title: Pressure pain and isometric strength of neck flexors are related in chronic tension-type headache.
abstract: BACKGROUND
  In patients with chronic tension-type headache (CTTH) changes in pressure pain in the cervical region are associated with peripheral or central sensitization. It is hypothesized that an increase of isometric strength of neck flexors would lead to a decrease of pressure pain in CTTH, as an expression of reduced peripheral or central sensitization
  
  
  OBJECTIVE
  In this study we aimed to analyze the correlation between change in isometric strength of the neck flexors and change in pressure pain scores (PPS) in patients with CTTH.
  
  
  METHODS
  Comparative analysis of data from previous study.
  
  
  METHODS
  Primary healthcare center.
  
  
  METHODS
  Data from 145 patients with CTTH who underwent a manual therapy program including isometric strength training of the neck flexors were analyzed at 8 and 26 weeks post-treatment. PPS were measured as a total of pain scores on a numeric rating scale (score 0 to 10) on application of a pressure stimulus of 3kg/cm at 8 cervical- and suboccipital muscles. Isometric strength of the neck flexors was measured in seconds. Correlations were computed between changes in PPS and isometric neck flexor strength.
  
  
  RESULTS
  Isometric strength of neck flexors scored significantly different compared to baseline measurement (mean 30.0 seconds, sd:25.2), and increased with a mean difference of 17.33 seconds (95%CI: 20.61 to 14.05) at 8 weeks and 19.18 seconds (95%CI: 23.48 to 14.87) at 26 weeks. Similarly, compared to PPS baseline measurement (31.6 points, sd:18.6), mean difference in PPS was significantly decreased at 8 and 26 weeks: -11.3 points (95%CI: -8.77 to -13.83) and -11.15 points (95%CI: -8.31 to -13.99). There is a negative correlation between changes in PPS and changes in isometric strength of neck flexors which is weak at 8 weeks (r = -0.243, P = 0.004) and moderate at 26 weeks (r = -0.318, P < 0.000).
  
  
  CONCLUSIONS
  Correlational analysis.
  
  
  CONCLUSIONS
  Decrease in PPS correlates with increases in isometric strength of neck flexors in patients with CTTH in short- and long-term.
authors: Department of General Practice and Elderly Care Medicine, EMGO Institute for Health and Care Research, VU University Medical, Amsterdam, Netherlands.
authors: Rene
authors: R
authors: Castien
authors: Annette
authors: A
authors: Blankenstein
authors: Willem
authors: W
authors: De Hertogh
mesh_terms: D000293:Adolescent; D000328:Adult; D059350:Chronic Pain / Q000175:diagnosis / Q000628:therapy*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology; D009334:Neck Muscles / Q000473:pathology* / Q000502:physiology; D010147:Pain Measurement / Q000379:methods; D011312:Pressure / Q000009:adverse effects; D011446:Prospective Studies; D055070:Resistance Training / Q000379:methods*; D018781:Tension-Type Headache / Q000175:diagnosis / Q000628:therapy*; D055815:Young Adult