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.