title: Blood pressure and heart rate response to posteriorly directed pressure applied to the cervical spine in young, pain-free individuals: a randomized, repeated-measures, double-blind, placebo-controlled study.
abstract: METHODS
  Randomized clinical trial. Objectives To compare the blood pressure (BP) and heart rate (HR) response of healthy volunteers to posteriorly directed (anterior-to-posterior [AP]) pressure applied to the cervical spine versus placebo.
  
  
  BACKGROUND
  Manual therapists employ cervical spine AP mobilizations for various cervical-shoulder pain conditions. However, there is a paucity of literature describing the procedure, cardiovascular response, and safety profile.
  
  
  METHODS
  Thirty-nine (25 female) healthy participants (mean ± SD age, 24.7 ± 1.9 years) were randomly assigned to 1 of 2 groups. Group 1 received a placebo, consisting of light touch applied to the right C6 costal process. Group 2 received AP pressure at the same location. Blood pressure and HR were measured prior to, during, and after the application of AP pressure. One-way analysis of variance and paired-difference statistics were used for data analysis.
  
  
  RESULTS
  There was no statistically significant difference between groups for mean systolic BP, mean diastolic BP, and mean HR (P >.05) for all time points. Within-group comparisons indicated statistically significant differences between baseline and post-AP pressure HR (-2.8 bpm; 95% confidence interval: -4.6, -1.1) and between baseline and post-AP pressure systolic BP (-2.4 mmHg; 95% confidence interval: -3.7, -1.0) in the AP group, and between baseline and postplacebo systolic BP (-2.6 mmHg; 95% confidence interval: -4.2, -1.0) in the placebo group. No participants reported any adverse reactions or side effects within 24 hours of testing.
  
  
  CONCLUSIONS
  AP pressure caused a statistically significant physiologic response that resulted in a minor drop in HR (without causing asystole or vasodepression) after the procedure, whereas this cardiovascular change did not occur for those in the placebo group. Within both groups, there was a small but statistically significant reduction in systolic BP following the procedure.
authors.affiliation: Doctor of Physical Therapy Program, Sacred Heart University, Fairfield, CT.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Yung
authors.forename: Michael
authors.initials: M
authors.lastname: Wong
authors.forename: Haddie
authors.initials: H
authors.lastname: Williams
authors.forename: Kyle
authors.initials: K
authors.lastname: Mache
mesh_terms: D000328:Adult; D001794:Blood Pressure; D002574:Cervical Vertebrae / Q000502:physiology*; D004311:Double-Blind Method; D005260:Female; D064368:Healthy Volunteers; D006339:Heart Rate; D006801:Humans; D008297:Male; D026201:Musculoskeletal Manipulations / Q000009:adverse effects; D011312:Pressure; D055815:Young Adult
keywords: cardiovascular; manual therapy; mobilization; neck