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RESEARCH ARTICLES
Highly Challenging Balance Program Reduces Fall Rate
in Parkinson Disease
David Sparrow, DSc, Tamara R. DeAngelis, PT, DPT, GCS, Kathryn Hendron, PT, DPT, NCS,
Cathi A. Thomas, RN, MS, CNRN, Marie Saint-Hilaire, MD, FRCPC, and Terry Ellis, PT, PhD, NCS
Background and Purpose: There is a paucity of effective treatment
options to reduce falls in Parkinson disease (PD). Although a variety
of rehabilitative approaches have been shown to improve balance,
evidence of a reduction in falls has been mixed. Prior balance trials
suggest that programs with highly challenging exercises had superior
outcomes. We investigated the effects of a theory-driven, progressive,
highly challenging group exercise program on fall rate, balance, and
fear of falling.
Methods: Twenty-three subjects with PD participated in this random-
ized cross-over trial. Subjects were randomly allocated to 3 months
of active balance exercises or usual care followed by the reverse.
During the active condition, subjects participated in a progressive,
highly challenging group exercise program twice weekly for 90 min-
utes. Outcomes included a change in fall rate over the 3-month
active period and differences in balance (Mini-Balance Evalua-
tion Systems Test [Mini-BESTest]), and fear of falling (Falls Ef-
ficacy Scale-International [FES-I]) between active and usual care
conditions.
Results: The effect of time on falls was significant (regression
coefficient =−0.015 per day, P<0.001). The estimated rate ra-
tio comparing incidence rates at time points 1 month apart was 0.632
(95% confidence interval, 0.524-0.763). Thus, there was an estimated
37% decline in fall rate per month (95% confidence interval, 24%-
48%). Improvements were also observed on the Mini-BESTest (P=
0.037) and FES-I (P=0.059).
VA Boston Healthcare System and Department of Medicine (D.S.), Boston
University School of Medicine, Boston, Massachusetts; Center for Neu-
rorehabilitation (T.R.D., K.H., T.E.), Department of Physical Therapy and
Athletic Training, College of Health and Rehabilitation Sciences: Sargent,
Boston University, Boston, Massachusetts; and Department of Neurology
(C.A.T., M.S.H.), Boston University Medical Campus, Boston University,
Boston, Massachusetts.
This study was funded by the Boston Claude D. Pepper Older Americans
Independence Center (NIH 5P30AG031679). Additional support was pro-
vided by the American Parkinson Disease Association (ADPA); ADPA MA
Chapter.
The authors declare no conflict of interest.
ClinicalTrials.gov registration number: NCT02302144.
Supplemental digital content is available for this article. Direct URL citation
appears in the printed text and is provided in the HTML and PDF versions
of this article on the journal’s Web site (www.jnpt.org).
Correspondence: Terry Ellis, PT, PhD, NCS, Boston University, College
of Health and Rehabilitation Sciences: Sargent, 635 Commonwealth Ave,
Boston, MA 02215 (tellis@bu.edu).
Copyright C2016 Neurology Section, APTA.
ISSN: 1557-0576/16/4001-0024
DOI: 10.1097/NPT.0000000000000111
Discussion and Conclusions: The results of this study show that a
theory-based, highly challenging, and progressive exercise program
was effective in reducing falls, improving balance, and reducing fear
of falling in PD.
Video Abstract available for more insights from the authors (see
Supplemental Digital Content 1, http://links.lww.com/JNPT/A120).
Key words: balance, exercise, falls, Parkinson disease, postural
control, rehabilitation
(JNPT 2016;40: 24–30)
INTRODUCTION
Impaired balance is one of the cardinal signs of Parkinson
disease (PD). Sixty-eight percent of people living with PD in
the community sustain at least one fall per year, which is double
the fall rate reported in healthy older adults.1Notably, 50.5%
of fallers with PD report recurrent falls (at least 2) over a 1-
year period.2Falls are a major cause of disability and reduced
quality of life in people with PD and result in devastating
injuries such as hip fractures, which are significantly more
common in PD than in those with other medical conditions.3,4
In addition, falls are associated with increased risk of hospital
and nursing home admissions and ultimately with decreased
survival rates. The economic impact related to health care costs
is about twice as much in fallers as nonfallers with PD.5
Identifying interventions that successfully improve pos-
tural control and reduce fall rate is critical to reduce disabil-
ity, improve quality of life, and potentially increase survival
in people with PD. Although the gold standard dopaminer-
gic pharmacological interventions are effective in reducing
bradykinesia, rigidity, and tremor, these medications are not
effective in ameliorating balance deficits and reducing falls in
people with PD.6,7 Several randomized controlled trials show
that a variety of rehabilitative approaches have been effective
in improving balance in persons with PD.8A meta-analysis
of 15 randomized and quasi-randomized controlled trials of
exercise and motor training interventions targeting balance in
PD found significant improvement in balance in the context
of walking velocity, transitioning from sitting to standing, and
standing balance activities.9Despite the evidence of improved
balance, results revealed no evidence of a reduction in falling;
however, only 2 trials included falls as an outcome.9
More recent clinical trials have specifically examined the
effects of exercise interventions on reducing falls in persons
with PD. A 10-week group strengthening and balance training
Copyright © 2016 Neurology Section, APTA. Unauthorized reproduction of this article is prohibited.
24 JNPT rVolume 40, January 2016
JNPT rVolume 40, January 2016 Highly Challenging Balance Program Reduces Fall Rate in Parkinson Disease
program in persons with PD showed no significant difference
in incidence rate for falls compared with a usual care con-
trol condition.10 A 6-month tai chi program in PD resulted
in a lower incidence of falls compared with stretching but not
compared with resistance training.11 An 8-week strength train-
ing program and a movement strategy training program both
resulted in significantly fewer falls at 12 months compared
with a life-skills education program.12 In addition, a 6-month
minimally supervised, home-based balance and strengthening
program plus cueing strategies to reduce freezing of gait did
not significantly reduce fall rate compared with a usual care
condition.13 Finally, a 4-week sensorimotor agility program
was found to be of value for improving balance when deliv-
ered as individualized physical therapy, but not when delivered
as a group class, or through a home exercise program.14 Al-
though these recent studies provide some evidence suggesting
that falls are modifiable in PD, results are mixed.
Balance exercises alone, balance combined with
strengthening exercises, cueing, gait training on a treadmill,
tai chi, and functional training have all been shown to improve
balance control in PD.8,9,15−17 The large degree of variabil-
ity in these rehabilitative approaches suggests they may share
salient, common features that contribute to the greatest im-
provements in balance and therefore may be most likely to
impact falls.8,9 The aforementioned meta-analysis suggested
that higher doses of training and highly challenging balance
training (ie, exercises that specifically involved movement of
the center of mass, narrowing the base of support, and minimiz-
ing the upper extremity support) had the most robust outcomes
(5 studies) and may be necessary to reduce falls.9
Given the relative paucity of trials examining the effects
of exercise training on falls and the suggestion that higher
doses of highly challenging approaches may lead to better out-
comes, the purpose of this study was to investigate the effects
of a theory-driven, highly challenging balance program on fall
rate in a randomized, controlled cross-over trial. We hypoth-
esized that the number of falls among subjects in the active
treatment period would significantly decline over the course of
the 3-month intervention period. In addition, we hypothesized
that balance and fear of falling would significantly improve
during the active treatment period compared with the inactive
period in which usual care was provided.
METHODS
Design Overview
A randomized cross-over trial of a 3-month high-
intensity balance exercise intervention for people with PD
was conducted in 2012 to 2013. Participants were recruited
from Boston University’s Parkinson’s Disease and Movement
Disorders Center and the Center for Neurorehabilitation. Sub-
jects participated in a baseline assessment session, followed by
random allocation to 3 months of active balance exercises or
3 months of inactivity. After this 3-month period, active sub-
jects were switched to 3 months of usual care and subjects
receiving usual care were switched to 3 months of active bal-
ance exercises. A computerized randomization schedule was
generated and held by an investigator not involved in subject
recruitment or assessment (TE). All subjects were reassessed at
3 and 6 months by a physical therapist blinded to participants’
group allocations (Figure 1).
Participants
Twenty-three subjects with idiopathic PD (using UK
Brain Bank Criteria) were enrolled (Figure 2). Subjects had
stage 2 and 3 disease on the Hoehn and Yahr (H&Y) staging
scale in the “on” medication state, were on a stable dose of
PD medications for 2 or more weeks before enrollment, ex-
perienced 1 or more fall in the past 3 months and 2 or more
falls in the past year, and were able to walk without physi-
cal assistance or an assistive device for at least 5 continuous
minutes. Subjects were excluded if they had a diagnosis of
atypical Parkinsonism, a Mini-Mental Status score of less than
26, previous surgical management of PD, or serious comorbidi-
ties that may interfere with ability to participate in the exercise
program. Subjects were required to sign informed consent ap-
proved by the institutional review board at Boston University
(ClinicalTrials.gov: NCT02302144).
Intervention
During the active condition, subjects participated in
a highly challenging group exercise program focusing on
improving balance and reducing falls. The exercise pro-
gram was held twice weekly for 90-minute sessions over a
3-month period at the Center for Neurorehabilitation at Boston
University. Three physical therapists with expertise in PD ad-
ministered the group exercise program. To ensure an adequate
level of challenge across all sessions for all participants, the
exercise program was conducted in the clinical setting only—
without supplemental practice of the exercises at home.
The intervention was developed using Horak’s theoret-
ical balance framework for PD, which describes 6 interacting
systems contributing to balance control (Figure 3).18 Each
of the exercises (ie, strengthening, range of motion, anticipa-
tory and reactive balance activities, altering sensory input, and
gait training) was developed to address one or more of the 6
systems of balance control (Figure 3) and consisted of a pro-
gression ranging from less challenging to more challenging.
Figure 1. Study design.
Copyright © 2016 Neurology Section, APTA. Unauthorized reproduction of this article is prohibited.
C2016 Neurology Section, APTA 25
Sparrow et al JNPT rVolume 40, January 2016
Figure 2. CONSORT diagram.
Participants rated the challenge level of each exercise using
a 10-point Likert scale (10 being the greatest level of chal-
lenge and 1 being no challenge) as it related specifically to
balance control. Exercises were tailored to each individual and
were progressed to increase challenge level when perceived
challenge to balance was less than 7. Weighted vests and/or
variable surface conditions were used to increase resistance
and challenge level in a strengthening exercise. During the
inactive condition, participants received usual care.
Outcomes
Falls
Subjects from both groups were interviewed during the
active intervention phase to collect detailed information about
falls following the recommendations of the Prevention of Falls
Network Europe consensus statement.19 At each session, pa-
tients were asked whether they had any falls since the previous
session. A fall was defined as a loss of balance where the person
inadvertently came to rest on the ground or other lower level.2
The date of the fall along with the circumstances surrounding
it (ie, location, direction of fall, activity being performed, and
presence of environmental trigger) was recorded.
Balance
The Mini-Balance Evaluation Systems Test (Mini-
BESTest) assesses dynamic balance and contains 14 items
from the original BESTest.20 Each item is scored on a 3-level
ordinal scale from 0 to 2, with 2 representing no impairment
in balance and 0 representing severe impairment of balance.
The maximum total score is 28. The Mini-BESTest has high
interrater and test-retest reliability in PD.21 The Mini-BESTest
was administered by a trained physical therapist not involved
in the intervention and blinded to treatment condition.
Fear of Falling
The Falls Efficacy Scale-International (FES-I) is a self-
report questionnaire developed for use in elderly populations
to assess fear of falling.22 A series of 16 questions assesses
the respondent’s fear of falling for a range of activities of daily
living. Each one is rated on a 4-point scale from 1 (not at all
concerned) to 4 (very concerned). The FES-I has been found to
Copyright © 2016 Neurology Section, APTA. Unauthorized reproduction of this article is prohibited.
26 C2016 Neurology Section, APTA
JNPT rVolume 40, January 2016 Highly Challenging Balance Program Reduces Fall Rate in Parkinson Disease
Figure 3. Balance interventions corresponding to the 6 interacting systems contributing to balance control.
have extremely good internal consistency (Cronbach α=0.96)
and test-retest reliability (intraclass correlation coefficient =
0.96).22
Statistical Analysis
A paired ttest was used to compare each outcome (FES-I
and Mini-BEST) measured at the end of the active period with
that measured at the end of the inactive period in the same
patient.23 Thus, for each subject in sequence group 1 (active
→inactive), the outcome score at the end of period 2 (inactive)
was subtracted from the outcome score at the end of period
1 (active). For each subject in sequence group 2 (inactive →
active), the outcome score at the end of period 1 (inactive)
was subtracted from the outcome score at the end of period 2
(active). Thus, the overall treatment effect is the mean of the
mean differences in outcome measurements between the active
and inactive periods in sequence group 1 and sequence group 2,
respectively. To assess carry-over effects, the mean of the 2
outcome scores measured at the end of each period (active,
inactive) is calculated for each subject ([subject score period
1+subject score period 2] / 2). The mean of these subject
means of sequence group 1 is compared with that of sequence
group 2 using a 2-sample ttest for independent samples. If
there is no carry-over effect, there would be no difference in
the means of the subject mean scores between the 2 sequence
groups.
To test whether the number of falls is a function of length
of time in the intervention among subjects in the active treat-
ment period, we modeled daily fall count as a linear function of
time (intervention day) using generalized estimating equations
with the log link function, the negative binomial distribution,
and the exchangeable correlation structure to account for cor-
related counts from each patient.24
Analyses were carried out using SAS v9.3 using PROC
TTEST with the CROSSOVER option to account for the
crossover design and PROC GENMOD to fit the negative bi-
nomial regression model for the number of falls.
RESULTS
Twenty-three subjects with PD were enrolled and 16
completed the study. Six subjects withdrew due to scheduling,
transportation issues, or unrelated comorbidities, and one was
withdrawn by the principal investigator due to a change in
diagnosis from typical to atypical PD. Sixty-three percent of
participants were male, and the mean age was 66.7 years with
a disease duration of 4.3 years (Table 1). Participants had mild-
to-moderate PD (mean H&Y stage 2.5, mean motor Unified
Parkinson’s Disease Rating Scale [UPDRS] score 36).
There was no significant difference between the mean
scores of the 2 sequence groups at baseline on FES-I and Mini-
BESTest scores. Analysis of the overall treatment effect of
Table 1. Baseline Characteristics (n =16)
Mean ±Standard
Variable Deviation or n (%)
Age, y 66.7 ±5.7
Sex
Male 10 (62.5)
Female 6 (37.5)
Disease duration, y 4.3 ±3.3
Hoehn and Yahr stagea
2 4 (25)
2.5 8 (50)
3 4 (25)
MDS-UPDRS-III score 36.0 ±9.6
FES-I 28.3 ±7.3
Mini-BESTest 20.9 ±4.1
Abbreviations: FES-I, Falls Efficacy Scale-International; Mini-BESTest, Mini-
Balance Evaluation Systems Test; MDS-UPDRS-III, MovementDisorder Society Unified
Parkinson’s Disease Rating Scale-III.
aHoehn and Yahr stage in the “on” state.
Copyright © 2016 Neurology Section, APTA. Unauthorized reproduction of this article is prohibited.
C2016 Neurology Section, APTA 27
Sparrow et al JNPT rVolume 40, January 2016
the exercise intervention (active vs inactive) on each outcome
was performed using a paired ttest with a cross-over design
(Table 2). The estimated overall treatment effect on FES-I
scores was −3.2 (95% confidence interval [CI], −6.4to0.1;
P=0.059). To check for a carry-over effect, we analyzed the
mean patient scores of both periods comparing the 2 groups
using a 2-sample ttest for independent samples, which was not
significant (P=0.944). The estimated overall treatment effect
on Mini-BESTest scores was 1.5 (95% CI, 0.1-2.9; P=0.037).
Although the test for the carry-over effect was only borderline
significant (P=0.061), as a precaution, we analyzed the treat-
ment effect in the first period only using a 2-sample ttest for
independent samples. This yielded an estimated treatment ef-
fect of 4.8 (95% CI, 1.3-8.2; P=0.010). L-dopa equivalents
were not significantly different between the active and inactive
conditions (P=0.54).
The number of daily falls per patient was modeled on the
length of time in the active phase of the intervention (number
of days) to determine whether the intervention reduced falls
over time (total falls observed =150). A repeated measures
negative binomial regression using the generalized estimating
equation approach indicated a statistically significant effect
(coefficient =−0.015 per day, P<0.001). The estimated rate
ratio comparing incidence rates at time points 1 month apart
was 0.632 (95% CI, 0.524-0.763) indicating an estimated 37%
decline in the fall rate per month (95% CI, 24%-48%).
There were 2 adverse events (back pain and abdominal
pain) during the inactive period. There were 5 adverse events
(back pain, knee pain, abdominal pain, quadriceps pain, and
lightheadedness) during the active period. Two of these were
considered to be related to the intervention (knee pain and
quadriceps pain). These occurred during one exercise session
and were resolved by the subsequent session.
DISCUSSION
The results of this study show that a theory-based, highly
challenging, and progressive exercise program was effective in
reducing falls, improving balance, and reducing fear of falling
in persons with PD. Although previous studies show improved
balance in PD with a variety of approaches to rehabilitation,
there is limited evidence of the impact of rehabilitation on
reducing falls.9Few studies have included falls as an outcome,
and results have been mixed among studies investigating the
impact of rehabilitation on reducing falls.9−13, 25 ,26 Studies
included in a recent meta-analysis provided a relatively low-
dose of intervention, which may have contributed to the lack
of impact on fall reduction.9
Previous studies that included highly challenging bal-
ance training programs seemed to have the most robust out-
comes regarding improvements in balance-related activity
performance.9Prior studies also suggest that balance train-
ing that included a strengthening component was more ef-
fective in improving balance compared with balance training
alone.27−30 In addition, a recent randomized controlled trial in
PD also showed significant improvements in off-medication
UPDRS-III scores after a 2-year progressive resistance exer-
cise program compared with a nonprogressive stretching, bal-
ance, and strengthening program suggesting the importance of
progressively more challenging exercises.31 Also, prior work
in the area of exercise in both animal models and humans with
PD suggests the importance of goal-based motor skill training
to enhance motor learning and motor control.32, 33
Balance exercise programs derived from a sound theo-
retical framework targeting the essential postural control sub-
systems may also contribute to more robust improvements in
balance control and a subsequent reduction in falls. Despite
an incomplete understanding of postural control mechanisms
underlying postural instability and falling in PD,34 multiple
physiological systems are known to contribute to postural
control. Horak and colleagues18, 35 have identified 6 different
balance control systems (biomechanical constraints, stability
limits/verticality, anticipatory postural adjustments, postural
responses, sensory orientation, and stability in gait) underly-
ing the complex skill of balancing that may be important to
systematically target in exercise programs aimed at fall reduc-
tion in PD.
The exercise program in our study incorporated the most
salient features from prior work (eg, theory-driven, highly chal-
lenging, progressive, goal oriented, balance plus strengthening
exercises, and high dose), which may explain the significant re-
duction in falls observed over 3 months. Exercises were chosen
on the basis of theoretical framework described by Horak and
colleagues18, 35 to address key elements of postural instability
in PD while ensuring sufficient challenge across the 6 interact-
ing systems. We operationalized “challenge to balance” using
a 10-point Likert scale to determine when to progress sub-
jects. At each session, subjects rated the level of difficulty of
Table 2. Summary Statistics of Treatment Efficacy
Sequence Group
Active →Inactive (n =7) Inactive →Active (n =9) Overall Treatment Effect
Active Inactive DifferenceaMeanbActive Inactive DifferenceaMeanbActive vs Inactive
FES-I
Mean 24.1 26.0 −1.9 25.1 22.7 27.1 −4.4 24.9 −3.2 (P=0.059)
SD 7.1 7.6 6.1 6.7 3.5 5.3 6.0 3.3
Mini-BESTest
Mean 25.0 24.1 0.9 24.6 22.3 20.2 2.1 21.3 1.5 (P=0.037)
SD 2.3 2.1 1.7 2.0 4.5 3.7 3.1 3.9
Abbreviations: FES-I, Falls Efficacy Scale-International; Mini-BESTest, Mini-Balance Evaluation Systems Test; SD, standard deviation.
aPatient difference between active and inactive scores.
bPatient mean of active and inactive scores.
Copyright © 2016 Neurology Section, APTA. Unauthorized reproduction of this article is prohibited.
28 C2016 Neurology Section, APTA
JNPT rVolume 40, January 2016 Highly Challenging Balance Program Reduces Fall Rate in Parkinson Disease
each exercise on the basis of the level of challenge to balance.
Exercises were goal oriented in that patients were given a tar-
get to achieve (ie, reaching greater distances out of base of
support). The program included both balance and strengthen-
ing exercises that were progressive (eg, increased load added
to weighted vests); 90-minute sessions were performed twice
weekly over 3 months (total of 36 hours over 12 weeks) that
exceeds the dosage provided in most of the previous balance
trials (average 18 hours over 7 weeks).9
Our results also revealed significant improvements in
balance and fear of falling. In a meta-analysis examining the
effect of balance interventions on gait and balance outcomes,
Hedge’s g effect sizes ranged from −0.622 to 1.271 among
the 19 PD studies reviewed.9In the present study, the Hedges’
g effect size for the mini-BESTest was 1.22, suggesting that
the exercise program contributed to a large improvement in
balance. With regard to the FES-I, the effect size (−0.77)
suggested that fear of falling can be attenuated with a highly
challenging balance exercise program.
There are several limitations to our study including a
small sample size. However, despite a small sample, signifi-
cant improvements were observed in fall rates, balance, and
fear of falling, suggesting the potential benefits of this in-
tervention approach. Consistent with other exercise trials in
PD, our results revealed a limited carry-over effect, suggesting
that the benefits of treatment dissipate over time—confirming
the need for ongoing, sustained participation. Study subjects
had mild-to-moderate PD (stages 2 and 3 on the H&Y stag-
ing scale), so results may not be generalizable to more severe
disease. Although frequent, in-person interviews were used to
optimize ascertainment of all falls, this approach still relied on
the accuracy of patient report.
CONCLUSIONS
These results show that a theory-based, highly challeng-
ing, and progressive exercise program was effective in reduc-
ing falls, improving balance, and reducing fear of falling in
persons with mild-to-moderate PD. The data suggest the po-
tential efficacy of these aspects of training in persons with
mild-to-moderate PD, but this requires further investigation.
ACKNOWLEDGMENTS
We thank Bernard Rosner for his assistance in many
aspects of the study design and data analysis and Deborah De-
Molles for her invaluable technical and programming support.
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