title: Long-Term Monitoring of Physical Behavior Reveals Different Cardiac Responses to Physical Activity among Subjects with and without Chronic Neck Pain.
abstract: BACKGROUND
  We determined the extent to which heart rate variability (HRV) responses to daily physical activity differ between subjects with and without chronic neck pain.
  
  
  METHODS
  Twenty-nine subjects (13 women) with chronic neck pain and 27 age- and gender-matched healthy controls participated. Physical activity (accelerometry), HRV (heart rate monitor), and spatial location (Global Positioning System (GPS)) were recorded for 74 hours. GPS data were combined with a diary to identify periods of work and of leisure at home and elsewhere. Time- and frequency-domain HRV indices were calculated and stratified by period and activity type (lying/sitting, standing, or walking). ANCOVAs with multiple adjustments were used to disclose possible group differences in HRV.
  
  
  RESULTS
  The pain group showed a reduced HRV response to physical activity compared with controls (p = .001), according to the sympathetic-baroreceptor HRV index (LF/HF, ratio between low- and high-frequency power), even after adjustment for leisure time physical activity, work stress, sleep quality, mental health, and aerobic capacity (p = .02). The parasympathetic response to physical activity did not differ between groups.
  
  
  CONCLUSIONS
  Relying on long-term monitoring of physical behavior and heart rate variability, we found an aberrant sympathetic-baroreceptor response to daily physical activity among subjects with chronic neck pain.
authors.affiliation: Department of Occupational and Public Health Sciences, Centre for Musculoskeletal Research, University of Gävle, Kungsbäcksvägen 47, 801 76 Gävle, Sweden.
authors.forename: David M
authors.initials: DM
authors.lastname: Hallman
authors.affiliation: Department of Occupational and Public Health Sciences, Centre for Musculoskeletal Research, University of Gävle, Kungsbäcksvägen 47, 801 76 Gävle, Sweden.
authors.forename: Svend Erik
authors.initials: SE
authors.lastname: Mathiassen
authors.affiliation: Department of Occupational and Public Health Sciences, Centre for Musculoskeletal Research, University of Gävle, Kungsbäcksvägen 47, 801 76 Gävle, Sweden.
authors.forename: Eugene
authors.initials: E
authors.lastname: Lyskov
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D059350:Chronic Pain / Q000453:epidemiology / Q000503:physiopathology*; D005260:Female; D040362:Geographic Information Systems; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000379:methods*; D009043:Motor Activity / Q000502:physiology*; D019547:Neck Pain / Q000453:epidemiology / Q000503:physiopathology*