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Radiosteriometric analysis of movement in the sacroiliac joint during a
single-leg stance in patients with long-lasting pelvic girdle pain
Thomas J. Kibsgård
, Olav Røise
, Stephan M. Röhrl
, Britt Stuge
Department of Orthopaedics, Division of Surgery and Clinical Neuroscience, Oslo University Hospital, Oslo, Norway
Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Norway
Department of Orthopedics, Ängelholm Hospital, Ängelholm, Sweden
abstractarticle info
Article history:
Received 14 November 2013
Accepted 10 February 2014
Sacroiliac joint
Radiostereometric analysis
Pelvic girdle pain
Single-leg stance
Background: Chamberlain's projections (anteriorposterior X-ray of the pubic symphysis) have been used to
diagnose sacroiliac joint mobility during the single-leg stance test. This study examined the movement in the
sacroiliac joint during the single-leg stance test with precise radiostereometric analysis.
Methods: Under general anesthesia, tantalum markers were inserted into the dorsal sacrum and the ilium of 11
patients with long-lasting and severe pelvic girdle pain. After two to three weeks, a radiostereometric analysis
was conducted while the subjects performed a single-leg stance.
Findings: Small movements were detected in the sacroiliac joint during the single-leg stance. In both the
standing- and hanging-leg sacroiliac join, a total of 0.5 degree rotation was observed; however, no translations
were detected. There were no differences in total movement between the standing- and hanging-leg sacroiliac
Interpretation: The movement in the sacroiliac joint duringthe single-leg stance is small and almost undetectable
by the precise radiostereometric analysis. A complex movement pattern was seen during the test, with a combi-
nation of movements in the two joints. The interpretation of the results of this study is that, the Chamberlain
examination likely is inadequate in the examination of sacroiliac joint movement in patients with pelvic girdle
© 2014 Elsevier Ltd. All rights reserved.
1. Introduction
The sacroiliac joint (SIJ) is a possible cause of pain in patients with
low back and pelvic girdle pain (PGP), with a reported prevalence rang-
ing from 10% to 60% depending on the patient population and choice
of diagnostic criteria (Cohen et al., 2013; Simopoulos et al., 2012;
Vleeming et al., 2008). A large amount of force is transferred from the
spine to the legs through the pelvis and SIJ joints. In an upright position,
when gravitational forces are transferred throughthe sacrum, the anat-
omy of the SIJ, ligaments and muscles locks the joint and stabilizes the
pelvic girdle (Snijders et al., 1993). Locking occurs when the sacrum
rotates forward (Sturesson et al., 1989) and is explained by the theory
of form and force closure (Sturesson et al., 2000a). An increased move-
ment in the SIJ might reduce stability and result in stress of the SIJ
ligaments, impaired motor control and consequently pain (Mens et al.,
2009; Siegel et al., 2008; Snijders et al., 1993). However, the exact
movements that occur in the SIJ are still debated (Goode et al., 2008;
Jacob and Kissling, 1995; Mens et al., 1999; Walker, 1992).
Despite the difculty in measuring true movement of the SIJ, several
attempts have been made using different experimental techniques,
such as k-wires, CT, cadaver studies, skin markers, X-rays and radio-
stereometric analysis (RSA) (Hungerford et al., 2004; Jacob and
Kissling, 1995; Lavignolle et al., 1983; Smidt et al., 1995; Sturesson
et al., 1989; Sturesson et al., 1999; Sturesson et al., 2000a; Sturesson
et al., 2000b). However, these techniques are impractical in a clinical
practice. In 1930, Chamberlain described an easy and practical method
to measure pubic movement on an anteriorposterior (AP) pelvic
X-ray while the patient stands on one leg with the other leg hanging
down (single-leg stance) (Chamberlain, 1930). In patients with SIJ
pain, Chamberlain found that weight bearing caused a cranial dis-
placement of the pubic bone on the side of the painful joint. This dis-
placement was explained by a rotation around the axis that was
perpendicular to the SIJ surface. The Chamberlain technique has since
been used to examine pubic bone movement and indirect SIJ hypermo-
bility (Mens et al., 1999).
Since the Chamberlain technique was rst described, researchers
have attempted to correlate pubic movement to SIJ pain (Anderson
Clinical Biomechanics xxx (2014) xxxxxx
Corresponding author at: Department of Orthopaedics, Division of Surgery and
Clinical Neuroscience, Oslo University Hospital, Sognsvannsveien 20, 0372 Oslo, Norway.
E-mail addresses: (T.J. Kibsgård),
(O. Røise), (B. Sturesson),
(S.M. Röhrl), (B. Stuge).
P.B. 4950 Nydalen, 0424 Oslo, Norway.
JCLB-03753; No of Pages 6
0268-0033/© 2014 Elsevier Ltd. All rights reserved.
Contents lists available at ScienceDirect
Clinical Biomechanics
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Please citethis article as: Kibsgård,T.J., et al., Radiosteriometric analysis of movement in the sacroiliacjoint during a single-leg stance in patients
with long-lasting pelvic girdle pain, Clin. Biomech. (2014),
and Peterson, 1944; Mens et al., 1999; Siegel et al., 2008). Chamberlain
found a clear pattern in his patients, but later Mens et al. (2009) found
the exact opposite where the hanging leg caused a downward displace-
ment of the pubic bone on the side of the painful joint. These differences
have made it hard for clinicians to use the results of the test in the diag-
nosis of PGP, especially when normal variations of the movement in the
pubic symphysis have proven to be large (Garras et al., 2008). Measure-
ments of the movement in the SIJ during the single-leg stance have been
done using k-wires, however only measured on healthy subjects without
SIJ pain (Jacob and Kissling, 1995). As the Chamberlain technique is an
indirect measure of SIJ movement, it is still unknown what really occurs
in the SIJ during the single-leg stance test in patients with PGP.
In a systematic review Goode et al. (2008) concluded that the mea-
surement techniques with the lowest level of error also reported
the lowest values of movement in the SIJ. The RSA technique is highly
accurate and precise (Kibsgard et al., 2012), but has not been utilized
to examine SIJ movements during the single-leg stance test. Therefore,
the aims of the present study were to measure movement in the SIJs
during the single-leg stance test by using RSA, in patients with severe
PGP and to identify whether there are any differences between move-
ments in the SIJs of the standing leg and the hanging leg.
2. Methods
We used RSA to measure the in vivo movement of the SIJ in patients
with PGP. All patients signed an informed consent, and the study was
approved by the Regional Committee for Medical and Health Research
Ethics (Number: 1.2006.1574).
2.1. Patients
From 2007 to 2010, 17 patients with severe PGP were assigned for
SIJ fusion at two orthopedic centers, Oslo University Hospital, Norway
and Ängelholm Hospital, Sweden. The inclusion criteria were long-
lasting pain localized to one or both SIJs, minimum of two out of ve
positive SIJ tests (posterior pelvic pain provocation test, active straight
leg raise, palpation of the long dorsal sacroiliac ligament, modied
Trendelenburg test, palpation of the symphysis (Vleeming et al.,
2008)) and a high degree of pain and disability as measured by the
visual analog scale (VAS) and the Oswestry disability index (ODI).
Patient characteristics at inclusion are presented in Table 1.Allpatients
had normal spinal MRIs, and the patients had either CT scan or/and MRI
of the SIJ. The pelvic MRI or CT was primary done to exclude patients
with sacroiliitis. Seven out of 11 did not have any radiographic abnor-
malities. In three patients there were light unilateral degenerative
changes in the side that were later operated on, and one had bilateral
degenerative changes. Two out of these patients also had anterior
osteophytes on the side that were operated. After evaluating the RSA
data, six patients were excluded because of poor X-ray quality, leaving
11 patients for the nal analysis (10 females and 1 male). The patients
were excluded because of misplaced markers in the soft tissue or insuf-
cient visualization of the markers on radiographs during the software
2.2. RSA protocol
Under general anesthesia, 1 mm RSA tantalum markers were
inserted into the dorsal sacrum and the ilium with a marker gun
through small skin incisions. An imaging intensier was used to assure
proper placement. RSA X-rays were taken after 23 weeks. Three pairs
of X-rays were taken under the following conditions: 1) standing on
both legs, 2) standing on the right leg and 3) standing on the left leg,
with full weight bearing according to Chamberlain examination proce-
dure (Fig. 1). Each pair of radiographs was taken with two X-ray
tubes. As we used the standard set-ups in Norway and Sweden respec-
tively, the RSA set-ups were slightly differently in the two centers. The
software program has, however, the ability to compensate for the devi-
ation automatically because its retrograde calculates the position of the
tubes depending on the control markers in calibration cage. In Norway,
X-ray tubes from the GE system (GE Healthcare, Piscataway, NJ, USA)
and Philips OPTIMUS (Philips Healthcare, Best, The Netherlands) were
used. The tubes were at an approximately 40° angle to each other,
with a lm-focus distance of 155 cm, an exposure of 133 kV and 6.5 to
8 mAs using UmRSA Calibration Cage number 43. In Sweden, two GE
systems (GE Healthcare, Piscataway, NJ, USA) tubes were used. The
tubes were at a 30° angle to each other, with a lm-focus distance of
130 cm, an exposure of 125 kV and 13 mAs using UmRSA Calibration
Cage number 41. The digital images were analyzed using UmRSA
Version 6.0 software (UmRSA Biomedical), and the markers were iden-
tied with user-assisted edge detection (UmRSA digital measure).
The RSA software calculates the translation and rotations in a x,y,z
Table 1
Patient characteristics, n = 11.
Mean (Range)
Age (years) 39 (2947)
Body mass index 24 (1930)
Female/male 10/1
Duration of symptoms (years) 8 (1.520)
Oswestry disability index 56 (2676)
Evening VAS 75 (5391)
Etiology (numbers)
Post-pregnancy 6
Trauma 4
Idiopathic 1
Bilateral pain/unilateral pain 7/4
VAS = visual analog scale.
Fig. 1. RSA setup. APatient standing on both feet, BPatientstanding onleft leg with the right leg hanging down, CPatient standing on right leg with the left leg hanging down.
2T.J. Kibsgård et al. / Clinical Biomechanics xxx (2014) xxxxxx
Please citethis article as: Kibsgård,T.J., et al., Radiosteriometric analysis of movement in the sacroiliacjoint during a single-leg stance in patients
with long-lasting pelvic girdle pain, Clin. Biomech. (2014),
coordinate system (Fig. 2). This coordinate system differs from the coor-
dinate system used in the guidelines from the International Society of
Biomechanics (Wu et al., 2002), but is the standard when reporting
RSA results. The rotational angles are Euler angles that describe the
movement as rotations about the xed x-, y- and z axis. Additionally
the true axis of rotations and translation is also presented (helical
axis) (Valstar et al., 2005).
The use of RSA to assess SIJ movements has proven to be highly
accurate (Kibsgard et al., 2012). The reported precision of the RSA
measurements for rotation is as follows: x = 0.7°, y = 0.3° and z =
0.3°, whereas the precision for translation is as follows: x = 0.5 mm,
y = 0.3 mm and z = 0.4 mm, and these precision data are calculated
by double examination in the Norwegian patients in the current study
(Kibsgard et al., 2012). The precision for both translation and rotation
was expressed by the mean of the absolute value of the difference
between two double examinations + t
(n 1)0.005
Absolute value
where tfollows the Student's t-distribution with n 1degreesof
freedom and 99% level of condence. These values are the limits of
signicance; therefore, movements beyond this limit are actual move-
ments between the marker segments and cannot be explained by mea-
surement error.
The RSA radiographs were analyzed for visual movement in the
symphysis during the single-leg stance. The patients were split into
two groups: those with no visible movement and those with clearly
visible movement. A line was drawn at the top of the pubic bone on
each side of the RSA radiographs, and pubic movement was registered.
No attempt was made to quantify the exact translation in mm because
the software was not calibrated to perform this function.
2.3. Statistical analysis
The patients were examined with weight-bearing on the right side
followed by the left side. Since there are differences in interpretation
of positive and negative movement betweenleft and right side, we con-
verted the sign. So all calculations were performed in a setting where
the patients were standing on the right leg with the left leg hanging
down. The mean of the two sides was then used in the analysis. The
movement in each direction is presented as the mean, standard devia-
tion and range. The H
hypothesis was that there was no movement
in the SIJ during the single-leg stance. A one-sample t-test was used to
determine whether the mean was signicantly different from zero. To
determine if there were any differences between the hanging leg and
standinglegs SIJ a paired sample t-test were used. Because the measure-
ment values were close to the RSA precision, the fraction of measure-
ments that exceeded this threshold is presented along with the range.
We used SPSS® Version 18 (SPSS Inc., Chicago, IL, USA) for the statistical
3. Results
Eleven patients (4 from Norway and 7 from Sweden) with long-
lasting PGP were analyzed. Only small movements in the SIJ were
detected, and only 15% of the measurements exceeded the RSA preci-
sion. Although some mean values were signicantly different from
zero, all but one of these mean values was below the RSA precision.
When the patients performed a single-leg stance there were almost
no detectible movement (Table 2). There were mean 0.5° of rotation on
both sides around a helical axis (the true axis of rotation). When the
movements were assessed based on the coordinate system (Fig. 2),
a small 0.3-degree (SD 0.2) rotation around the z-axis in the SIJ of
the standing leg (Pb0.001) was observed (Fig. 3), and this rotation
was signicantly different from the hanging-leg SIJ (P= 0.036).
Although the 0.3-degree rotation was signicantly different from zero,
only 50% of the patients had a movement that exceeded the threshold
of precision, with a maximum value of 1.0°. No translations were detect-
ed (Table 2). With the exception of the 0.2degree differenceobserved in
the z-axis rotation (P= 0.036), no differences were observed in the
movement between the SIJs of the standing leg and the hanging leg
(P-values between 0.055 and 0.978).
Four patients presented with clear unilateral symptoms. All other
patients had one or more positive SIJ provocation test(s) or pain local-
ized bilaterally on pain diagrams. There were no difference between
the 18 symptomatic joints and the four asymptomatic joints with re-
gard to the total amount of rotation (diff: 0.2, P= 0.335 on the
standing side; diff: 0.0, P= 0.896 on the hanging side) and transla-
tion (diff: 0.1, P= 0.398 on the standing side; diff: 0.1, P= 0.687
on the hanging side).
Fig. 2. The x, y, z coordinate system.
Table 2
Movement in the sacroiliac joint during the one-leg stance (n = 11).
Movement in the standing-leg SIJ (right) Movement in the hanging-leg SIJ (left)
Mean (SD) P-value Range % above precision Mean (SD) P-value Range % above precision
Rotation X 0.1 (0.2) 0.074 (0.70.9) 5% 0.1 (0.2) 0.150 (0.31.0) 5%
Y 0.1 (0.2) 0.359 (0.60.9) 14% 0.2 (0.3) 0.056 (0.51.1) 18%
Z 0.3 (0.2) 0.001 (0.21.0) 50% 0.1 (0.2) 0.084 (0.30.8) 14%
Translation X 0.0 (0.2) 0.607 (0.40.8) 27% 0.1 (0.1) 0.017 (0.40.4) 14%
Y 0.0 (0.1) 0.881 (0.20.5) 14% 0.1 (0.1) 0.039 (0.30.1) 14%
Z 0.1 (0.1) 0.115 (0.50.4) 0% 0.1 (0.1) 0.172 (0.60.4) 5%
Helical axis
Rotation 0.5 (0.3) b0.001 (0.71.3) 0.5 (0.2) b0.001 (0.11.3)
Translation 0.0 (0.1) 0.995 (0.40.7) 0.0 (0.1) 0.809 (0.31.3)
Mean = mean movement in the sacroiliac joint; rotations in degrees and translations in mm; P-value = t-test whether the mean values were differentfrom zero; % above precision =
the fraction of the measurements that are above the RSA precision; helical axis = the true axis of rotation.
3T.J. Kibsgård et al. / Clinical Biomechanics xxx (2014) xxxxxx
Please citethis article as: Kibsgård,T.J., et al., Radiosteriometric analysis of movement in the sacroiliacjoint during a single-leg stance in patients
with long-lasting pelvic girdle pain, Clin. Biomech. (2014),
Only two patients had a visible step in the symphysis during the
single-leg stance (Fig. 4), and these patients had bilateral symptoms,
with the right side being more painful. On the X-ray of the pubic bone,
there was a visible caudal shift of the pubic bone onthe side of the hang-
ing leg, and this shift was observed on both sides. The RSA measures
showed a combination of rotation in the SIJ of the standing leg and in
the SIJ of the hanging-leg side, with a relative forward rotation of the
hanging leg's innominate (Fig. 4). When the patients went from stand-
ing on the right leg to standing on the left leg a 1 and 1.4° of rotation
around the x-axis were seen between the two innominates.
Because the patients were observed in two different centers with
different laboratory setups, the results from the two labs were com-
pared. There was a 0.3 degree difference in the X-axis rotation of the
standing legs SIJ, but this statistical signicant difference was only a
small variation below the precision of 0.7°. Except for this, no differ-
ences were found between the two labs.
4. Discussion
This is the rst study to directly measure the movement in the SIJ
during the single-leg stance in patients with PGP. Only small move-
ments were detected. A total of 0.5° of movement were observed on
both sides, and there were no differences in total movement between
the SIJ of the hanging and standing legs.
One limitation of our study is that only 11 patients were included.
They were recruited from two different clinics. However, the results
were uniform between the two clinics, which strengthen the validity
of our results. A strength of this study is that the patients were selected
by strict criteria and had a long-standing history of severe PGP. The
patients reported a high degree of disability and pain and were referred
for SIJ fusion due to the severity of their symptoms and the failure of
non-surgical treatment. We believe that these patients are representa-
tive of patients with severe PGP.
A major strength of this study is that we used the RSA technique,
which has a high degree of precision and accuracy (Kibsgard et al.,
2012). To our knowledge, more precise techniques evaluating move-
ments than RSA do not exist. Because the tantalum markers are stable
in the bone segments and are situated close to the joint line, RSA is
more precise than other techniques that are used to examine SIJ move-
ment. A possible limitation is that we only used RSA radiographs, and
Fig. 3. Meanmovement in the SIJ withweight-bearing on theright leg. A mean z-rotation
of 0.3° is observed and corresponds to the force of the hanging leg on the sacrum.
Fig. 4. Sacroiliac jointmovement in the two patients witha detectible movement in the pubic symphysison an anteriorposterior RSA X-ray.AStanding on both legs, BStanding on the
right leg, CStanding on the left leg. Numbers presented are degreeof rotation around the x-axis (positive value = forward rotation, negative value = backward rotation).
4T.J. Kibsgård et al. / Clinical Biomechanics xxx (2014) xxxxxx
Please citethis article as: Kibsgård,T.J., et al., Radiosteriometric analysis of movement in the sacroiliacjoint during a single-leg stance in patients
with long-lasting pelvic girdle pain, Clin. Biomech. (2014),
not AP X-rays, to measure and identify patients with a large and clear
pubic movement. Hence, we might have missed those withsmall move-
ments in the pubic symphysis. The RSA X-rays are, however, sufcient
to identify large and abnormal movements. It would have been an
advantage to have included the Chamberlain X-ray in our protocol,
even though the Chamberlain X-ray is associated with measurement
errors and normal variations (Garras et al., 2008; Ruch and Ruch,
2005). According to Garras et al. (2008) the normal variation could be
up to 5 mm in asymptomatic volunteers (1.5 mm in men and nullipa-
rous women and 3.1 mm in multiparous woman).
Chamberlain reported a clear pattern of cranial displacement of the
pubic bone on the symptomatic side upon weight bearing (Anderson
and Peterson, 1944; Chamberlain, 1930). These ndings contradict
those of Mens et al. (2009), who observed a caudal displacement on
the hanging-leg side when symptoms were localized to the hanging-
leg SIJ. However, both Chamberlain and Mens observed a caudal slip
of the hanging-leg pubic symphysis. Their reported differences in the
correlation between pubic movement and clinical manifestations may
be a result of the different patient populations (Mens et al., 1999).
Chamberlain (1930) included patients with acute low back pain and
Mens et al. (1999) included women with SIJ pain after delivery.
Although there are some discrepancies among the studies that have
used the Chamberlain technique (Anderson and Peterson, 1944;
Chamberlain, 1930; Mens et al., 1999), these studies conclude that
hypermobility in the painful SIJ is responsible for movement in the
pubic symphysis. In our study, we observed only a small amount of
movement in the SIJ. Moreover, there were similar movements in
both the standing- and hanging-leg SIJs. We discovered two cases
with a visible step in the pubic symphysis on X-ray. However, these
two patients reported bilateral SIJ pain and possibly the results might
have been different if their symptoms were unilateral. Nonetheless,
four cases with unilateral symptoms did not have any asymmetrical
movement in the SIJ. Based on these results, the movement pattern of
the SIJ appears to be more complex than a single unidirectional rotation.
Instead, SIJ movement patterns are likely best explained by a combina-
tion of movements between the two innominates. With this level of
complexity, the Chamberlain technique is likely insufcient to quantify
SIJ movement. Hence, our interpretation is that the Chamberlain exam-
ination should not be recommended in the examinationof patients with
The literature disagrees on the degree of SIJ movement that occurs
during a single-leg stance, with reports ranging from movement that
can be felt by an examiner (Hungerford et al., 2007)toourRSAstudies
that have demonstratedalmost no movement. Theresults of our current
study were similar to the RSA study by Sturesson et al. (2000a) in which
the patients performed a standing hip exion test (with the hip maxi-
mally exed). Sturesson et al. (2000a) found 0.6° of rotation in the SIJs
of both the standing and contra-lateral legs. In the standing exion
test the joint is theoretically compressed and stabilized, and one could
have expected more movement during the Chamberlain examination
because the absence of muscular stabilization of the joint. In addition,
Sturesson et al. (1989) reported no differences between the symptom-
atic and asymptomatic joints. Jacob and Kissling (1995) used k-wires
to measure movement during the single-leg stance and found a total
movement of 1.5° between the two innominates; however, these
analyses were performed with healthy participants aged between
20 and 50 years. Our study supports previous studies that demon-
strate minimal movement in the SIJ in standing positions. Based
on this observation, the SIJ pain is unlikely to be caused by hyper-
mobility of the SIJ and the SIJ movement is probably too small to
assess with palpation (Freburger and Riddle, 2001). It is important
to note that these studies were performed in the standing position,
during which movement is expected to be small due to the theory of
Future studies will need to address the movements of the SIJ in an
unloaded pelvis.
With the minimal movement detected in this study it could be
questioned whether it is theoretically possible that these small move-
ments could result in a detectible movement in the pubic symphysis.
In this scenario, most of the rotation would be around the x-axis. The
normal distance from the sacral promontory to the pubic symphysis is
approximately 1012 cm, and the distance likely increases to 15 cm
because the markers are placed in the dorsal parts of the pelvis. With
these assumptions and simple trigonometry, we calculate that a rota-
tion of 23° would be necessary to trigger a 5 mm shift of the pubic sym-
physis. In the two patients with a visible step, a 1.0 and 1.4° of rotation
between the two innominates were observed (Fig. 4), and this rotation
should theoretically result in a 34 mm step. The total amount of
rotation around the helical axis (true axis of rotation) was in the same
patients 1.1 and 1.5, which support earlier assumptions of the axis of
rotation close to the x-axis. Mens et al. (1999) observed a caudal shift
of the pubic symphysis during the single-leg stance at the symptomatic
hanging leg and concluded that a SIJ rotation had occurred on the side
of the hanging leg. We found the same caudal shift, but the rotation in
the SIJ was a combination of rotation (rotation around the x-axis) of
the hanging-leg SIJ and a rotation of the standing-leg SIJ. Although our
theoretical assumption is simplied, it is unlikely that this minimal SIJ
movement can cause a clear and large movement in the pubic symphy-
sis. This can easily be explained by differences in X-ray projection
between the three different positions, a factor which has been reported
to be of importance in the analysis of Chamberlain test (Ruch and Ruch,
2005). An alternative explanation is the plasticity of the bone and defor-
mation of the innominates. There are some indications that deformation
of the innominate boneexists andcould contribute to this phenomenon
(Pool-Goudzwaard et al., 2012).
5. Conclusion
In patients with PGP the movements in the SIJs during the single-leg
stance are small and almost undetectable by the precise RSA method.
We measured a mean rotation of 0.5° on both the standing- and
hanging-legs SIJs, andno translation was detected. There were no differ-
ences in total movement between the standing- and hanging-leg SIJs.
The interpretation of the results of this study is that, the Chamberlain
examination is likely inadequate in the examination of SIJ movement
in patients with PGP.
This studywas supported by grants from the Norwegian Foundation
for Health and Rehabilitation. The sponsor had no involvement in the
planning, data collection, analysis, writing or other decisions regarding
the submission of this paper. We acknowledge the assistance of Alexis
Hinojosa (MRI radiographer; Department of Radiology and Nuclear
Medicine, Oslo University Hospital, Oslo, Norway) with the RSA radio-
graphs and analyses and Ingar Holme Ph.D. (statistician, Department of
Biostatistics and Epidemiology, Oslo University Hospital, Oslo, Norway)
for his help with statistics.
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6T.J. Kibsgård et al. / Clinical Biomechanics xxx (2014) xxxxxx
Please citethis article as: Kibsgård,T.J., et al., Radiosteriometric analysis of movement in the sacroiliacjoint during a single-leg stance in patients
with long-lasting pelvic girdle pain, Clin. Biomech. (2014),
... As for the possible angular motion in the frontal plane and linear displacements, invasive studies showed negligible position changes between the innominate bones and sacrum in more stressful situations for the pelvis. 22,33,34 Therefore, although the present method does not detect interinnominate axial rotations and linear displacements, it could be used to identify the different effects in RLRA and APRA, which was required for the present investigation related to the lateralview measure of sagittal torsion. ...
... Jacob and Kissling (1995) observed that a subject with recurrent sacroiliac joint symptoms had large sagittal interinnominate rotations in comparison with asymptomatic subjects, which contrasts with findings of small sacroiliac rotation in patients with long-lasting pain. 34 Therefore, LLD might have different effects on interinnominate posture in individuals with sacroiliac joint dysfunction. ...
Objective To investigate whether a common measure of sagittal pelvic torsion based on the superior iliac spines behave similarly to predictions of a rigid (non-torsioned) plane, when leg length discrepancies (LLD) are induced. Method Twenty-four young asymptomatic participants were subjected to pelvic posture measurements that use the anterior-superior iliac spines (ASISs) and posterior-superior iliac spines (PSISs) as references, while standing on level ground and with a one-, two- and three-centimeter lifts under the left foot. A special caliper with digital inclinometers was used. The following angles were measured: angles of the right and left PSIS-to-ASIS lines; right-left relative angle (RLRA), as the angle between the right and left PSIS-to-ASIS lines, which is a traditional lateral-view measure intended to detect sagittal torsions; angle of the inter-ASISs line; angle of the inter-PSISs line; anterior-posterior relative angle (APRA), as the angle between the inter-ASISs and inter-PSISs lines. According to trigonometric predictions based on the geometry given by the lines linking the superior iliac spines (i.e. a trapezoid plane), a pure lateral tilt of the pelvis, without interinnominate sagittal motion, would change RLRA in a specific direction and would not change APRA. Results Repeated-measures ANOVAs revealed that RLRA (p<0.001) and right and left PSIS-to-ASIS angles (p≤0.001) changed, and APRA did not change (p=0.33), as predicted. Conclusions At least part of the sagittal torsion detected by measures that assume the PSIS-to-ASIS angles as the sagittal angles of the innominates is due to pelvic geometry and not to the occurrence of actual torsion, when LLDs are induced.
... Five of these studies used patient data, one used healthy volunteers, three used fresh cadavers, and one study compared SIJ movement between patients and healthy volunteers (Table 1). [18][19][20][21][22][23][24][25][26][27] Among these, Lindsey et al. 21 showed the largest SIJ range of motion in the sagittal plane through motion analysis using seven fresh cadavers, and the SIJ moved 2.27 6 1.35°in the sagittal plane. ...
... 27 Hammer et al. 24 Other studies showed less than 1°of rotation in the sagittal plane. 19,20,22,23 Among the researched articles regarding spinopelvic parameter change, 10 articles that measured PI change of the spinopelvic parameters were selected to study SIJ movement. Three articles compared PI change between pre-and post-operative patient data, and seven studies assessed PI change with different postures (Table 2). ...
Several researchers investigated the anatomy and biomechanics of the sacroiliac joint (SIJ) to understand the relationship between lower back pain and the SIJ. Many studies concluded that the SIJ has little movement; however, some studies using spinopelvic parameters mentioned high change in pelvic incidence (PI). In this study, SIJ movement and PI change reported in previous studies were reviewed according to position and posture changes. Literature on SIJ movement was reviewed by searching through the publication databases. In biomechanical studies, the result of the rotational angle in the sagittal plane was mainly investigated to compare with the results of PI change. From the results of SIJ movement studies, the minimum movement of nutation and count-nutation was 0.01°, and maximum movement was 2.27°. From the results of PI change studies with different positions and movements, the highest change was 9°, and the lowest change was 0°. Movement of the SIJ was limited by its anatomical structure; maximum movement of the SIJ was 9° in a previous study. Therefore, SIJ movement should be studied more intensely as biomechanical perspective to understand its movement.
... Estimates range from 10% to 60% (depending on diagnostic criteria) of the population will suffer from primary SIJ dysfunction at some point during their life. 1 More likely, however, it is a concurrent low back pain (LBP) pathology with an SIJ component. An estimated 70-85% of the population will experience LBP at some point during their lifetime and 15-30% of these patients will have associated SIJ pain. ...
Background: Sacroiliac joint (SIJ) pain is a common cause of low back pain, a problem experienced by two-thirds of adults in the United States population. Traditionally, the management of persistent SIJ-related pain has involved conservative therapies (physical therapy, topical medications, oral anti-inflammatory medications), interventional therapies (SIJ steroid injections or ablation), and surgery (SIJ fusion; open and lateral approach). Recent advancements in technology have paved the way for SIJ fusion via a posterior approach, which aims to minimize complications and enhance recovery. Objective: The purpose of this study is to introduce the concept of the posterior approach to SIJ fusion as a feasible adjunct and salvage technique for patients with inadequate pain relief from other minimally invasive surgical procedures, and to validate its efficacy through a retrospective multicenter data analysis. Design: Multicenter retrospective observational study. Methods: Patients with refractory SIJ pain were treated by interventional pain physicians at one of the eight different pain management centers. All patients underwent posterior SIJ fusion via the LinQTM sacroiliac fusion procedure. Demographical data were collected, in addition to patient-reported pain relief. Results: A total of 111 patients were included in the study and underwent posterior SIJ fusion for refractory SIJ-related pain following the use of spinal cord stimulation (SCS), interspinous spacer (ISS), intrathecal drug delivery (IDDS), and/or minimally invasive lumbar decompression (MILD). Overall, the mean patient reported pain relief following posterior SIJ fusion was 67.6%. In patients with a history of failed back surgery syndrome, the mean patient reported pain relief was 76.5%. Conclusion: In this retrospective case series of patients with continued intolerable pain following SCS, ISS, IDDS, or MILD, a novel posterior SIJ fusion device provided significant pain relief in a salvage manner. These early results suggest that this intervention may be a therapeutic option to consider in these patients.
... Firstly, this novel case series only included a small number of patients. Despite previous studies using small cohort numbers reporting effectiveness of RSA due to the method's high precision [28][29][30], we acknowledge that no generalisation should be drawn from this study and that larger RSA studies are required before any evidence-based recommendations can be made. However, our results demonstrate the ability of RSA to detect translational and rotational instability of the pelvic ring during healing not visible on plain radiographs. ...
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There is currently no accurate data on fracture displacement during the rehabilitation of pelvic ring injuries. This study investigated the use of radiostereometric analysis (RSA) in assessing the stability of C1 pelvic ring injuries stabilised with a posterior plate and an anterior external fixator. Six patients, instructed to weight-bear as tolerated after surgery, were reviewed at 2, 4, 6, 12, 26, 52 and 104 weeks. The external fixators were removed at 6 weeks. Outcomes, including the Iowa Pelvic Score (IPS), and complications were recorded. Fracture stability was assessed using measurements on plain radiographs and RSA. All patients progressed to full weight-bearing without support within 6 weeks. At 104 weeks, the IPS was excellent in four patients, good in one patient and fair in one patient. Plain radiographs showed that all fractures were well reduced, and no loss of reduction occurred over time. By contrast, RSA measurements identified displacement in all cases. The maximum three-dimensional (3D) displacement at any time point in each patient ranged from 2 to 10 mm. Two patients with the largest displacement over time had the lowest IPS. RSA also demonstrated displacements above the currently defined normal threshold through the ‘un-injured’ sacroiliac joint in the same two patients, suggesting a subtle C2 injury, missed at initial assessment. This study demonstrates the limitations of plain radiographs in assessing pelvic fracture stability and displacement during healing, and the potential of RSA to monitor more accurately the effects of stabilisation and weight-bearing on fracture stability.
... The Stork test has been used to assess intra-pelvic motion by clinical palpation of the non-weight-bearing innominate relative to the ipsilateral sacrum (Hungerford et al., 2007;Lee, 2011). As sacro-iliac joint (SIJ) movements are found to be small (Kibsgard et al., 2012;Kibsgard et al., 2014;Sturesson et al., 2000a;Sturesson et al., 2000b) and clinical mobility tests of the SIJ in general show poor clinimetric properties (Klerx et al., 2019), the clinical value of motion palpation appears questionable. Nevertheless, as the body's center of mass moves in a more lateral direction over the standing leg during transition from double to SLS, it seems plausible that the Stork test particularly challenges medial-lateral trunk, pelvic and hip kinematics. ...
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Background: Pelvic girdle pain is prevalent during pregnancy, and women affected report weight-bearing activities to be their main disability. The Stork test is a commonly used single-leg-stance test. As clinicians report specific movement patterns in those with pelvic girdle pain, we aimed to investigate the influence of both pregnancy and pelvic girdle pain on performance of the Stork test. Methods: In this cross-sectional study, 25 pregnant women with pelvic girdle pain, 23 asymptomatic pregnant and 24 asymptomatic non-pregnant women underwent three-dimensional kinematic analysis of the Stork test. Linear mixed models were used to investigate between-group differences in trunk, pelvic and hip kinematics during neutral stance, weight shift, leg lift and single leg stance. Findings: Few and small significant between-group differences were found. Pregnant women with pelvic girdle pain had significantly less hip adduction during single leg stance compared to asymptomatic pregnant women (estimated marginal means (95% confidence intervals) -1.1° (-2.4°, 0.3°) and 1.0° (-0.4°, 2.4°), respectively; P = 0.03). Asymptomatic pregnant women had significantly less hip internal rotation compared to non-pregnant women 4.1° (1.6°, 6.7°) and 7.9° (5.4°, 10.4°), respectively (P = 0.04) and greater peak hip flexion angle of the lifted leg in single leg stance 80.4° (77.0°, 83.9°) and 74.1° (70.8°, 77.5°), respectively (P = 0.01). Variation in key kinematic variables was large across participants in all three groups. Interpretation: Our findings indicate that trunk, pelvic and hip movements during the Stork test are not specific to pregnancy and/or pelvic girdle pain in the 2nd trimester. Instead, movement strategies appear unique to each individual.
... The normal motion is only 2.5° (5)(6)(7). The emergence of a pronounced sexual dimorphism in joint structure occurs after puberty. ...
Background: The sacroiliac joint has a structure in which the direction of the load relative to the articular surface is irrational, as the joint surface is not perpendicular to the trunk load axis, it is likely to incur more degenerative changes than other weight-bearing joints. Methods: This retroprospective study consisted of a total of 145 cases 104 (71.7%) men and 41 (28.3%) women who applied to Gaziantep University Medical Faculty Radiology Department Polyclinic with pelvic CT from 2013 to 2018. The mean age was 33.5 years (range: 18 to 60 years). Pelvis CT images were performed according to the exclusion criteria specified by the experienced orthopedic surgeon. Patients were excluded from the study if they were younger than the age of 18; had a condition involving the sacroiliac joint, had an endocrine disorder, or had a history of a trauma affecting the pelvis CT examination. Results: In this current study, six types of anatomic variations were detected. Iliosacral complex variation has been determined as the most common type of variation. The incidence of variations of SJ in all cases was 28.9%. Degenerative changes were seen in 5.5% of patients fewer than 30 years of age. When it comes to the patients whose age range is 30-60, the percentage of the degenerative changes is 12.4%. In patients who were thirty years and older, the prevalence of degenerative changes increased progressively with increasing age. Conclusions: In this study, it is thought that the knowledge of variations in normal population and degenerative changes will contribute to the better understanding of normal morphological structure of SJ and to the anatomical literature. It's seen that there is not a statistically significant relationship between degenerative changes and anatomical variations.
Pelvic incidence (PI) is often quantified in patients undergoing total hip arthroplasty. Errors in radiographic PI measurements can affect clinical outcomes. The purposes of this study were 1) to evaluate the error in radiographic PI measurement in patients with hip osteoarthritis (OA) and 2) to analyze the factors related to the error. Radiographs and computer tomography (CT) images of 100 patients (24 men and 76 women; mean age 63.7 years) with unilateral OA were reviewed. The error in radiographic PI measurement was defined as the difference between the radiographic measurement of the PI (rPI) and the accurate value of PI measured using CT images (cPI). Factors related to the error in the rPI were analyzed, including the coronal and axial rotation of the pelvis on lateral radiographs. The degree of coronal and axial rotation was expressed as the angle of rotation around the anteroposterior and craniocaudal axes. The mean rPI was significantly larger than the cPI (57.8°and 54.1°, p <0.01). The error in the rPI was 3.6° on average and 15.8° at maximum. The mean coronal and axial rotation of the pelvis was 9.6° and 4.4°, respectively. The error in the rPI positively correlated with coronal pelvic rotation and rPI, and negatively correlated with axial pelvic rotation (p <0.01, r = 0.35, 0.43, and -0.45, respectively). The rPI was 3.6° larger on average than the cPI in patients with hip OA. Coronal and axial rotation of the pelvis and a large PI were related to the error in the rPI. This article is protected by copyright. All rights reserved.
Pregnancy and childbirth bring along several changes to a woman’s body, especially to the musculoskeletal system. On one hand, pregnancy and childbirth not only represents a window of opportunity for the adoption of an active and healthy lifestyle, but it is also a risk period for the development of musculoskeletal disorders that may negatively affect ability to participate in physical activity both during pregnancy, in the postpartum period and for some, if the conditions are not treated, the rest of their lives. This chapter addresses the most prevalent musculoskeletal complaints related to pregnancy and the postpartum period: pelvic floor dysfunction; urinary incontinence, diastasis recti abdominis, and low back pain and/or pelvic girdle pain.KeywordsDiastasis recti abdominisExerciseLow back painPelvic floor pelvic girdle painPhysical activityPostpartumPregnancy
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Introduction Sacroiliac joint (SIJ) can be a nociceptive source of the pain in lower back. Clinical diagnosis of SIJ pain remains yet problematic. The cause of SIJ pain is multifactorial. The pain may be a result of an inflammatory disease, arthrosis, traumatic injury, infectious process or overload. The potential role in SIJ examination have pain provocation tests. Objective To review and further discuss the validity of some of the mostly used clinical provocation tests such as Distraction test, Thigh Thrust test, Compression test, Sacral Thrust test, Patrick’s (FABER), Gaenslen’s test, Standing Flexion Test, Gillet Test and Shimpi Prone test. Method A literature search was conducted using PubMed. Reviewed were studies between 2005 and 2020 in English, Slovak and Czech with keywords: sacroiliac joint, sacroiliac assessment, provocation tests. The methodology of studies was not considered. Discussion It is challenging to determine whether SIJ is the actual source of the pain by using only one of the provocation tests. Therefore, it is beneficial to combine more compression tests, what will also increase the validity of testing. Other widely used SIJ tests are palpation test, however their validity is poor.
[Purpose] The validity of the measurement of the direction of pelvic motion using a 3D motion analysis with skin markers during a sit-to-stand task was determined. [Participants and Methods] Fifteen healthy subjects were recruited and the motion of 30 sacroiliac joints in total were captured during the task. The markers on the skin surfaces of bony landmarks of the pelvis were set in a relaxed seated position and in the position just before seat-off. The angle of the innominate motion relative to the sacrum was calculated from the initiation of the task to the instant of seat-off and compared between the two conditions. [Results] In the 2 conditions, the direction of sacroiliac motion coincided in all joints. [Conclusion] The results suggest that in order to determine the direction of sacroiliac motion a procedure applying the markers on the skin surface in a seated position can be used to study sit-to-stand movement.
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Sacroiliac joint (SIJ) pain is an underappreciated source of mechanical low back pain, affecting between 15 and 30% of individuals with chronic, nonradicular pain. Predisposing factors for SIJ pain include true and apparent leg length discrepancy, older age, inflammatory arthritis, previous spine surgery, pregnancy and trauma. Compared with facet-mediated and discogenic low back pain, individuals with SIJ pain are more likely to report a specific inciting event, and experience unilateral pain below L5. Owing in part to its size and heterogeneity, the pain referral patterns of the SIJ are extremely variable. Although no single physical examination or historical feature can reliably identify a painful SIJ, studies suggest that a battery of three or more provocation tests can predict response to diagnostic blocks. Evidence supports both intra- and extra-articular causes for SIJ pain, with clinical studies demonstrating intermediate-term benefit for both intra- and extra-articular steroid injections. In those who fail to experience sustained relief from SIJ injections, radiofrequency denervation may provide significant relief lasting up to 1 year. This review covers all aspects of SIJ pain, with the treatment section being primarily focused on procedural interventions.
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Objective signs to assess impairment in patients who are disabled by peripartum pelvic girdle pain hardly exist. The purpose of this study was to develop a clinical test to quantify and qualify disability in these patients. The study examined the relationship between impaired active straight leg raising (ASLR) and mobility of pelvic joints in patients with peripartum pelvic girdle pain, focusing on (1) the reduction of impairment of ASLR when the patient was wearing a pelvic belt, and (2) motions between the pubic bones measured by X-ray examination when the patient was standing on one leg, alternating left and right. Twenty-one non-pregnant patients with peripartum pelvic girdle pain in whom pain and impairment of ASLR were mainly located on one side were selected. ASLR was performed in the supine position, first without a pelvic belt and then with a belt. The influence of the belt on the ability to actively raise the leg was assessed by the patient. Mobility of the pelvic joints was radiographically visualized by means of the Chamberlain method. Assessment was blinded. Ability to perform ASLR was improved by a pelvic belt in 20 of the 21 patients (binomial two-tailed P = 0.0000). When the patient was standing on one leg, alternating the symptomatic side and the reference side, a significant difference between the two sides was observed with respect to the size of the radiographically visualized steps between the pubic bones (binomial two-tailed P = 0.01). The step at the symptomatic side was on average larger when the leg at that side was hanging down than when the patient was standing on the leg at that side. Impairment of ASLR correlates strongly with mobility of the pelvic joints in patients with peripartum pelvic girdle pain. The ASLR test could be a suitable instrument to quantify and qualify disability in diseases related to mobility of the pelvic joints. Further studies are needed to assess the relationship with clinical parameters, sensitivity, specificity and responsiveness in various categories of patients. In contrast with the opinion of Chamberlain, that a radiographically visualized step between the pubic bones is caused by cranial shift of the pubic bone at the side of the standing leg, it is concluded that the step is caused by caudal shift of the pubic bone at the side of the leg hanging down. The caudal shift is caused by an anterior rotation of the hip bone about a horizontal axis near the sacroiliac joint.
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Different techniques have been used to quantify the movement of sacroiliac (SI) joints. These include radiostereometric analysis (RSA), but the accuracy and precision of this method have not been properly evaluated and it is unclear how many markers are required and where they should be placed to achieve proper accuracy and precision. The purpose of this study was to test accuracy and precision of RSA, applied to the SI joint, in a phantom model and in patients. We used a plastic phantom attached to a micrometer to obtain a true value of the movement of the SI joint and compared this value with the measured value obtained by RSA; the difference represented the accuracy. The precision of the system was measured by double examination in the phantom and in six patients, and was expressed by a limit of significance (LOS). We analyzed different marker distributions to find optimal marker placement and number of markers needed. The accuracy was high and we identified no systematic errors. The precision of the phantom was high with a LOS less than 0.25° and 0.16 mm for all directions, and in patients, the precision was less than 0.71° for rotations and 0.47 mm translations. No markers were needed in the pubic symphysis to obtain good precision. The accuracy and precision are high when RSA is used to measure movement in the SI joint and support the use of RSA in research of SI joint motion.
About 45% of all pregnant women and 25% of all women postpartum suffer from pelvic girdle pain and/or low back pain (PLPP). It has been suggested that increased motion of the three joints in the pelvic ring is one of the causes of PLPP. However, in spite of the availability of high technology the relation between enlarged motion of the pelvic joints and pain remains unclear. This article presents 14 studies on this topic, of which 8 are of sufficient quality to draw conclusions. The conclusion is that, during the last months of pregnancy and the first 3 weeks after delivery, motion of the pelvic girdle joints is 32-68% larger in patients with PLPP than in healthy controls. The overlap in the range of symphyseal motion between PLPP patients and healthy controls is too large to use motion as a diagnostic tool in individual cases. The findings support the idea that enlarged motion is one of the factors that causes PLPP and justifies treatment with measures to reduce this motion.
This study deals primarily with the stability of the base of the spine. The sacroiliac joints are vulnerable to shear loading on account of their predominantly flat surfaces. This raises the question of what mechanisms are brought into action to prevent dislocation of the sacroiliac joints when they are loaded by the weight of the upper part of the body and by trunk muscle forces. First a model is introduced to compare load transfer in joints with spherical and with flat joint surfaces. Next we consider a biomechanical model for the equilibrium of the sacrum under load, describing a self-bracing effect that protects the sacroiliac joints against shear according to 'the sacroiliac joint compression theory', which has been demonstrated in vitro. The model shows joint stability by the application of bending moments and the configuration of the pelvic arch. The model includes a large number of muscles (e.g. the gluteus maximus and piriformis muscles), ligaments (e.g. the sacrotuberous, sacrospinal, and dorsal and interosseous sacroiliac ligaments) as well as the coarse texture and the ridges and grooves of the joint surfaces.
The Standardization and Terminology Committee (STC) of the International Society of Biomechanics (ISB) proposes a general reporting standard for joint kinematics based on the Joint Coordinate System (JCS), first proposed by Grood and Suntay for the knee joint in 1983 (J. Biomech. Eng. 105 (1983) 136). There is currently a lack of standard for reporting joint motion in the field of biomechanics for human movement, and the JCS as proposed by Grood and Suntay has the advantage of reporting joint motions in clinically relevant terms.In this communication, the STC proposes definitions of JCS for the ankle, hip, and spine. Definitions for other joints (such as shoulder, elbow, hand and wrist, temporomandibular joint (TMJ), and whole body) will be reported in later parts of the series. The STC is publishing these recommendations so as to encourage their use, to stimulate feedback and discussion, and to facilitate further revisions.For each joint, a standard for the local axis system in each articulating bone is generated. These axes then standardize the JCS. Adopting these standards will lead to better communication among researchers and clinicians.
The question of sacroiliac slip has been discussed for years. Snelling published a paper on this subject in 1870. Goldthwaite and Osgood made an important contribution in 1905. Fick, Smith-Petersen and others have also made their contributions. There seems to be no question at the present time but that the sacroiliac joint is a movable joint.Chamberlain in 1919 first began to use his x-ray technic of demonstrating slipping of the sacroiliac joints. He read a report on this subject at a meeting of the American Roentgen Ray Society in September 1922. Allen published the description of a somewhat similar technic in 1923. Chamberlain1 has published papers in 1930 and 1932 on this subject.Chamberlain states that "there is no reason to expect the ordinary anteroposterior view of the sacroiliac region to reveal the normal or abnormal movement occurring in these joints because motion of the sacroiliac joint is