ArticlePDF Available

Effects of an abdominal belt on trunk muscle activity during treadmill walking

Authors:

Abstract and Figures

Studies on the effect of abdominal belts on trunk muscles show contradictory outcomes. Therefore, this study focused on investigating the fundamental effects of a lumbar support on trunk muscles of healthy subjects (22 women, 20 men). Surface electromyography was used to measure the muscle activity of 6 trunk muscles on both sides while subjects were walking on a treadmill with speeds between 2 and 6 km/h. Measurements were initially taken without a belt (U1), followed by wearing the abdominal belt (U2) and additionally after three hours of wearing time (U3), with the belt still fitted. Wearing the belt did not have a generalizable effect on all trunk muscles. Instead, muscle-specific reactions were observed: while mean muscle activity in the oblique abdominal muscles generally decreased independent of the wearing time (-40% to -7%), for the back muscles (multifidus muscle (lumbar part, MF) and erector spinae muscle (longissimus, LO)) effects were found only directly after attaching the belt at median and high walking speeds (MF: -10% to -5%, LO: -11% to -6%). After three hours of wearing time values increased towards the original values with effects being unsystematic and non-significant. The mean amplitude values of the ilicostalis muscle generally increased independent of the wearing time, a significant increase could be shown for women at U3 at low walking speeds (10% to 11%). For the minimum to maximum variation in amplitude values calculated across the time-standardized stride, wearing the abdominal belt resulted in higher values mostly in the back muscles (9% to 44%) and women’s internal oblique muscle (13% to 22%), i.e. an increase in phasicity and therefore the precondition for improved supply of nutrients to the muscles. Differences in trunk muscle activity in healthy subjects evoked by wearing the belt are detectable, but are subject to localization. Therefore, no generalizable effect of abdominal belts on trunk muscle activation can be assumed.
Content may be subject to copyright.
Research Article
Biomechanics
Open Library
Cite this article: Hubner A., Niemeyer F, Schilling K and Anders C. (2017).
Effects of an abdominal belt on trunk muscle activity during treadmill walking,
Biomech Open Lib, 1(1): 7-15
Science Fair Open Library | Inspiring the World of Science 2017 | Volume 1 | Issue 1
Eects of an abdominal belt on trunk muscle activity during
treadmill walking
Agnes Hubner1, Friederike Niemeyer, Kirsti Schilling and Christoph Anders*
1-Clinic for Trauma, Hand and Reconstructive Surgery, Division of Motor Research, Pathophysiology and Biomechanics, Jenna Uni-
versity Hospital
*Corresponding Author: Christoph Anders, Clinic for Trauma, Hand and Reconstructive Surgery, Division of Motor Research,
Pathophysiology and Biomechanics, Jenna University Hospital, 07740 Jena, Germany, Phone: 0049 3641 934 142, Fax: 0049 3641 934
091, Email: christoph.anders@med.uni-jena.de
ABSTRACT: Studies on the effect of abdominal belts on trunk muscles show contradictory outcomes. erefore, this study focused
on investigating the fundamental effects of a lumbar support on trunk muscles of healthy subjects (22 women, 20 men). Surface elec-
tromyography was used to measure the muscle activity of 6 trunk muscles on both sides while subjects were walking on a treadmill
with speeds between 2 and 6 km/h. Measurements were initially taken without a belt (U1), followed by wearing the abdominal belt
(U2) and additionally after three hours of wearing time (U3), with the belt still fitted. Wearing the belt did not have a generalizable
effect on all trunk muscles. Instead, muscle-specific reactions were observed: while mean muscle activity in the oblique abdominal
muscles generally decreased independent of the wearing time (-40% to -7%), for the back muscles (multifidus muscle (lumbar part,
MF) and erector spinae muscle (longissimus, LO)) effects were found only directly after attaching the belt at median and high walk-
ing speeds (MF: -10% to -5%, LO: -11% to -6%). After three hours of wearing time values increased towards the original values with
effects being unsystematic and non-significant. e mean amplitude values of the ilicostalis muscle generally increased independent
of the wearing time, a significant increase could be shown for women at U3 at low walking speeds (10% to 11%). For the minimum to
maximum variation in amplitude values calculated across the time-standardized stride, wearing the abdominal belt resulted in higher
values mostly in the back muscles (9% to 44%) and women’s internal oblique muscle (13% to 22%), i.e. an increase in phasicity and
therefore the precondition for improved supply of nutrients to the muscles. Differences in trunk muscle activity in healthy subjects
evoked by wearing the belt are detectable, but are subject to localization. erefore, no generalizable effect of abdominal belts on trunk
muscle activation can be assumed.
Running Title: Effects of abdominal belts
INTRODUCTION
Keywords: Surface EMG, lumbar support, healthy, human, orthotic device, abdominal muscle physiology
Abdominal belts are primarily used to prevent [1,2] or to treat
[3,4] back pain. e large number of studies investigating abdomi-
nal belts [5,6] might suggest that the potential for investigations
in this area has already been exhausted. However, many of these
studies in fact looked at the use of trunk orthoses [7,8]. Studies
evaluating the effects of abdominal belts must be considered sepa-
rately from those on trunk orthoses, as the latter limit trunk mo-
bility and promote stiffness to a considerably greater degree than
abdominal belts. Of course, abdominal belts also limit mobility to
a certain degree, but they do not contain any fixed elements that
prevent movements. While trunk orthoses are primarily used as
mechanical supports for fixing (and reclination) of the spinal col-
umn, abdominal belts are mainly applied to support the muscles
and are thereby intended to contribute to increased stability of the
vertebral column (VC).
e various investigation approaches for abdominal belts include
measuring the intra-abdominal pressure (IAP) [9] and intramus-
cular pressure of back muscles [10]. Ultrasound [11], CT [12] and
MRI examinations [13] were applied as well, the latter in order
to identify changes in the cross-sectional area of trunk muscles
that might have occurred as a result of wearing abdominal belts.
Model-based approaches were also applied in order to analyze the
effect of lumbar supports on muscle-generated active lumbar spine
stability [14].
For quite some time, Surface Electromyography (SEMG) has been
increasingly used to examine the effects of abdominal belts on the
activation characteristics of trunk muscles [15,16]. A meta-analy-
sis by Jellema et al. [6] described contradictory outcomes related to
the effects of abdominal belts, thus illustrating the ongoing need
for research. It was shown that several lumbar supports limit the
trunk range of motion [5,17] and increase the passive trunk stiff-
ness by supporting the generation of the IAP [12,15,18], result-
ing in increased spine stability. However, any belt-mediated IAP
increase that has been proven to date is limited to highly strenuous
exercises [9,10] Also, there is conflicting data relating to the influ-
ence of abdominal belts on SEMG activity of trunk muscles, i.e. on
muscle strength and endurance. is was convincingly summarized
Page 8
Cite this article: HubnerA., Niemeyer F, Schilling K and Anders C. (2017). Effects of an abdominal belt on trunk muscle activity during treadmill walking, Biomech Open
Lib, 1(1): 7-15
Science Fair Open Library | Inspiring the World of Science 2017 | Volume 1 | Issue 1
in the meta-analysis by van Poppel et al. [5]. Depending on the
type of belt and the activity being carried out, the results varied
between an increase, decrease and undetectable changes in muscu-
lar activity of trunk muscles [19,20]. While the results of several
studies did not show any major differences in trunk muscle activa-
tion characteristics while wearing an abdominal belt [14,21,22],
another study investigating the effect of a weightlifting belt [23]
suggested a weakening of the muscles of healthy subjects during
long-term use and warned of an increased risk of injury to the
VC that manifested as the study’s participants took more days off
from work after they stopped wearing the belt. ese contradictory
results may be attributed to different belt models or designs be-
ing studied [20], different monitoring parameters (pain, number of
sick days, etc.), differently biased test subjects, e.g. healthy subjects
[16], acute low back pain patients [24] or other clinical pictures
[25,26], and the quality of the studies with regard to compliance
[27].
Today, lumbar/abdominal belts are used in back pain treatment
[24] aiming on counteracting the problems in muscular strength
and coordination that frequently occur in patients with back pain
[28,29]. However, the physiological effect of lumbar supports on
trunk muscles has still not been conclusively investigated. ere-
fore the study aim was to systematically examine the influence of
lumbar belts on all superficial trunk muscles of the abdomen and
the lumbar region during locomotion (i.e. walking on a treadmill)
by considering influences on mean amplitude levels and their
variability during the stride. Furthermore, influences of gender,
physical activity levels (i.e. walking speed), and wearing time were
evaluated. At low intensity physical activities the invariable passive
effect of lumbar belts should have a strong concordant effect. We
would therefore hypothesize a general decrease in muscle activity
of all lumbar trunk muscles at slow to normal walking speeds
MATERIALS AND METHODS
Level of evidence / study design
In this study physiological effects of wearing lumbar support in
healthy subjects were investigated. e according level of evidence
equals 2b. e study is a repeated-measures design in healthy con-
trols.
Test subjects
e study was conducted on 42 healthy test subjects of both sexes
(22 women, age: 24 ± 7 years, 20 men, age: 28 ±7 years), recruited
via personal contacts from the Jena university campus (please see
supplementary Tab. 1 for anthropometric data). All subjects were
clinically investigated and interviewed about their medical history.
Anyone with a history of back problems or currently experienc-
ing back pain was excluded from the study. A positive vote was
obtained from the ethics committee of Jena University Hospital
(3793-06/13). e test subjects were fully informed about the
study and gave their written consent.
Experimental setup
Walking was tested on a treadmill (QUASARmed., HP Cosmos,
Germany). e test subjects had the opportunity to familiarize
themselves with the treadmill before every measurement. e mea-
surement was only begun once the test subject was able to sustain
a natural gait on the treadmill. Individual’s gait pattern was deter-
mined as “natural gait” if the locomotion pattern on the treadmill
conformed to regular walking on level ground by visual assessment
by the investigator as well as the subject’s personal feedback on
comfort. Every set of measurements always included at least 30
complete stride cycles [30] of every walking speed between 2 and
6 km/h in increments of 1 km/h. e order of walking speeds was
randomized once, separately for each subject. is order was re-
tained for subsequent measurement sets of the respective subject.
Randomization of walking speeds was used to avoid effects due to
ordered change of walking speeds. Each subject took part in three
sets of measurements: without the abdominal belt (U1), wearing
the abdominal belt (U2, directly after U1) and a repetition of U2
after three hours of wearing the belt (U3).
Subjects were equipped with a gender-specific version of the Lum-
boTrain® abdominal belt (Bauerfeind AG, Germany) in their indi-
vidual size to ensure comparable conditions across subjects (Fig. 1).
Page 9
Fig. 1: Front and rear view of a completely equipped female subject
with the standardized positions of the SEMG electrodes. ampli-
fiers and abdominal belt.
SEMG recording and processing
e muscular activity was measured via SEMG. Disposable
SEMG electrodes (Ag-AgCl electrodes, solid gel: H93SG, Co-
vidien, Germany) with a circular uptake area of 1.6 cm diameter
were used (interelectrode distance: 2.5 cm). e SEMG electrode
positions were always marked by the same, experienced researcher
and positioned according to the international standards [31,32].
Subject’s skin was shaved (if applicable) and abraded with abrasive
paste (Epicont, GE Medical Systems, Germany) prior to electrode
positioning. SEMG electrodes were kept in place throughout the
entire investigation to ensure invariable electrode positioning. e
signals were recorded using a standard bipolar montage (amplifier:
Biovision, Germany, gain: 1000, input impedance: 1200 GΩ, noise
Cite this article: HubnerA., Niemeyer F, Schilling K and Anders C. (2017). Effects of an abdominal belt on trunk muscle activity during treadmill walking, Biomech Open
Lib, 1(1): 7-15
Science Fair Open Library | Inspiring the World of Science 2017 | Volume 1 | Issue 1
level: <1 µV, CMRR > 120 dB, 10–700 Hz, 1st order RC filter;
measuring system: ToM, DeMeTec, Germany: A/D rate 2048/s,
anti-aliasing filter: 1024 Hz, resolution: 24 bit at ±5 V (0.6 µV/bit);
software; GJB, Germany).
SEMG was taken from rectus abdominis muscle (RA), obliquus
internus abdominis muscle (OI), obliquus externus abdominis
muscle (OE), multifidus muscle (lumbar part, MF) and erector
spinae muscle (longissimus, LO). ese muscles were chosen on
account of their contribution to trunk stability, in accordance with
the research question. Exact electrode positions are given in Table
1. e measurements were conducted symmetrically on both sides
of the body.
In addition, one pair of electrodes (plus the ground electrode) was
positioned along the heart axis in order to eliminate the QRS com-
plexes by recording the heart activity as this can show up as inter-
ference with the SEMG signals during data evaluation. Pressure
sensors (FS402, Interlink Electronics, USA) were fastened to the
heel regions of both shoes to detect individual steps.
All recorded data was evaluated in the same manner: elimination
of DC components, 35 Hz high pass and 400 Hz low pass filter,
and a 50 Hz notch filter. A template function was used to elimi-
nate the ECG artifacts [33]. Only complete strides that deviated
from the median time interval of all detected strides per speed by
10% or less were used for further calculation [34]. All valid strides
were time normalized to 100%, i.e. the time scale was converted
to “percent of cycle with a resolution of 0.5% equaling 201 values
[35]. ese time normalized amplitude curves were used to de-
termine a representative grand average curve for each stride and
further to calculate the mean amplitude and range values of all
strides for each test situation. e range represents the span be-
tween the minimum and maximum amplitude values normalized
to the mean, thus describing the signal variation independently of
the respective amplitude level. A repeated measurements ANOVA
was calculated separately for mean amplitudes and ranges. Relative
changes were calculated comparing U1 vs. U2 and U1 vs. U3 to ac-
count for inter-individual and situational variability in amplitude
levels and thus enabling a more precise assessment of the effect of
wearing the belt and effects due to walking speed. For the range,
these calculations were conducted directly with the range values
since they are already normalized.
Statistical analysis
A repeated measurements ANOVA was calculated using the with-
in-subjects factors side (2 levels), situation (3) and walking speed
(5), with sex serving as the between-subject factor. e differences
between all test situations were examined systematically using the
Wilcoxon test for paired samples, which was conducted individu-
ally for both sexes and for the walking speeds. Post-hoc tests were
also conducted (Bonferroni, p < 0.0167). All statistical tests were
calculated for both the mean amplitude values and the range.
Table 1: Investigated trunk muscles and respective recommended
electrode positions [31,32]
Muscle Electrode position and orientation
M. rectus abdominis
(RA)
4 cm lateral of navel, lower electrode at
navel level, vertical
M. obliquus internus
abdominis (OI)
Along horizontal line between both
ASIS's, distal electrode medial from
inguinal ligament
M. obliquus externus
abdominis (OE)
Upper electrode directly below most
inferior point of costal margin, on line
to opposite pubic tubercle
M. multifidus lumba-
lis (MF)
1 cm medial from line between PSIS's
and 1st palpable spinous process, lower
electrode at L4 level, parallel to line
M. erector spinae
(iliocostalis) (ICO)
Center between electrodes 1 cm medial
of line between PSIS and the most
inferior point of costal margin, L2 level
M. erector spinae
(longissimus) (LO)
Vertical, over palpable bulge of muscle
(approx. 3 cm lateral midline) caudal
electrode at L1 level
ASIS: anterior superior iliac spine. PSIS: posterior superior iliac spine.
RESULTS
1. ANOVA
1.1 Mean amplitude values
e ANOVA results showed significant differences between body
sides for ICO and LO (Table 2) with higher values occurring at
the right side. Sex-specific differences occurred for RA, OE (males
< females), and MF and LO (males > females) that for the men-
tioned abdominal muscles increased with walking speed (Table 2).
erefore, the detailed results will be given separately for each sex
and body side.
Situation irregularly influenced mean amplitude values for the
back muscles (see 2), for OI and OE amplitude values were sig-
nificantly lower when wearing the abdominal belt (U2, U3). To-
gether with walking speed amplitude values increased in all trunk
muscles. All data are quantitatively presented in Fig. 2 that enables
the interpretation of the ANOVA results.
1.2 Range
e range showed differences between body sides for ICO and
LO (Table 3) with lower values for the right side that increased
together with speed. Sex-specific effects occurred in RA, OI, and
MF with higher values for women for RA and MF. For the back
muscles range values were significantly higher when wearing the
abdominal belt (U2, U3). For RA range values at U3 were clearly
above those of U1 and U2 while for OE decreased range values
occurred, but only at U2. Together with walking speed range values
increased in all trunk muscles. All data are quantitatively presented
in Fig. 2.
Page 10
Cite this article: HubnerA., Niemeyer F, Schilling K and Anders C. (2017). Effects of an abdominal belt on trunk muscle activity during treadmill walking, Biomech Open
Lib, 1(1): 7-15
Science Fair Open Library | Inspiring the World of Science 2017 | Volume 1 | Issue 1
Fig. 2: Quantitative representation of the mean amplitude values and the range while walking, divided according to side of the body
and sex. e colored scale represents the magnitude of the values and was created via normalization across sexes, walking speeds and test
situations separately for each bilaterally recorded muscle and variable (see frames). w = women, m = men
Table 2: ANOVA results for the mean amplitude values. e p values and effect sizes (in brackets) are given in each case with p values
< 0.05 marked in red. Interactions that were not significant in any of the muscles are not listed.
Muscle RA OI OE MF ICO LO
side 0.648 (0.005) 0.209 (0.04) 0.549 (0.009) 0.377 (0.02) <0.001 (0.442) 0.001 (0.266)
situation 0.208 (0.04) <0.001 (0.283) <0.001 (0.449) <0.001 (0.261) 0.012 (0.118) 0.001 (0.178)
speed <0.001 (0.487) <0.001 (0.604) <0.001 (0.703) <0.001 (0.524) <0.001 (0.791) <0.001 (0.742)
speed*sex 0.001a (0.235) 0.391 (0.022) 0.024a (0.106) 0.001b sex (0.174) 0.009b speed (0.138) 0.017b sex (0.099)
side*speed 0.366 (0.024) 0.864 (0.003) 0.038b speed (0.092) 0.269 (0.033) 0.005a (0.145) 0.563 (0.011)
situation*speed 0.68 (0.012) 0.011a (0.076) 0.01a (0.086) 0.095 (0.049) 0.016b speed (0.074) 0.002a (0.088)
sex <0.001 (0.341) 0.199 (0.042) 0.001 (0.233) 0.001 (0.233) 0.657 (0.005) 0.019 (0.134)
Situation: U1, U2 and U3; speed: walking speeds (2–6 km/h);
a: ordinate interaction between main factors,
b: hybrid interaction between main factors with the suffix stating the interpretable main factor
Page 11
Cite this article: HubnerA., Niemeyer F, Schilling K and Anders C. (2017). Effects of an abdominal belt on trunk muscle activity during treadmill walking, Biomech Open
Lib, 1(1): 7-15
Science Fair Open Library | Inspiring the World of Science 2017 | Volume 1 | Issue 1
Fig. 3: Color-coded depiction of the differences in mean amplitude values between U1 vs. U2 and U3 for all walking speeds as well as
speed-independent differences, separately for both sexes and sides. Negative deviations from U1 appear in red, positive deviations in
green. e color intensity reflects the extent of the change and refers to the maximum absolute value. Significant differences between the
respective situations are marked with a black asterisk. a) relative differences in mean amplitude values; b) range differences.
p < 0.0167. w = women, m = men
Table 3: ANOVA results for the range. e p values and effect sizes (in brackets) are given in each case with p values < 0.05 marked in
red. Interactions that were not significant in any of the muscles are not listed.
Muscle RA OI OE MF ICO LO
side 0.856 (0.001) 0.562 (0.009) 0.353 (0.022) 0.926 (<0.001) <0.001 (0.563) 0.039 (0.104)
side*sex 0.361 (0.021) 0.917 (<0.001) 0.045c (0.099) 0.049b sex (0.096) 0.408 (0.018) 0.624 (0.006)
situation <0.001 (0.198) 0.051 (0.074) 0.001 (0.179) 0.002 (0.177) <0.001 (0.256) <0.001 (0.369)
speed <0.001 (0.504) <0.001 (0.841) <0.001 (0.673) <0.001 (0.721) <0.001 (0.764) <0.001 (0.765)
speed*sex 0.22 (0.038) 0.05a (0.071) 0.102 (0.057) 0.114 (0.053) 0.303 (0.03) 0.193 (0.041)
side*speed 0.198 (0.041) 0.179 (0.043) 0.53 (0.018) 0.181 (0.042) <0.001a (0.343) 0.045a (0.069)
situation*speed 0.706 (0.013) 0.024b speed (0.059) 0.531 (0.021) 0.299 (0.03) 0.058 (0.051) 0.952 (0.007)
sex 0.018 (0.135) 0.043 (0.101) 0.919 (<0.001) 0.01 (0.16) 0.618 (0.006) 0.184 (0.045)
Situation: U1, U2 and U3; speed: walking speeds (2–6 km/h);
a : ordinate interaction between main factors,
b: hybrid interaction between main factors with the suffix stating the interpretable main factor ;
c: disordinal interaction
Page 12
Cite this article: HubnerA., Niemeyer F, Schilling K and Anders C. (2017). Effects of an abdominal belt on trunk muscle activity during treadmill walking, Biomech Open
Lib, 1(1): 7-15
Science Fair Open Library | Inspiring the World of Science 2017 | Volume 1 | Issue 1
2. DIFFERENCES BETWEEN U1 VS. U2 AND U3
e relative differences of the mean amplitudes between U1 vs.
U2 and U3 show that wearing the abdominal belt led to a signifi-
cant reduction in mean amplitude values in the oblique abdominal
muscles of both sexes (-40% to -7%) (Fig. 3a). For women’s RA,
this was only evident at 2 km/h (-18% to -15%). In contrast, men’s
RA mean amplitudes decreased significantly at all walking speeds,
mainly at U2. is was also observed in the back muscles: a sig-
nificant amplitude reduction mainly occurred at U2 (in women for
MF and LO (-11% to -5%), in men for LO (-9% to -6%)). ICO
showed contrary outcomes: in women, wearing the abdominal belt
led to an increase in amplitude after 3 hours’ wearing time at low
walking speeds (10% to 11%). In men, no amplitude changes could
be statistically verified.
At low walking speeds there were several occurrences of an in-
crease in range in women’s abdominal muscles (RA, OI) at U3
(13% to 23%) (Fig. 3b). In contrast, in men a decrease in the range
was observed in RA and OE, but only in isolated cases. For the
back muscles an increase in the range was visible, especially for
women’s ICO and LO (13% to 44%). Overall, the number of sig-
nificant differences was again larger among the women.
Speed-independent calculations of the relative differences of the
mean amplitudes as well as the range showed equivalent effects
and are not listed separately due to redundancy of the results.
DISCUSSION
e aim of this study was to quantify the effect of a lumbar sup-
port on trunk muscles during walking in healthy subjects. Due to
the contrary sex-specific differences in amplitude values between
abdominal and back muscle that often interfered with body side
a simple take home message cannot be given. In contrary to the
hypothesis varying, muscle-specific reactions were observed for
the different test situations. While muscle activity decreased in
the oblique abdominal muscles, an increase in amplitude levels,
and therefore muscular effort was observed in women’s ICO at low
walking speeds after 3 hours of wearing the abdominal belt. MF
in women and LO in men and women showed a decrease in am-
plitude level at U2 only. e observed differences between U2 and
U3 may mostly be due to habituation effects after wearing the belt
for three hours. erefore, the observed changes after this period
seem to reflect the “real” effects on the investigated trunk muscles.
Given that the study design concerned short term effects only, the
question of effects on amplitude changes over longer periods of
wearing the abdominal belt still stands.
While a reduction in SEMG amplitude is usually considered to
be an indicator for lesser activation and therefore deconditioning
of muscles in the long term, we believe that the OI needs to be
considered as an exception: as it permanently stabilizes the trunk
during standing and walking it is constantly active at a compara-
tively high level [36]. If stability requirements increase due to dys-
functions in other muscles, the activity of OI has to be further in-
creased to maintain trunk stability. is compensatory, stabilizing
function has already been demonstrated by van Dieen et al. [37]
in 2003. If the belt can help reduce this additional stabilization
demand for the OI in this situation, apparent through an ampli-
tude drop, this would represent active protection against muscular
fatigue and is a positive outcome. e decrease in muscular activity
also observed in the OE could be attributed to the reduction of
rotational components by stiffening of the torso caused by the belt
[15] which may similarly have influenced ICO. A study by Hu et
al. [26] also showed a decrease in abdominal muscle activity while
walking on a treadmill, although a pelvic and not an abdominal
belt was worn in this case.
Wearing the belt led to an increase in SEMG amplitude range
in the back muscles in several situations as well as women’s RA
and OI at low and medium walking speeds, which represents more
pronounced differences between activation and relaxation of these
muscles. erefore, an increase in range may indirectly indicate im-
proved circulation conditions, thus enabling improved supply of
nutrients to the muscles. is is associated with an increase in per-
formance [38]. A drop in the amplitude range was only observed
in isolated cases in OE.
Influence of sex and side
e study contains largely confirmatory data concerning general
sex-specific differences in amplitude levels [36]. is was anticipa-
tory taken into account by the supplier who offers sex-specific belt
models that aim for equal quantitative effectiveness independently
of anatomical conditions. However, sex-specific responses due oc-
cur even though relative amplitude differences were calculated to
eliminate effects due to different amplitude levels. At this point we
cannot draw conclusions about the factors that contribute to these,
but anatomy seems to be a major candidate.
Trunk muscles are not well investigated with regard to symmetry
of muscle activity between body sides but side differences do occur
and are described in the literature [39]. In the present study the
found significant differences in muscle activity between body sides
may also be attributed to natural asymmetry which is related to
higher values for the right side in comparison to the left side for
ICO and LO in our investigation.
Influence of wearing time
Changes in muscle activity due to wearing time of the abdominal
belt are obvious, especially for the relative differences in the mean
amplitudes. us, LO of both sexes together with men’s RA and
women’s MF showed significant amplitude reductions at U2 which
however had ceased at U3. is confirms the need to conduct fur-
ther studies into the recommended wearing time for the abdomi-
nal belt in order to produce a more precise assessment of the time
component in the mode of action of abdominal belts. ere is also
a lack of objective studies into the optimum “environment condi-
tions”, i.e. the activities that the patients are to perform or refrain
from while wearing the belt.
Summary
Wearing the belt was not expected to have major effects on muscle
activity in healthy subjects but to generally reduce muscle activity
of trunk muscles. e belt is designed to support strained muscles
and stabilize the spine. In general, the observed changes in the
Page 13
Cite this article: HubnerA., Niemeyer F, Schilling K and Anders C. (2017). Effects of an abdominal belt on trunk muscle activity during treadmill walking, Biomech Open
Lib, 1(1): 7-15
Science Fair Open Library | Inspiring the World of Science 2017 | Volume 1 | Issue 1
mean amplitudes of the abdominal muscles caused by wearing the
support can be summarized as being subtle but largely confirm
the hypothesis that a considerable amount of strain is reduced by
the passive support. In contrast, the activity characteristics of the
back muscles were not altered systematically: while MF (women)
and LO (both sexes) showed a slight but systematic decrease at
medium and fast walking speed at U2 this effect vanished at U3. In
contrast although the values hardly reached levels of significance
while wearing the belt amplitudes of ICO tended to increase. Es-
pecially this characteristic could be caused by the stiffening effect
of the lumbar belt. However, these results need to be treated with
caution since the investigation was done on healthy subjects only.
Similar results of the effect of the belt can be assumed for low back
pain patients since an important symptom of back pain patients is
the altered recruitment pattern of trunk muscles to enhance spi-
nal stability [37]. If spinal stability can be augmented by wearing
an abdominal belt – as is indicated by the decrease of abdominal
muscle activity – effects between healthy subjects and back pain
patients should not differ considerably. However, in consequence
of disorders of the locomotor apparatus, e.g. pain, clearer effects
may be observed in patients wearing the belt. Further studies will
need to examine this topic.
Copyright:
© 2017 Hubner A., Niemeyer F., et al. Published by the Science
Fair Open Library under the terms of the Creative Commons Attribution 4.0
International License. e images or other third party material in this article are
included in the article’s Creative Commons license, unless indicated otherwise in
the credit line; if the material is not included under the Creative Commons li-
cense, users will need to obtain permission from the license holder to reproduce
the material.To view a copy of this license, visit http://creativecommons.org/li-
censes/by/4.0/
Funding: e study was funded by Bauerfeind AG, grant 809752 W2079.
Acknowledgements: is work was funded by Bauerfeind AG, grant 809752
W2079. Measurements were carried out at the kindly provided laboratory of the
Center for Interdisciplinary Prevention of Diseases related to Professional Ac-
tivities (KIP) founded and funded by the Friedrich-Schiller-University Jena and
the German Social Accident Insurance Institution for the foodstuffs and catering
industry. e authors would like to thank Eurotext and Ms. Marcie Matthews of
Polishedwords for language assistance.
Author contribution:
e manuscript represents original work without
fabrication, fraud or plagiarism. e research meets the ethical guidelines, includ-
ing adherence to the legal requirements of Germany. e Authors take full respon-
sibility for the content of the manuscript. All authors disclose any financial and
personal relationship with other people or organizations that could inappropriately
influence (bias) the work. e study sponsors were involved in the study design
but did not influence collection, analysis, interpretation of data, and writing of the
manuscript.
Conflict of interest:
ere is no conflict of interest to declare.
REFERENCES
[1] Aleksiev AR. 2014. Ten-year follow-up of strengthening versus flexibility ex-
ercises with or without abdominal bracing in recurrent low back pain. Spine (Phila
Pa 1976) 39: 997-1003.
[2] He LH, Wang S, Shen P, et al. 2004. Effect of lumbar protective belt on preven-
tion of low back fatigue in personnel during simulated driving. Chin J Ind Hyg Occ
Dis 22: 254-256.
[3] Calmels P, Queneau P, Hamonet C, et al. 2009. Effectiveness of a lumbar belt in
subacute low back pain: an open, multicentric, and randomized clinical study. Spine
(Phila Pa 1976) 34: 215-220.
[4] Valle-Jones JC, Walsh H, O’Hara J, et al. 1992. Controlled trial of a back sup-
port (‘Lumbotrain’) in patients with non-specific low back pain. Curr Med Res Opin
12: 604-613.
[5] van Poppel MN, de Looze MP, Koes BW, et al. 2000. Mechanisms of action of
lumbar supports: a systematic review. Spine (Phila Pa 1976) 25: 2103-2113.
[6] Jellema P, van Tulder MW, van Poppel MN, et al. 2001. Lumbar supports for
prevention and treatment of low back pain: a systematic review within the frame-
work of the Cochrane Back Review Group. Spine (Phila Pa 1976) 26: 377-386.
[7] Waters RL, Morris JM. 1970. Effect of spinal supports on the electrical activity
of muscles of the trunk. J Bone Joint Surg Am 52: 51-60.
[8] Hsieh CY, Phillips RB, Adams AH, Pope MH. 1992. Functional outcomes of
low back pain: comparison of four treatment groups in a randomized controlled
trial. J Manipulative Physiol er 15: 4-9.
[9] McGill SM, Norman RW, Sharratt MT. 1990. e effect of an abdominal belt
on trunk muscle activity and intra-abdominal pressure during squat lifts. Ergonom-
ics 33: 147-160.
[10] Miyamoto K, Iinuma N, Maeda M, et al. 1999. Effects of abdominal belts on
intra-abdominal pressure, intra-muscular pressure in the erector spinae muscles and
myoelectrical activities of trunk muscles. Clin Biomech (Bristol, Avon) 14: 79-87.
[11] Rostami M, Noormohammadpour P, Sadeghian AH, et al. 2014. e effect of
lumbar support on the ultrasound measurements of trunk muscles: a single-blinded
randomized controlled trial. PM R 6: 302-308.
[12] Miyamoto K, Iinuma N, Ueki S, Shimizu K. 2008. Effects of abdominal belts
on the cross-sectional shape of the trunk during intense contraction of the trunk
muscles observed by computer tomography. Clin Biomech (Bristol, Avon) 23: 1220-
1226.
[13] Miyamoto K, Shimizu K, Masuda K. 2002. Fast MRI used to evaluate the ef-
fect of abdominal belts during contraction of trunk muscles. Spine (Phila Pa 1976)
27: 1749-1755.
[14] Ivancic PC, Cholewicki J, Radebold A. 2002. Effects of the abdominal belt on
muscle-generated spinal stability and L4/L5 joint compression force. Ergonomics
45: 501-513.
[15] Cholewicki J, Juluru K, Radebold A, et al. 1999. Lumbar spine stability can be
augmented with an abdominal belt and/or increased intra-abdominal pressure. Eur
Spine J 8: 388-395.
[16] Majkowski GR, Jovag BW, Taylor BT, et al. 1998. e effect of back belt use
on isometric lifting force and fatigue of the lumbar paraspinal muscles. Spine (Phila
Pa 1976) 23: 2104-2109.
[17] Krag MH, Fox MJ, Haugh LD. 2003. Comparison of three lumbar orthoses
using motion assessment during task performance. Spine (Phila Pa 1976) 28: 2359-
2367.
[18] McGill S, Seguin J, Bennett G. 1994. Passive stiffness of the lumbar torso in
flexion, extension, lateral bending, and axial rotation. Effect of belt wearing and
breath holding. Spine (Phila Pa 1976) 19: 696-704.
[19] Ciriello VM, Snook SH. 1995. e effect of back belts on lumbar muscle fa-
tigue. Spine (Phila Pa 1976) 20: 1271-1278.
[20] Granata KP, Marras WS, Davis KG. 1997. Biomechanical assessment of lift-
ing dynamics, muscle activity and spinal loads while using three different styles of
lifting belt. Clin Biomech (Bristol, Avon) 12: 107-115.
[21] Cholewicki J, Lee AS, Peter Reeves N, Morrisette DC. 2010. Comparison of
trunk stiffness provided by different design characteristics of lumbosacral orthoses.
Clin Biomech (Bristol, Avon) 25: 110-114.
[22] Marras WS, Jorgensen MJ, Davis KG. 2000. Effect of foot movement and an
elastic lumbar back support on spinal loading during free-dynamic symmetric and
asymmetric lifting exertions. Ergonomics 43: 653-668.
[23] Reddell CR, Congleton JJ, Dale Huchingson R, Montgomery JF. 1992. An
evaluation of a weightlifting belt and back injury prevention training class for air-
line baggage handlers. Appl Ergon 23: 319-329.
[24] Dalichau S, Scheele K. 2000. Auswirkungen elastischer Lumbal-Stutzgurte
auf den Effekt eines Muskeltrainingsprogrammes fur Patienten mit chronischen
Ruckenschmerzen. Z Orthop Ihre Grenzgeb 138: 8-16.
[25] Mens JM, Vleeming A, Stoeckart R, et al. 1996. Understanding peripartum
pelvic pain. Implications of a patient survey. Spine (Phila Pa 1976) 21: 1363-1369.
[26] Hu H, Meijer OG, van Dieen JH, et al. 2010. Muscle activity during the ac-
tive straight leg raise (ASLR), and the effects of a pelvic belt on the ASLR and on
treadmill walking. J Biomech 43: 532-539.
[27] Van Tulder MW, Jellema P, van Poppel MN, et al. 2000. Lumbar supports for
prevention and treatment of low back pain. Cochrane Database Syst Rev: CD001823.
[28] Kankaanpää M, Taimela S, Laaksonen D, et al. 1998. Back and hip extensor
Page 14
Cite this article: HubnerA., Niemeyer F, Schilling K and Anders C. (2017). Effects of an abdominal belt on trunk muscle activity during treadmill walking, Biomech Open
Lib, 1(1): 7-15
Science Fair Open Library | Inspiring the World of Science 2017 | Volume 1 | Issue 1
fatigability in chronic low back pain patients and controls. Arch Phys Med Rehabil
79: 412-417.
[29] D’Hooge R, Hodges P, Tsao H, et al. 2013. Altered trunk muscle coordina-
tion during rapid trunk flexion in people in remission of recurrent low back pain. J
Electromyogr Kinesiol 23: 173-181.
[30] Arsenault AB, Winter DA, Marteniuk RG, Hayes KC. 1986. How many
strides are required for the analysis of electromyographic data in gait? Scand J Re-
habil Med 18: 133-135.
[31] Hermens HJ, Freriks B, Merletti R, et al. 1999. European Recommendations
for Surface ElectroMyoGraphy, results of the SENIAM project. Roessingh Re-
search and Development b.v., Enschede.
[32] Ng JK, Kippers V, Richardson CA. 1998. Muscle fibre orientation of abdomi-
nal muscles and suggested surface EMG electrode positions. Electromyogr Clin
Neurophysiol 38: 51-58.
[33] Mörl F, Anders C, Grassme R. 2010. An easy and robust method for ECG ar-
tifact elimination of SEMG signals. In, XVII Congress of the International Society
of Electrophysiology and Kinesiology Aalborg: Omnipress.
[34] Carrier DR, Anders C, Schilling N. 2011. e musculoskeletal system of hu-
mans is not tuned to maximize the economy of locomotion. Proc Natl Acad Sci U S
A 108: 18631-18636.
[35] Perry J, Burnfield J, Cabico LM. 2010. Gait Analysis: Normal and Pathologi-
cal Function. Slack Inc., orofare.
[36] Anders C, Wagner H, Puta C, et al. 2009. He`althy humans use sex-specific
co-ordination patterns of trunk muscles during gait. Eur J Appl Physiol 105: 585-
594.
[37] van Dieen JH, Cholewicki J, Radebold A. 2003. Trunk muscle recruitment
patterns in patients with low back pain enhance the stability of the lumbar spine.
Spine (Phila Pa 1976) 28: 834-841.
[38] Snell PG, Mitchell JH. 1984. e role of maximal oxygen uptake in exercise
performance. Clin Chest Med 5: 51-62.
[39] Butler HL, Hubley-Kozey CL, Kozey JW. 2009. Activation amplitude pat-
terns do not change for back muscles but are altered for abdominal muscles between
dominant and non-dominant hands during one-handed lifts. Eur J Appl Physiol
106: 95-104.
Page 15
... Own investigations in healthy subjects already provided hints that argue against the suspected deconditioning effect of elastic lumbar support belts [14], which is useful in trying to understand their use in prevention, but these results are not transferrable to therapeutic use in acute back pain patients. Therefore, the logical next step for us was to apply the same study measurement methodology to follow a cohort of patients suffering from non-specific acute back pain, thus combining surface EMG (sEMG) of muscle activation, with use of other important measures such as pain and functional disability. ...
... According to own previous results on the effects of elastic lumbar support belts in healthy volunteers during walking [14] we hypothesized to see initially reduced sEMG amplitudes for all trunk muscles while wearing elastic lumbar support belts, followed by a return to the values of non-wearers in the sequel for the back muscles while those of the abdominal muscles were expected to remain reduced. With respect to pain intensity and functional disability we expected a general improvement in both groups but a more distinct pain relief and improved functional status in the belt group. ...
... These single observation studies were conflicting and ultimately not useful for comparison to ours. If however we compare these results with our own previous results in healthy subjects [14], where we compared non-belt and belt use during walking in the same subjects, we see similar reductions in abdominal muscle activation. Also, in the current study we observed consistent differences between C and B groups over the three Trials, both of these congruities argue for a repeatable effect on abdominal activation of the elastic support belt during walking. ...
Article
Full-text available
Background: A well-known supportive treatment for acute nonspecific back pain, elastic back support belts, are valued for their ability to accelerate natural self-healing, but there are concerns of a deconditioning effect due to their reliance on passive stabilization. Methods: To evaluate the systematic effects of elastic abdominal belts on the trunk musculature, a total of 36 persons with acute lumbar back pain (no longer than one week) were divided into two groups: an abdominal belt wearing group (B) and a non-abdominal belt wearing control group (C). All were examined over a period of three weeks at three time points: T1 just after assignment, T2 one week later, and T3 further two weeks later. Surface EMG (sEMG) was used to record trunk muscle activation when walking on a treadmill at walking speeds of 2, 3, 4, 5, and 6 km/h. Similarly, pain intensity (VAS) and functional impairment (ODI) over time were recorded in both groups. Results: Over the observation period, a slight advantage for decreased pain intensity (C: p<0.05 T2 vs. T1; B: p<0.01 T2 vs. T1, p<0.05 T3 vs. T1) and decreased functional impairment (Cohen's d vs. T1, C: T2 0.45, T3 0.86; B: T2 1.1, T3 1.0) was observed for the belt group. For the belt group both oblique abdominal muscles exhibited significantly lower sEMG throughout the observation period (external abdominal oblique muscle: (T1), T2, (T3), internal abdominal oblique muscle: T1, (T2), (T3)) and the sEMG for the back muscles ranged from unchanged to slightly elevated for this group, but never reached statistical significance. Discussion: The reduced abdominal amplitude levels in the belt group likely result from the permanent elastic stabilization provided by the belt: the required elevated intra-abdominal pressure to enhance spinal stability is then provided by lessened abdominal muscle activity complemented by the belt's elastic support. With regard to the back muscles, the belt, due to its movement-restricting effect, tends to activate the paravertebral musculature. In this respect, the effect of elastic abdominal belts on the trunk muscles is not uniform. Therefore, the present results suggest that the effect of elastic abdominal belts appears to be more of a temporary neutral alteration of trunk muscle coordination, with some trunk muscles becoming more active and others less, and not a case of uniform deconditioning as is suspected.
... El uso de cinturón lumbar forma parte de estas estrategias teniendo como objetivo la prevención de lesiones y la mejora del desempeño deportivo, pues al levantar cargas máximas el TrA y otros músculos estabilizadores pueden ser insuficientes en estas intensidades (2,3). Sin embargo, el sobreuso de esta herramienta puede conseguir que la activación muscular llegue a ser inadecuada al momento de soportar cargas sin cinturón, perjudicando así a los deportistas (4). ...
... En efecto, nuestra población presenta un alto uso del cinturón al mes, contando con el 91.7%, apuntando hacia el sobreuso del accesorio, según el autor Everett, esta herramienta debe ser limitada a entrenamientos demandantes y a buscar la mejora de rendimiento, pues entrenamientos comunes no suelen requerir su uso (2). En adición, Anders menciona que el uso de cinturón en sujetos sanos disminuye la actividad de los músculos estabilizadores del tronco a corto plazo, pero, al no poseer datos de la planificación de entrenamiento de los levantadores se vuelve difícil definir si el uso es inadecuado (4). Por consiguiente, gran parte de los deportistas evaluados, al querer aumentar la carga y reducir las fuerzas de compresión tiene un alto uso mensual del cinturón lo que compromete la musculatura disminuyendo su función, lo cual concuerda Kingma, en donde relata que acompañar el uso de cinturón con una buena respiración disminuye las cargas de compresión sobre la columna (14). ...
Article
Full-text available
Objetivos: Determinar la capacidad estabilizadora del Transverso abdominal a través del Test de estabilidad central de Sahrmann en deportistas de halterofilia de la Federación Deportiva del Azuay. Métodos: Estudio descriptivo, transversal, realizado en deportistas de la FDA. Para la recolección de datos se utilizó un formulario de registro y para la evaluación el Test de Estabilidad Central de Sahrmann junto con el dispositivo Chattanooga Stabilizer Pressure Biofeedback. La tabulación y análisis de los datos requirió de los programas GNU PSPP v1.6.2 y Microsoft Excel 2016. La información se almacenó en una base de datos y los resultados fueron expresados en tablas. Resultados: Más de la mitad de la población estudiada (66.6%) presenta una menor capacidad estabilizadora alcanzando los niveles 1 y 2 en su mayoría mediante la ejecución del test de estabilidad central de Sahrmann. Conclusiones: Nuestros resultados permitieron identificar que la capacidad de activación del TrA es insuficiente, con una estabilidad reducida en un 66,7% de los atletas de la Federación Deportiva del Azuay, al no alcanzar un nivel superior a 2 en el test de estabilidad de Sahrmann, lo que sugiere un alto riesgo de lesión.
Article
Elastische Bandagen sind umstritten. Während Befürworter davon ausgehen, dass sie die natürliche Selbstheilung bei unspezifischen Rückenbeschwerden beschleunigen, wenden Gegner ein, dass die passive Unterstützung womöglich einen dekonditionierenden Effekt auf die Rumpfmuskeln haben könnte.
Article
Full-text available
To evaluate the effect of lumbopelvic belts on the thickness of lateral abdominal muscles and Cross Sectional Area (CSA) of Lumbar Multifidus (LM) muscles. A single blinded Randomized Controlled Trial (RCT). An academic and tertiary care referral spine and sports medicine center. Sixty healthy volunteers with no history of LBP in the previous year. The subjects were allocated into belt and control groups. Lumbar belts were given to the subjects in the belt group and they were asked to use the belts during the study period except during sleeping hours. The subjects were assessed at baseline, 4 and 8 weeks. The thickness of lateral abdominal muscles and the CSA of the LM were measured by ultrasound (US) in hook-lying position on the examination table. The thickness of lateral abdominal muscles and the CSA of LM on both sides decreased significantly among healthy subjects in the belt group after 8 weeks. The results of this study show that lumbopelvic belts might influence the US measurements of lateral abdominal and LM muscles and thereby on the spine stability.
Article
Full-text available
Humans are known to have energetically optimal walking and running speeds at which the cost to travel a given distance is minimized. We hypothesized that "optimal" walking and running speeds would also exist at the level of individual locomotor muscles. Additionally, because humans are 60-70% more economical when they walk than when they run, we predicted that the different muscles would exhibit a greater degree of tuning to the energetically optimal speed during walking than during running. To test these hypotheses, we used electromyography to measure the activity of 13 muscles of the back and legs over a range of walking and running speeds in human subjects and calculated the cumulative activity required from each muscle to traverse a kilometer. We found that activity of each of these muscles was minimized at specific walking and running speeds but the different muscles were not tuned to a particular speed in either gait. Although humans are clearly highly specialized for terrestrial locomotion compared with other great apes, the results of this study indicate that our locomotor muscles are not tuned to specific walking or running speeds and, therefore, do not maximize the economy of locomotion. This pattern may have evolved in response to selection to broaden the range of sustainable running speeds, to improve performance in motor behaviors not related to endurance locomotion, or in response to selection for both.
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: Randomized prevention trial. Objective: To compare the long-term effect of strengthening versus flexibility exercises and to evaluate the additional effect of abdominal bracing in recurrent low back pain (LBP). Summary of background data: No conclusions could be made regarding appropriate exercise types or parameters in recurrent LBP. Abdominal bracing increases trunk stiffness; however, its long-term effect has not been evaluated in recurrent LBP yet. Methods: Six hundred patients with recurrent LBP participated. They were randomized into 4 groups-150 patients (age: 42.5 ± 12.7) performed strengthening exercises; 150 patients (age: 41.3 ± 11.5) performed flexibility exercises; 150 patients (age: 41.0 ± 13.2) performed strengthening exercises and used abdominal bracing in daily activities/exercises; and 150 patients (age: 40.6 ± 12.3) performed flexibility exercises and used abdominal bracing in daily activities/exercises. At the beginning of the study and at the end of 10 consecutive years were recorded 6 outcomes-frequency, intensity, and duration of pain, as well as frequency, intensity, and duration of exercises. Results: Regarding the first 4 outcomes-all groups showed improvement from the beginning to the second year, but worsening from the second to the 10th year; there was no difference between strengthening and flexibility groups; bracing groups showed better results versus nonbracing groups. Intensity, frequency, and duration of the pain correlated with each other and with frequency of the exercises, but not with exercise duration or intensity. Conclusion: The exercise frequency is more important than the type, duration, or intensity of the exercise. Abdominal bracing adds to the exercise effect. It could be considered as a "preliminary muscle back belt on demand" increasing the trunk stiffness and the frequency of the trunk muscle contractions/cocontractions without interruption of daily activities, which may remind/convince the patients to exercise more frequently. Frequent exercising and bracing seems effective long-term prevention advices in recurrent LBP. Level of evidence: 2.
Article
People with a history of low back pain (LBP) are at high risk to encounter additional LBP episodes. During LBP remission, altered trunk muscle control has been suggested to negatively impact spinal health. As sudden LBP onset is commonly reported during trunk flexion, the aim of the current study is to investigate whether dynamic trunk muscle recruitment is altered in LBP remission. Eleven people in remission of recurrent LBP and 14 pain free controls performed cued trunk flexion during a loaded and unloaded condition. Electromyographic activity was recorded from paraspinal (lumbar and thoracic erector spinae, latissimus dorsi, deep and superficial multifidus) and abdominal muscles (obliquus internus, externus and rectus abdominis) with surface and fine-wire electrodes. LBP participants exhibited higher levels of co-contraction of flexor/extensor muscles, lower agonistic abdominal and higher antagonistic paraspinal muscle activity than controls, both when data were analyzed in grouped and individual muscle behavior. A sub-analysis in people with unilateral LBP (n=6) pointed to opposing changes in deep and superficial multifidus in relation to the pain side. These results suggest that dynamic trunk muscle control is modified during LBP remission, and might possibly increase spinal load and result in earlier muscle fatigue due to intensified muscle usage. These negative consequences for spinal health could possibly contribute to recurrence of LBP.
Article
To evaluate the effects of abdominal belts on lifting performance, muscle activation, intra-abdominal pressure and intra-muscular pressure of the erector spinae muscles. Simultaneous measurement of intra-abdominal pressure, intra-muscular pressure of the erector spinae muscles was performed during the Valsalva maneuver and some isometric lift exertions. While several hypotheses have been suggested regarding the biomechanics of belts and performance has been found to increase when lifting with belts, very little is known about the modulating effects on trunk stiffness. At present, there is no reason to believe that spine tolerance to loads increases with belts. An abdominal belt designed for weightlifting was used. Intra-abdominal pressure, intra-muscular pressure of the erector spinae muscles and myoelectric activities of trunk muscles (erector spinae, rectus abdominis and external oblique) were measured simultaneously during the Valsalva maneuver as well as three types of isometric lifting exertions (arm, leg and torso lift). A paired t-test was used to analyze for statistical differences between the two conditions (without-belt and with-belt) in intra-abdominal pressure, intra-muscular pressure of the erector spinae muscles and in the integrated EMG of the trunk muscles. Intra-muscular pressure of the erector spinae muscles increased significantly by wearing the abdominal belt during Valsalva maneuvers and during maximum isometric lifting exertions, while maximum isometric lifting capacity and peak intra-abdominal pressure were not affected. Integrated EMG of rectus abdominis increased significantly by wearing the abdominal belt during Valsalva maneuvers (after full inspiration) and during isometric leg lifting. Wearing abdominal belts raises intra-muscular pressure of the erector spinae muscles and appears to stiffen the trunk. Assuming that increased intra-muscular pressure of the erector spinae muscles stabilizes the lumbar spine, wearing abdominal belts may contribute to the stabilization during lifting exertions.
The ability of surface electrodes to accurately detect the activity of a particular muscle relies not only on their being placed over the muscle but also on their position in relation to muscle fibre orientation. For optimal pick-up of electromyographic (EMG) signals, surface electrodes are best aligned in parallel with the fibre orientation of the underlying muscle. This study aimed to measure muscle fibre orientation and other parameters of muscle morphology of the abdominal muscles in relation to palpable bony landmarks. Thirty-seven embalmed cadavers (19 males and 18 females) were examined. Results showed that the fibres of obliquus externus abdominis were about 4 degrees more vertical than the lower edge of the eighth rib. Below the rib cage, the muscle fibres of obliquus externus abdominis were approximately 5 degrees closer to vertical than a reference line between the most inferior point of the costal margin and the contralateral pubic tubercle. In the anterolateral abdominal wall area below the anterior superior iliac spine (ASIS), the obliquus internus abdominis was superficial being covered only by the aponeurosis of obliquus externus abdominis. At the level of ASIS, the muscle fibres of obliquus internus abdominis were almost horizontally orientated but at 2 cm below ASIS were aligned about 6 degrees inferomedially to the horizontal. The muscle fibres of upper rectus abdominis were 2 degrees inferolateral to the midline while the lower rectus abdominis muscle fibres deviated inferomedially from the midline by about 8 degrees. The appropriate surface electrode placements which follows the muscle fibre orientation of the obliquus externus abdominis, obliquus internus abdominis and rectus abdominis have been suggested.
Article
Women with pregnancy-related pelvic girdle pain (PPP), or athletes with groin pain, may have trouble with the active straight leg raise (ASLR), for which a pelvic belt can be beneficial. How the problems emerge, or how the belt works, remains insufficiently understood. We assessed muscle activity during ASLR, and how it changes with a pelvic belt. Healthy nulligravidae (N=17) performed the ASLR, and walked on a treadmill at increasing speeds, without and with a belt. Fine-wire electromyography (EMG) was used to record activity of the mm. psoas, iliacus and transversus abdominis, while other hip and trunk muscles were recorded with surface EMG. In ASLR, all muscles were active. In both tasks, transverse and oblique abdominal muscles were less active with the belt. In ASLR, there was more activity of the contralateral m. biceps femoris, and in treadmill walking of the m. gluteus maximus in conditions with a belt. For our interpretation, we take our starting point in the fact that hip flexors exert a forward rotating torque on the ilium. Apparently, the abdominal wall was active to prevent such forward rotation. If transverse and oblique abdominal muscles press the ilia against the sacrum (Snijders' "force closure"), the pelvis may move as one unit in the sagittal plane, and also contralateral hip extensor activity will stabilize the ipsilateral ilium. The fact that transverse and oblique abdominal muscles were less active in conditions with a pelvic belt suggests that the belt provides such "force closure", thus confirming Snijders' theory.