Context.— Carpal tunnel syndrome is a common complication of repetitive activities
and causes significant morbidity.
Objective.— To determine the effectiveness of a yoga-based regimen for relieving
symptoms of carpal tunnel syndrome.
Design.— Randomized, single-blind, controlled trial.
Setting.— A geriatric center and an industrial site in 1994-1995.
Patients.— Forty-two employed or retired individuals with carpal tunnel syndrome
(median age, 52 years; range, 24-77 years).
Intervention.— Subjects assigned to the yoga group received a yoga-based intervention
consisting of 11 yoga postures designed for strengthening, stretching, and
balancing each joint in the upper body along with relaxation given twice weekly
for 8 weeks. Patients in the control group were offered a wrist splint to
supplement their current treatment.
Main Outcome Measures.— Changes from baseline to 8 weeks in grip strength, pain intensity, sleep
disturbance, Phalen sign, and Tinel sign, and in median nerve motor and sensory
conduction time.
Results.— Subjects in the yoga groups had significant improvement in grip strength
(increased from 162 to 187 mm Hg; P =.009) and pain
reduction (decreased from 5.0 to 2.9 mm; P =.02),
but changes in grip strength and pain were not significant for control subjects.
The yoga group had significantly more improvement in Phalen sign (12 improved
vs 2 in control group; P =.008), but no significant
differences were found in sleep disturbance, Tinel sign, and median nerve
motor and sensory conduction time.
Conclusion.— In this preliminary study, a yoga-based regimen was more effective than
wrist splinting or no treatment in relieving some symptoms and signs of carpal
tunnel syndrome.
CARPAL TUNNEL syndrome (CTS) is a common problem in the workplace and
causes significant morbidity. In addition to its potentially debilitating
physical aspects, CTS has a negative financial impact resulting from lost
time from work and increasing medical expenses.1
Traditionally, CTS has been treated with wrist splints, anti-inflammatory
agents, avoidance of occupational duties, career changes, injection therapy,
and surgery. However, many of these options have provided less than satisfactory
symptom relief.1
Yoga and relaxation techniques have been used to help alleviate musculoskeletal
symptoms.2 However, except for a previous study
on osteoarthritis of the hand,3 to our knowledge,
these methods have not been studied in a prospective controlled trial. Our
previous investigation showed significant improvement in range of motion,
decreased tenderness, and decreased hand pain during activity in patients
with osteoarthritis who followed a supervised program of yoga and relaxation.
The purpose of this study was to evaluate whether a program of yoga
and relaxation techniques might offer an effective treatment alternative for
patients with CTS. Yoga was proposed to be helpful because stretching may
relieve compression in the carpal tunnel, better joint posture may decrease
intermittent compression, and blood flow may be improved to decrease ischemic
effects on the median nerve. In this article, we report the results of a randomized
controlled trial examining the effects of an intervention using supervised
yoga and relaxation techniques specifically designed for patients with CTS.
Approximately 400 potential subjects were recruited through advertisements
in the city newspaper and notices posted at study sites. After initial screening
by telephone, 72 interested, available, and suitable patients with characteristic
symptoms of CTS were interviewed in person and examined; 51 subjects met the
criteria for inclusion in the study.
Entry criteria included the presence of at least 2 of 5 of the following
clinical findings: positive results on Tinel sign, positive results on Phalen
sign, pain in the median nerve distribution, sleep disturbances resulting
from hand symptoms, and numbness or paresthesias in the median nerve distribution.
All potential subjects were required to have abnormal median nerve conduction
latencies on neuroelectrical testing.4 All
subjects were required to agree not to change medications, receive other new
treatments, or change work duties during the study. Exclusion criteria were
previous surgery for CTS, rheumatoid arthritis or other recognized inflammatory
arthritis, CTS related to systemic disease (such as hypothyroidism), and pregnancy.
The study took place at Ralston House, the Geriatric Center of the University
of Pennsylvania in Philadelphia, and at QVC Corporation, an industrial site
in West Chester, Pa. Participants from QVC were actively employed and were
compensated to arrive 1 hour before their shift began. Ralston House participants
included employed and retired subjects. The study was approved by the institutional
review boards of Presbyterian Medical Center, Philadelphia, Pa, and the University
of Pennsylvania Medical Center. Written informed consent was obtained from
study subjects.
Subjects were randomized into 2 groups by having them select sealed
envelopes containing a group assignment. Subjects in the control group were
offered a standard wrist splint with a metal insert (if not already in use)
to supplement their current treatment. Subjects in the yoga-based intervention
group received a program focused on upper body postures: improving flexibility;
correcting alignment of hands, wrists, arms, and shoulders; stretching; and
increasing awareness of optimal joint position during use. We used the Iyengar
approach to hatha yoga, which emphasizes proper structural alignment of the
body and is based on the teachings of yoga master B. K. S. Iyengar.3,5 The method of study is orderly and
progressive, and postures are adjusted to meet the physical conditions of
the subjects. With education in the postures (asanas), habitual poor posture
can improve. As musculoskeletal alignment improves, the ability to perform
the asanas also should improve. Potential benefits of this method include
improvements in strength, coordination, and flexibility and an increased sense
of well-being.
The sequence of postures used in this study was designed to focus on
the upper body for subjects with CTS. The exercises were performed while the
subject was sitting and standing and were designed to take each joint in the
upper body through its full range of motion with strengthening, stretching,
and balancing each part.5 Instructions for
the 11 asanas used and the relaxation technique are shown in Table 1.
Every session ended with relaxation using the relaxation response of
savasana (corpse pose), which is proposed to help counteract the energy-draining
effects of prolonged stress and chronic pain.5
During relaxation, the body remains still and movement is not possible.
The yoga program was given for 1 to 112 hours twice weekly by 1 instructor (M.S.G.) for 8 weeks.
Subjects reported the approximate number of hours of disturbed sleep
per night during the previous week. Subjects indicated the intensity of pain
for the previous week on a visual analog scale of 0 to 10, with 10 indicating
the greatest level of pain.6 Phalen7 sign (90 seconds) and Tinel sign8
were assessed, with results recorded as positive or negative for each involved
wrist. Patterns of paresthesia and numbness were recorded on hand diagrams.
Grip strength was measured with a sphygmomanometer cuff that was rolled, taped,
and inflated to 20 mm Hg. The subject was encouraged to squeeze with maximum
strength and the best of 3 efforts was recorded for each hand.
An electroneurometer4 (NERVEPACE, NeuMed
[Neurotron Medical], Lawrenceville, NJ) was used to measure the distal latency
of the median nerve across the wrist. This electroneurometer has been validated
to show comparable specificity to standard nerve conduction studies.9 All tests were assessed at baseline and were repeated
at the end of 8 weeks. The assessments all were conducted by 1 physician (A.S.)
who was blinded to the patient's group assignment and the intervention.
Differences between the pretest and posttest changes were examined using
repeated-measures analysis of variance for within-group differences in improvement
for continuous measures of grip strength and nerve conduction times (sensory
and motor) for each involved wrist, and for pain intensity for each subject.
Paired difference t tests were conducted to examine
pretest vs posttest differences on continuous variables within each group. χ2 Tests were used to examine the relationship between group membership
and categorically coded variables of improvement on Phalen sign, Tinel sign,
and sleep disturbance. The P<.05 level of significance
was used. Post hoc analysis was carried out to calculate the appropriate sample
size to detect clinically meaningful differences in each of the proposed tests.
For variables measured on a continuous scale this sample size would yield
a power of 80%, and for variables measured on a categorical scale power would
be 64%.
Of the 51 subjects who met inclusion criteria and were randomized, 9
dropped out or were excluded (Figure 1).
Final data were analyzed for 42 subjects (67 unique wrists with CTS), 22
(35 wrists) in the yoga group and 20 subjects (32 wrists) in the control
group (Table 2).
Table 3 shows a comparison
between pretest and posttest results for pain, grip strength, and nerve conduction
time (sensory and motor) in the yoga-treated and control groups. Patients
in the yoga-treated group had statistically significant improvements for
grip strength and pain reduction. Trends toward improvement also were observed
within the yoga-treated group in pretest to posttest measures of motor nerve
conduction time, Phalen sign, Tinel sign, and sleep disturbance, although
these trends were not statistically significant. Both groups also showed
trends toward improvement in sensory and motor nerve conduction times, but
no significant differences between pretest and posttest values were found.
Results of repeated-measures analyses for between-group differences were
not statistically significant for any of the variables. Improvement on Tinel
sign, Phalen sign, and reported sleep disturbance were more common in the
yoga-treated group, but were statistically significant only for improvement
in Phalen sign(Table 4).
Occupationally related health problems such as CTS are the leading cause
of lost earnings in the workplace.10 As a result
of cumulative trauma disorders, businesses sustain substantial losses annually
due to medical expenses and lost productivity. In this study, a program of
yoga-based simple stretching and postural alignment, which does not require
drugs, expensive equipment, or surgery, reduced pain and improved grip strength
for patients with CTS.
Yoga classes such as the one used in this study can improve awareness
of proper postures and use of the upper extremities. Although not studied
here, we propose that a properly supervised program may be helpful not only
to treat symptoms, but also to prevent recurrences or the onset of symptoms.
Our study was designed as a preliminary study and as such has several
limitations including small sample size, lack of generalizability, and the
use of a simple wrist splint as a control. We did not obtain data on medication
use, time lost from work, or patient compliance with wrist splint use or other
therapies.
Although not systematically studied, many subjects in the yoga group
reported that they maintained improvement in their CTS symptoms 4 weeks after
conclusion of the program. Further studies are needed to ascertain whether
a single course of yoga intervention with occasional reinforcement can be
effective for long-term relief. Programs could be initiated at workplaces
with a high incidence of CTS, perhaps with 2 classes per week for 8 to 10
weeks, with monthly follow-up sessions to monitor home practice. Continued
evaluations of outcomes are needed to evaluate long-term effects of yoga on
CTS symptoms, lost time from work, and patient satisfaction.
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