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Osteopathic Manipulative Treatment and Its Relationship to Autonomic Nervous System Activity as Demonstrated by Heart Rate Variability
Charles E. Henley, DO, MPH, FAAFPUniversity of Oklahoma College of Medicine, Tulsa
Department of Family Medicine, Tulsa OK
Bruce A. Benjamin, PhDOklahoma State University College of Osteopathic Medicine,
Department of Pharmacology/Physiology, Tulsa OK
Introduction
Validation of OMT largely observational, based on patient outcomes
Little quantitative data evaluating relationship between manipulation and ANS
Lack of ability to accurately measure autonomic activity directly
Heart rate variability (HRV) has developed into noninvasive, commonly used method to measure autonomic activity1,2
Objective
To study the relationship between Osteopathic manipulative therapy (OMT) and the autonomic nervous system using heart rate variability (HRV) as a surrogate for autonomic activity.
Methodology
Recruitment 28 OSU COM students, staff and faculty Inclusion criteria
Written informed consent Normal, healthy adults age 19-50 years Normal ECG Normal blood pressure (as per JNC-7 criteria)
Methodology
Exclusion criteria Chronic disease conditions Pregnancy Smoker PVC exceeding 20% total heart beats Resting supine heart rate >75 bpm or <45 bpm Blood pressure <90 mmHg or >140 mmHg Failure of heart rate to increase with passive tilt Long-distance runners, other conditioned athletes
Methodology
General Study Design: Repeated Measures Each subject acted as own control Random assignment to first group 30 minute study protocol
10 minutes Horizontal 1 (H1) 10 minutes 50 degree head-up Tilt (T)
Sham or OMT 10 minutes Horizontal 2 (H2)
Continuous recording of ECG and respiration data
Methodology
Study groups Control: Positional changes only (H1, Tilt, H2) Sham: Positional changes with operator’s
hands in OMT treatment position without applied treatment
Treatment: OMT – Cervical myofascial release Positional changes with OMT for 2 minutes
in 50 degree head-up position
Methodology
Data Collection and Analysis R-R intervals determined by R-wave peak
detection algorithm Frequency analysis of HRV by LF, HF, LF/HF Within subjects repeated measure t-tests and repeated ANOVA pairings Repeated ANOVA using multivariate approach Power analysis: N=14
alpha=0.05, beta=0.80 Estimated 25% difference in group mean ratios Standard deviation = 2.6
Results
17 of 28 subjects (61%) completed study 9 men and 8 women No adverse effects of the study
Heart Rate
0
20
40
60
80
100
Horizontal 1 Tilt Horizontal 2
Mean + SE
bea
ts/m
inu
te
Control
OMT
Sham
* ** #
Results
Heart Rate Significant increase (p<0.001) with position change
from H1 to Tilt within all groups (*) In Tilt, HR for OMT was significantly decreased
(p<0.001) from Control and Sham Returned to baseline for all groups upon return to
horizontal
Low Frequency
0
20
40
60
80
100
Horizontal 1 Tilt Horizontal 2
Mean + SE
LF (n
u)
Control
OMT
Sham
***
#
Results
Low Frequency Significant increase (p<0.001) with positional
change from H1 to Tilt in Control and Sham Significantly less increase in OMT compared to
Control and Sham Returned to baseline for all groups upon return to
horizontal
High Frequency
0
20
40
60
80
Horizontal 1 Tilt Horizontal 2
Mean + SE
HF
(n
u) Control
OMT
Sham* *
* #
Results
High Frequency (HF) In Tilt, HF in Control and Sham groups was
significantly decreased compared to H1 Change with OMT was not as great compared to
Control and Sham Returned to baseline for all groups upon return to
horizontal
Results
LF/HF Ratio Tilt significantly increased ratio in Control and
Sham due to increase in LF and decrease in HF OMT significantly reduced ratio in Tilt position Ratio returned to baseline upon subject return
to horizontal Ratio for OMT at Tilt was statistically different
(p<0.001) from Control and Sham at Tilt
Results
LF/HF Ratio
0
1
2
3
4
5
6
Horizontal 1 Tilt Horizontal 2
Mean + SE
LF
/HF Control
OMT
Sham* #
* *
Results
Respiration Continuously measured throughout study No change in respiration with body position Rate of respiration was similar in all 3 groups
Respiration Rate
10
12
14
16
18
20
Horizontal 1 Tilt Horizontal 2
Mean + SE
Re
sp
ira
tio
n
(bre
ath
s/m
in)
Control
OMT
Sham
Discussion
Increase in LF/HF at Tilt reflects an increase in sympathetic tone
Initiation of OMT at Tilt resulted in change back to parasympathetic tone
Shift from sympathetic to parasympathetic environment demonstrates OMT ability to overcome sympathetic tone
Discussion
Lee et al3 studied effect of head-down flexion on HRV Maneuver significantly affected autonomic
balance as measured by LF/HF ratio Generally recognized that respiration has
important effect on HRV4
Our study showed respiration was not affected by body position or group
Study results not influenced by alterations in respiration
Discussion
Montano et al5 observed comparable changes in heart rate and spectral analysis 60 degree head-up tilt LFnu increased in tilt position; HFnu decreased LF/HF ratio increased
Primary difference in studies was OMT intervention in present study Application of OMT in Tilt eliminated 62% of
increase in LF/HF seen in Control Tilt
Conclusions
Quantitative relationship exists between OMT and sympathovagal balance Cervical myofascial release shifts
sympathovagal balance from sympathetic to parasympathetic
Establishes plausible mechanism for how OMT works in the body
Support for using HRV as method to measure autonomic change
Future Studies
Use of different OMT techniques Use of subjects with various chronic health
conditions
References
Kautzner J, Camm AJ. Clinical relevance of heart rate variability. Clin Cardiol. 1997 Feb;20(2):162-8.
Sztajzel J. Heart rate variability: a noninvasive electrocardiographic method to measure the autonomic nervous system. Swiss Med Wkly. 2004 Sep 4;134(35-36):514-22.
Lee CM, Wood RH, Welsch MA. Influence of head-down and lateral decubitus neck flexion on heart rate variability. J Appl Physiol. 2001 Jan;90(1):127-32.
Hayano J, Mukai S, Sakakibara M, Okada A, Takata K, Fujinami T. Effects of respiratory interval on vagal modulation of heart rate. Am J Physiol. 1994 Jul;267(1 Pt 2):H33-40.
Montano N, Ruscone TG, Porta A, Lombardi F, Pagani M, Malliani A. Power spectrum analysis of heart rate variability to assess the changes in sympathovagal balance during graded orthostatic tilt. Circulation. 1994 Oct;90(4):1826-31.