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A systematic review and meta-analysis of studies on the putative mechanisms of action of lumbar supports in lifting activities. To summarize the evidence bearing on the putative mechanisms of action of lumbar supports. A restriction of trunk motion and a reduction in required back muscle forces in lifting are two proposed mechanisms of action of lumbar supports. Available studies on these putative mechanisms of action of lumbar supports have reported contradictory results. A literature search for controlled studies on mechanisms of action of lumbar supports was conducted. The methodologic quality of the studies was assessed. The evidence for the two proposed mechanisms of action of lumbar supports was determined in meta-analyses. Thirty-three studies were selected for the review. There was evidence that lumbar supports reduce trunk motion for flexion-extension and lateral bending, with overall effect sizes of 0.70 (95% confidence interval [CI] 0.39-1. 01) and 1.13 (95% CI 0.17-2.08), respectively. The overall effect size for rotation was not statistically significant (0.69; 95% CI -0. 40-4.31). There was no evidence that lumbar supports reduce the electromyogram activity of erector spinae muscles (effect size of 0. 09; 95% CI -0.41-0.59) or increase the intra-abdominal pressure (effect size of 0.26; 95% CI -0.07-0.59). There is evidence that lumbar supports reduce trunk motion for flexion-extension and lateral bending. More research is needed on the separate outcome measures for trunk motion before definite conclusions can be drawn about the work conditions in which lumbar supports may be most effective. Studies of trunk motion at the workplace or during specified lifting tasks would be especially useful in this regard.
Content may be subject to copyright.
SPINE Volume 25, Number 16, pp 2103–2113
©2000, Lippincott Williams & Wilkins, Inc.
Mechanisms of Action of Lumbar Supports
A Systematic Review
Mireille N. M. van Poppel, PhD,* Michiel P. de Looze, PhD,†‡ Bart W. Koes, PhD,*
Tjabe Smid, PhD,*†§ and Lex M. Bouter, PhD*
Study Design. A systematic review and meta-analysis
of studies on the putative mechanisms of action of lum-
bar supports in lifting activities.
Objective. To summarize the evidence bearing on the
putative mechanisms of action of lumbar supports.
Summary of Background Data. A restriction of trunk
motion and a reduction in required back muscle forces in
lifting are two proposed mechanisms of action of lumbar
supports. Available studies on these putative mecha-
nisms of action of lumbar supports have reported contra-
dictory results.
Methods. A literature search for controlled studies on
mechanisms of action of lumbar supports was conducted.
The methodologic quality of the studies was assessed.
The evidence for the two proposed mechanisms of action
of lumbar supports was determined in meta-analyses.
Results. Thirty-three studies were selected for the re-
view. There was evidence that lumbar supports reduce
trunk motion for flexion– extension and lateral bending,
with overall effect sizes of 0.70 (95% confidence interval
[CI] 0.39–1.01) and 1.13 (95% CI 0.17–2.08), respectively.
The overall effect size for rotation was not statistically
significant (0.69; 95% CI 0.40 4.31). There was no evi-
dence that lumbar supports reduce the electromyogram
activity of erector spinae muscles (effect size of 0.09; 95%
CI 0.41– 0.59) or increase the intra-abdominal pressure
(effect size of 0.26; 95% CI 0.07–0.59).
Conclusion. There is evidence that lumbar supports
reduce trunk motion for flexion– extension and lateral
bending. More research is needed on the separate out-
come measures for trunk motion before definite conclu-
sions can be drawn about the work conditions in which
lumbar supports may be most effective. Studies of trunk
motion at the workplace or during specified lifting tasks
would be especially useful in this regard. [Key words:
biomechanics, low back pain, lumbar support, meta-anal-
ysis, review] Spine 2000;25:2103–2113
Low back pain occurs very frequently and is one of the
most costly health problems affecting industry and soci-
ety. Low back disorders are one of the major reasons
for work disability
55,63
and sick leave.
18,55
In the Neth
-
erlands in 1991 the total (direct and indirect) cost for
back pain represented 1.7% of the gross national prod-
uct.
58
In the United States, the total costs for back pain
were estimated to be $27.9 billion in 1990,
12
which
represented approximately 0.5% of the gross national
produce.
In an attempt to reduce the incidence and conse-
quences of back pain in industry, many prevention pro-
grams have been introduced.
25
Lumbar supports are fre
-
quently used in industry, and they increasingly receive
attention in the scientific literature. Besides their use as a
preventive measure, lumbar supports are also used in the
treatment of patients with back pain. Several putative
mechanisms of action of lumbar supports have been pro-
posed. One hypothesis is that the use of a support may
positively affect trunk motion. The support may either
physically obstruct extreme postures, or it may improve
body postures through tactile feedback (reminder func-
tion). Excessive trunk motion, especially axial rotation,
is often assumed to be the cause of a back injury,
3,40
and
the prevention of excessive motion would therefore lead
to a reduction in the risk of low back pain. Another
hypothesis is that less back muscle force may be required
to extend the trunk when wearing a support, because of
an increase in the intra-abdominal pressure (IAP) with-
out a concomitant increase in abdominal muscle activa-
tion. This would yield less muscle loading, less muscle
fatigue, and less compressive loading on the lumbar
spine. Both reduced muscle fatigue
6
and reduced com
-
pressive loading
46
may result in a decrease of the risk for
low back pain. The same mechanism may result in a
higher maximal lifting capacity of the person wearing a
lumbar support. Using a lumbar support may also make
the workers feel more secure and make them inclined to
lift heavier loads. This could increase the risk of low back
injuries.
Available reviews argue that, partly because of con-
flicting results, no definite conclusions on the mechanism
of action of lumbar supports can be drawn.
3,40,44,46
The
objective of this review is to evaluate the evidence for the
two hypothetical mechanisms of action of lumbar sup-
ports with the use of a systematic literature search and by
combining the results of individual studies in a meta-
analysis. Even if the results are contradictory, it should
be possible to draw conclusions based on the results of
the meta-analysis.
Methods
A search of MEDLINE (1966–1997), EMBASE (1988–1997),
and Psychlit (1984–1997) was conducted (key words used:
back, spine, orthotic devices, protective devices, biomechan-
ics). No language restriction was used. References of relevant
publications were screened for additional studies.
From the *Institute for Research in Extramural Medicine and †Human
Movement Sciences Vrije Universiteit, Amsterdam; ‡TNO Work and
Employment, Hoofddorp; and §Health Safety and Environment, KLM
Royal Dutch Airlines, Schiphol Airport, The Netherlands.
Acknowledgment date: July 14, 1998.
First revision date: December 17, 1999.
Acceptance date: December 21, 1999.
Device status category: 9.
Conflict of interest category: 14.
2103
The following inclusion criteria were used: 1) The study
should have a design in which the same subjects were tested
with and without lumbar support. Studies without a prospec-
tive study design were excluded. 2) The study should include
healthy human subjects. Studies with only patients with back
pain were excluded, because posture and movements can be
influenced by back symptoms, which in turn may alter the effect
of lumbar supports. 3) Outcome measures should include one
or more of the following: electromyographic activity; intra-
abdominal pressure (IAP); and parameters on trunk motion,
maximum lifting capacity, perceived exertion, or subjective
maximum acceptable weight of lift (MAWL). 4) Interventions
should consist of any lumbar support (orthotic corset, weight-
lifting belt, and elastic support). Studies of thoracic supports
were excluded.
Methodologic Assessment. All studies were scored accord-
ing to the methodologic criteria listed in Table 1. These criteria
are based on generally accepted principles of intervention re-
search, and similar criteria have been used in previous reviews
concerning therapeutic interventions for low back pain.
21–23
Possible scores were yes/no. The criteria are described in more
detail in a separate Appendix, which is available from the first
author on request. Items concerning internal validity were: (A)
randomization, (B) a fixed washout period, (C) outcome assess-
ment, (D) reproducibility reported, (E) blinding of outcome
assessment, (F) description of missing data or no missing data,
and (G) correct analysis of the data. The other items (H, I, J)
covered quality of reporting. Two reviewers assessed the meth-
ods of the studies independently, and disagreement was solved
in a consensus meeting.
Data Extraction and Meta-Analysis. Data extracted from
the original papers were: the number of subjects, the number of
missing values, and the mean and standard deviation (SD) or
confidence interval (CI) of outcome measures of subjects with
and without a lumbar support or the mean and SD or CI of the
difference between conditions with and without lumbar sup-
port. Because outcome measures within the same category
(e.g., trunk motion) differed between studies, effect sizes and in
particular the Hedges’s g were calculated before results of in-
dividual studies were statistically combined.
50
The Hedges’s g
is the difference between the means of the outcome measure in
the two intervention groups or testing conditions, divided by
the average population SD. The effect size thus expresses the
magnitude of an effect as the number of SDs. As a rule of
thumb, effect sizes less than 0.4 represent a small effect, 0.4
0.8 a medium-sized effect, and more than 0.8 a large effect.
8
Because heterogeneity of the studies was expected, due to va-
riety in outcome measurements, study populations, and lumbar
supports tested, the random effects model was used for com-
bining the effect sizes for the meta-analysis.
51
Studies were
weighted using the variance in effect size at issue. A statistical
test for homogeneity was conducted.
51
If the data were not
homogeneous, subsequent analyses with specific subsets of
studies were performed to search for study characteristics that
could account for the heterogeneity.
For investigating the hypothesis concerning an effect of lum-
bar supports on trunk motion, the outcome measures consid-
ered were vertebral displacement, the maximum range of mo-
tion (ROM), and the observed ROM in specified lifting tasks in
the sagittal, transverse and lateral planes. Regarding the hy-
pothesis about a reduction of back muscle force, the outcome
measure considered most relevant was the electromyogram of
erector spinae muscles. Intra-abdominal pressure was also con-
sidered as an outcome measure for this hypothesis, because it
was assumed that an increase in IAP would lead to a decrease in
electromyogram of erector spinae muscles and subsequently to
a reduction in back muscle force. However, the correlation
between IAP and electromyogram is under debate,
46
and IAP
was therefore considered to be a less relevant outcome for this
hypothesis than electromyogram of erector spinae muscles.
Other, less important outcomes that could indicate a reduction
in back muscle force were maximal lifting capacity, intradiscal
pressure, and spinal shrinkage. To investigate whether workers
may be inclined to lift heavier loads when using a lumbar sup-
port, subjective outcome measures were considered, such as the
maximum acceptable weight of a lift, perceived exertion, and
perceived discomfort due to lifting.
The effects of a specific type of support on different outcome
measures within one study are not independent. In addition,
because in most studies different types of supports were tested
by the same subjects, the effects of different types of supports
are not independent either. For this reason, only one outcome
measure for one particular support was used per study in each
pooled estimate of effect. In the meta-analyses on reduction in
trunk motion, the outcomes concerning lumbar motion were
thought more relevant than outcomes on thoracic motion. If
both outcomes were available, only the lumbar outcomes were
included in the meta-analysis. If more than one support was
tested in a study, the effect size for a weight-lifting belt was
chosen for statistically combining the results of electromyo-
gram and IAP, because this type of lumbar support was most
commonly tested in these studies. For combining the results on
trunk motion, the effects of lumbosacral corsets were chosen
for the same reason. If these belts were not tested and data on
more than one support were available, the support most resem-
bling a weight-lifting belt or lumbosacral corset was chosen. A
subgroup analysis for elastic lumbar supports was performed,
because these supports are commonly used in industry and are
importantly different from rigid supports.
The influence of the methodologic items on the reported
effect size was assessed by calculating the mean effect size of
studies that scored less than four items and studies that scored
more than four items positive of the seven methodologic items
separately. Differences in the mean effect size between studies
that scored less than four and more than four items positive
were tested for statistical significance with Student’s t test. If a
Table 1. Criteria List for the Methodologic Assessment
of Controlled Studies on the Mechanisms of Action of
Lumbar Supports
Criteria*
A Randomization of the order belt/no belt
B Wash-out period
C Description of outcome assessment
D Reproducibility of outcome assessment
E Blinding of outcome assessment
F No missing values or description of missing values
G Appropriate analysis
H Description of study population
I Description of lumbar support
J Adequate reporting of most important results
* All items were scored yes/no. A copy of the operationalization of the items
can be obtained from the first author on request.
2104 Spine
Volume 25
Number 16
2000
statistically significant difference in effect size was observed
between these groups of studies, only studies that scored more
than four items positive were used in the meta-analysis.
Results
Thirty-three studies were identified that met our selec-
tion criteria.
4,5,7,11,13,15–17,19,20,24,26–34,36
39,42,43,45,49,52,53,6062
There was initial disagreement
between the reviewers on 77 (17%) of 462 items scored
in the methodologic assessment of the studies. Disagree-
ment was mostly due to reading and interpretation errors
and was solved in a single consensus meeting. The studies
scored from one to six positive items of the seven items
for internal validity. The number of validity items scored
positive per study is shown in Tables 2 and 3. A validity
score of four or more items positive was found for 8
(24%) of the 33 studies. No statistically significant dif-
ference in the mean effect size was found between studies
that scored less than four or four or more validity items
positive. Therefore, all studies were included in the meta-
analyses. The most prevalent shortcomings were (A) that
the procedure was not randomized or the randomization
was not described, inadequate analysis of the data (G),
and the absence of an assessment or description of the
reproducibility (D). Many studies used a computerized
outcome measurement that could not be influenced by
the investigators. Therefore, they scored positive on the
item on blinded outcome assessment (E).
Changes in Body Posture or Movements
In Table 2 the 13 studies that reported on trunk motion are
listed. In these, investigators measured the maximal range
of motion (ROM) of the trunk,
5,28,32,38,42,45,60
the ob
-
served range of motion during specified tasks,
13,20,31,34
or
the range of angular movement of spinal disks.
11,39,45
In
eight of the 13 studies, researchers reported a reduction
in trunk motion in at least one of the planes of motion
due to wearing a support. Three groups reported incon-
sistent results,
32,39,45
and two reported that no effect of a
support on trunk motion was observed.
20,34
The study of Marley and Duggasani
34
was excluded
from the meta-analysis, because the outcome measure
used (displacement angle of the hip) was not considered
similar enough with the other studies. Thus, 12 studies
were included in the meta-analyses. Figure 1 shows the
results for the restriction of flexion–extension, lateral
bending, and rotation separately. For two planes of mo-
tion (flexion–extension and lateral bending) a statisti-
cally significant overall effect was found, with an overall
effect size of 0.70 (95% CI: 0.39–1.01) for flexion–
extension and 1.13 (95% CI: 0.17–2.08) for lateral
bending. The overall effect on rotation was not statisti-
cally significant (0.69; 95% CI: 0.40–1.78).
The results of the studies included in the meta-analysis
for flexion–extension were statistically homogeneous. In
the analyses for lateral bending and rotation, they were
heterogeneous. Possible reasons for the heterogeneity
were differences in type of lumbar support and outcome
measure. To assess the influence of the type of lumbar
support on heterogeneity and to determine whether there
were important differences in effect between elastic and
rigid supports, a subgroup analysis was performed. Het-
erogeneity was still present within subgroups with only
rigid or elastic lumbar supports. The effect sizes for rigid
supports were 1.07 (95% CI: 0.09–2.24) for lateral
bending and 0.29 (95% CI: 0.35–0.93) for rotation.
The effect size for flexion–extension (0.70; 95% CI:
0.39–1.01) was already based on rigid belts only. Elastic
supports were studied in four studies.
5,13,15,31
Combined
effect sizes of these studies were 1.01 (95% CI: 0.10
1.92) for flexion–extension, 0.84 (95% CI: 0.24–1.43)
for lateral bending, and 1.81 (95% CI: 0.22–3.84) for
rotation.
Subsequently, the influence of differences in outcome
measure was assessed. In the analyses for lateral bending
and rotation, heterogeneity was still present within sub-
groups with the same outcome measure, and the effect
sizes were not importantly different between the sub-
groups (data not shown).
Reduction in Back Muscle Force
Electromyogram or Intra-abdominal Pressure as Outcome
Measurement.
Twelve studies reported data on electro-
myogram measurements.
7,13,17,19,26,27,29,33,37,42,43,61
Characteristics of these studies are shown in Table 3. In
most of these, investigators measured electromyogram of
erector spinae and internal or external oblique muscles.
Results of the studies were contradictory: Four groups
reported a reduction of electromyogram of back muscles
by one of the supports tested,
13,19,27,33
three could not
find any consistent result,
29,43,61
and four found no effect
on electromyogram.
7,17,26,37
In one study only electro
-
myogram of the abdominal muscles was measured and a
decrease in electromyogram was reported in subjects
wearing a lumbar support.
42
In four of the above-mentioned studies, investigators
measured the electromyogram of back muscles and IAP
simultaneously.
17,26,27,37
Reported results in all four
showed an increase in IAP, but electromyogram in the
erector spinae muscles consistently decreased in only
one.
27
In seven studies, investigators measured IAP but
did not simultaneously record an electromyogram of the
back muscles (Table 3),
15,16,24,43,42,52,62
Investigators in
two of these studies reported an increase in IAP in sub-
jects using lumbar supports,
16,52
in two studies they re
-
ported inconsistent results,
15,43
and three they found no
effect of a lumbar support on IAP.
24,42,62
Separate meta-analyses for studies on electromyo-
gram of erector spinae muscles and on IAP were con-
ducted. In the statistical pooling, only studies in which
subjects performed a lifting task were included. Two
studies with squat exercises were excluded from the
meta-analysis, because no regular lifting tasks were stud-
ied.
26,27
There were insufficient data reported in three
studies for the calculation of an effect size on electromyo-
gram.
13,17,19
Thus, three studies on electromyogram and
2105Mechanisms of Action of Lumbar Supports
van Poppel et al
Table 2. Description of Studies on Trunk Motion
Authors
[Validity score*] Conditions Subjects Test Procedure Outcome Measures Result According to Authors
Buchalter et al
5
[3]
I No belt Healthy From upright position, free motion in Maximum ROM II–V: reduction in range of motion
II Raney jacket 33 (sex ?) three planes
III Camp corset
IV TLSO
V Elastic support
Fidler & Plasmans
11
[1]
I No belt Healthy Radiographic film in max. flexion and Segmental sagittal II–V: restricted sagittal movement
II Canvas lumbosacral
corset
5 extension movement of lumbar
spine (from L1–L2 to
Considerable variation among
individuals.
III Raney flexion jacket L5–S1)
IV Baycast jacket
V Baycast spica
Granata et al
13
[3]
I No belt
II Elastic support
III Leather weightlifting
belt
IV Fabric belt with
rigid posterior
Healthy
15
Lifting from knee height to upright
position, both symmetrical and
asymmetrical with 14 and 23 kg
EMG
Trunk and pelvis motions
during lifting activities
Trunk moments
Spinal loading (modeled)
II: reduced EMG of erector spinae and
increased EMG in internal oblique
muscles; reduced observed peak
trunk motion in all planes; increased
peak pelvic flexion, reduced spinal
load.
support III: no effect on EMG or spinal load;
reduced peak trunk lateral bending
and flexion; increased peak pelvic
flexion.
IV: no effects on EMG or spinal load;
peak trunk motion reduced only in
lateral bending.
Large variation among individuals.
Grew & Deane
15
[2]
I No belt
II Semielastic corset
with rigid anterior
section
LBP patients
8 (sex ?)
Healthy
10
Movement to limit of comfort: flexion,
circumduction, extension, lateral
bend
Different activities; lying, standing from
Lumbar spinal motion
IAP
Skin temperature
II–IV: increased lumbar skin
temperature; reduced motion of the
lumbar spine; increased IAP by
walking and sitting; no effect during
III Narrow fabric
corset
IV Long fabric corset
with steel posterior
strengthening
V Leathered covered
steel brace
lying, walking, ascending and
descending stairs, sitting, lifting
between high and low shelves,
lifting with flexed hips and straight
legs, lifting with flexed hips and
knees, holding weight, lifting from
the side
other activities
VI Polythene jacket
Jonai et al
20
[3]
I No belt
II Pelvic belt
Healthy
12 (sex ?)
Analysis of trunk motion during normal
working day
Observed ROM in
flexion/extension,
lateral bending, and
rotation
Decrease in max. angular velocity in
flexion
No consistent effect on max. angular
velocity in flexion/extension,
Max. angular velocity rotation, or lateral bending or on
observed ROM
Lantz & Schultz
28
[2]
I No belt
II Lumbosacral corset
III TLSO
Healthy
5
Flexion, extension, right and lift
twisting, right and left lateral
bending, both standing and sitting
Maximum ROM II–IV: restricted gross body motion
IV Chairback brace
Lavender et al
31
[4]
I No belt
II Elastic support
Healthy
8 ,8
Lifting box from floor to elbow height,
symmetrical and 45 and 90
asymmetry.
Observed trunk motion
during lifting activities
Reduction in trunk motion in lateral
plane and transverse plane. No
effect in sagittal plane.
Weight 20% of max. isometric lifting
strength. Seven lifts at each
asymmetry level with foot
movements, and seven lifts without
moving foots.
Lumsden et al
32
[1]
I No belt Healthy Rotating trunk standing, straddling . Axial rotation II: effect varied unpredictably
II Lumbosacral corset
III Chairback brace
10 bicycle seat, and walking at three
speeds
III: reduced axial rotation while
straddling bicycle seat and
standing. Increased axial rotation
during walking.
Marley & Duggasani
34
[3]
I No belt
II Elastic support
Healthy
8
Lifting box from floor to 76 cm (squat
lifting style encouraged). Weights 7
or 14 kg; 3, 6, and 9 lifts/min.
Trunk motion
Perceived exertion
Cardiovascular
parameters
Increase in blood pressure. No effect
on other cardiovascular parameters,
trunk motion, or perceived exertion.
2106 Spine
Volume 25
Number 16
2000
seven on IAP were included in the meta-analyses (Figure
2). No statistically significant overall effect of lumbar
supports on electromyogram (0.09; 95% CI 0.41–
0.59) or IAP was observed (0.26; 95% CI: 0.07–0.59).
Both analyses were statistically homogeneous.
Other Outcome Measurements Related to Back
Muscle Force
In three studies the effect of lumbar supports on muscle
strength and endurance was determined.
7,49,53
In two of
these studies, researchers found no effect of a lumbar
support on muscle strength or endurance,
7,49
and in the
other they reported an increase in force production in
men wearing a lumbar support.
53
Intradiscal pressure
was measured in one study and no consistent effect of
any type of support could be demonstrated.
43
In two
studies spinal shrinkage was measured, and investigators
found no effect of supports on spinal shrinkage.
4,33
Overall, an outcome that might influence back muscle
force was measured in 20 studies (Table 3). Assuming
that a increase in IAP without a concomitant decrease in
electromyogram of the back muscles does not reduce the
back muscle force, investigators in 7 (35%) of the 20
studies reported an effect that could possibly lead to a
reduction of the back muscle force.
Subjective Outcome Measures
Results of five studies showed outcomes that could indi-
cate that workers are inclined to lift heavier loads while
wearing a lumbar support. The MAWL was assessed in
three studies,
30,36,49
and perceived exertion,
34
discom
-
fort,
4
or intensity of the task
7
in an additional three stud
-
ies. In only one study on MAWL did researchers report
an increase for subjects wearing a lumbar support.
36
Bourne and Reilly
4
reported less perceived discomfort
for subjects wearing a support.
4
The other groups study
-
ing MAWL or other subjective outcome measures re-
ported no effect of a support. The results of the six stud-
ies on subjective outcome measures were statistically
combined. No statistically significant overall effect of
lumbar supports on subjective outcomes was found (ef-
fect size: 0.002; 95% CI: 0.41–0.41).
Discussion
Limitations of the Review
A potential limitation of this systematic review, and of
most reviews in general, is the completeness of the liter-
ature search. It is possible some relevant published stud-
ies were missed that had other key words or unclear
abstracts. Furthermore, not all studies are indexed in the
bibliographical databases used. In fact, most studies
were identified by screening the references of already
identified studies. It is very possible that studies were
missed that were not included in these reference lists. In
addition, because the review was limited to published
studies, it may be biased toward positive findings, be-
cause of publication bias.
9
There is no evidence-based consensus on which crite-
ria should be used for the methodologic assessment of
studies at this moment. Although the criteria used are
included in most other available checklists,
41
the criteria
are, to some extent, arbitrarily chosen.
In all studies a design was used in which the same
subjects were tested with and without lumbar support. In
the original studies paired data-analyses were used. In
the meta-analysis this was impossible, because the mean
difference between conditions was not reported in all
Table 2. (Continued)
Authors
[Validity score*] Conditions Subjects Test Procedure Outcome Measures Result According to Authors
McGill et al
38
[3]
I No belt
II Leather weightlifting
belt
Healthy
22 ,15
Lateral bending, flexion-extension with
pelvis and lower body rigid.
Resisting bending forces
Bending angle with
increasing torque
Belt wearing stiffens torso in lateral
bending and axial rotation, not in
flexion/extension.
Miller et al
39
[1]
I No belt LBP patients Radiographic film in flexion and Lumbosacral motion II: no effect
II Lumbosacral corset
III Jewett brace
IV TLSO
n 7
Healthy
n 7
extension (S1–L4) III and IV: reduced motion at L3–L4
and L4–L5 level, but not at L5–S1
Norton & Brown
45
[1]
I No belt Healthy Standing, bending, and sitting L5–S1 interspace II–XI: inconsistent effects
II Chairback brace
III Lumbosacral corset
(N ?) Force produced by brace
on back
IV Goldwaith Lumbosacral motion
V Williams
VI Abbott
VII Jewett
VII Plaster jacket
IX Rigid Taylor
X Flex. Taylor
XI Reenf. Taylor
Wasserman &
McNamee
60
[2]
I No belt
II Lumbosacral corset
LBP status ?
6 ,2
Rotating shoulders to a standardized
position while seated
Twist angle of vertebral
column (L3–T10)
Reduction of rotation
* The number of validity items scored positive. A copy of a more detailed methodologic assessment can be obtained on request from the first author.
TLSO thoracolumbosacral orthosis; ROM range of motion; EMG electromyographic activity; IAP intra-abdominal pressure; LBP low back pain.
2107Mechanisms of Action of Lumbar Supports
van Poppel et al
Table 3. Description of Studies on EMG Activity, IAP, or Other Outcome Measures Related to Back Muscle Force
Authors
[Validity Score*] Conditions Subjects Test Procedure Outcome Measures Result According to Authors
Ciriello & Snook
7
[4]
I No belt
II Nylon weightlifting
belt
Healthy
13
Lifting and lowering box from floor to
76.2 cm for 4 hrs with MAWL, 4.3
lifts/min
EMG median frequency
slope
No effect on any of the outcome
measurements
5 sets of 10 repetitions of isokinetic
extensions (baseline and after 4 hrs
lifting)
EMG median frequency
Perceived intensity of
task
Maximum isokinetic
endurance
Granata et al
13
[3]
I No belt
II Elastic support
III Leather weightlifting
belt
IV Fabric belt with rigid
posterior
Healthy
15
Lifting from knee height to upright
position, both symmetrical and
asymmetrical with 14 and 23 kg
EMG
Trunk and pelvis motions
during lift
Trunk moments
Spinal loading (modeled)
II: reduced EMG of erector spinae and
increased EMG in internal oblique
muscles; reduced observed peak
trunk motion in all planes; increased
peak pelvic flexion, reduced spinal
load.
support III: no effect on EMG or spinal load;
reduced peak trunk lateral bending
and flexion; increased peak pelvic
flexion.
IV: no effects on EMG or spinal load;
peak trunk motion reduced only in
lateral bending.
Large variation among individuals.
Hilgen et al
19
[4]
I No belt
II Airbelt
III Elastic support
Healthy
5
Lifting box from floor to knuckle
height, 1 lift/min, 10 lifts with 5
random weights of 11.5 kg to 31.5 kg.
EMG erector spinae and
external oblique
muscles
II: reduced EMG in stooped phase of
lift, not in initial phase of lift
III: no statistically significant effect
Lantz & Schultz
29
[3]
I No belt
II Lumbosacral corset
III TLSO
Healthy
5
9 tasks (standing, flexing, and bending
while holding 1-kg weight, resisting
twist, etc) both standing and sitting
EMG erector spinae and
oblique abdominal
muscles.
II–IV: no consistent effect
IV Chairback brace
Magnusson et al
33
[4]
I No belt
II Elastic lumbar
Healthy
5 ,7
Repetitive lifting of 10 kg from floor to
72 cm. Two lifts/min for 5 min.
Spinal shrinkage
No effect on spinal
Reduction of EMG
support Immediate height change when
donning or doffing support
EMG erector spinae muscles
shrinkage
Increase in spinal height
when donning the
support
Waters & Morris
61
[3]
I No belt
II Chairback brace
III Lumbosacral corset
Healthy
6 ,4
Standing and treadmill walking with
three intensities
EMG erector spinae and
abdominal oblique
muscles
Step frequency
II and III: decrease or no effect on
EMG at rest, no effect during
walking, increased EMG at high
speed walking (II); No effect on
step frequency
Hemborg et al
17
[3]
I No belt
II Nonelastic flexible
support of
thermoplastic
LBP patients
20
Healthy
10
Lifting from floor to upright position
with 0, 10, 25 kg, using back and
leg lifting style, syrlon support only
(patients)
EMG
IAP
II and III: no effect on EMG; Increased
IAP
material (syrlon)
III Leather weightlifting
belt
Lifting with 55 kg using leg lifting
style, both syrlon and weightlifting
belt (healthy subjects)
Lander et al
27
[3]
I No belt Healthy Squat exercise with 70 to 90% of 1RM, EMG II and III: Increased IAP; Decreased
II Light leather
weightlifting belt
6 3 trials with each weight IAP EMG in erector spinae muscles and
external oblique muscles
III Heavy leather
weightlifting belt
Lander et al
26
[4]
I No belt Healthy Eight repetitions of squat exercise EMG Increased IAP
II Leather weightlifting
belt
5 with 8RM IAP No effect on EMG erector spinae or
external oblique muscles
McGill et al
37
[3]
I No belt
II Leather weightlifting
belt
Healthy
6
Lifts on lifting machine, while holding
breath and with continuously
expiring
EMG
IAP
Dynamic hand forces
Slightly increased IAP
No effect on EMG
II Nepalese patuka
(5m long piece of
cloth worn around
waist)
10 Lumbosacral
compression force
Decrease in lumbosacral compression
force in 2 of 10 postures
2108 Spine
Volume 25
Number 16
2000
Table 3. Continued
Authors
[Validity Score*] Conditions Subjects Test Procedure Outcome Measures Result According to Authors
Morris & Lucas
42
[3]
I No belt
II Inflatable corset
Healthy
10
Pulling against a fixed resistance in
upright position and 30, 60, 90°
flexed
EMG of abdominal and
intracostal muscles
IAP
Decrease in EMG of abdominal and
intracostal muscles
Increase in resting IAP, but not in
Intra-thoracic pressure peak IAP
Slight increase in intra-thoracic
pressure
Nachemson et al
43
[1]
I No belt
II Camp canvas corset
III Raney flexion
jacket
Healthy
1 ,3
Resisting flexion, extension, twist, and
lateral bend and weight-holding
tasks while standing relaxed and
upright
EMG of erector spinae
and abdominal
oblique muscles
Intradiscal pressure
II–IV: no consistent effect on IAP,
EMG, or intradiscal pressure
IV Boston brace with 0,
15, and 30° lumbar
extension
IAP
Harman et al
16
[4]
I No belt
II Leather weightlifting
belt
Healthy
8 ,1
Dead lift with bent knees and straight
back, 90% of 1RM
IAP Increased IAP
Kumar & Godfrey
24
[3]
I No belt
II Camp sacroiliac
corset
III Camp lumbosacral
corset
IV Harris brace
V Macnab brace
VI Knight brace
VII Taylor brace
Healthy
11 ,9
Sagittal, lateral, and oblique stoop
lifting, from ground to knee, ground
to hip and ground to shoulder level;
same level side to side weight
transfer, at ground, knee, hip, and
shoulder level.
All exercises with 9 kg ()or7kg
()
IAP II–VII: no effect on IAP
Woodhouse et al
62
[2]
I No belt Healthy Lifting box from squat to standing IAP II–IV: no effect on any of the outcome
II Weightlifting belt
III Weightlifting belt
9 position, 90% of 1RM L5–S1 kinetics (peak
force/shear force)
measures
with rigid pad
IV Elastic support
Lifting strategies and
lifting speed
Grew & Deane
15
[2]
I No belt
II Semielastic corset
with rigid anterior
section
III Narrow fabric
LBP patients
8 (sex ?)
Healthy
10
Movement to limit of comfort: flexion,
circumduction, extension, lateral
bend
Different activities: lying, standing from
lying, walking, ascending, and
Trunk motion
IAP
Skin temperature
II–IV: increased lumbar skin
temperature; reduced motion of the
lumbar spine; increased IAP by
walking and sitting; no effect during
other activities.
corset
IV Long fabric corset
with steel posterior
strengthening
V Leathered covered
steel brace
descending stairs, sitting, lifting
between high and low shelves,
lifting with flexed hips and straight
legs, lifting with flexed hips and
knees, holding weight, lifting from
the side
VI Polythene jacket
Shah
52
[1]
I No belt
II Nepalese patuka
(5m long piece of
cloth worn around
waist)
Healthy
10
Standing, flexion, extension, bending,
rotating, walking, climbing stairs,
lifting 10 kg, doko lift, walking,
climbing stairs, and standing with
doko
IAP
Lumbosacral
compression force
Increase in IAP
Decrease in lumbosacral compression
force in 2 of 10 postures
Bourne & Reilly
4
[3]
I No belt Healthy Six common weight-training exercises. Spinal shrinkage No effect on spinal shrinkage
II Leather weightlifting
belt
8 Three sets of 10 repetitions at 10RM. Perceived discomfort
and pain
Less perceived discomfort with belt
Reyna et al
49
[3]
I No belt Healthy Lumbar extension machine Isolated lumbar extensor No effect on MAWL or isolated lumbar
II Soft, heat-retaining
neoprene belt
9 ,13 Lifting box from knuckle level to
shoulder level, from floor to knuckle
level, from floor to shoulder level,
both one or four repetitions, with
increasing weight
strength
MAWL
muscle strength
Sullivan & Mayhew
53
[6]
I No belt
II Leather weightlifting
belt
III Elastic support
Healthy
30 ,30
Static leg lift: simulated lifting activity
in partial squat (back straight,
knees bent), pulling upward
Isometric muscle force
production
II: no effect
III: increased produced force for
males only
* The number of validity items scored positive. A copy of a more detailed methodologic assessment can be obtained on request from the first author.
TLSO thoracolumbosacral orthosis; MAWL maximum acceptable weight of lift; EMG electromyographic activity; IAP intra-abdominal pressure; LBP
low back pain; RM repetition maximum.
2109Mechanisms of Action of Lumbar Supports
van Poppel et al
studies, but rather the mean and SD for each condition. A
paired analysis is more efficient than comparing two
means. Therefore, some of the effects that were statisti-
cally significant in the original study were not signifi-
cant in the meta-analysis presented in this article. Fur-
thermore, it is possible that the overall effects would
have had smaller CIs if a paired meta-analysis had been
feasible.
In almost any meta-analysis, the decision to statisti-
cally combine the results of studies can be questioned. In
this meta-analysis, it was decided to combine three dif-
ferent outcome measures on trunk motion. The authors
chose to do this, because the objective was to test the
hypothesis that lumbar supports affect trunk motion,
and all three outcome measures represent an aspect of
trunk motion. However, by combining these outcome
measures no conclusions can be drawn about which as-
pect of trunk motion is affected or about the (clinical)
relevance of the effect. Those who disagree with this de-
cision may want to disregard the overall estimates of
effect and pay attention only to the effects of lumbar
supports in subgroups with the same outcome measure.
Methodologic Assessment
The methodologic assessment showed that most studies
on mechanisms of action of lumbar supports did not
have a valid randomization procedure or description of
the randomization and an adequate data analysis. Fur-
thermore, the reproducibility of the outcome measure-
ments was seldom determined and described. Future ar-
ticles on this subject could easily be improved if more
attention is paid to these features. No systematic differ-
ences in mean effect size were observed between studies
that scored less than four or four or more items positive
of the seven internal validity items. This indicates that
studies with a lower score were not more likely to report
an effect of lumbar supports than studies with a higher
score. Therefore, all studies were included in the meta-
analyses.
Mechanisms of Action
Change in Body Posture or Movements . A restriction of
trunk motion was observed in all three planes of motion,
and the overall estimate of effect was statistically signif-
icant for lateral bending and flexion–extension. In a sub-
Figure 1. Meta-analysis of the effects of lumbar supports on trunk motion during flexion– extension (A), lateral bending (B), and
rotation (C).
Figure 2. Meta-analysis of the effects of lumbar supports on elec-
tromyographic activity of erector spinae muscles and on intra-
abdominal pressure (IAP).
2110 Spine
Volume 25
Number 16
2000
group analysis for elastic and rigid supports, it was found
that both types of support restrict trunk motion. There
was considerable heterogeneity in the meta-analyses on
lateral bending and rotation. Likely sources for this het-
erogeneity are the outcome measure and the type of lum-
bar support. Subgroups of studies using the same out-
come measure were formed. The overall estimates of
effect for lateral bending and rotation were not impor-
tantly different between the subgroups. Furthermore,
differences in outcome measures alone could not explain
the heterogeneity in results. Another potential source for
heterogeneity is the type of lumbar support. However,
heterogeneity was still present within the subgroups with
rigid or elastic supports only. It is likely that the hetero-
geneity in the analyses for lateral bending and rotation
was due to a combination of differences in outcome mea-
sure and type of support. It should be noted that, because
the meta-analyses of all studies and the subgroup analyses
on rigid belts included only belts resembling a lumbosacral
corset as much as possible, it may be that completely differ-
ent types of support (e.g., a thoracolumbosacral orthosis or
a flexion jacket) have other effects on trunk motion.
Aside from the heterogeneity of the results between
studies, it should be noted that a large variation was
present in results among subjects within the original
studies. In a small number of studies, even an increase in
lumbosacral motion was observed in some of the sub-
jects when they were wearing a lumbar sup-
port.
32,39,45,60
The results of the current meta-analysis indicate that
lumbar supports decrease trunk motion. In theory, a re-
duction of trunk motion could be beneficial in the pre-
vention of low back pain, because it may decrease both
the net muscle moments and the stresses acting on the
internal structures of the spine due to extreme joint an-
gles. Spinal rotation has been reported to be a risk factor
for low back pain.
35,47
Furthermore, fatigue failure of
posterior spinal structures may occur at large flexion an-
gles in repetitive lifting for long periods, specifically in
individuals whose spinal segments are stiffer than aver-
age.
10
Therefore, a reduction of spinal rotation and of the
flexion angle may lead to a reduced risk of back injuries. In
practice, however, it remains to be seen whether a restric-
tion in trunk motion by lumbar supports indeed has a ben-
eficial effect on the risk of back injury, because, so far, con-
tradictory results have been reported on lumbar supports in
the prevention of back pain.
1–3,15,25,48,54,56,57–59
Reduction in Back Muscle Force. Investigators reported
inconsistent results on the effects of lumbar supports on
outcomes possibly related to the back muscle force. Al-
though the role of IAP in the reduction of spinal com-
pression is inconclusive,
46
it was decided to include IAP
in the review. In the meta-analysis, no statistically signif-
icant effect of supports on electromyogram of erector
spinae muscles or IAP was observed. Other reviews con-
cluded that no conclusive statement could be made on
the effects of lumbar supports on electromyogram or
IAP, because the available studies failed to show consis-
tent results.
3,40,46
The results of the current meta-
analyses, however, are very homogeneous and indicate
that lumbar supports may not influence electromyogram
or IAP. Therefore, the authors conclude that the hypoth-
esis that lumbar supports decrease the back muscle force
by means of a decrease in electromyogram of back mus-
cles or an increase in IAP is not supported by the avail-
able evidence.
Subjective Outcome Measures. No overall effect of lum-
bar supports was observed on the maximum acceptable
load and other subjective outcomes. This is reassuring,
because critics of lumbar supports are afraid that work-
ers may have a false feeling of security when wearing a
lumbar support. They could be tempted to lift heavier
loads with a support, although the spinal load is not
diminished. This potentially adverse effect of lumbar
supports does not seem to take place.
Conclusion
The hypothesis that lumbar supports decrease the back
muscle force by means of a decrease in electromyogram
of back muscles or an increase in IAP is not supported by
the results of the meta-analyses presented in this article.
Neither is there evidence that workers would be inclined
to lift heavier weights when wearing a lumbar support.
The only hypothesis that could be confirmed was that
lumbar supports affect trunk motion. However, no defi-
nite conclusions can be drawn about the clinical rele-
vance of this effect. At this moment, there is no evidence
for the effectiveness of lumbar supports in the prevention
of back pain in industry, because clinical trials on the
effect of lumbar supports on the incidence of back pain
report contradictory results.
3,25,56
More research is
needed on the effects of lumbar support on the separate
outcome measures for trunk motion before definite con-
clusions can be drawn about work conditions in which
lumbar supports may be most effective. Studies of trunk
motion at the workplace or during specified lifting tasks
would be especially useful in this regard.
Key Points
A systematic review of the literature on mecha-
nisms of action of lumbar supports was conducted.
No evidence was found that lumbar supports in-
fluence back muscle electromyogram or intra-
abdominal pressure.
There was evidence in the literature that lumbar
supports restrict trunk motion, especially for flex-
ion–extension and lateral bending.
2111Mechanisms of Action of Lumbar Supports
van Poppel et al
Future studies of trunk motion in the workplace
or during lifting tasks are needed to examine the
conditions under which lumbar supports are most
effective.
Appendix
Operationalization of Criteria List
(A copy of the operationalization of the criteria list can
be obtained on request from the corresponding author).
(A) Yes, if age, gender, back pain status, and work
type or global fitness status of the study population
were reported.
(B) Yes, if the order of conditions was determined
randomly. Methods for randomization should be ad-
equate (e.g., use of random number Table). No, if
method of randomization was not described. Order
allocation by means of date of birth for instance is also
scored no.
(C) Yes if subject had a fixed rest period between
conditions.
(D) Yes, if the type of corset or belt was described
sufficiently to replicate the study procedure.
(E) Yes, if the test procedure, the test equipment, and
outcome measurement were described sufficiently to
replicate the study. The test procedure and equipment
should also be appropriate for assessing the main out-
come measure.
(F) Yes, if reproducibility of the test procedure is de-
scribed and if the test is sufficiently reproducible (
0.4 for categorical data and intraclass correlation co-
efficient; test–retest reliability, Pearson’s coefficient;
0.60 for continuous data).
(G) Yes, if outcome assessment was blinded. Also, yes
if blinding is not relevant for the particular outcome
measure, because the investigator is unable to influ-
ence the outcome measurement (e.g., computerized
registration of outcome).
(H) Yes, if no values were missing or if all missing
values were described and not more than 20% of the
observations were missing values (reason for missing
value, in which condition is the value missing and for
which outcome measure).
(I) Yes, if a period effect is determined. If there is a
period effect, further testing should determine
whether there is period–treatment interaction (carry-
over). If there is period–treatment interaction, only
data from the first period should be used in the anal-
ysis. Otherwise, a paired analysis should be con-
ducted.
(J) Yes, if for the most important outcome measures
the frequency, percentage or mean and SD or CI is
reported or if individual patient data are reported.
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Address reprint requests to
Dr. M. N. M. van Poppel
Faculty of Medicine
Institute for Research in Extramural Medicine
Vrije Universiteit
Van der Boechorststraat 7
1081 BT Amsterdam, The Netherlands
E-mail: MNM.van_Poppel.EMGO@Med.VU.nl
2113Mechanisms of Action of Lumbar Supports
van Poppel et al
... The trunk ROM was significantly lower in the experimental group in this study, which is consistent with the result of the previous study. With regard to the biomechanical factors, it was reported that continuously wearing a LB reduces the ROM of the trunk in various loads and movements [51,52]. Hence, it was considered that these effects of the LB reduced the ROM of the trunk in both the experimental and control groups while performing the STD movement. ...
... LB may decrease the stress on posterior viscoelastic structures or compression load on the lumbar region [25,26]. This may decrease the load on specific spinal structures as an effect of lumbar movement limitation due to increased mechanical rigidity caused by the LB [51,52]. Further, it is thought that the maximum trunk flexion angle was increased as a protective strategy to decrease the effect of the reduced trunk flexion angle in order to avoid stress in the pain area by wearing a LB. ...
... Pain intensity measured by VAS was significantly decreased in Condition 1 (without LB) compared with that in Conditions 2 and 3 (with LB). The possible mechanisms of pain relief of the LB include decreased ROM [60,61], improved proprioceptive sense or motor sense [62,63], and strengthened trunk [51,60,64]. Results of this study are in accordance with those of a previous study that reported a significant decrease in pain after wearing a LB for an hour for three weeks [65]. ...
Article
Full-text available
This study aimed to investigate the effects of wearing extensible and non-extensible lumbar belt (LB) on biomechanical factors of the sit-to-stand (STD) movement and pain-related psychological factors affecting office workers with low back pain. Among 30 office workers, 15 with low back pain (LBP) were assigned to the experimental group and 15 healthy adults were assigned to the control group. The participants performed STD movement in random order of three different conditions: without LB (Condition 1), with extensible LB (Condition 2), and with non-extensible LB (Condition 3). Biomechanical variables of STD movement in each condition were measured using a three-dimensional motion analysis system and force plate. Pain-related psychological factors were measured only in the experimental group. Among the biomechanical factors of STD movement, an interaction effect was found in the maximum anterior pelvic tilt angle and total-phase range of motion of the trunk (p < 0.05). Pain intensity, pain-related anxiety, and pain catastrophizing were decreased in the conditions with lumbar belts (Conditions 2 and 3) compared to the condition without LB (Condition 1) (p < 0.05). Extensible and non-extensible lumbar belts engender biomechanically beneficial effects during STD movement in both office workers with LBP and healthy office workers. Further, pain intensity, pain-related anxiety, and pain catastrophizing were decreased in office workers with LBP. Therefore, both types of extensible lumbar belts may be helpful in the daily life of patients with LBP and office workers.
... Primarily, the back support belt served to immobilize and support on the lumbar spine of the wearer (22) where the mechanical stiffness provide a direct biomechanical benefits that decreases lumbar range of motion (ROM) (23), reduced stresses in the passive tissues of the posterior lumbar spine (24) and possibly reduced compressive loading of the lumbar spine (25). However, it should be noted that these features described may or may not be applicable on users who perform manual handling which nature of work are dynamic and requires activation of various muscles groups in their tasks. ...
... According to Van et al. (23), wearing a back support belt can prevent stooped shoulders and serve as a reminder to workers in maintaining appropriate posture while limiting the lumbar range of motion (ROM). Due to the restraining properties of the back support belt, workers must squat to lift loads on the floor rather than bending the lower back forward (26). ...
Article
Introduction: The usage of back support belt for manual handling activities particularly lifting/lowering of loads in occupational setting has been a sore point of conflicting agreement between industrial practitioners and academician on its effectiveness in prevention of back injuries. As such, this pre-test and post-test experimental study was designed to investigate the effectiveness of back support belt in reducing localized musculoskeletal discomfort among male agricultural workers. Methods: A total of 38 subjects were randomly assigned into control and intervention groups (19 subjects in each group). The subjects were required to carry out a series of lifting and lowering of incremental weight load similar to the protocol as described in Progressive Isoinertial Lifting Evaluation (PILE) techniques. After completing each lift, subjects were required to rate the discomfort felt in the back region using the Localized Musculoskeletal Discomfort questionnaire. Results: Results showed that only several pairs showing statistically significant differences with no discernible trend. Within the control group, the median calculated from group data showed an overall increased discomfort rating as the weight load increases except for 19.4kg but an overall decreased discomfort within intervention group. Comparison between control and intervention group for post-test results showed significant difference between 5.9kg and middle back although the trend of LMD ratings across body part investigated may suggest interesting relationship. Conclusion: Despite positive subjective perception amongst the wearer as conveyed by industrial practitioners, the epidemiological data, clinical trials, and various other experimental studies in the past few decades including in this study has not shown sufficient evidence of effectiveness.
... The lumbar belt can reduce the stress on the posterior viscoelastic structure of the lumbar vertebrae or the compression load of the lumbar vertebrae [26,27]. This is an effect of the limited lumbar movement due to the increased mechanical rigidity when the lumbar belt is worn, and it can prevent the load of a specific vertebral structure [61]. In this study, we found that the protection mechanism for reducing the angle of trunk flexion was reduced by wearing a lumbar belt to avoid stress on the painful area and thus the angle of trunk flexion was increased. ...
Article
Full-text available
Although lumbar belts can be used for the treatment and prevention of low back pain, the role of the lumbar belt remains unclear without clear guidelines. This study aimed to investigate the effect of lumbar belts with different extensibilities on the kinematics, kinetics, and muscle activity of sit-to-stand motions in terms of motor control in patients with nonspecific low back pain. A total of 30 subjects participated in the study: 15 patients with nonspecific low back pain and 15 healthy adults. Participants performed the sit-to-stand motion in random order of three conditions: no lumbar belt, wearing an extensible lumbar belt, and wearing a non-extensible lumbar belt. The sit-to-stand motion’s kinematic, kinetic, and muscle activity variables in each condition were measured using a three-dimensional motion analysis device, force plate, and surface electromyography. An interaction effect was found for the time taken, anterior pelvic tilt angle, and muscle activity of the vastus lateralis and biceps femoris. The two lumbar belts with different extensibilities had a positive effect on motor control in patients with nonspecific low back pain. Therefore, both types of extensible lumbar belts can be useful in the sit-to-stand motion, which is an important functional activity for patients with nonspecific low back pain.
... Although the mechanism of lumbar supports is unclear, it is hypothesized that the lumbar braces correct deformity, limit spinal motion, provide additional stability and redistribute forces on the spine. 13 In a Cochrane review of seven preventive RCTs (14 437 people) and eight treatment RCTs ...
Article
Full-text available
Background Low back pain (LBP) is a healthcare problem with high global prevalence, with non-operative management being the first line of treatment in the majority of patients. This literature review summarizes the current evidence for various modalities of non-operative treatment for LBP. Methods We did a literature search to elicit high-quality evidence for non-operative treatment modalities for LBP, including Cochrane Database reviews and systematic reviews or meta-analysis of randomized controlled trials. Only when these were not available for a particular treatment modality, other level 1 studies were included. The quality of evidence was categorized in accordance with the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) method—a globally adopted tool for grading the quality of evidence and making treatment recommendations. Results The treatment modalities that were reviewed included: general measures, medications/pharmacotherapy, exercises, electromagnetic therapies, alternative treatment modalities and interventional therapies. We found that high-quality evidence is lacking for most non-operative treatment modalities for LBP. The majority of interventions have small benefits or are similar to placebo. Conclusion The current evidence for non-operative treatment modalities for LBP is insufficient to draw conclusions or make recommendations to clinicians. High-quality trials are required before widespread use of any treatment modality. Considering that non-operative treatment is usually the first line of therapy for most patients with LBP, it deserves to be the focus of future research in spinal disorders.
... We anticipate that the study results will have significant implications for practitioners and specialists by increasing the scientific basis and contributing to the successful implementation of effective rehabilitation programs in clinical settings. Earlier studies have shown that both pelvic compression belts in pregnant women with PPGP [28] and lumbosacral orthosis in low back pain can significantly decrease pain [51] and improve proprioception [52], which can be explained by the biomechanical support provided [53] and proprioceptive impact of the orthosis [22]. At present, it is impossible to quantify which support is superior in reducing pain and improving proprioception and quality of life in women with PPGP. ...
Article
Full-text available
Background: Pregnancy-related posterior pelvic girdle pain (PPGP) is one of the most important clinical manifestations of postpartum back pain. Those affected often complain of discomfort during daily activities. It is hypothesized that altered motor control is associated with perceived pain. Pelvic support can regulate possible underlying altered motor control mechanisms and decrease pain. However, the influence of a lumbosacral orthosis, which is broader support that allows for a wider contact area and more skin sensory stimulation to restore proper motor function, has not yet been investigated in women with postpartum PPGP. Objective: This study investigates the efficacy of broader lumbar support and narrower pelvic support on pain, proprioception, disability, and muscle strength in women with pregnancy-related PPGP. Methods: This study will be a single-center, 3-armed, participant-blinded, randomized controlled trial. In total, 84 women diagnosed with pregnancy-related PPGP will be recruited and randomly assigned into 3 groups. Intervention groups A and B will receive pelvic and lumbar supports, respectively. Group C (control) will receive only a patient education leaflet containing advice on strengthening exercises, comfortable positions, and other practical information. The study outcomes are pain, effort score during the active straight leg raising test, maximum isometric hip flexion force, maximum isometric hip external rotation force, maximum isometric trunk rotation force, and joint position reproduction of hip abduction. The study outcomes will be measured at 4 time points: baseline (T1), immediately after the intervention (T2), 4 weeks following interventions began (at this time, the intervention period is completed) (T3), and 1 week after discontinuing the interventions (T4) to evaluate the possible lasting effects of wearing supports. Multivariate analysis of variance will be used to test between- and within-group differences. Results: Recruitment for this study will be started in summer 2022 and is expected to be completed by the end of fall 2022. Conclusions: This study will examine the efficacy of broader lumbar support as an early rehabilitative treatment for women receiving postpartum posterior pelvic pain support compared to those receiving a narrower pelvic support. We expect the broader lumbar support to impact pain management and disability better than the current narrower pelvic belt. Long-term follow-up studies will help determine whether such lumbosacral orthosis reduces pain and improves daily activities in women with pregnancy-related PPGP. Trial registration: Iranian Registry of Clinical Trials IRCT20150210021034N11; https://www.irct.ir/trial/54808. International registered report identifier (irrid): PRR1-10.2196/40553.
... We anticipate that the study results will have significant implications for practitioners and specialists by increasing the scientific basis and contributing to the successful implementation of effective rehabilitation programs in clinical settings. Earlier studies have shown that both pelvic compression belts in pregnant women with PPGP [28] and lumbosacral orthosis in low back pain can significantly decrease pain [51] and improve proprioception [52], which can be explained by the biomechanical support provided [53] and proprioceptive impact of the orthosis [22]. At present, it is impossible to quantify which support is superior in reducing pain and improving proprioception and quality of life in women with PPGP. ...
Preprint
BACKGROUND Pregnancy-related pelvic girdle pain is one of the most important clinical manifestations of postpartum back pain. Those affected often complain of discomfort during daily activities. It is hypothesized that altered motor control is associated with perceived pain. Pelvic support can regulate possible underlying altered motor control mechanisms and decrease pain. However, the influence of a lumbosacral orthosis which is broader support that allows for a wider contact area and more skin sensory stimulation to restore proper motor function has not yet been investigated in women with postpartum pregnancy-related posterior pelvic girdle pain. OBJECTIVE This study investigates the efficacy of broader lumbar support and narrower pelvic support on pain, proprioception, disability, and muscle strength in women with pregnancy-related posterior pelvic girdle pain. METHODS This study will be a single-center, three-armed, participant-blinded, randomized controlled trial. Eighty-four women diagnosed with pregnancy-related posterior pelvic pain will be recruited and randomly assigned into three groups. Intervention groups A and B will receive pelvic and lumbar supports, respectively. Group C (control) will receive only a patient-education leaflet containing advice on strengthening exercises, comfortable positions, and other practical information. The study outcomes are pain, effort score during active straight leg raising test, maximum isometric hip flexion force, maximum isometric hip external rotation force, maximum isometric trunk rotation force, and joint position reproduction of hip abduction. The study outcomes will be measured at four time-points: baseline (T1), immediately after the intervention (T2), four weeks following interventions began (at this time, the intervention period is completed) (T3), and one week after discontinuing the interventions (T4) to evaluate the possible lasting effects of wearing supports. Multivariate analysis of variance will be used to test between- and within-group differences. RESULTS Recruitment for the present study will be started in Summer 2022 and is expected to be completed by the end of fall 2022. CONCLUSIONS This study will examine the efficacy of broader lumbar support as an early rehabilitative treatment for women involved in postpartum posterior pelvic pain compared to a narrower pelvic support. We expect the broader lumbar support to impact pain management and disability better than the current narrower pelvic belt. Long-term follow-up studies will help determine whether such lumbosacral orthosis reduces pain and improves daily activities in women with pregnancy-related posterior pelvic girdle pain. CLINICALTRIAL The study protocol is recorded in the Iranian Registry of Clinical Trials on April 31, 2021 (Registration reference: IRCT20150210021034N11).
... Wearing an LSO increases the pressure exerted on the skin, which provides additional afferent sensory information to the central nervous system via mechanical receptors [19], which may ultimately improve the proprioceptive sense of the lumbar region [20]. Wearing an LSO increases the mechanical rigidity, which may decrease the structural load of the spine by limiting the lumbar movement [21]. To treat low back pain, patients are often advised to wear an appropriate orthosis and utilize a tailor-made exercise therapy program to maintain their bodies' flexibility and muscular strength [22]. ...
Article
Background and Objective: Back pain is a common orthopedic disease that affects up to 80% of the population at some point in life. Brace is one of the tools that used to reduce pain. The relationship between brace application and gait parameters in people with low back pain is not well understood. This study was done to determine the effects of simple and sensor thoracolumbosacral braces on gait kinetics in patients with low back pain.
Chapter
This chapter reviews non pharmacologic and non surgical treatments for spine pain. Evidence based treatments are emphasized and discussed. Non pharmacological treatments are recommended as first line care, reducing the need for more aggressive interventions.KeywordsNon pharmacological treatment Back pain ExerciseEvidence based treatment
Article
Background Wearing a lumbosacral orthosis (LSO) is known to influence spine mechanics, but less is known about how LSOs affect motor control. Whether the use of a LSO can negatively affect motor control of the lumbar spine is still under debate. Objective The current study examined the immediate effects of two flexible LSOs (extensible and non-extensible) on the anticipatory postural adjustments that prepare the spine for a predictable perturbation. Design A comparative study using a repeated measures design in a laboratory setting. Methods Healthy controls (n = 20) and participants with low back pain (n = 40) performed a rapid arm flexion/extension cycle with and without these LSOs. The latency between the activations of the shoulder and different back (iliocostalis lumborum) and abdominal (rectus abdominis, internal and external obliques) muscles, as measured with surface electromyography, was used as the outcome. Results The effects, which were comparable between groups and between LSOs, were mixed, with some muscles showing significantly (p ˂ 0.05) earlier activation and others showing delayed activation with the use of a LSO, relative to the control condition. The corresponding effect sizes were low to average (Hedges’s g range: 0.17 – 0.48). Conclusions These findings suggest a change in the motor program before task initiation, which might be generalizable to other activities of daily living or work. However, none of the effects were large, making it difficult to provide clear conclusions with regard to their clinical relevance. It remains to be tested whether these immediate adaptations in motor planning can induce long term detrimental effects to the control of lumbar stability.
Article
Clinical observations indicating that a weightlifter's belt can relieve low back pain and may also prevent low back complaints, have been made in a recent study. Before recommending such a belt or some other support for preventive purposes its immeditate physiological effects should be studied. Twenty male subjects, with a history of 2-18 years of more or less continuous low back pain, and ten healthy, welltrained weightlifters were put through a series of leg lifts and back lifts of 0-55 kg, with and without a non-elastic lumbar support of a thermoplastic material or a weightlifter's belt. Continuous recording of the EMG activity of the obliqueabdominal muscles, and of the erector spinae and the intraabdominal and the intra-thoracic pressures were made. The two supports gave the same effects. The intra-abdominal pressure increased by 1-3 kPa before, during and after the lifts and lowerings but the intra-thoracic pressure was only slightly increased during some of the lifts. The myoelectrical activities of the oblique abdominals and the erector spinae were quite unaffected by the two supports. Further studies are needed to elucidate the effects of longstanding use, before these smaller supports and belts can be recommended prophylactically.
Article
This work investigated the passive bending properties of the intact human torso about its three principal axes of flexion: extension, lateral bending, and axial rotation. Additionally, the effects of wearing an abdominal belt and holding the breath (full inhalation) on trunk stiffness was investigated. The torsos of 22 males and 15 females were subjected to bending moments while ''floating'' in a frictionless jig with isolated torso bending measured with a magnetic device. Belts and breath holding appear to stiffen the torso about the lateral bending and axial rotation axes but not in flexion or extension. Torsos are stiffer in lateral bending and capable of storing greater elastic energy. Regression equations were formulated to define stiffness and energy stored for input to biomechanical models that examine low back function and for bioengineers designing hardware for stabilization and bracing or investigation of traumatic events such as automobile collision.
Article
Objective: To assess the efficacy of bed rest and orthoses for low-back pain. Design: computer-aided search of published, randomized, clinical trials, and assessment of the study methods. Subjects: 5 randomized trials evaluating bed rest, and 5 randomized trials evaluating the efficacy of orthoses. Main outcome measures: quality score of the methods, based on the 4 categories of study population, interventions, effect measurement, and data presentation and analysis; conclusions of the author(s) with regard to the efficacy of bed rest or orthoses. Results: 2 of the 5 bed rest trials scored more than 50 points (maximum is 100). The results indicated that short periods of bed rest (2 or 5 days, respectively) were as effective as longer periods (4 or 8 days, respectively). Short periods of bed rest were more beneficial regarding absenteeism from work and return to a normal level of activities. 3 of the 5 orthoses trials scored more than 50 points. One of these indicated that orthoses were more effective than the advice on rest and life-style; the 2 others did not report any difference between orthoses and the reference treatments. Conclusions: Randomized trials evaluating the efficacy of bed rest and orthoses vary widely in their methodological quality. Short periods of bed rest are as effective as longer periods and have less side-effects (including absenteeism from work). Whether a short period of bed rest is more beneficial than no bed rest at all, has yet to be demonstrated. The efficacy of orthoses for treating low-back pain remains controversial, although there are some promising results in the literature.
Article
Published reports of relevant empirical research do not suggest a consistent relationship between intraabdominal pressure and the activity of the erector spinae muscles or the magnitude of the intradiscal pressure during lifting. Intraabdominal pressure varies in response to load magnitude and lift method, but there is no pattern of activity that would suggest that an increase in intraabdominal pressure decreases intradiscal pressure. Early models of back biomechanics predicted that the increase in intraabdominal pressure relieved the compressive forces on the low back by providing an extensor momen. In the newer models, intraabdominal pressure functions to stabilize the loaded spine. Studies of human subjects fail to consistenlly show any clear biomechanical advantage from using a back belt. Some studies suggest a slight decrease in back injury incidence when using a back belt; however, there are conflicting results regarding the severity of the injuries involved and the cost-effectiveness of back belts.