ArticlePDF Available

Abstract and Figures

Background Research suggests that in some patients with low back pain, lumbar belts (LB) may derive secondary prophylactic benefits. It remains to be determined, however, which patients are most likely to benefit from prophylactic LB use, and which LB design is optimal for this purpose. The objective of this study was to determine the effect of different lumbar belts designs on range of motion and lumbopelvic rhythm. Methods Healthy subjects (10 males; 10 females) performed five standing lumbar flexion/extension cycles, with knees straight, during a control (no belt) and four lumbar belt experimental conditions (extensible, with and without dorsal and ventral panels; non-extensible). Motion of the pelvis and lumbar spine was measured with 3D angular inertial sensors. Results The results suggest that adding dorsal and ventral panels to an extensible LB produces the largest lumbar spine restrictions among the four tested lumbar belt designs, which in turn also altered the lumbopelvic rhythm. On a more exploratory basis, some sex differences were seen and the sex × experimental condition interaction just failed to reach significance. Conclusions LB may provide some biomechanical benefit for patients with low back disorders, based on the protection that may be provided against soft tissue creep-based injury mechanisms. More comprehensive assessment of different LB designs, with additional psychological and neuromuscular measurement outcomes, however, must first be conducted in order to produce sound recommendations for LB use. Future research should also to take sex into account, with sufficient statistical power to clearly refute or confirm the observed trends.
Content may be subject to copyright.
R E S E A R C H A R T I C L E Open Access
The effect of different lumbar belt designs on the
lumbopelvic rhythm in healthy subjects
Christian Larivière
1,3*
, Jean-Maxime Caron
2,3
, Richard Preuss
2,3
and Hakim Mecheri
1,3
Abstract
Background: Research suggests that in some patients with low back pain, lumbar belts (LB) may derive secondary
prophylactic benefits. It remains to be determined, however, which patients are most likely to benefit from
prophylactic LB use, and which LB design is optimal for this purpose. The objective of this study was to determine
the effect of different lumbar belts designs on range of motion and lumbopelvic rhythm.
Methods: Healthy subjects (10 males; 10 females) performed five standing lumbar flexion/extension cycles, with
knees straight, during a control (no belt) and four lumbar belt experimental conditions (extensible, with and
without dorsal and ventral panels; non-extensible). Motion of the pelvis and lumbar spine was measured with 3D
angular inertial sensors.
Results: The results suggest that adding dorsal and ventral panels to an extensible LB produces the largest lumbar
spine restrictions among the four tested lumbar belt designs, which in turn also altered the lumbopelvic rhythm.
On a more exploratory basis, some sex differences were seen and the sex × experimental condition interaction just
failed to reach significance.
Conclusions: LB may provide some biomechanical benefit for patients with low back disorders, based on the
protection that may be provided against soft tissue creep-based injury mechanisms. More comprehensive
assessment of different LB designs, with additional psychological and neuromuscular measurement outcomes,
however, must first be conducted in order to produce sound recommendations for LB use. Future research should
also to take sex into account, with sufficient statistical power to clearly refute or confirm the observed trends.
Keywords: Lumbar support, Coordination, Kinematics
Background
While lumbar belts (LB) do not appear to reduce the risk
of a first episode of low back pain [1,2], some patients with
low back pain may derive secondary prophylactic benefits
from LB use [1]. It remains to be determined, however,
which patients are most likely to benefit from prophylactic
LB use, and which LB design is optimal for this purpose.
Psychological [3], neuromuscular and biomechanical
[4] mechanisms have all been proposed to explain the
clinical benefits of LB, but remain unproven. Psycho-
logical benefits are likely associated with the perceived
mechanical support derived from the LB [3], while any
neuromuscular likely involves mechanisms that influence
lumbar stability, such as lumbar proprioception, trunk
muscle feedforward and reflex activity [5-8]. The direct
biomechanical benefits of LB, on the other hand, are likely
related to the mechanical stiffness of the LB, leading to de-
creased lumbar range of motion (ROM) [3,4,9], reduced
stresses in the passive tissues of the posterior lumbar spine
[10,11] and potentially to reduced compressive loading of
the lumbar spine [12]. The direct biomechanical impact of
LB is the focus of the current study. Specifically, we aim
to assess the influence of LB stiffness on lumbar spine
ROM and on the coordination between the pelvis and the
lumbar spine during movement, hereafter called the lum-
bopelvic rhythm.
To the authorsknowledge, three previous studies have
assessed body segment kinematics during lifting, while
* Correspondence: lariviere.christian@irsst.qc.ca
1
Occupational Safety and Health Research Institute Robert-Sauvé (IRSST), 505,
boul. De Maisonneuve Ouest, Montreal, Quebec H3A 3C2, Canada
3
Centre for Interdisciplinary Research in Rehabilitation of Greater Montreal
(CRIR), Montreal, Canada
Full list of author information is available at the end of the article
© 2014 Larivière et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain
Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article,
unless otherwise stated.
Larivière et al. BMC Musculoskeletal Disorders 2014, 15:307
http://www.biomedcentral.com/1471-2474/15/307
wearing a LB [9,13,14]. One of these studies only ad-
dressed body position at peak compression force, and
thereforeprovideslittleinsightintotheeffectsofLBon
movement coordination [14]. The other two studies, how-
ever, provide evidence of altered inter-segmental coor-
dination compared to lifting without a LB, suggesting that
LB use changes the natural style of lifting [9,13]. Only
McGorry and Hsiang [13], however, treated the lum-
bar spine and pelvis as separate segments. Their results
showed similar ROM measures for two types of LB (elastic
and rigid), with a decrease in lumbar flexion compensated
for by an increase in pelvic flexion. No significant change
in the lumbopelvic rhythm, however, was found for any
of the lifting and lowering stages. Unfortunately, these
authors did not provide a detailed description of the LBs
used in the study, making the interpretation and applica-
tion of these findings difficult. Furthermore, the LB ten-
sion was volunteer-selected, which may have affected the
outcomes. Further study of the effect of different LB de-
signs on the lumbopelvic rhythm, therefore, is necessary
to enhance the knowledge in this field, and ultimately to
guide the prescription of LB by healthcare practitioners.
The objective of the current study was to determine the
effect of different LBs designs on the lumbopelvic rhythm
of healthy male and female subjects during a forward
bending task. Two broad categories of LBs were studied -
categorized as extensible (elastic) and non-extensible -
having first been identified as flexible enough to be used
at work. Furthermore, as many commercial LB also allow
the possibility of adding dorsal and/or ventral inserts,
which is purported to enhance lumbar stiffness, these
designs were also included. A standardized, maximal
trunk flexion/extension task (without lifting) was used
to reduce any variability in movement patterns associated
with lower and upper limb movements, with the goal of
better isolating the intrinsic effect of a LB on the lumbo-
pelvic rhythm. Sex effects were also investigated, as differ-
ences have been previously found between males and
females for both pelvic and lumbar ROM [15,16] and lum-
bopelvic rhythm [17] during trunk flexion/extension tasks.
Methods
Subjects
Twenty healthy subjects (10 men + 10 women), aged be-
tween 18 and 65 years, were recruited on a word of
mouth basis, with male and female subjects matched for
age (Table 1). Exclusion criteria were as follows: back
pain in the preceding month; having a body mass index
(BMI) greater than 31.5 kg/m
2
(women) or 33 kg/m
2
(men); prior surgery of the pelvis or spinal column;
scoliosis; systemic or degenerative disease; one positive
response to the Physical Activity Readiness Question-
naire [18]; history of neurological diseases or deficits not
related to back pain (e.g., stroke, peripheral neuropa-
thies, balance deficits); use of anticonvulsive, antide-
pressive and anxiolitic medication (use of antispasmodic,
anti-inflammatory and analgesic drugs for back pain were
accepted); pregnancy; claustrophobia; abnormal arterial
blood pressure (hypertension). All subjects were informed
about the experimental protocol and potential risks and
gave written consent prior to their participation. The eth-
ics committee of the Centre for Interdisciplinary Research
in Rehabilitation of Greater Montreal (CRIR) approved
the study and consent form.
Lumbar belts investigated
The two models of LB are illustrated in Figure 1, and
were chosen, in consultation with an orthotist, based on
functionality for use at work (flexible, comfortable), af-
fordability and durability. The first was an extensible LB
that allowed for insertion of dorsal and ventral panels
(model LumboLux from Hope Orthopedic). The second
was a non-extensible LB without panels (model 582
from MBrace). Both LBs had two layers of straps, se-
cured with Velcro material; the first layer allowing for
initial adjustment and placement of the LB, and the
Table 1 Characteristics of the male and female subjects
Males (n = 10) Females (n = 10) T-test
Mean (SD) Mean (SD) Pvalue
Age (yr) 26 (8) 27 (11) 0.551
Height (m) 1.80 (0.06) 1.68 (0.07) 0.007
Mass (kg) 80 (13) 65 (10) 0.024
BMI (kg/m
2
) 25 (3) 23 (3) 0.286
Spine length* 0.449 (0.034) 0.393 (0.021) 0.002
Extensible belt upper edge at …† T12 [T11-T12] T11 [T9-T12] /
N-extensible belt upper edge at …† T12 [T11-T12] T11 [T9-T12] /
Thoracic sensor upper edge at …† T9 [T8-T9] T8 [T7-T9] /
*:C7 spinous process height minus L5 spinous process height; : spinous process touched by the upper edge of the belt or upper edge of the thoracic inertial
sensor, reported as mean [min-max].
Significant P values are identified in bold characters.
Larivière et al. BMC Musculoskeletal Disorders 2014, 15:307 Page 2 of 13
http://www.biomedcentral.com/1471-2474/15/307
second layer (elastic material for the extensible LB and
non-extensible nylon straps for the non-extensible LB)
allowing the final tension adjustment. The optional ven-
tral panel for the extensible LB was semi-rigid and cov-
ered with a Velcro material, allowing it to be anchored
with the first Velcro strap. The dorsal panel was a rigid
Kydex insert, with a hole in the middle to allow the
spine to flex without discomfort.
Both LBs are commercially available in seven lengths,
but have a standard height (front: 6 inches; back: 10
inches). The 6-inch front is typical of most low-profile
LBs on the market, and is purported to be less restricting
for trunk flexion. The use of these commercially-available
LBs, therefore, did not allow for standardization of LB
height based on the height of the individual subjects,
which may impact the findings of this study; in particular
the comparison between sexes, as women tend to be shor-
ter than men. Consequently, the highest vertebral spinous
process covered by the LB was recorded, and spine length,
as defined by the distance between the L5 and C7 pro-
cesses, was used as a covariate for sex comparisons (see
Statistical analyses section).
During testing, each LB was positioned over a T-shirt,
with the subject sitting, so that the lower edge of the LB
covered the antero-superior iliac spines, without touch-
ing the thighs. Before each experimental condition in-
volving a new LB, the tension of the LB was adjusted at
rest, with the subject standing upright. This step was
performed with the use of a FSR sensor (Force Sensing
Resistor; Interlink Electronics; model FSR400; see Figure 2)
fastened on the skin between the lateral aspect of the left
iliac crest and the 12
th
rib. During task performance, sub-
jects reported that the presence of the sensor was imper-
ceptible. Using this feedback system, the subject adjusted
thetensionintheLBtoreachapressureof70mmHgor
9.
3 KPa [19], allowing for a 5% error. For some smaller
subjects (mostly women), however, the target pressure
of 9.
3 KPa could not be reached. In these cases, the
belt pressure was applied at a target between 8.0 and
8.8 KPa ± 5%, and a matching belt pressure was used
with the subsequent male subject(s).
Task and experimental conditions
From a standing position, keeping the knees as straight
as possible during the task, subjects were asked to flex
the trunk forward as far as possible without contracting
the abdominals, and return to the upright position. For
each of the five experimental conditions (detailed below),
five consecutive cycles of the movement were performed,
following the pace of a metronome (4 s to flex, 4 s to
relax, 4 s to extend, 4 s to relax). The head was fully flexed
through the whole task to prevent movement of the cer-
vical vertebrae. Subjects performed the task during five
randomly-ordered experimental conditions: (1) the con-
trol condition without LB (Control), (2) extensible LB
without panels (ExtLB), (3) extensible LB with dorsal
panel (ExtLB-D), (4) extensible LB with dorsal and ven-
tral panels (ExtLB-DV), (5) non-extensible LB (NExtLB).
These experimental conditions were designed to progres-
sively increase the stiffness provided by LBs.
AB
Figure 1 Illustration of the tested lumbar belts. On the left (A), the extensible lumbar belt with dorsal (upper left) and ventral (upper right)
panels. On the right (B), the non-extensible lumbar belt. The two nylon straps make this belt non-extensible.
Figure 2 The FSR pressure sensor allowing to standardize the
tension of the lumbar belts. To homogenize the pressure applied
on the sensor, the 4.0 × 4.0 cm sensor was supported with a
semi-rigid plastic sheet and covered with a Styrofoam layer (total
thickness of the three layers: 2 mm).
Larivière et al. BMC Musculoskeletal Disorders 2014, 15:307 Page 3 of 13
http://www.biomedcentral.com/1471-2474/15/307
Measurement techniques and procedures
The angular kinematics of the pelvis and lumbar spine
was recorded (sampling rate: 100 Hz) with a 3D-motion
system comprising inertial sensors (X-Sens Motion Tech-
nologies, Enschede, The Netherlands). A first sensor fol-
lowed the motion of the sacrum while a second sensor
was positioned on the thoracic vertebrae not covered by
the LBs, as illustrated in Figure 3. The highest spinous
process covered by the thoracic sensor (generally covers
two spinous processes) was identified and recorded.
Data processing and analyses
All angular position signals recorded in the sagittal plane
were first filtered using a fourth-order, zero-lag Butter-
worth filter with 3-Hz cut-off frequency. The five flexion/
extension cycles were then separated into individual cycles
and phases (flexion, extension), using a threshold of 5% of
the thoracic sensor peak angular velocity.
The angular position of the sensor at the sacrum/
pelvis (Ang
PE
)andonthethorax(Ang
TH
)wereused
to calculate the lumbar spine angle (Ang
LU
=Ang
TH
-
Ang
PE
). Ang
PE
and Ang
LU
values at the beginning and
end of trunk flexion were used to compute the range
of motion (ROM) of the pelvis (ROM
PE
)andlumbar
spine (ROM
LU
), respectively. ROM
PE
and ROM
LU
were
summed to calculate the total trunk ROM (ROM
Tot
). The
relative contribution of the lumbar spine to the total trunk
ROM was then computed as follows:
%ROMLU ¼ROMLU
ROMTot

100
Statistical analyses of these data showed that the
%ROM
LU
captures the same information as the cor-
responding variable computed for the pelvis (%ROM
PE
)
or as the popular lumbopelvic ratio (ROM
LU
/ROM
PE
).
The lumbopelvic ratio, however, may produce outliers
when the denominator is close to zero. To provide clear
and concise results, therefore, only the analysis of the
%ROM
LU
is reported as a measure of relative segmental
motion.
Each phase of the motion task (flexion, extension) was
further separated into four intervals (0-25; 25-50; 50-75;
75-100% of ROM
Tot
), and the intervals for the extension
phase were inverted to allow for direct comparison with
the flexion phases. Intervals 1 and 4, therefore, corres-
pond to the upright and flexed positions respectively, for
both phases.
The coordination between the pelvis and lumbar spine
was quantified using a relative phase angle (RPA) ana-
lysis, in which the phase difference between the lumbar
and pelvic segments is determined based on the velocity
profiles of each segment as a function of its relative an-
gular position [20,21]. New standards to compute these
analyses were followed [22]. A difference between the
two segments of 0° indicates that the lumbar spine and
pelvis segments are moving perfectly in phase, positive
values indicate that the lumbar spine is leading the pelvis
in the phase space, negative values indicate that the lum-
bar spine is lagging behind the pelvis, and 180° indicates
that the segments are perfectly out of phase. Three vari-
ables were extracted from the relative phase angle curve
for both the flexion and extension phases of the cycle;
RPA
Mean
,RPA
Std
and RPA
Max
, which are the mean, the
AB C
Figure 3 Procedure used to allow the monitoring of the pelvis and lumbar spine without interference from the lumbar belts. The upper
inertial sensor, positioned on the thoracic spine, was secured on a piece of foam (A), allowing the wire not to interfere with the LB. The lower
inertial sensor was glued on an angulated piece of plastic (A), which was inserted in a hole just below the short pants elastic band (B) and
secured on the sacrum by three means (glue, Hypafix tape, 3-cm wide elastic band surrounding the sacrum and antero-superior iliac spines).
The elastic band was deemed required during the control (no LB) condition and could not provide any lumbar support. The LBs were simply
overlying the 3-cm elastic band, the plastic plate and the sacrum (C), which prevented any discomfort during the trials. Consent to publish was
given by the model in this image.
Larivière et al. BMC Musculoskeletal Disorders 2014, 15:307 Page 4 of 13
http://www.biomedcentral.com/1471-2474/15/307
standard deviation (variability of the coordination) and
the extreme values (maximum when positive and mini-
mum when negative) of the relative phase angle curve,
respectively.
Statistical analyses
All statistical analyses were done with NCSS software
(version 6.0 for Windows), using a significance level
(alpha) of 0.05. Because some variables showed abnor-
mal distributions, we elected to systematically transform
all variables [23] to normalize their distributions, as ve-
rified with the Wilk-Shapiro test, thus allowing the use
of parametric statistical analyses. Note, however, that
values reported in tables and figures are the untrans-
formed values.
Preliminary analyses (repeated measures ANOVAs) re-
vealed that the first movement cycle was significantly
different than some of the remaining cycles (cycle 2 and/
or 3 and/or 4 and/or 5) for many kinematic variables
and pressure measures, possibly because of learning or
some repositioning of the sensors or LBs during the first
cycle. In other words, cycles 2, 3, 4 and 5 were always
non-significantly different. Consequently, for each vari-
able, the average value of the last four cycles was retained
for further analyses.
Two-way ANOVAs (2 SEX × 5 CONDITION) for re-
peated measures on the CONDITION factor (1 control
and 4 LB conditions) were carried out on all dependent
variables except %ROM
LU
, for which a 3-way ANOVA (2
SEX × 5 CONDITION × 4 INTERVAL) for repeated
measures on the CONDITION and INTERVAL (0-25;
25-50; 50-75; 75-100% of ROM
Tot
) factors was used. Sep-
arate analyses were performed for the flexion and exten-
sion phases. Post-hoc pairwise comparisons were carried
out with the Tukey-Kramer test.
To determine whether sex comparisons could be con-
founded by the number of vertebrae covered by the LBs
(for variables specific to the lumbar spine), ANCOVAs
were carried out for each condition (for all dependent
variables) and interval (for %ROM
LU
only), using spine
length as a covariate.
Results
Assessment of potential confounding variables
The area covered by the LB in males and females is de-
scribed in Table 1, confirming that LBs covered more
vertebrae in women, which in turn forced the position-
ing of the upper inertial sensor on higher thoracic verte-
brae. However, on average, the difference was only one
vertebra. These results are explained by the significantly
smaller spine length of females (39.3 ± 2.1 cm) relative
to males (44.9 ± 3.4 cm).
The pressure generated by the belt during the upright
and flexed trunk postures, as well as during the entire
task (last four cycles), did not show SEX main effects,
although a SEX × CONDITION interaction reached signi-
ficance in the upright position (Table 2). Women showed
a decrease of pressure across the belt conditions (from C2
to C5) whereas the opposite was seen in males, although
these changes were not significantly different (1-way
ANOVAs for each sex separately). However, this led to a
significant SEX effect during the NExtLB condition (Δ=
0.95 KPa; P= 0.027), as further disclosed with separate T-
tests. This might be explained by the fact that even though
we paired the belt pressures of some men with those of
smaller women, the difference in belt pressure between
sexes increased as the stiffness of the belt increased since
the belt could adapt less to the body surface. A stiffer LB
would prevent the belt from wrapping tightly around the
abdomen of smaller women relatively to male subjects,
which were bigger in general.
Although no significant difference was seen in the
upright position, the NExtLB condition showed a sig-
nificantly lower pressure (8.36 KPa) than other belt
conditions (8.76 to 8.78 KPa) in the flexed position
(Table 2). This may be explained by a pouch created at
the position of the pressure sensor, which likely corre-
sponded to the space between the straps of the NExtLB.
Table 2 Lumbar belt pressure values (KPa) corresponding to different trunk postures and statistical analyses
Trunk posture Sex Mean (SD) values for each experimental condition ANOVA (P values) Post hoc (C)
ExtLB (C2) ExtLB-D (C3) ExtLB-DV (C4) NExtLB (C5) Sex (S) Condition (C) S × C
Upright 8.85 (0.78) 8.91 (0.77) 9.09 (0.64) 9.29 (0.58) 0.172 0.993 0.008 /
8.86 (0.62) 8.74 (0.79) 8.62 (0.70) 8.34 (1.09)
Flexed 8.93 (0.55) 9.00 (0.40) 8.93 (0.46) 8.53 (0.55) 0.188 < 0.001 0.976 C2,C3,C4 > C5
8.60 (0.61) 8.55 (0.78) 8.57 (0.60) 8.19 (0.80)
Mean across 8.89 (0.67) 8.96 (0.61) 9.01 (0.56) 8.91 (0.68) 0.160 0.168 0.140 /
Entire task 8.73 (0.62) 8.65 (0.79) 8.60 (0.65) 8.27 (0.96)
: males; : females; LB: lumbar belt; ExtLB: extensible LB without panels; ExtLB-D: extensible LB with the dorsal panel; ExtLB-DV: extensible LB with dorsal and
ventral panels; NExtLB: non-extensible LB. Significant P values are identified in bold characters.
Larivière et al. BMC Musculoskeletal Disorders 2014, 15:307 Page 5 of 13
http://www.biomedcentral.com/1471-2474/15/307
However, although statistically significant, this differ-
ence was small (4.6%) and considered negligible.
Effect of experimental conditions (LB designs) on ROM
The SEX × CONDITION interactions were not statisti-
cally significant (Table 3), although a trend (P= 0.071)
was observed for ROM
LU
(Figure 4). SEX was significant
only for ROM
PE
, with females showing a 13° higher
ROM than males (52° > 39°). For ROM
LU
, accounting for
sex differences in spine length with the use of ANCO-
VAs (for each experimental condition) did not change
the conclusions (no SEX effect; spine length covariate
was not significant).
Wearing a LB did not influence ROM
PE
but affected
ROM
LU
(Table 3). More precisely, wearing any LB de-
creased ROM
LU
relative to the control condition by an
amount ranging from 9 to 15° (Figure 4). Considering
that ROM
PE
was not affected, ROM
Tot
, represented by
the sensor positioned at the thoracic level, also signifi-
cantly decreased (ANOVA P< 0.001; Post hoc compari-
sons: C1 > C3,C4,C5 and C2 > C5) by an amount ranging
from 6 to 13°. Also, the ExtLB-DV condition limited
more ROM
LU
than the ExtLB condition.
Effect of experimental conditions (LB designs) on the
lumbopelvic rhythm variables
The %ROM
LU
variable, computed across phases (flexion,
extension) and intervals, revealed that all main effects
(SEX, CONDITION, INTERVAL) and some interactions
reached statistical significance (Table 4). The ANCOVAs
carried out to account for spine length differences be-
tween sexes did not uncover any difference relative to
sex effects for this variable. SEX × CONDITION interac-
tions just failed to reach statistical significance (0.05 <
P< 0.10) but a SEX × INTERVAL (during extension) and
CONDITION × INTERVAL interaction reached signifi-
cance. Details of these findings are illustrated in Figure 5.
Table 5 provides additional statistical explanations of the
CONDITION × INTERVAL interactions based on separ-
ate one-way ANOVAs for repeated measures between
conditions for each interval and between intervals for
each condition. For space constraints, these results are
described and immediately interpreted in details in the
discussion.
The relative phase angle variables showed neither sta-
tistically significant SEX × CONDITION interactions,
nor sex differences (Table 6), and the ANCOVAs carried
out to account for spine length differences between sexes
did not make any difference relative to sex effects on these
variables. The CONDITION factor was significant for the
three RPA variables (RPA
Max
,RPA
Mean
and RPA
Std
)and
the two phases (flexion and extension), as further illus-
trated in Figure 6. More specifically, during the flexion
phase, the three RPA variables were significantly higher
during the control condition than all the LB conditions.
RPA
Mean
showed further differences between the different
LB designs, with the ExtLB-DV condition showing lower
values than the ExtLB and NExt-LB conditions. During
the extension phase, the three RPA variables were signifi-
cantly higher during the ExtLB-DV condition than the
control, the ExtLB and NExt-LB conditions. Additional
differences involved the ExtLB-D condition, showing
higher RPA
Mean
values than the control and NExt-LB con-
ditions, and showing lower RPA
Std
values than the control,
ExtLB and NExt-LB conditions.
Discussion
The findings of this study provide direct evidence of the
biomechanical effects of LB use during trunk flexion/
extension. Wearing a LB significantly reduced lumbar
ROM while pelvis ROM remained unchanged. An effect
of LB design was also found, with lumbar ROM being
more greatly reduced by theExtLB-DVthanbythe
ExtLB design. LB use also significantly changed the
lumbopelvic rhythm, as revealed by different coordin-
ation variables.
On a more exploratory basis, sex differences were also
seen. Males showed less pelvic ROM and, in general,
more contribution to overall trunk ROM from the lum-
bar spine (%ROM
LU
). SEX × CONDITION interactions,
however, did not reach statistical significance, although
some trends (0.05 < P< 0.10) were observed. Further-
more, only a single interaction effect was found between
sex and other independent variables. Consequently, for
clarity, the effect of experimental conditions and of sex
will be discussed separately.
Effect of experimental conditions (LB designs) on ROM
The first finding of note was that all LB designs signifi-
cantly reduced lumbar ROM relative to the control
condition, while pelvis ROM remained unchanged. This
emphasizes the specific effect of LB use on lumbar
ROM, and is likely explained by an increase in lumbar
stiffness [24].
Previous studies have also shown a reduced lumbar ROM
with LB use [3,4,9]. This, however, was often accompanied
Table 3 Statistical results (Pvalues*) corresponding to
the effect of sex and experimental conditions on range of
motion (ROM) variables during the flexion phase
Variable ANOVA (P values) Post hoc (C)
Sex (S) Condition (C) S × C
ROM
PE
0.049 0.332 0.790 /
ROM
LU
0.122 < 0.001 0.071 C1 > C2,C3,C4,C5; C2 > C4
LB: lumbar belt; C1 (control): no LB; C2 (ExtLB): extensible LB without panels;
C3 (ExtLB-D): extensible LB with the dorsal panel; C4 (ExtLB-DV): extensible LB
with dorsal and ventral panels; C5 (NExtLB): non-extensible LB. *Significant
Pvalues are identified in bold characters, while trends (0.05 < P< 0.10) are
identified in italics.
Larivière et al. BMC Musculoskeletal Disorders 2014, 15:307 Page 6 of 13
http://www.biomedcentral.com/1471-2474/15/307
by an enhanced ROM at peripheral joints such as at the
knees and hip, or in the thoracic spine [3,9]. The current
study, however, was specifically designed to isolate the in-
trinsiceffectofaLBonthelumbopelvicrhythm.Pain-free
subjects were used, and, unlike freestyle lifting, the selected
task was limited to trunk flexion/extension. Under these
strict conditions, no effect of LB use was found on pelvis
ROM, which suggests that the direct mechanical effect of
LBs is limited to the lumbar spine (the immediate effect on
thoracic spine ROM, however, was not assessed). Further-
more, the purpose of the task being to achieve maximal
trunk flexion, the possibility that a part of the reduced lum-
bar ROM was explained by sensory feedback serving as a
reminder for good postural hygiene was excluded.
The lumbar ROM was also more affected by the ExtLB-
DV than by the ExtLB design, the former showing the
largest effect (15°) relative to the control condition. This
suggests that adding ventral and dorsal panels further
stiffens the lumbar spine, as proposed by LB manufac-
turers. One previous study has directly evaluated the ef-
fects of different LB designs on lumbar stiffness, using a
sudden trunk perturbation task [19]. The non-extensible
LB used in this previous study increased trunk stiffness by
14% relative to an extensible LB. Adding a ventral panel to
the non-extensible LB, however, produced no further mea-
sureable increase in stiffness (the effect of panels with the
extensible LB was not assessed). Assessing the findings of
this previous study, along with the different effects of LB
design on different task and outcome measures (ROM
LU
,
%ROM
LU,
relative phase angle variables) in the current
study, suggests the need to consider both mechanical and
neuromuscular outcome measures to better delineate the
pros and cons of different LB designs.
From a clinical perspective, the decrease in lumbar
ROM that was observed with all LB designs in the cur-
rent study may have a positive impact on mechanisms of
injury linked with the progressive creep of the lumbar
spine posterior passive-tissues. Induced tissue creep, via
sustained or repetitive lumbar flexion, is known to re-
duce intrinsic lumbar stiffness, impair back muscle re-
flexes [25-28] and disturb trunk postural control [29].
Tissue creep may also trigger inflammatory processes
and enhance muscle spasm [30]. Cumulative exposure to
repetitive or sustained trunk flexion, which is common
in many occupations (e.g. manual materials handlers,
roofers, bricklayers, gardeners, movers, etc.), may there-
fore predispose workers to low back injury and pain. A
non-negligible reduction of lumbar flexion, by 9 to 15°
with the use of LB may therefore reduce these risks by
decreasing tissue creep. This might be particularly help-
ful when back muscle fatigue develops during repetitive
activities, knowing that lumbar flexion progressively
arises in these circumstances [31]. This may also help
patients with lumbar posterior passive-tissue injuries to
return to work more rapidly without exacerbating their
pain or compromising their safety.
Figure 4 Range of motion of the pelvis (ROM
PE
) and lumbar spine (ROM
LU
) in males and females for each lumbar belt (LB)
experimental condition. C1 (control): no LB; C2 (ExtLB): extensible LB without panels; C3 (ExtLB-D): extensible LB with the dorsal panel; C4
(ExtLB-DV): extensible LB with dorsal and ventral panels; C5 (NExtLB): non-extensible LB. *Statistically significant differences between experimental
conditions are identified at the top of each graph.
Table 4 Statistical results (Pvalues*) corresponding to the effect of sex, experimental conditions and intervals on the
relative contribution of the lumbar spine to the total trunk range of motion (%ROM
LU
)
Phase ANOVA (Pvalues)
Sex (S) Condition (C) Interval (I) S × C S × I C × I S × C × I
Flexion 0.024 <0.001 <0.001 0.059 0.514 <0.001 0.444
Extension 0.041 <0.001 <0.001 0.086 0.032 <0.001 0.935
*Significant Pvalues are identified in bold characters, while trends (0.05 < P< 0.10) are identified in italics.
Larivière et al. BMC Musculoskeletal Disorders 2014, 15:307 Page 7 of 13
http://www.biomedcentral.com/1471-2474/15/307
Effect of experimental conditions (LB designs) on the
lumbopelvic rhythm variables
The findings of the current study indicate that LB use
may affect the coordination of movement between the
lumbar spine and pelvis. As might be expected from the
reduced lumbar spine ROM with LB use, the contri-
bution of the lumbar spine to the overall trunk ROM
(%ROM
LU
) was also reduced for all LB conditions, in
both the flexion and extension phases (Figure 5 -upper
plots). No difference, however, was noted between any
of the LB conditions. This effect is illustrated in the
interval-specific results (Figure 5 middle and lower
plots). As in previous studies [32-35], the lumbar spine
contributed progressively less to overall trunk flexion
Figure 5 The relative contribution of the lumbar spine to the total trunk ROM (%ROM
LU
variable), illustrated in different plots to
understand the SEX × CONDITION (upper plots), SEX × INTERVAL (middle plots) and CONDITION × INTERVAL (lower plots) interactions.
Pvalues reported at the top of each plot correspond to the shown interaction. Left and right plots are for the flexion and extension phases,
respectively. Please keep in mind that the extension interval values were inverted to allow comparisons with the flexion phase intervals.
Experimental conditions (upper plots) or intervals (middle plot) that were different (P< 0.05) are identified with different letters (here A, B and
sometimes C) at the bottom of the corresponding graphs. When the interaction was significant, asterisks (*) were positioned to indicate where
SEX differences for a specific interval (right middle plot) or CONDITION differences for a specific interval (lower plots) were significant according
to post hoc analyses. C1 (control): no LB; C2 (ExtLB): extensible LB without panels; C3 (ExtLB-D): extensible LB with dorsal panel; C4 (ExtLB-DV):
extensible LB with dorsal and ventral panels; C5 (NExtLB): non-extensible LB. Standard deviations were not shown for clarity.
Larivière et al. BMC Musculoskeletal Disorders 2014, 15:307 Page 8 of 13
http://www.biomedcentral.com/1471-2474/15/307
(%ROM
LU
) as trunk flexion increased, with the differ-
ence becoming significant in the later intervals for both
the flexion (left middle plot) and extension (right middle
plot) movements. During the flexion movement, how-
ever, the progressive decrease of %ROM
LU
across inter-
vals was less pronounced with all LB designs conditions
relative to the control condition (Figure 5 left lower
plot). A similar, although less evident effect also appears
during the extension movement (Figure 5 right lower
plot). In other words, the reduction of the lumbar spines
contribution to overall trunk motion, as a result of LB
use, is more pronounced when standing than when the
trunk is fully flexed (Figure 5; Table 5). This more in-
depth analysis also revealed some differences between
specific LB designs in the more upright intervals of
motion (1
st
and 2
nd
interval during flexion; 1
st
interval
during extension). Here, the ExtLB-DV design produced
the greatest reduction in relative lumbar ROM when
compared to one or more of the remaining LB designs.
Once again, this is likely reflective of the additional stiff-
ness provided by the dorsal and ventral panels in the
ExtLB-DV design, leading to an altered lumbopelvic
rhythm in addition to a reduction in lumbar ROM, as
previously discussed.
The RPA variables (RPA
Max
,RPA
Mean
and RPA
Std
)were
all sensitive to the CONDITION factor during both fle-
xion and extension. RPA
Max
and RPA
Mean
values indicated
that the lumbar spine was leading the pelvis during flexion
(positive values) whereas the opposite was observed dur-
ing extension (negative values). However, all LB designs
reduced the leading of the lumbar spine over the pelvis
during flexion, which was in line with %ROM
LU
results
(Figure 5 left lower plot). Moreover, RPA
Mean
results
showed that the ExtLB-DV produced the largest effect
in this respect, leading to significant differences with
the ExtLB and NExt-LB conditions. Likewise, the largest
Table 5 Statistical results (Pvalues*) corresponding to the post-hoc comparisons required to explain the CONDITION ×
INTERVAL significant interactions obtain for the %ROM
LU
variable
Flexion phase Extension phase
ANOVA Post-hoc comparisons ANOVA Post-hoc comparisons
P value (Tuckey-Kramer) P value (Tuckey-Kramer)
Interval* Between conditions Between conditions
1<0.001 1 > all; 2 > 3,4; 5 > 4 <0.001 1,5 > 3,4; 2 > 4
2<0.001 1 > all; 2,3,5 > 4 0.011 1>4
30.009 1 > 2,4,5 0.004 1 > 2,4,5
40.084 / 0.135 /
ConditionBetween intervals Between intervals
1<0.001 1,2 > 3 > 4 <0.001 1,2 > 3 > 4
2<0.001 1 > 3,4; 2 > 4 <0.001 1,2 > 3 > 4
3<0.001 1,2,3 > 4 <0.001 1,2 > 3 > 4
40.027 1>4 <0.001 1,2 > 3 > 4
5<0.001 1 > 3,4; 2 > 4 <0.001 1>2>3>4
*In the first part of the table, a one-way ANOVA for repeated measures on the CONDITION factor was carried out for each interval separately. A one-way ANOVA
for repeated measures on the INTERVAL factor was carried out for each condition separately. *Significant Pvalues are identified in bold characters, while trends
(0.05 < P< 0.10) are identified in italics.
Table 6 Statistical results (Pvalues*) corresponding to the effect of sex and experimental conditions on relative phase
angle variables
Phase angle Phase ANOVA (P values) Post hoc (C)
Variable Sex (S) Condition (C) S × C
RPA
Max
Flexion 0.592 <0.001 0.913 C1 > C2,C3,C4,C5
Extension 0.080 <0.001 0.445 C4 > C1,C2,C5
RPA
Mean
Flexion 0.546 <0.001 0.921 C1 > C2,C3,C4,C5 C4 < C2,C5
Extension 0.114 <0.001 0.599 C4 > C1,C2,C5 C3 > C1,C5
RPA
Std
Flexion 0.927 <0.001 0.871 C1 > C2,C3,C4,C5
Extension 0.064 <0.001 0.456 C1,C2,C5 > C3,C4
LB: lumbar belt; C1 (control): no LB; C2 (ExtLB): extensible LB without panels; C3 (ExtLB-D): extensible LB with dorsal panel; C4 (ExtLB-DV): extensible LB with dorsal
and ventral panels; C5 (NExtLB): non-extensible LB. *Significant Pvalues are identified in bold characters, while trends (0.05 < P< 0.10) are identified in italics.
Larivière et al. BMC Musculoskeletal Disorders 2014, 15:307 Page 9 of 13
http://www.biomedcentral.com/1471-2474/15/307
effects were observed for the ExtLB-DV condition (for
RPA
Max
and RPA
Mean
variables) during the extension
phase, but in the opposite direction (pelvis leading the
lumbar spine to a lesser degree relative to the control,
ExtLB and NExt-LB conditions). This was also observed
for the ExtLB-D condition, but to a lesser extent (RPA
Mean
variable only; relative to the control and NExt-LB con-
ditions). Overall, these findings further confirm that all
of the investigated LB designs altered the lumbopelvic
rhythm, and that this effect was enhanced with the use of
the dorsal panel, although the clinical significance of these
findings remains to be determined. These findings are
likely directly related to the mechanical stiffness provided
by the LB, as inter-segmental coordination is inextricably
linked to the control of segmental stiffness [36]. However,
the use of the ventral panel, in addition to the dorsal
panel, did not make a further difference.
All LB designs led to a reduction in the variability of
the relative phase angle (RPA
Std
)between the lumbar
spine and pelvis during trunk flexion, with a similar ef-
fect observed for the ExtLB-D and ExtLB-DV designs
during trunk extension. While an external support may
reduce the risk of injury due to a temporary loss of ac-
tive segmental control (due to muscle fatigue, loss of
concentration, etc.), it may also allow for less room for
variability in movement patterns by the central nervous
system. According to a recent hypothesis [37,38], such a
reduced variability may be detrimental for musculoske-
letal health, particularly when repetitive work activities
are performed, as it will lead to repetitive loading of the
same anatomical structures, and potentially to mechani-
cal tissue fatigue. Reduced motor variability, for example,
has been observed in subjects with chronic pain [39], and
may be emblematic of a pre-existing motor dysfunction or
of an inappropriate long-term compensation following an
acute injury [40].
Effect of sex
While differences between the sexes were not the pri-
mary focus of this study, some effects of sex were ob-
served that may be important in future work. Males
showed less pelvic ROM, which concurs with previous
findings [15,17]. Unlike previous studies [15,16], how-
ever, no difference was found in our data between men
and women for lumbar spine ROM.
Fitting with the findings above, the male participants
in our study showed more contribution from the lumbar
spine (%ROM
LU
) during trunk extension, particularly in
the flexed trunk posture. This is in line with the findings
of Nelson-Wong et al. [17], who showed a higher lum-
bar/hip ratio in males during extension from trunk
flexion. While our analysis suggests that spine length
Figure 6 Relative phase angle variables, all showing statistically significant differences between experimental conditions. C1 (control):
no LB; C2 (ExtLB): extensible LB without panels; C3 (ExtLB-D): extensible LB with dorsal panel; C4 (ExtLB-DV): extensible LB with dorsal and ventral
panels; C5 (NExtLB): non-extensible LB. *Experimental conditions that were different (P< 0.05) are identified at the top of each graph.
Larivière et al. BMC Musculoskeletal Disorders 2014, 15:307 Page 10 of 13
http://www.biomedcentral.com/1471-2474/15/307
differences did not drive these sex effects, certain SEX ×
CONDITION interactions did near statistical signifi-
cance (0.05 < P< 0.10) for ROM
LU
and %ROM
LU
(see
Figure 5 upper plots) variables. This suggests that fu-
ture studies should account for sex, as these differences
may become more apparent in studies conducted with
larger sample sizes.
Perspectives
Although current evidence suggests that LB use does
not reduce the risk of a first episode of low back pain
[1,2], there may be a role for LBs for secondary and ter-
tiary prevention, as suggested by a systematic review
showing more controversial findings for patients with
low back pain [1] and the positive clinical findings ob-
served in the more recent randomized clinical trials
(RCTs) [41,42]. Interestingly, these RCTs were of longer
duration (>3 months). More research is needed to deter-
mine which workers with low back pain will benefit
more from this type of conservative intervention.
The results of the present study show that LB use, for
all designs tested, leads to a reduction in lumbar ROM.
This suggests that LB may be a good short or long-term
solution for patients with low back disorders, based on
the protection that may be provided against soft tissue
creep-based injury mechanisms [30]. Our results also
suggest that adding dorsal and ventral panels to an ex-
tensible LB produces the largest restrictions to lumbar
spine motion, among the four tested LB designs and the
largest alterations in the relative amplitude (%ROM
LU
)
and RPA (RPA
Max
and RPA
Mean
) measures of the lumbo-
pelvic rhythm. LB use, however, also led to a reduction
in the variability of segmental coordination patterns
(RPA
Std
). This may be viewed as a negative effect, in
light of current hypotheses related to the protective ef-
fects of motor variability against tissue fatigue and over-
use injury, and suggests that LB are a poor long term
solution for patients. It is thus difficult to give clear rec-
ommendations for LB use, and even trickier to propose
a specific LB design, based on the findings of this study.
A more comprehensive assessment of different LB de-
signs, with the use of different neuromuscular measure-
ment outcomes, must still be conducted, however, to
produce more individualized recommendations for LB
use. Longitudinal studies must also be conducted to de-
termine any long-term effects of LB use, taking into ac-
count any possible central nervous system adaptations,
and their effect on neuromuscular [43,44], psychological
(e.g. fears of pain/movement; not tested so far) and clin-
ical [1,41,42] outcomes.
The identification of patients that benefit more from
the use of LBs during clinical trials would demonstrate
that the net clinical benefits (pain, disability) of this sim-
ple intervention might outweigh the hypothesized but
not yet supported detrimental effects feared by some cli-
nical practitioners (false sense of security, psychological
dependence, maladaptative neuromuscular adaptations,
muscle atrophy and weakness). In the interim, the cau-
tious practitioner might prescribe a LB on working days
on which the patient had, or expected that they might
develop, low back pain [42]. This is in line with the rec-
ommendation of not using a LB over several consecutive
days or weeks [45]. Such a prescription might also be ac-
companied with clear messages about the importance of
trunk muscle support, the beneficial effect of physical/
work activity for the low back, and as such that activities
involving the low back must be progressively resumed as
soon as possible when symptoms decrease, and espe-
cially when the LB is withdrawn. Key messages provided
in the Backbookleaflet [46] would be recommended in
this perspective.
Strengths and limitations of the study
This study comprises several strengths. Firstly, great care
was taken to minimize any potential interference be-
tween the LBs and the kinematic sensors and to control
for LB pressure. The only potential confounding vari-
able, which was related to the relative height of the LBs,
was statistically accounted for to make valid sex compar-
isons. Secondly, a comprehensive study of the lumbopel-
vic rhythm was provided with the use of complementary
kinematic analyses, as discussed above. Third, more than
two LB designs were contrasted. Finally, we used a stan-
dardized task that allowed us to isolate the intrinsic ef-
fect of a LB on the lumbopelvic rhythm.
Limitations must also be acknowledged. These results
cannot be generalized to people with back pain. Further-
more, our analysis did not account for any effect on the
lumbothoracic rhythm. Finally, this exploratory study of
the possible effect of sex was likely underpowered, and
as such we encourage further testing of these findings
with a larger sample size.
Conclusions
LB may provide some biomechanical benefit for patients
with low back disorders, based on the protection that
may be provided against soft tissue creep-based injury
mechanisms. A more comprehensive assessment of dif-
ferent LB designs, with the use of different psychological
and neuromuscular measurement outcomes, however,
must be conducted to more fully understand the effects
of LB use, before more targeted recommendations for
LB use (or avoidance) can be produced for patient sub-
groups. Future research should also take sex into ac-
count, with sufficient statistical power to clearly refute
or confirm the observed trends.
Larivière et al. BMC Musculoskeletal Disorders 2014, 15:307 Page 11 of 13
http://www.biomedcentral.com/1471-2474/15/307
Abbreviations
Ang
LU
:Lumbar spine angle; Ang
PE
: Pelvis angle; Ang
TH
: Thorax angle;
ANCOVA: Analysis of covariance; ANOVA: Analysis of variance; BMI: Body
mass index; C1 to C5: Experimental conditions: control (C1), ExtLB (C2),
ExtLB-D (C3), ExtLB-DV (C4) et NExtLB (C5); ExtLB: Extensible LB without
panels; ExtLB-D: Extensible LB with dorsal panel; ExtLB-DV: Extensible LB with
dorsal and ventral panels; LB: Lumbar belt; NExtLB: Non-extensible LB;
RCT: Randomized clinical trial; ROM: Range of motion; ROM
PE
: ROM of the
pelvis; ROM
LU
: ROM of the lumbar spine; %ROM
LU
: Relative contribution of
the lumbar spine to ROM
Tot
;ROM
Tot
: Total trunk ROM; RPA: Relative phase
angle; RPA
Max
: Extreme values of the RPA curve; RPA
Mean
: Mean value of the
RPA curve; RPA
Std
: Standard deviation value of the RPA curve.
Competing interests
The authors declare that they have no competing interests.
Authorscontributions
CL participated to the conception and design of the study, to the
supervision of the data acquisition, data processing and statistical analyses
and drafted the first version of the manuscript. JMC participated to the
conception and testing of the laboratory measurement protocol, recruited
the participants, collected all the data, carried out the statistical analyses and
revised the manuscript. RP participated to the conception and design of the
study and contributed heavily to the intellectual content of the manuscript.
HM performed the data processing, participated to the statistical analyses
and revised the manuscript. All authors have read and approved the final
manuscript.
Acknowledgements
This research project was funded by the Occupational Health and Safety
Research Institute Robert-Sauvé (IRSST) of Quebec (Canada). Jean-Maxime
Caron was supported (summer bursary) by the Quebec Rehabilitation
Research Network (REPAR). Special thanks go to Marilee Nugent, Daniel
Marineau and Michel Goyette for their technical assistance.
Author details
1
Occupational Safety and Health Research Institute Robert-Sauvé (IRSST), 505,
boul. De Maisonneuve Ouest, Montreal, Quebec H3A 3C2, Canada.
2
School of
Physiotherapy and Occupational Therapy, McGill University, Montreal,
Quebec J1K 2R1, Canada.
3
Centre for Interdisciplinary Research in
Rehabilitation of Greater Montreal (CRIR), Montreal, Canada.
Received: 14 February 2014 Accepted: 11 September 2014
Published: 19 September 2014
References
1. van Duijvenbode IC, Jellema P, van Poppel MN, van Tulder MW: Lumbar
supports for prevention and treatment of low back pain. Cochrane
Database Syst Rev 2008, CD001823.
2. Verbeek JH, Martimo KP, Karppinen J, Kuijer PP, Viikari-Juntura E, Takala EP:
Manual material handling advice and assistive devices for preventing
and treating back pain in workers. Cochrane Database Syst Rev 2011,
6:CD005958.
3. Meyer JP: Lombalgie et ceinture lombaire. Dossier médico-technique 2000.
no 34, 4
e
trimestre, 349-362.
4. van Poppel MNM, De Looze MP, Koes BW, Smid T, Bouter LM: Mechanisms
of action of lumbar supports. A systematic review. Spine 2000,
25:21032113.
5. Panjabi MM: The stabilizing system of the spine. Part I. Function,
dysfunction, adaptation, and enhancement. J Spinal Disord 1992,
5:383389.
6. Panjabi MM: A hypothesis of chronic back pain: ligament subfailure
injuries lead to muscle control dysfunction. Eur Spine J 2006, 15:668676.
7. Panjabi MM: Clinical spinal instability and low back pain. J Electromyogr
Kinesiol 2003, 13:371379.
8. Preuss R, Fung J: Can acute low back pain result from segmental spinal
buckling during sub-maximal activities? A review of the current
literature. Man Ther 2005, 10:1420.
9. Nimbarte AD, Aghazadeh F, HARVEY CM: Effect of back belt on inter-joint
coordination and postural index. Occup Ergon 2005, 5:219233.
10. McGill SM, Kippers V: Transfer of loads between lumbar tissues during
flexion-relaxation phenomenon. Spine 1994, 19:21902196.
11. Potvin JR, McGill SM, Norman RW: Trunk muscle and lumbar ligament
contributions to dynamic lifts with varying degrees of trunk flexion.
Spine 1991, 16:10991107.
12. Katsuhirra J, Sasaki H, Asahara S, Ikegami T, Ishihara H, Kikuchi T, Hirai Y,
Yamasaki Y, Wada T, Maruyama H: Comparison of low back joint moment
using a dynamic 3D biomechanical model in different transferring tasks
wearing low back belt. Gait Posture 2008, 28:258264.
13. McGorry RW, Hsiang SM: The effect of industrial back belts and breathing
technique on trunk and pelvic coordination during a lifting task. Spine
(Phila Pa 1976) 1999, 24:11241130.
14. Woodhouse ML, Mccoy RW, Redondo DR, Shall LM: Effects of back support
on intra-abdominal pressure and lumbar kinetics during heavy lifting.
Hum Factors 1995, 37:582590.
15. Hoffman SL, Johnson MB, Zou D, Van Dillen LR: Differences in end-
range lumbar flexion during slumped sitting and forward bending
between low back pain subgroups and genders. Man Ther 2012,
17:157163.
16. McGregor AH, McCarthy D, Hughes SP: Motion characteristics of the
lumbar spine in the normal population. Spine 1995, 20:24212428.
17. Nelson-Wong E, Alex B, Csepe D, Lancaster D, Callaghan JP: Altered muscle
recruitment during extension from trunk flexion in low back pain
developers. Clin Biomech (Bristol, Avon) 2012, 27:994998.
18. Thomas S, Reading J, Shephard RJ: Revision of the Physical Activity
Readiness Questionnaire (PAR-Q). Can J Spt Sci 1992, 17:338345.
19. Cholewicki J, Lee AS, Peter RN, Morrisette DC: Comparison of trunk
stiffness provided by different design characteristics of lumbosacral
orthoses. Clin Biomech (Bristol, Avon) 2010, 25:110114.
20. Burgess-Limerick R, Abernethy B, Neal RJ: Relative phase quantifies
interjoint coordination. J Biomech 1993, 26:9194.
21. Scholz JP: Organizational principles for the coordination of lifting.
Hum Mov Sci 1993, 12:537576.
22. Lamb PF, Stockl M: On the use of continuous relative phase: review of
current approaches and outline for a new standard. Clin Biomech (Bristol,
Avon) 2014, 29:484493.
23. Van Albada SJ, Robinson PA: Transformation of arbitrary distributions to
the normal distribution with application to EEG test-retest reliability.
J Neurosci Methods 2007, 161:205211.
24. McGill SM, Seguin J, Bennett G: Passive stiffness of the lumbar torso in
flexion, extension, lateral bending, and axial rotation. Effect of belt
wearing and breath holding. Spine 1994, 19:696704.
25. Toosizadeh N, Bazrgari B, Hendershot B, Muslim K, Nussbaum MA, Madigan
ML: Disturbance and recovery of trunk mechanical and neuromuscular
behaviours following repetitive lifting: influences of flexion angle and lift
rate on creep-induced effects. Ergonomics 2013, 56:954963.
26. Muslim K, Bazrgari B, Hendershot B, Toosizadeh N, Nussbaum MA, Madigan
ML: Disturbance and recovery of trunk mechanical and neuromuscular
behaviors following repeated static trunk flexion: influences of
duration and duty cycle on creep-induced effects. Appl Ergon 2013,
44:643651.
27. Bazrgari B, Hendershot B, Muslim K, Toosizadeh N, Nussbaum MA, Madigan
ML: Disturbance and recovery of trunk mechanical and neuromuscular
behaviours following prolonged trunk flexion: influences of duration and
external load on creep-induced effects. Ergonomics 2011, 54:10431052.
28. Hendershot B, Bazrgari B, Muslim K, Toosizadeh N, Nussbaum MA, Madigan
ML: Disturbance and recovery of trunk stiffness and reflexive muscle
responses following prolonged trunk flexion: influences of flexion angle
and duration. Clin Biomech (Bristol, Avon) 2011, 26:250256.
29. Hendershot BD, Toosizadeh N, Muslim K, Madigan ML, Nussbaum MA:
Evidence for an exposure-response relationship between trunk flexion
and impairments in trunk postural control. J Biomech 2013, 46:25542557.
30. Solomonow M: Neuromuscular manifestations of viscoelastic tissue
degradation following high and low risk repetitive lumbar flexion.
J Electromyogr Kinesiol 2012, 22:155175.
31. Caldwell JS, McNair PJ, Williams M: The effects of repetitive motion on
lumbar flexion and erector spinae muscle activity in rowers. Clin Biomech
(Bristol, Avon) 2003, 18:704711.
32. Paquet N, Malouin F, Richards CL: Hip-spine movement interaction and
muscle activation patterns during sagittal trunk movements in low back
pain patients. Spine 1994, 19:596603.
Larivière et al. BMC Musculoskeletal Disorders 2014, 15:307 Page 12 of 13
http://www.biomedcentral.com/1471-2474/15/307
33. Esola MA, McClure PW, Fitzgerald GK, Siegler S: Analysis of lumbar spine
and hip motion during forward bending in subjects with and without a
history of low back pain. Spine 1996, 21:7178.
34. Pal P, Milosavljevic S, Sole G, Johnson G: Hip and lumbar continuous
motion characteristics during flexion and return in young healthy males.
Eur Spine J 2007, 16:741747.
35. van Wingerden JP, Vleeming A, Ronchetti I: Differences in standing and
forward bending in women with chronic low back or pelvic girdle pain:
indications for physical compensation strategies. Spine (Phila Pa 1976)
2008, 33:E334E341.
36. Hogan N: The mechanics of multi-joint posture and movement control.
Biol Cybern 1985, 52:315331.
37. Madeleine P: On functional motor adaptations: from the quantification of
motor strategies to the prevention of musculoskeletal disorders in the
neck-shoulder region. Acta Physiol (Oxf ) 2010, 199(Suppl 679):146.
38. Srinivasan D, Mathiassen SE: Motor variability in occupational health and
performance. Clin Biomech (Bristol, Avon) 2012, 27:979993.
39. Cote JN, Hoeger Bement MK: Update on the relation between pain
and movement: consequences for clinical practice. Clin J Pain 2010,
26:754762.
40. Hodges PW, Tucker K: Moving differently in pain: a new theory to explain
the adaptation to pain. Pain 2011, 152:S90S98.
41. Calmels P, Queneau P, Hamonet C, Le Pen C, Maurel F, Lerouvreur C,
Thoumie P: Effectiveness of a lumbar belt in subacute low back pain: an
open, multicentric, and randomized clinical study. Spine (Phila Pa 1976)
2009, 34:215220.
42. Roelofs PD, Bierma-Zeinstra SM, van Poppel MN, Jellema P, Willemsen SP,
van Tulder MW, van Mechelen W, Koes BW: Lumbar supports to prevent
recurrent low back pain among home care workers: a randomized trial.
Ann Intern Med 2007, 147:685692.
43. Cholewicki J, Shah KR, McGill KC: The effects of a 3-week use of lumbosacral
orthoses on proprioception in the lumbar spine. J Orthop Sports Phys Ther
2006, 36:225231.
44. Cholewicki J, McGill KC, Shah KR, Lee AS: The effects of a three-week use
of lumbosacral orthoses on trunk muscle activity and on the muscular
response to trunk perturbations. BMC Musculoskelet Disord 2010, 11:154.
45. McGill SM: Should industrial workers wear abdominal belts? Prescription
based on the recent literature. Int J Ind Ergon 1999, 23:633636.
46. Burton AK, Waddell G, Tillotson KM, Summerton N: Information and advice
to patients with back pain can have a positive effect. A randomized
controlled trial of a novel educational booklet in primary care. Spine
(Phila Pa 1976) 1999, 24:24842491.
doi:10.1186/1471-2474-15-307
Cite this article as: Larivière et al.:The effect of different lumbar belt
designs on the lumbopelvic rhythm in healthy subjects. BMC
Musculoskeletal Disorders 2014 15:307.
Submit your next manuscript to BioMed Central
and take full advantage of:
Convenient online submission
Thorough peer review
No space constraints or color figure charges
Immediate publication on acceptance
Inclusion in PubMed, CAS, Scopus and Google Scholar
Research which is freely available for redistribution
Submit your manuscript at
www.biomedcentral.com/submit
Larivière et al. BMC Musculoskeletal Disorders 2014, 15:307 Page 13 of 13
http://www.biomedcentral.com/1471-2474/15/307
... To explain the clinical benefits of lumbar belts, psychological, neuromuscular, and biomechanical mechanisms have been proposed, but these remain unproven [23]. Psychological benefits may be related to the perception of mechanical support generated by the lumbar belt, and neuromuscular benefits may include mechanisms that affect lumbar stability, such as lumbar proprioception, trunk muscle feedforward, and reflex activity [24,25]. ...
... The post hoc analysis indicated no difference between the lumbar belt-wearing conditions in the healthy adult group, but there was a decrease in the time taken in the patients with nonspecific low back pain in the conditions in which the lumbar belt was worn (conditions 2 and 3) compared with the condition in which the lumbar belt was not worn (condition 1). The lumbar belt had effects such as improving proprioception [49], increasing mechanical stiffness [23], and relieving pain [30]. Although the mechanical stiffness increased in both the nonspecific low back pain group and the healthy adult group, wearing a lumbar belt in this study reduced the required time only in the group with nonspecific low back pain. ...
... In the control group, the angle of the anterior pelvic tilt was greater in the conditions in which the lumbar belt was worn (conditions 2 and 3) than in the condition in which the lumbar belt was not worn (condition 1). In a previous study analyzing the effect of the lumbar belt on the range of motion of the lumbar spine and the lumbar-pelvic rhythm, it was reported that wearing a lumbar belt restricts the range of motion of the lumbar spine and also changes the lumbar-pelvic rhythm [23]. In this study, the lumbar belt was worn so that the lower edge of the lumbar belt covered the ASIS and the iliac crest to include the pelvis, which may have had a stiffening effect on the lumbar belt, as in the previous study on the spine-pelvic connection. ...
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.
... Back orthoses (a.k.a. back belts) are commonly used by individuals with a recent back injury, and have been shown to correlate with short-term reduction in LBP symptoms (Larivière et al., 2014); however, the purpose of these devices is to reduce lumbar range of motion in attempt to prevent injury from overuse. Therefore, back orthoses are not suitable for correction of the above noted abnormalities in LPC of patients with LBP that have been widely reported to be associated with a reduced lumbar motion. ...
... Similar to the hip orthosis investigated in this study, back belts can alter LPC but primarily by restricting the lumbar motion. Back orthoses have been reported to be capable of reducing lumbar motion between 24 and 64% (Cholewicki et al., 2003;Jegede et al., 2011;Larivière et al., 2014). The hip orthosis in our study was similarly found capable of decreasing pelvic rotation, a decrease that ranged between 19% (among patients) and 34% (among asymptomatic individuals) and appeared to depend on the magnitude of unrestricted pelvic rotation. ...
... The hip orthosis in our study was similarly found capable of decreasing pelvic rotation, a decrease that ranged between 19% (among patients) and 34% (among asymptomatic individuals) and appeared to depend on the magnitude of unrestricted pelvic rotation. Back orthoses were not found to affect pelvic rotation, but decreased thoracic rotation by 6 to 13 • (Larivière et al., 2014) and 42 to 47% (Cholewicki et al., 2003). ...
Article
Full-text available
Individuals with low back pain demonstrate an abnormal lumbo-pelvic coordination compared to back-healthy individuals. This abnormal coordination presents itself as a reduction in lumbar contributions and an increase in pelvic rotations during a trunk forward bending and backward return task. This study investigated the ability of a hip orthosis in correcting such an abnormal lumbo-pelvic coordination by restricting pelvic rotation and, hence increasing lumbar contributions. The effects of the hip orthosis on the lumbo-pelvic coordination were investigated in 20 low back pain patients and 20 asymptomatic controls. The orthosis reduced pelvic rotation by 12.7° and increased lumbar contributions by 11%. Contrary to our expectation, orthosis-induced changes in lumbo-pelvic coordination were smaller in patients; most likely because our relatively young patient group had smaller unrestricted pelvic rotations compared to asymptomatic individuals. Considering the observed capability of a hip orthosis in causing the expected changes in lumbo-pelvic coordination when there is a relatively large pelvic contribution to trunk motion, application of a hip orthosis may provide a promising method of correcting abnormal lumbo-pelvic coordination, particularly among patients who demonstrate larger pelvic rotation, that warrants further investigation.
... Experimentally, it has been seen that patients with LBP display increased lumbar stiffness (Hodges et al., 2009;Miller et al., 2013), which is likely due to different muscle activation strategies to enhance lumbar stability (van Dieën et al., 2003). LBs have been shown to increase lumbar stiffness as well (Cholewicki et al., 1999b;Ivancic et al., 2002;Lavender et al., 2000;McGill et al., 1994), though recent studies show conflicting results with regard to the efficiency of different flexible LBs (extensible vs non-extensible) (Cholewicki et al., 2010;Larivière et al., 2014). ...
... No additional dorsal or ventral panels were used. The tension on each belt was set such that the belt applied a pressure of 60 mmHg, as measured by a force sensing resistor (Interlink Electronics FSR400, Westlake Village, CA, USA) (Larivière et al., 2014). This pressure was selected as it is similar to the pressure subjects naturally use, and was feasible to achieve using both belts. ...
... Subjects were instructed to maintain a constant lumbar (L5/S1) extensor torque of 10 Nm for women or 15 Nm for men (equivalent to approximately 5% of an average maximal voluntary contraction (Lariviere et al., 2002;Lariviere et al., 2006;Lariviere et al., 2009;Larivière et al., 2014)) while random perturbations were applied. The perturbation consisted of a pseudo-random binary sequence with a switching rate of 150 ms and an amplitude of 4 mm. ...
Article
Background: Lumbar belts have been shown to increase lumbar stiffness, but it is unclear if this is associated with trunk muscle co-contraction, which would increase the compression on the spine. It has been hypothesized that lumbar belts increase lumbar stiffness by increasing intra-abdominal pressure, which would increase spinal stability without increasing the compressive load on the spine. Methods: Trunk muscle activity and lumbar stiffness and damping were measured in healthy and low-back pain subjects during three conditions: no lumbar belt; wearing an extensible lumbar belt; wearing a non-extensible lumbar belt. Muscle activity was measured while subjects performed controlled forward and backward 20° trunk sways. Lumbar stiffness and damping were measured by applying random continuous perturbation to the chest. Findings: External oblique activity was decreased when wearing either lumbar belt during all phases of movement, while rectus abdominis and iliocostalis activity were decreased during the phase of movement where the muscles were maximally active while wearing either belt. Trunk stiffness was greatly increased by wearing either belt. There were no consistent differences in either lumbar stiffness or muscle activity between the two belts. Wearing a lumbar belt had little to no effect on damping. There were no group differences in any of the measures between healthy and low-back pain populations. Interpretation: The findings are consistent with the hypothesis that lumbar belts can increase spinal stability by increasing intra-abdominal pressure, without any increase in the compressive load on the spine. The findings can also be generalized, for the first time, to subjects with low-back pain.
... Wearing a LB increases the pressure exerted on the skin, which provides additional afferent sensory information to the central nervous system via mechanical receptors, which may ultimately improve the proprioceptive sense of the lumbar region [23]. In addition, wearing a LB increases mechanical rigidity, which may decrease the structural load of the spine by limiting lumbar movement [24]. For example, LB can decrease the stress in viscoelastic structures of the back and the compressive loads on the lumbar spine [25,26]. ...
... The maximum anterior pelvic tilt angle was increased only in the control group in Conditions 2 and 3 (with LB) compared with Condition 1 (without LB), with no significant difference between the two groups. In a previous study that analyzed the effect of a LB on the lumbar ROM and lumbopelvic rhythm, it was reported that wearing LB limits the lumbar ROM and alters the lumbopelvic rhythm [24]. In this study, a LB was worn to cover the pelvis such that the lower edge of the LB covered the ASIS and lilac crest. ...
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.
... A recent systematic review (Azadinia et al., 2017) and a meta-analysis (Takasaki and Miki, 2017), however, concluded that there is no long term detrimental effects on muscle mass and strength from wearing an LSO. Our own laboratory findings have substantiated strong mechanistic effects of LSOs on lumbar spine stiffness (Larivière et al., 2015b, which likely explain why LSO decrease lumbar range of motion (ROM) during maximal trunk flexion-extension motions (Larivière et al., 2014, Shahvarpour et al., 2018 and during lifting activities (Shahvarpour et al., 2018). Trunk muscle activity, however, was only slightly reduced (1-2% of maximal EMG) , as substantiated in other studies (Cholewicki et al., 2007, Reeves et al., 2006. ...
... Contrary to our hypothesis, the neLSO did not impact APAs more than the eLSO. This is in line with our previous studies on how our two LSO types affect lumbar stiffness (Larivière, Ludvig, 2015b;Ludvig et al., 2019), lumbar motion restriction (Larivière et al., 2014;Shahvarpour et al., 2018), trunk muscle activity , trunk postural control (Shahvarpour et al., 2019) and proprioception (Boucher et al., 2017). ...
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.
... Hence, wearing an LSO may be beneficial in such patients [18]. 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]. ...
... These results were not generalized still for low back pain people. We did not use a Force Sensing Resistor (FSR) or FSR pressure sensor to standardize the tension of the LSO as Larivière et al. [42] did. Instead, we used a clinically accepted approach based on the maximum tolerable tension for the LSO (i.e. the highest applicable belt tautness without perceiving pelvic belt-related pain or discomfort) [27][28][29][30]43]. ...
Article
Background: Lumbosacral orthosis (LSO) and/or the isolated contraction of the transversus abdominis muscle by the abdominal drawing-in maneuver (ADIM) can increase lumbar stiffness, consequently influencing postural control. The purpose of this study was to compare the effects of LSO and ADIM on postural control during two balance tasks and determine their reliability. Methods: Twenty participants (50% men) randomly performed three experimental conditions: 1) without lumbar stabilization, 2) with LSO), and 3) with ADIM. Each experimental condition was tested in two postural tasks: semi-tandem and one-legged stance on a force platform for 30 seconds, while the Center of pressure postural (COP) parameters were computed. Results: The two methods of lumbar stabilization were comparable and did not significantly reduce the COP values across time, even though a few individuals presented a change in their COP data above the levels of measurement errors. The reliability of these measurements was generally acceptable and sometimes excellent ( ≥ 0.90 and ≤10% error measurement). Conclusions: Both LSO and isolated contraction of the transversus abdominis muscle by ADIM do not change postural control in one-legged stance and in semi-tandem tasks. These results have implications for use or not these methods for postural control on a rehabilitation perspective.
... Two methods of measuring motion of the spine are employed in the literature and subsequently can be applied to test the effectiveness of back braces: biomechanical models (Ivancic et al. 2002), and through electromyography (EMG) data from live healthy subjects in brace conditions (Cholewicki et al. 2007) (Cholewicki et al. 2010) (Lariviere et al. 2014). Cholewicki et al. (Cholewicki et al. 1995) conducted experiments on subjects in the upright standing posture position and performed near maximal ramp contraction, which is the body moving from rest to the maximum angle it can bend in flexion, extension and lateral bending, in each case checking the extent of muscle recruitment of torso muscles for spine stability. ...
Article
The spine or ‘back’ has many functions including supporting our body frame whilst facilitating movement, protecting the spinal cord and nerves and acting as a shock absorber. In certain instances, individuals may develop conditions that not only cause back pain but also may require additional support for the spine. Common movements such as twisting, standing and bending motions could exacerbate these conditions and intensify this pain. Back braces can be used in certain instances to constrain such motion as part of an individual’s therapy and have existed as both medical and retail products for a number of decades. Arguably, back brace designs have lacked the innovation expected in this time. Existing designs are often found to be heavy, overly rigid, indiscrete and largely uncomfortable. In order to facilitate the development of new designs of back braces capable of being optimised to constrain particular motions for specific therapies, a numerical and experimental design strategy has been devised, tested and proven for the first time. The strategy makes use of an experimental test rig in conjunction with finite element analysis simulations to investigate and quantify the effects of back braces on flexion, extension, lateral bending and torsional motions as experienced by the human trunk. This paper describes this strategy and demonstrates its effectiveness through the proposal and comparison of two novel back brace designs.
Article
Objective The purpose of this study was to assess the protective influence of the Serola Sacroiliac Belt on pain and functional impairment in individuals with low back pain (LBP) during 5 days of strenuous manual labor. Methods Thirty-three participants (mean ± standard deviation: age, 43.2 ± 11.4 years; height, 1.74 ± 0.11 m; body mass index, 88.3 ± 16.7 kg) with LBP were randomized to either condition A (wearing the Serola Sacroiliac Belt during a 10-minute daily repeated strenuous lifting task) during week 1 or condition B (not wearing a Serola Sacroiliac Belt during the same lifting task) in week 2 or vice versa. All 33 participants completed 1 week under condition A and 1 week under condition B for comparison. At the beginning and end of each week, the following dependent variables were measured: lumbar spine pain on a 0 to 10 Numeric Rating Scale (NRS), spine and thigh discomfort on a Nordic Musculoskeletal Questionnaire, and completion of a toe-touch surface electromyography flexion relaxation phenomenon test. Results During the week that participants used the Serola Sacroiliac Belt, spine pain increased 0.2 compared with 0.9 on the NRS for those who did not use the belt. No statistically significant difference was observed for Nordic Musculoskeletal Questionnaire data or the flexion relaxation phenomenon test in this study. Conclusion The findings of this preliminary study suggest participants using the Serola Sacroiliac Belt while performing a daily repeated lifting task had less progression of their LBP. However, this protective value did not meet the recommended NRS for minimally clinically important difference, and there was no effect on functional impairment.
Article
Nonspecific back pain is a common complaint, especially among older people. Traditionally, nonspecific back pain has been associated with heavy physical activities. However, static activities such as prolonged sitting and standing are contributing factors to nonspecific lumbar pain as well. Lumbar orthoses, such as belts, have been used for heavy physical activity to alleviate or even prevent back pain; however, studies have been inconclusive as to their effectiveness. Furthermore, the use of lumbar orthosis for prolonged sitting and standing is questionable. This case study and review examines the general effectiveness of lumbar orthosis for a variety of activities, including prolonged standing and sitting. The findings provide implications for orthopaedic nurses in occupational settings.
Article
Full-text available
Background: In this paper we review applications of continuous relative phase and commonly reported methods for calculating the phase angle. Signals with known properties as well as empirical data were used to compare methods for calculating the phase angle. Findings: Our results suggest that the most valid, robust and intuitive results are obtained from the following steps: 1) centering the amplitude of the original signals around zero, 2) creating analytic signals from the original signals using the Hilbert transform, 3) calculating the phase angle using the analytic signal and 4) calculating the continuous relative phase. Interpretations: The resulting continuous relative phase values are free of frequency artifacts, a problem associated with most normalization techniques, and the interpretation remains intuitive. We propose these methods for future research using continuous relative phase in studies and analyses of human movement coordination.
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
Study Design. A double-blind, randomized controlled trial of a novel educational booklet compared with a traditional booklet for patients seeking treatment in primary care for acute or recurrent low back pain. Objective. To test the impact of a novel educational booklet on patients’ beliefs about back pain and functional outcome. Summary of Background Data. The information and advice that health professionals give to patients may be important in health care intervention, but there is little scientific evidence of their effectiveness. A novel patient educational booklet, The Back Book, has been developed to provide evidence-based information and advice consistent with current clinical guidelines. Methods. One hundred sixty-two patients were given either the experimental booklet or a traditional booklet. The main outcomes studied were fear-avoidance beliefs about physical activity, beliefs about the inevitable consequences of back trouble, the Roland Disability Questionnaire, and visual analogue pain scales. Postal follow-up response at 1 year after initial treatment was 78%. Results. Patients receiving the experimental booklet showed a statistically significant greater early improvement in beliefs which was maintained at 1 year. A greater proportion of patients with an initially high fear-avoidance beliefs score who received the experimental booklet had clinically important improvement in fear-avoidance beliefs about physical activity at 2 weeks, followed by a clinically important improvement in the Roland Disability Questionnaire score at 3 months. There was no effect on pain. Conclusion. This trial shows that carefully selected and presented information and advice about back pain can have a positive effect on patients’ beliefs and clinical outcomes, and suggests that a study of clinically important effects in individual patients may provide further insights into the management of low back pain.
Article
Study Design. A systematic review and meta-analysis of studies on the putative mechanisms of action of lumbar supports in lifting activities. Objective. To summarize the evidence bearing on the putative mechanisms of action of lumber 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 lumber supports. Available studies on these putative mechanism of action of lumber supports have reported contradictory results. Methods. A literature search for controlled studies on mechanisms of action of lumber supports was conducted. The methodologic quality of the studies was assessed. The evidence for the two proposed mechanism of action of lumber supports was determined in meta-analyses. Results. Thirty-three studies were elected 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). Conclusion. 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 maya be most effective. Studies of trunk motion at the workplace or during specified lifting tasks would be especially useful in this regard.
Article
Unlabelled: Repetitive lifting is associated with an increased risk of occupational low back disorders, yet potential adverse effects of such exposure on trunk mechanical and neuromuscular behaviours were not well described. Here, 12 participants, gender balanced, completed 40 min of repetitive lifting in all combinations of three flexion angles (33, 66, and 100% of each participant's full flexion angle) and two lift rates (2 and 4 lifts/min). Trunk behaviours were obtained pre- and post-exposure and during recovery using sudden perturbations. Intrinsic trunk stiffness and reflexive responses were compromised after lifting exposures, with larger decreases in stiffness and reflexive force caused by larger flexion angles, which also delayed reflexive responses. Consistent effects of lift rate were not found. Except for reflex delay no measures returned to pre-exposure values after 20 min of recovery. Simultaneous changes in both trunk stiffness and neuromuscular behaviours may impose an increased risk of trunk instability and low back injury. Practitioner summary: An elevated risk of low back disorders is attributed to repetitive lifting. Here, the effects of flexion angle and lift rate on trunk mechanical and neuromuscular behaviours were investigated. Increasing flexion angle had adverse effects on these outcomes, although lift rate had inconsistent effects and recovery time was more than 20 min.
Article
Occupations involving frequent trunk flexion are associated with a higher incidence of low back pain. To investigate the effects of repeated static flexion on trunk behaviors, 12 participants completed six combinations of three static flexion durations (1, 2, and 4 min), and two flexion duty cycles (33% and 50%). Trunk mechanical and neuromuscular behaviors were obtained pre- and post-exposure and during recovery using sudden perturbations. A longer duration of static flexion and a higher duty cycle increased the magnitude of decrements in intrinsic stiffness. Increasing duty cycle caused larger decreases in reflexive muscle responses, and females had substantially larger decreases in reflexive responses following exposure. Patterns of recovery for intrinsic trunk stiffness and reflexive responses were consistent across conditions and genders, and none of these measures returned to pre-exposure values after 20 min of recovery. Reflexive responses may not provide a compensatory mechanism to offset decreases in intrinsic trunk stiffness following repetitive static trunk flexion. A prolonged recovery duration may lead to trunk instability and a higher risk of low back injury.
Article
Near-continuous measures of inter-joint coordination and the smoothness and variability of individual joint motions were studied to explore principles underlying the coordination of squat-lifting. Measures of relative phasing between joint movements changed continuously as the lifted load was increased, despite subjects' attempts to maintain the same pattern of coordination for all lifts. Differences were found between the lifting and lowering phases of the task. The stability of coordination among lower extremity joints was found to decrease continuously with changes in the relative phase of these joints when lifting heavier loads. However, knee-lumbar spine and knee-shoulder coordination showed minimal or no change in stability with load changes.Inter-trial variability and jerkiness of individual joint excursions were greater than similar measures of the hand/crate trajectory. The results support movement planning in terms of the end-effector spatial trajectory rather than individual joint trajectories.