Sawacha et al. Journal of NeuroEngineering and Rehabilitation 2013, 10:95
http://www.jneuroengrehab.com/content/10/1/95
RESEARCH
JNER
JOURNAL OF NEUROENGINEERING
AND REHABILITATION
Open Access
Relationship between clinical and instrumental
balance assessments in chronic post-stroke
hemiparesis subjects
Zimi Sawacha1†, Elena Carraro2†, Paola Contessa1†, Annamaria Guiotto1, Stefano Masiero2 and Claudio Cobelli1*
Abstract
Background: Stroke is often associated with balance deficits that increase the risk of falls and may lead to severe
mobility disfunctions or death. The purpose of this study is to establish the relation between the outcome of
instrumented posturography and of the most commonly used clinical balance tests, and investigate their role for
obtaining reliable feedback on stroke patients’ balance impairment.
Methods: Romberg test was performed on 20 subjects, 10 hemiplegic post-stroke subjects (SS, 69.4 ± 8.2 years old)
and 10 control subjects (CS, 61.6 ± 8.6 years old), with 1 Bertec force plate. The following parameters were
estimated from the centre of pressure (CoP) trajectory, which can be used to define subjects’ performance during
the balance task: sway area; ellipse (containing 95% of the data); mean CoP path and velocity in the anteriorposterior and medio-lateral directions. The following clinical scales and tests were administered to the subjects:
Tinetti Balance test (TB); Berg Balance test (BBT); Time up and go test (TUG), Fugl-Meyer (lower limbs) (FM), Motricity
Index (lower limbs), Trunk Control Test, Functional Independence Measure. Comparison between SS and CS
subjects was performed by using the Student t-test. The Pearson Correlation coefficient was computed between
instrumental and clinical parameters.
Results: Mean ± standard deviation for the balance scales scores of SS were: 12.5 ± 3.6 for TB, 42.9 ± 13.1 for BBT,
24 s and 75 cent ± 25 s and 70 cent for TUG. Correlation was found among some CoP parameters and both BBT
and TUG in the eyes open and closed conditions (0.9 ≤ R ≤ 0.8). Sway area correlated only with TUG. Statistically
significant differences were found between SS and CS in all CoP parameters in eyes open condition (p < 0.04);
whereas in eyes closed condition only CoP path and velocity (p < 0.02) differed significantly.
Conclusions: Correlation was found only among some of the clinical and instrumental balance outcomes,
indicating that they might measure different aspects of balance control. Consistently with previous findings in
healthy and pathological subjects, our results suggest that instrumented posturography should be recommended
for use in clinical practice in addition to clinical functional tests.
Background
Stroke is the third leading cause of death and the major
cause of severe disability and impairment in the industrialized world [1]. In Europe, about 250 strokes/100.000
inhabitants occur every year, with a rising trend [2].
Following a stroke, patients frequently suffer severe disability and marked limitations in activities of daily living.
Postural instability is one of the major deficits following
* Correspondence: cobelli@dei.unipd.it
†
Equal contributors
1
Department of Information Engineering, University of Padova, Padova, Italy
Full list of author information is available at the end of the article
a stroke, with associated increased risk of fall; a consequence of this problem is reduced mobility, increased
disability and even mortality [3-8]. Stroke subjects who
retain the ability to stand show delayed and disrupted
equilibrium reactions, exaggerated postural sway in both
sagittal and frontal planes, reduced weight-bearing on
the paretic limb and increased risk of falling [9]. The
clinical and social impact of postural instability has produced a great deal of research in this field that allowed
the development of several functional tests and laboratory methods (posturography) to explore the extent of
balance dysfunction [10].
© 2013 Sawacha et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.
Sawacha et al. Journal of NeuroEngineering and Rehabilitation 2013, 10:95
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Both these functional test and posturographic techniques have been applied to specifically investigate balance deficits in stroke patients [11,12]. Quantitative
posturography utilizes force plates to monitor the trajectory of the centre of pressure (CoP). The CoP trajectory
reflects the body sway during standing and the ability of
the nervous and musculoskeletal systems to integrate information from multiple sensory systems, including the
visual, the somatosensory, and the vestibular system to
maintain balance [13,14]. Alterations of the postural
control system are reflected in changes of CoP characteristics and parameters [13,14], which is therefore a key
variable for monitoring the postural control system
[13-16]. Although instrumented posturography has demonstrated its validity in monitoring balance, the use of
force plates in the clinical practice is not yet common
and simple test batteries and questionnaires to test balance and mobility are often employed as useful alternatives [7,11,17]. Some of these tests and scales, which are
described in detail in the Methods section, include the
Fugl-Meyer scale (FM) [18]; the lower Motricity Index
(lo-MI) [19]; the Trunk Control Test (TCT) [20]; the
Functional Independence Measure (FIM) [21-24]; the
Tinetti Balance scale (TB) [7]; the Berg Balance Test
(BBT) [24]; and the Time up and go Test (TUG) [17].
Some of these tests have proved to be a valid and reliable indicator for balance ability [12]. For instance, in a
study by Bogle et al. (1996), falls in stroke patients were
associated with poor performance in the Berg Balance
Scale [25]. However, the individual clinical functional
tests do not reflect the complexity and multidimensional
nature of balance [26].
While both functional tests and instrumented measures are used to monitor balance function in stroke
subjects, with the clinical settings relying mostly on the
former, their relationship and their usefulness as means
for obtaining reliable feedback on the patient balance
impairments and for evaluating the effects of a rehabilitative treatment has not been investigated yet. Therefore,
the aim of this study is to assess postural stability using
both computerised posturography and functional balance tests in chronic post-stroke patients and to investigate their relation.
Methods
Participants
20 subjects participated in the study, 10 control subjects
(CS) and 10 hemiplegic post-stroke subjects (SS).
SS patients were recruited from the outpatient clinic
of the Rehabilitation Department of the University of
Padova (Italy). All patients were diagnosed with chronic
post-stroke hemiplegia/hemiparesis (> 1 year from onset) and were able to walk independently or with supervision (Functional Ambulation Classification scores ≥3)
Page 2 of 7
[27]. Exclusion criteria for SS were: concomitant cardiovascular disease; other neurological or psychiatric diseases; severe visual or auditory impairments (reduced
visual acuity was accepted if adequately corrected). Patients with multiple cerebrovascular lesions or with
infratentorial lesion were not recruited. Patients were
also excluded if their pharmacological therapy changed
during the trial or in the previous month; or if they
attended a rehabilitation treatment during the study or
in the 3 months before the study.
The CS consisted of healthy subjects enrolled among
hospital personnel. The study was approved by the ethics committee of the Hospital of Padova (Italy). An informed consent form was obtained from all participants.
SS and CS subject groups were matched for age and
BMI. Mean age was 69.4 ± 8.21 years for SS and 61.60 ±
8.57 years for CS (p = 0.058); mean BMI was 25.16 ± 2.48
kg/m2 for SS and 27.30 ± 2.24 kg/m2 for CS (p = 0.066).
Body mass and height did not differ: mean body mass
for SS and CS was 80.00 ± 12.26 kg and 80.30 ± 8.12 kg,
respectively (p = 0.950); mean height was 177.56 ± 9.08
cm and 172.30 ± 5.43 cm, respectively (p = 0.140). The
time since stroke for the SS group was on average 7.5 ±
8.9 years.
Clinical and instrumental evaluation
Instrumental evaluation consisted in the Romberg test,
which was performed on all subjects with 1 Bertec force
plate (FP4060-10, 960 Hz). Subjects were asked to stand
on the force plate, with their feet placed so as to maintain the heels together and a 30 degrees angle between
the right and left toes, and to relax the arms along the
body [28]. To ensure similar angles between the feet
throughout the test, a guide made of heavy cardboard
was placed on the force plate, and the subjects lined
their feet up along both arms of the foot-guide. Once
the subjects assumed the correct posture, they were
asked to maintain the upright standing position for 60 s
with their eyes open (EO) while looking at a circular target placed at a distance of 4 m in front of them and then
to maintain the same position for 60 s with their eyes
closed (EC) [29]. The CoP trajectory was acquired during the Romberg test. The signal underwent a postacquisition filtering and downsampling technique, thus
reducing the frequency to 100 samples/s (the first 20 s
of the signal were not analyzed) [13,14,18,29] From the
CoP signals the following posturographic parameters
were computed [13,14,18,29]: the sway area, which is a
measure of the area included in CoP displacement per
unit of time (mm2/s); the ellipse containing 95% of the
CoP data point; the CoP path, calculated as the total
length of the CoP path; the CoP path in both in the
anterior-posterior (AP) and in the medio-lateral (ML) directions, which are approximated by the sum of the
Sawacha et al. Journal of NeuroEngineering and Rehabilitation 2013, 10:95
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distances between consecutive points in the AP and ML
directions; and the CoP velocity (CoPv), as well the CoP
velocity in both the AP and in the ML directions. All
data analysis was performed using the Matlab software.
The following clinical tests were administered exclusively to the SS subjects to quantify their motor and
functional impairment and their degree of disability:
Fugl-Meyer scale for lower limbs (FM); Motricity Index
for lower limbs (lo-MI); Trunk Control Test (TCT); and
Functional Independence Measure (FIM).
The FM scale is a multi-item Likert-type scale developed as an evaluative measure of recovery from hemiplegic stroke. We used the subscale for motor domain of
the lower limbs that includes items quantifying movement, coordination, and reflex action about the hip,
knee, and ankle; with motor score ranging from 0 (hemiplegia) to a maximum of 34 points (normal motor performance) [19]. lo-MI is an ordinal weighted scale used
to assess the severity of motor impairment of the lower
limb after a stroke. Essentially, it tests 6 limb movements
while the patient is sitting on a chair or on the edge of
the bed [20]. The Trunk Control Test evaluates three
movements and one posture (balance in sitting position).
The total score ranges from 0 to 100 points, a higher
score indicating a better trunk performance [21]. FIM is
a scale that measures the severity of disability and the
outcomes of adult inpatient medical rehabilitation. It describes the level of independence on 18 items covering
the domains of self-care, sphincter management, transfers, locomotion, communication, and social cognition.
Each item is rated 1–7, with the higher rating indicating
more independent performance. Total scores range from
18 to 126. The 13-item motor domain (range, 13–91)
and the five-item cognitive domain (range, 5–35) are
commonly scored separately [22-24,30].
The following clinical balance scales were administered to SS subjects to specifically evaluate their balance
impairment: Tinetti Balance assessment tool (TB); Berg
Balance Test (BBT); Time up and go Test (TUG).
The TB assessment tool is a simple, easily administered test that measures a patient’s gait and balance.
Scoring is performed on a three point ordinal scale, ranging from 0 to 2. The individual scores are then combined to form three measures: an overall gait assessment
score, an overall balance assessment score, and a gait
and balance score [7]. In our work, we only considered
the balance assessment score, with a maximum of 16
points. The BBT was developed to measure balance impairment among elderly people by assessing the performance of specific functional tasks. It’s a 14-item scale
with a five-point scale, ranging from 0 to 4: ′0′ indicates
the lowest level of function abilities and ′4′ the highest
level of function abilities, with a total score of 56 [30].
The TUG test is a simple and quick functional mobility
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test that measures the time taken by an individual resting on a chair to stand in an upright position and to sit
down again [17].
Statistical analysis
Comparison between SS and CS subjects was performed
by means of the Student t-test or Mann–Whitney U-test
(SPSS v 13 Software), when appropriate based on the
Levene’s Test for Equality of means. The Pearson Correlation coefficient was computed between instrumental
and clinical balance parameters (SPSS v 13 Software).
The threshold for statistical significance was set to p <
0.05.
Results
Clinical measures are reported in Table 1 for SS subjects.
Note that one of the subjects abandoned the study
because his pharmacological therapy changed during
the trial. Mean values for the balance scale scores were
12.5 ± 3.6 for TB, 42.9 ± 13.1 for BBT, 24 s and 75 cent ±
25 s and 70 cent for TUG, respectively.
The CoP trajectory was computed from the force data
acquired during the Romberg test in the EO and EC
conditions. Results of all posturographic parameters are
reported in Table 2 (EO) and Table 3 (EC) and in
Figure 1 for SS and CS subjects, together with the pvalue for significance. Statistically significant differences
were found between SS and CS in all CoP parameters in
EO condition (p < 0.05). In EC condition, significant differences were observed in the CoP path and in the CoP
velocity and both the CoP path and velocity in the AP
direction.
Regarding the correlation analysis results, it should be
noticed that TB scores did not correlate with any instrumental measurements. Similarly, no correlation was observed among clinical scales and ellipse values, CoP path
values, and CoP path values in the ML direction. In contrast, BBT was correlated with CoP path and CoPv in
the AP direction in EO condition; with all CoPv-based
parameters in EC condition. Similarly, moderate to high
correlation was found, both in the EO and EC conditions, among TUG scores and sway area, CoP path in
the AP direction and all CoPv-based parameters; with
the only exceptions of CoP path in the AP direction with
EC and CoPv in the ML direction with EO. See Table 4
for details.
Discussion
The main purpose of the study was to investigate the
relation between the outcomes of instrumented
posturography (the CoP parameters) and those of functional balance tests and scales in stroke subjects.
Analysis of CoP components has proved to be useful in
predicting the risk of falling and changes in postural
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Table 1 Clinical measurements for post-stroke subjects
Subject #
1
2
3
4
5
6
7
8
9
10
Fugl-Meyer (leg)
28
25
31
24
28
24
27
26
22
20
Motricity Index (leg)
99
64
99
83
36
83
91
91
59
72
Trunk Control Test
41
37
100
74
99
61
100
87
87
61
Functional Indipendence Measure
125
50
126
122
126
115
123
117
83
101
16′05
1′34′37
8′33
25′02
10′94
29′
9′09
10′36
29′09
8′45
MOTOR IMPAIRMENT
BALANCE SCORES
Time up and go (minutes/seconds)
Berg Balance Test
48
14
56
46
56
36
52
48
30
43
Tinetti Balance
14/16
6/16
16/16
11/16
16/16
12/16
16/16
16/16
9/16
9/16
Values for the clinical tests performed for post-stroke subjects. Note that only 9 subjects are reported because the pharmacological therapy of one subject
changed during the trial.
performance [12-14,23,24,30-33] in healthy and pathologic subjects, and can detect changes in balance control
produced by different treatments [12-16,31,32].
In terms of the outcomes of the posturographic analysis, our results showed statistical difference for all the
parameters between healthy and stroke subjects in the
EO condition, whereas only four parameters were statistically different between the two subject populations in
the EC condition (CoP path and CoPv, AP CoP path and
AP CoPv). The lack of significant difference in the EC
condition should not be necessarily attributed to a worst
performance of SS subjects in EO condition, but could
simply reflect the decrease in balance control in EC condition for CS subjects, decrease that has been well documented in previous studies [25]. While CS group’s
performance clearly worsens in EC condition, SS group
shows poor balance in both EC and EO conditions. It is
well known that visual information is an important component of balance even during quiet stance, as evidenced
by the fact that both the amplitude and variability of
body sway increase during EC condition [12-16]. The
Table 2 Centre of pressure (CoP) parameters: Romberg
test in eyes open (EO) condition
CoP Parameters
SS
CS
P-values
647.9 ± 449.6
312.26 ± 168.5
0.042*
43.6 ± 31.2
15.4 ± 7.4
0.005*
Path (mm)
665.1 ± 295.9
352.9 ± 82.6
0.005*
Path ML (mm)
384.9 ± 266.0
186.4 ± 43.4
0.032*
Path AP (mm)
444.4 ± 214
259.1 ± 62.9
0.018*
CoPv (mm/s)
17.80 ± 9.1
8.82 ± 2.1
0.007*
CoPv ML (mm/s)
10.1 ± 6.8
4.7 ± 1.1
0.022*
CoPv AP (mm/s)
12.1 ± 7.3
6.5 ± 1.6
0.031*
Ellipse (mm2)
Sway Area (mm2/s)
Parameters computed from the CoP trajectory acquired during the Romberg
Test in the EO condition for post-stroke (SS, second column) and control
subjects (CS, third column). All parameters were significantly different between
SS and CS, as indicated by the p-values on the right-hand side column (the
asterisks mark the values exceeding the threshold for significance, p < 0.05).
Values are reported as mean ± standard deviation.
results of this study indicate that in SS subjects visual information did not improve balance performance as
much as in healthy subjects. The control of upright
posture is a complex mechanism that involves the continuous integration of afferent signals from the visual,
vestibular and somatosensory systems [14,15]; and it
requires intact effectors in order to realize the correct
postural program. Individuals who have experienced injury to the central nervous system in the form of a
stroke may exhibit difficulty with sensory processing
and/or motor planning. In these patients, the inability of
peripheral sensory receptors to gain information about
the environment may result in impaired postural
control. Results might provide evidence that subjects affected by stroke rely on their vestibular and proprioceptive system in a greater degree than healthy subjects,
who rely heavily on their visual feedback [26].
CoP path was significantly larger for the SS group in both
AP and ML directions in EO and EC conditions, similarly
to what reported by Corriveau et al. [31]. Consequently, the
Table 3 Centre of pressure (CoP) parameters: Romberg
test in eyes closed (EC) condition
CoP Parameters
Ellipse (mm2)
2
Sway Area (mm /s)
Stroke subjects
Control subjects
P-values
425.5 ± 180.5
309.3 ± 169.2
0.195
38.3 ± 31.6
17.9 ± 8.4
0.067
610.8 ± 192.2
412.7 ± 122.6
0.020*
Path ML (mm)
275.5 ± 86.1
215.80 ± 76.4
0.153
Path AP (mm)
494.4 ± 170.4
305.1 ± 85.5
0.008*
CoPv (mm/s)
Path (mm)
18.2 ± 10.0
10.3 ± 3.1
0.033*
CoPv ML (mm/s)
8.4 ± 5.2
5.4 ± 1.9
0.117
CoPv AP (mm/s)
14.6 ± 7.6
7.6 ± 2.1
0.015*
Parameters computed from the CoP trajectory acquired during the Romberg
Test in the EC condition for post-stroke (SS, second column) and control
subjects (CS, third column). CoP path and velocity (CoPv), and the component
in the antero-posterior direction were significantly different between SS and
CS, as indicated by the p-values on the right-hand side column (the asterisks
mark the values exceeding the threshold for significance, p < 0.05). Values are
reported as mean ± standard deviation.
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Figure 1 Boxplots of the posturographic parameters. Stroke subjects (SS) always on the right, Control Subjects (CS) always on the left. From
left to right vertical axes represent: the ellipse 95% (Ellipse 95%), the sway area (Sway Area), the total path (Path), the path in medio-lateral
direction (Path ML), the path in anterior-posterior direction (Path AP), the total mean velocity (Mean Velocity), the mean velocity in in mediolateral direction (Mean Velocity ML), and the mean velocity in anterior-posterior direction (Mean Velocity AP). Both eyes open (EO) and eyes
closed (EC) condition have been reported.
difference is clinically significant and confirms the postural
instability in both directions (AP, ML) of the SS compared
with the group of age-matched CS. In contrast, only the AP
component of CoP was significantly different in the EC
condition. Similar results were obtained for the CoP
velocity, a parameter that is highly correlated to CoP path.
In disagreement with Corriveau et al. [31] results on CoP
path in SS suggests that patients affected by hemiplegia do
not rely primarily on vision to compensate for motor
control deficits in the lower extremity.
Table 4 Correlations between clinical balance scales and laboratory measures
EO
2
Ellipse (cm )
Sway Area (cm2)
Path (cm)
Path ML (cm)
Path AP (cm)
CoPv (cm/s)
CoPv ML (cm/s)
CoPv AP (cm/s)
2
TB
BBT
EC
TUG
TB
BBT
TUG
R
0.08
−0.20
0.18
0.25
−0.24
0.47
p-value
0.580
0.400
0.320
0.558
0.560
0.240
R2
−0.15
−0.59
0.76
−0.25
−0.69
0.89
p-value
0.470
0.090
0.011*
0.545
0.06
0.004*
R2
−0.15
−0.25
0.33
−0.37
−0.49
0.50
p-value
0.470
0.330
0.110
0.361
0.280
0.210
R2
−0.17
0.15
−0.02
−0.42
−0.64
0.69
p-value
0.450
0.380
0.670
0.299
0.080
0.060
R2
−0.06
−0.74
0.86
−0.33
−0.33
0.37
p-value
0.600
0.010*
0.001*
0.417
0.430
0.360
R2
−0.18
−0.43
0.67
−0.32
−0.75
0.89
p-value
0.430
0.146
0.034*
0.445
0.030*
0.003*
R2
−0.19
0.09
0.09
−0.31
−0.79
0.93
p-value
0.410
0.550
0.500
0.454
0.018*
0.001*
R2
−0.10
−0.78
0.92
−0.32
−0.71
0.86
p-value
0.540
0.010*
< 0.001*
0.430
0.040*
0.010*
R2-values and p-values for the correlation analysis between clinical measures (Tinetti Balance Test, TB; Berg-Balance Test, BBT; Time up and go Test, TUG) and
laboratory measures (centre of pressure parameters, CoP) in the eyes open (EO) and eyes closed (EC) conditions for post-stroke subjects. Significant correlation is
indicated with an asterisk (p < 0.05).
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When analyzing the relation between posturographic
analysis and clinical measures in SS subjects, the TUG
scale showed the greater amount of correlation to CoP
parameters (sway area, CoPv, CoPv in the AP direction
for both the EO and EC condition; CoP path in the AP
direction and EO condition; CoPv in the ML direction
and EC condition). BBT was also correlated to CoP parameters, although to a lesser degree (CoP path in the
AP direction and EO condition; CoPv and CoPv in the
ML direction and EC condition; CoPv in the AP direction in both the EC and EO conditions). TB was never
correlated to posturographic parameters. These results
are in agreement with those of Corriveau et al. [31], who
showed significant correlation between CoP-Center of
mass amplitude and balance scales (BBS, Tinetti scale).
Only one study [30] compared clinical evaluation with
laboratory measures in a stroke population maintaining
a quiet standing position in EO. BBS was compared with
CoP speed, CoP root-mean-square (RMS) value, and CoP
mean frequency in the AP and ML directions. In the AP
direction, their results were comparable (R2 range, 0.50 to
0.57) to ours (R2 = 0.56). Surprisingly, significant correlations were not found in the ML direction.
An interesting result of our study is the correlation
found between CoP path in the ML direction (R2 =
0.69) with the evaluation of the functional walking
time measured by the TUG test. Also note that in a recent study, the TUG test proved to be a valid measure
for predicting falls [12] as well as functional daily
activity in elderly SS [12].
The correlation between functional evaluations and instrumental measures suggests that some of the CoP parameters provide an indication of postural instability in a
quasi-static position that is also provided by functional
tests used in a dynamic clinical evaluation. However, not
all the CoP variables and the functional outcomes were
correlated, and often only moderately. This results might
indicate that the two techniques provide information
about different aspects of balance. However, the precise
balance characteristics described by functional balance
evaluations are not easy to define, since a measure of
deficit can never be perfectly related to a measure of incapacity because other factors enter into play to reduce
performance. Certainly, the outcomes of instrumented
posturography are useful to understand how a sensorimotor deficit results in functional limitations due to balance problems. In this respect, posturography is an
essential tool in understanding the risk of falls [8,23,31].
Rehabilitations services are largely provided during the
post-acute phase of a stroke and therapists and physiatrists document the clinical manifestations of stroke in
order to select appropriate rehabilitation treatment [32].
The treatments are generally focused on optimizing SS
motor performance by means of postural control
Page 6 of 7
exercises in order to diminish maladaptive strategies and
promote increase loading of the affected lower limb, encourage reactive and anticipatory postural control strategies when displacement of center of mass increases
[33]. With this in mind, the present results may indicate
a specific role of CoP measurement in identifying those
patients who will most likely benefit from rehabilitation
and in identifying the more appropriate rehabilitation
protocols.
Our results suggest that combining quantitative
posturography and clinical evaluation whenever possible would enhance comprehension of postural
impairments and disabilities in SS patients.
Conclusions
This study provides the first attempt at finding a correlation between clinical and instrumental measures of
balance in post-stroke subjects, understanding their individual and combined usefulness.
The observation that only some clinical and instrumental balance assessments are related might indicate
that they measure different aspects of balance. Consistently with previous findings in healthy and pathologic
subjects [12-16], results suggest that posturography parameters were found to provide insight into the postural
control mechanisms of post-stroke subjects. Thus, this
methodology should be recommended for use in clinical
practice. As it has been previously demonstrated in
other pathologies (e.g. Parkinson disease, see [16]) poststroke subjects could also take advantage from the
inclusion of quantitative posturography in their balance
assessment. Our results may lead to a step forward towards the recommendation of the CoP parameters for
use in clinical practice and in research.
Additional investigations are necessary to understand
specificity and reliability of the individual center of
pressure measures and to further clarify whether they
are good candidate measures to discriminate among
postural strategies used by post-stroke subjects.
Competing interests
Each of the authors has read and concurs with the content in the final
manuscript. The contributing authors guarantee that this manuscript has not
been submitted, nor published elsewhere. Each of the authors declares that
don’t have any financial and non-financial competing interests.
Authors’ contributions
Each of the authors has read and concurs with the content in the final
manuscript. ZS, EC, SM and CC participated in conceiving the study. ZS, EC,
PC, SM and CC participated in its design and coordination and carried out
the drafting of the manuscript. PC helped to draft the manuscript. ZS, PC, AG
carried out the experimental part of the study relatives to centre of pressure
data collection and carried out and coordinated the data analysis. ZS
performed the data analysis. EC carried out the experimental part of the
study relatives to the clinical evaluation and participated to the center of
pressure data collection. EC made the diagnosis of SS, followed the
treatment and supervised the manuscript. All authors read and approved the
final manuscript.
Sawacha et al. Journal of NeuroEngineering and Rehabilitation 2013, 10:95
http://www.jneuroengrehab.com/content/10/1/95
Acknowledgements
We acknowledge Verena Postal for her support in the subjects’ clinical
evaluation.
Author details
Department of Information Engineering, University of Padova, Padova, Italy.
Department of Rehabilitation Medicine, University of Padova, Padova, Italy.
1
2
Received: 26 September 2012 Accepted: 26 July 2013
Published: 13 August 2013
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doi:10.1186/1743-0003-10-95
Cite this article as: Sawacha et al.: Relationship between clinical and
instrumental balance assessments in chronic post-stroke hemiparesis
subjects. Journal of NeuroEngineering and Rehabilitation 2013 10:95.
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