physiology*; D019547:Neck Pain / Q000503:physiopathology*; D010147:Pain Measurement; D011434:Proprioception / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D020377:Self Efficacy; D011795:Surveys and Questionnaires; D014911:Whiplash Injuries / Q000503:physiopathology*