Jacobs B, Avins A, Epel E, Acree M, Maurer S, Goldberg
H, Miaskowski C.
Iyengar yoga for the treatment of chronic low back pain:
a randomized controlled pilot study.
Osher Center for Integrative Medicine, University
of California, San Francisco, PO Box 1726, San Francisco, CA 94143-1726.
jacobsb@ocim.ucsf.edu
PURPOSE: There are no clearly effective treatments
for chronic back pain. Preliminary research suggests yoga may have clinical
benefits. The purpose of this study was to obtain pilot data on the
effect of Iyengar yoga for the treatment of chronic mechanical low back
pain.
METHODS: 52 patients with chronic low back pain
were randomly assigned to receive either twice-weekly Iyengar yoga (n=28)
or wait-list control (N=24) for 12 weeks. The primary outcome was the
change in the functional disability scores between baseline and study
end (12 weeks) using the Roland-Morris Questionnaire (RMQ) and Oswestry
Disability Index (ODI). Secondary outcomes included change in pain severity,
general health status by SF-36, anxiety by State-Trait Anxiety Instrument
(STAI), insomnia by the Impaired Sleep Index (ISI), and stress levels
measured by salivary cortisol levels.
RESULTS: Baseline clinical and demographics
variables were similar between groups, except for gender (65% female
in the intervention group vs. 39% in the controls). Yoga was associated
with a 2.5 point and 2.9 point improvement in RMQ and ODI when compared
with wait-list controls (RMQ yoga change score= - 2.7 versus control
change score= - 0.2 (p=0.07); ODI yoga change score= - 4.2 points versus
control change score= - 1.3 points (p=0.07)). When compared with waitlist
controls, the yoga intervention was associated with significant improvements
in emotional well-being subscale of the SF-36 (p=0.03) and insomnia
using ISI (p=0.02), as well as significant reductions in evening salivary
cortisol levels among men (p=0.05). There were no differences between
groups in pain intensity, anxiety, depression, and positive affect.
CONCLUSION: This pilot study found that yoga
was associated with a large effect size for improvement in functional
disability that approached statistical significance. Furthermore, yoga
may be associated with improved emotional well-being, sleep, and salivary
cortisol levels among people with chronic back pain. This study supports
the need for adequately powered trials to evaluate the clinical effects
of yoga among people with chronic back pain, and for trials to evaluate
the mechanism through which yoga may have its clinical effects.
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