title: Immediate effects of upper thoracic spine manipulation on hypertensive individuals.
abstract: OBJECTIVE
  The aims of this study were to determine if there were any statistically significant immediate effects of upper thoracic spinal manipulative therapy (SMT) on cardiovascular physiology in hypertensive individuals.
  
  
  BACKGROUND
  Preliminary research suggests that SMT to various regions of the spine may be capable of lowering systolic and diastolic blood pressure in hypertensive individuals. Further studies are warranted to corroborate or refute these findings as well as measure how other attributes of cardiovascular physiology are impacted by SMT.
  
  
  METHODS
  Fifty hypertensive participants (age = 45.5±13.9 years, height = 1.69±0.10 m, body mass = 93.9±21.5 kg: mean±standard deviation (SD)) were equally randomized into a single-blind, controlled trial involving two study groups: supine diversified anterior upper thoracic SMT of T1-4, or a 'no T-spine contact' control. Outcome measures were electrocardiogram, bilateral pulse oximetry, and bilateral blood pressure measurement performed at baseline, post 1-minute intervention, and post 10-minute intervention. An independent samples t-test was used to compare between-group differences at baseline. A repeated measures ANOVA was used to compare within-group changes over time.
  
  
  RESULTS
  Within-group changes in PR interval and QRS duration demonstrated that the atria were transiently less active post-SMT and the ventricles were more active post-SMT, however the changes were clinically minimal.
  
  
  CONCLUSIONS
  The results of this study, and the limited existing normotensive, thoracic-specific SMT research in this field, suggest that cardiovascular physiology, short-term, is not affected by upper thoracic spine SMT in hypertensive individuals to a clinically relevant level.
authors: Department of Physiology and Chemistry, Texas Chiropractic College, Pasadena, TX, USA.
authors: John
authors: J
authors: Ward
authors: Department of Technique, Texas Chiropractic College, Pasadena, TX, USA.
authors: Ken
authors: K
authors: Tyer
authors: Department of Clinical Specialties, Texas Chiropractic College, Pasadena, TX, USA.
authors: Jesse
authors: J
authors: Coats
authors: Department of Physiology and Chemistry, Texas Chiropractic College, Pasadena, TX, USA.
authors: Gabbrielle
authors: G
authors: Williams
authors: Department of Physiology and Chemistry, Texas Chiropractic College, Pasadena, TX, USA.
authors: Kristina
authors: K
authors: Kulcak
keywords: Blood pressure; Chiropractic; Heart rate; Manipulation