Journal of Rehabilitation Medicine 51-1CompleteIssue | Page 78

Unstable board balance test for fall identification
of the TUG. With regard to the generalizability of our
finding, it is important to note the greater proportion
of women in the faller (78%) than non-faller (31%)
group. This difference in the proportion of sex across
the 2 groups also biased the physical attributes between
the 2 groups, height specifically, which can influence
outcomes, in addition to age (27, 28). While the effect
size for each test was modified by matching, the MLSI
consistently maintained a higher effect size than for the
TUG and FRT. Thus, the ability of the MLSI to discri-
minate between fallers and non-fallers was unaffected
by age and the physical attributes of subjects, with the
discriminating value for the MLSI being greater than
the moderate accuracy previous reported for other fall
assessments that have been used in the community (15,
30). Thus, we believe that the Unstable Board Balance
Test might be superior in its ability to detect fall risk
among healthy, high-functioning, elderly people. The
inclusion of the unstable board balance test should be
considered in future comparative studies.
The MLSI reflects the left-right tilt angle of the
unstable board during the balance task, requiring
maintaining the position of the centre of pressure
(COP) in centre of the board being required to de-
crease the MLSI. Previous studies have demonstrated
the reliability of using COP measurement to detect
small decreases in balance capacity, which could not
be detected by functional balance tests, such as the
BBS (31–34). Maki et al. (34) reported that, while
the anterior-posterior sway was larger in fallers than
non-fallers, the ML component of COP displacement
provided the best prediction of falls. In addition, Mel-
zer et al. (35) reported a significant increase in ML
sway (during narrow-base standing) among elderly
individuals who have experienced falls compared with
those with no fall history. Using COP measurements,
previous studies have shown that tasks incorporating
dynamic elements, such as a perturbation or leaning
movement, provide a better discrimination of small
decreases in balance capacity than static balance
tasks, with age-related degradation occurring early
for dynamic than static balance tasks (35–39). Thus,
balance tasks with dynamic elements would be more
effective in challenging balance capacity than static
standing tasks (40). Therefore, measuring MLSI
using an unstable board, which therefore includes a
dynamic element, might be an effective method for
early detection of a decrease in the balance ability of
high-functioning elderly individuals.
Although COP measurements using a force platform,
there are various limitations in using force platforms
in the community-dwelling, including the prohibitive
cost of devices and poor portability. In contrast, the
Unstable Board Balance Test used in our study pro-
75
vided a dynamic balance task that was effective in
discriminating fallers and non-fallers among healthy,
high-functioning, community-dwelling individuals,
while providing the low cost and portability that are
not available with force platforms. Therefore, this ba-
lance board can be easily used in various environments
and not only in a laboratory, and it provides easy-to-
interpret outcomes.
Limitations
This study has a few limitations that need to be ack-
nowledged. First, because of the case-control design
of the study, the predictive capacity of the MLSI for
falls could not be evaluated, and thus, prospective stu-
dies are needed in this respect. Furthermore, the study
group was rather homogeneous with regard to physical
characteristics, age, and function, and therefore, it is
unclear to which extent elderly individuals with dif-
ferent demographic and personal characteristics could
complete the task. The usefulness of the assessment for
individuals with different levels of functioning remains
to be determined (29), thereby refining the MLSI for
accurate detection of the risk of falling among elderly
individuals.
Conclusion
The Unstable Board Balance Test was useful in discri-
minating between fallers and non-fallers, which was
not possible using the FRT and TUG. Based on our
results, we suggest that the Unstable Board Balance
Test could be useful for early detection of elderly
individuals at risk of falling, and allowing timely fall
prevention programmes to be implemented.
ACKNOWLEDGEMENTS
The authors would like to thank the subjects in this study. This
work was supported by JSPS KAKENHI Grant Number JP
18K17763.
The authors have no conflicts of interest to declare.
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J Rehabil Med 51, 2019