TITLE: Effect of space balance 3D training using visual feedback on balance and
mobility in acute stroke patients

  ABSTRACT:
[Purpose] The purpose of the study was to determine the effects of balance training with
Space Balance 3D, which is a computerized measurement and visual feedback balance
assessment system, on balance and mobility in acute stroke patients. [Subjects and
Methods] This was a randomized controlled trial in which 52 subjects were assigned
randomly into either an experimental group or a control group. The experimental group,
which contained 26 subjects, received balance training with a Space Balance 3D exercise
program and conventional physical therapy interventions 5 times per week during 3 weeks.
Outcome measures were examined before and after the 3-week interventions using the Berg
Balance Scale (BBS), Timed Up and Go (TUG) test, and Postural Assessment Scale for Stroke
Patients (PASS). The data were analyzed by a two-way repeated measures ANOVA using SPSS
19.0. [Results] The results revealed a nonsignificant interaction effect between group and
time period for both groups before and after the interventions in the BBS score, TUG
score, and PASS score. In addition, the experimental group showed more improvement than
the control group in the BBS, TUG and PASS scores, but the differences were not
significant. In the comparisons within the groups by time, both groups showed significant
improvement in BBS, TUG, and PASS scores. [Conclusion] The Space Balance 3D training with
conventional physical therapy intervention is recommended for improvement of balance and
mobility in acute stroke patients.

BODY.INTRODUCTION:
Stroke results from occlusion or hemorrhage of a major artery in the brain1) and is a major cause of severe
disability2). Stroke survivors have
difficulty in postural control for standing upright because of asymmetric posture, abnormal
body imbalance, and a deficiency in weight transfer3). Stroke patients suffer from difficulties in balance, mobility,
activities of daily living, and task performance caused by loss of postural control3). Previous studies have demonstrated the
particular importance of balance and walking in stroke patients4, 5).  Various therapeutic methods have been used for treatment of stroke patients such as the
Bobath approach, proprioceptive neuromuscular facilitation (PNF) technique6), auditory feedback training7), strengthening exercise, ball exercise, and
visual biofeedback training8). Among the
various therapeutic methods, visual biofeedback training is effective for recovery of
upright standing and symmetric posture in stroke patients9). The use of visual biofeedback training increases patient motivation
and individualizes exercise difficulty according to a patient's current status10). Also, visual biofeedback training using a
NeuroCom Balance Master with force plates was significantly effective for improvement of
balance function in stroke patients when compared with conventional standing balance
training11).  Visual biofeedback training has often been used for ordinary people such as the elderly and
women, but there is little evidence regarding the effectiveness of visual biofeedback
training in stroke patients with hemiparesis12). In the study cited above, there were some limitations, including a
small number of subjects and absence of a control group. Space Balance 3D, which can be used
for fixation of a patient's trunk, is more convenient and suitable for balance training and
testing in acute stroke patient at high risk of falling.  The purpose of the present study was to investigate the effects of visual biofeedback
training using Space Balance 3D on balance and mobility function in acute stroke
patients.

BODY.SUBJECTS AND METHODS:
We selected 56 acute stroke patients who were 18–65 year old and had been diagnosed with
stroke within the last 6 months (Table
1Table1.General characteristics of the subjectsParametersExperimentalgroup(n=26)Controlgroup(n=26)Gender (male/female)20/616/10Age (years)48.1 ± 4.445.3 ± 4.2Height (cm)169.1 ± 4.4164.3 ± 4.2Weight (kg)61.4 ± 6.253.5 ± 6.7Stroke type (Ischemic/hemorrhagic)16/1014/12Right plegia/Left plegia12/1410/16Values represent the mean ± SD). The inclusion criteria were; 1) able to walk more than 10 meters without or
with assisting devices such as orthotics, a walker, or a cane; 2) no symptoms with any lower
motor neuron lesion and orthopedic diseases; 3) a score higher than 24 points on the MMSE;
and 4) able to read the words on a monitor 60 cm away at eye level. We explained the purpose
of this study and got their consent. The study's protocol was approved by the institutional
review board (IRB) of Sahmyook University in Seoul, Republic of Korea.  This study was performed over the course of 3 weeks. The balance training was implemented
with the Space Balance 3D programmed for 30 minutes per session, 5 times a week, for 3
weeks. The subjects were assessed before and after 3-week interventions. Fifty-two subjects
were randomly assigned to either an experimental group (n=26) or a control group (n=26). The
experimental group was treated with 30-min sessions of Space Balance 3D training and
conventional rehabilitation exercise for a total 15 sessions. The control group was treated
with conventional rehabilitation exercise only. The examiner assessed the balance and gait
function of subjects with the BBS (Berg Balance Scale) and PASS (Postural Assessment Scale
for Stroke Patients), and TUG (Timed Up and Go) test before and after the intervention.  The Space Balance 3D training system is equipped with two wireless force plates. It can
check the distribution of weight on four plates placed under the left and right forefeet and
heels. The degree of tilting is assessed by a tilt sensor in the front of the apparatus.
Three kinds of balance training were implemented using Space Balance 3D, which can be used
for both training and testing. According to the subjects' movement, the real-time tilting
angle and foot plates are indicated on a computer screen. Horizontal exercise is used as a
training program for left and right balance. In this exercise, the patient moves in the left
or right direction to "hit" a predetermined target. This exercise is for improving control
of left and right balance. Vertical exercise is used as a training program for forward and
backward balance. In this exercise, the patient moves in the forward or backward direction
to hit a predetermined target. This exercise is for improving control of forward and
backward balance. A horizontal exercise program is more difficult than a circle exercise
program. In this exercise, the patient moves horizontally in a pattern to hit a
predetermined target. In this program, deviation of the movement of the patient from the
line indicates decreased balance function.  The 14-item BBS identifies and evaluates balance impairment in stroke patients13). When a patient was unable to
independently complete a test, the patient was instructed 3 attempts, and the best score was
recorded. A total score for all attempts was determined for each patient (maximum score=56
points). This measure has been reported to have excellent intrarater reliability
(ICC=0.99)14). The PASS was developed to
assess balance function in patients with stroke. The PASS contains 12 four-point items that
evaluate a patient's balance function in situations of varying difficulty, namely,
maintaining or changing a lying, sitting, or standing position. The range of its total score
from 0 to 3615). For the TUG test, the
patients were seated in a chair with armrests and then instructed to stand and walk as
quickly and as safely as possible a distance of 3 meters, and turn around, walk back, turn
around, and sit down again. The time from the point at which the patient's spine left the
chair until they returned back to that same sitting position was recorded. This was followed
by 3 trials. The average time of the 3 test trials was calculated. The TUG test has been
shown to have high interrater (ICC=0.99) and intrarater (ICC=0.99) reliability16). Podsiadlo and Richardson suggested that
the TUG test has content validity in that it evaluates a well-known series of measure used
in daily living and that it has suitable concurrent validity because this measurement is
well correlated with data corrected with more extensive measurements of gait speed, balance,
and functional abilities16, 17).  All statistical tests were performed with SPSS version 21.0. Two-way repeated measures
ANOVA for the interaction effect between group and time period was used to compare
differences in balance ability between the control and experimental group. A value of
p<0.05 was taken indicate to statistical significance.

BODY.RESULTS:
After completion of the 3-week intervention, the results revealed a nonsignificant
interaction effect between group and time period for both groups before and after the
interventions in the BBS score, TUG score, and PASS score. In addition, the experimental
group showed a more improvement than the control group in the BBS, TUG and PASS scores, but
the differences were not significant. In the comparisons within the groups by time, both
groups showed significant improvement in BBS, TUG, and PASS scores (Table 2Table 2.Changes in BBS, PASS, and TUG scores before and after the interventionsTestExperimental groupControl groupBBS (score)Before36.6 ± 15.021.1 ± 18.1After49.8 ± 8.7*37.0 ± 14.8*PASS (score)Before27.0 ± 6.418.1 ± 9.7After33.2 ± 3.1*26.8 ± 7.6*TUG (sec)Before26.7 ± 20.941.5 ± 25.3After15.8 ± 14.2*25.2 ± 14.5*Values represent the mean ± SD. *Significant difference between before and
after training in each group (p<0.05)).

BODY.DISCUSSION:
Static and dynamic balance are essential functions of the human body that affect walking
function and activities of daily living. Therefore, static and dynamic balance training
programs are an important part of rehabilitation18).  Recently, many studies have demonstrated the effects of visual feedback training on
postural balance in stroke patients9).
Visual information may compensate for the loss of somatosensory function and facilitate the
human motor program in the brain; thus it would increase the effectiveness of treatment19). Shumway-Cook et al.20) suggested that visual feedback of body weight while
standing can reduce an asymmetry of body alignment and be a more effective balance training
method than auditory or tactile feedback. Also, Winstein et al.21) reported that a stroke rehabilitation program using foot
force plates led to improvement of symmetry while standing. Sackley et al.22) demonstrated that visual biofeedback
training with symmetric distribution of body weight had a benefit for symmetry standing
recovery in hemiplegic patients. Accordingly, visual feedback training can be a powerful
therapeutic method for improvement of standing balance and gait function in stroke
patients9).  However, many previous studies had some limitations, including a small number of subjects
and no control group in the experimental procedures, so it is difficult to secure objective
data about the effectiveness of visual biofeedback. In addition, the training methods
applied to the patients varied greatly.  Our study was implemented to investigate the effect of balance training with Space Balance
3D, which is consisted of visual biofeedback using force plates, on balance and mobility in
acute stroke patients.  In this study, BBS, PASS, and TUG tests were performed before and after 3 weeks of
training. In comparison of the results from before and after training, all test results were
improved after the 3 weeks of training in both groups. Also, an unexpected finding of our
study was that there were no statistical differences in the changes in any outcome measures
between the control group and the experimental group. It is conceivable that the
conventional therapy was sufficient to enable the patients to maximize their potential or
that the patients recovered spontaneously, which has been shown to mostly occur in the first
3 to 6 months after a stroke23). Also, all
subjects received specialized care such as occupational therapy and gait training in the
rehabilitation unit. However, the differences in the changes in all outcomes showed that the
experimental group was more improved than the control group, but the differences was not
statistically significant. In previous studies in stroke patients, visual biofeedback
training with foot force plate was significantly effective for improvement of a balance
function24) and walking speed21). Also, it has been reported that visual
feedback training using a NeuroCom Balance Master was significantly effective for the
improvement of balance compared with conventional balance training in chronic stroke
patients25). However, the NeuroCom
Balance Master had a limitation with respect to application to acute stroke patients. In our
study, the Space Balance 3D, which is similar to the NeuroCom Balance Master but equipped
with a trunk fixing device, was suitable for balance assessment and training of acute stroke
patients with decreased dynamic balance ability.  It appears that Space Balance 3D training using visual biofeedback can be safely applied
for improvement of balance and mobility function in acute stroke patients. A limitation of
this study is that we could not determine the effects of a long period of training because
our study was a short-term study lasting for 3 weeks. We suggest that further study is
needed with a longer term so that the training period is long enough to determine if there
are any improvements in balance.

Question: Compared to Control what was the result of Space Balance 3D exercise program on Berg Balance Scale score?
Evidence: the experimental
group showed a more improvement than the control group in the BBS, TUG and PASS scores, but
the differences were not significant. 
Answer: no significant difference