|Year : 2022 | Volume
| Issue : 2 | Page : 65-71
Balance training in individuals with Parkinson's disease: Biodex Stability System versus supervised exercise program
Gurpreet Singh1, Tarang Kumar Jain2, Yvonne M Colgrove3, Neena K Sharma3, Rajesh Pahwa3, Kelly Lyons3
1 Division of Physical Therapy, Decker College of Nursing and Health Sciences, Binghamton University, New York, USA
2 Northern Arizona University, AZ, Kansas, USA
3 University of Kansas Medical Center, Kansas, USA
|Date of Submission||21-Jul-2022|
|Date of Decision||18-Aug-2022|
|Date of Acceptance||30-Oct-2022|
|Date of Web Publication||31-Jan-2023|
Dr. Gurpreet Singh
Binghamton University, New York
Source of Support: None, Conflict of Interest: None
OBJECTIVE: The objective of this study was to evaluate the effect of balance training, using the Biodex Stability System (BSS) or supervised exercises, on balance and gait in individuals with Parkinson's disease (PD).
DESIGN: This was a prospective, pilot interventional cohort study.
PARTICIPANTS: Twenty individuals with PD at Hoehn and Yahr stages I–III were included in the study.
INTERVENTIONS: Ten subjects in the BSS group and 10 subjects in the non-BSS group (supervised balance exercise training without BSS) participated in 55-min exercise sessions 3 times a week for 4 weeks.
OUTCOME MEASUREMENTS: Postural sway measures-sway area, anterior-posterior (AP) and medial-lateral (ML) center of pressure path length, and root mean square velocity in AP and ML directions were collected at baseline and postintervention. Secondary outcome measures of the Berg Balance Scale (BBS), spatiotemporal gait measures-gait velocity, step length, and stride length, Timed Up and Go, and 6-min walk test data were also collected at baseline and postexercise intervention for both the groups.
RESULTS: Improvements in postural sway were seen in the BSS group postintervention (sway area mean change = −435.3 mm2; 95% confidence interval = −818.5, −52.2). Postural sway data from the non-BSS group were unavailable, due to a technical failure. All secondary outcome measures improved in both the groups; however, we did not find any significant between-group differences in any of the secondary measures.
CONCLUSIONS: A 4-week exercise training using BSS improved measures of balance and gait in individuals with PD. However, improvements were also seen after an exercise program that did not use BSS. This suggests that at least for the measures used in this study, there were no differences between BSS training and supervised exercise balance training.
Keywords: Balance, Biodex Stability System, exercise, gait, Parkinson's disease
|How to cite this article:|
Singh G, Jain TK, Colgrove YM, Sharma NK, Pahwa R, Lyons K. Balance training in individuals with Parkinson's disease: Biodex Stability System versus supervised exercise program. Physiother - J Indian Assoc Physiother 2022;16:65-71
|How to cite this URL:|
Singh G, Jain TK, Colgrove YM, Sharma NK, Pahwa R, Lyons K. Balance training in individuals with Parkinson's disease: Biodex Stability System versus supervised exercise program. Physiother - J Indian Assoc Physiother [serial online] 2022 [cited 2023 Jun 5];16:65-71. Available from: https://www.pjiap.org/text.asp?2022/16/2/65/368879
| Introduction|| |
Poor balance is one of the most disabling symptoms of Parkinson's disease (PD), which increases with the progression of the disease and leads to decreased mobility and an increased number of falls. About 68% of individuals with PD fall at least once a year, leading to injuries and gait impairments.,, Hip fractures caused by PD alone cost about $192 million every year in the US. These injuries can cause a significant negative impact on physical function and quality of life in these individuals. Medications and surgical treatment provide limited improvement for balance and postural problems; therefore, better intervention strategies are needed to improve postural instability (PI) in individuals with PD.
Biomechanical postural sway measures of balance are altered in PD. The center of pressure (CoP) sway area, path length in anterior-posterior (AP) and medial-lateral (ML) directions, and root mean square (RMS) velocity of mean CoP in AP and ML directions are increased in individuals with PD.,,, Błaszczyk et al. also demonstrated significant increases in sway area, sway range, and path length in people with PD as compared to healthy controls. Similar findings have been reported by several other authors., In spite of documented increase in postural sway in individuals with PD, very few studies have examined specific interventions to improve PI in this patient population. Further, there is a scarcity of studies that have examined the efficacy of specific balance training equipment on biomechanical measures that are shown to be more sensitive in demonstrating treatment efficacy.
The Biodex Stability System (BSS) is a commercially available device, which consists of a circular platform that provides up to 20° of surface tilt and can move in a 360° range of motion. The platform is interfaced with computer software (Biodex, Version 3.1, Biodex Medical Systems, 49 Natcon Drive, Shirley, NY, USA) that enables the subject to visually track the movement of CoP. BSS challenges static and dynamic balance by either moving the platform or guiding subjects to move in AP or ML directions well beyond the person's limits of stability. Studies indicate that individuals with diabetic neuropathy have demonstrated significant improvements in overall stability index, AP, and ML stability index using the BSS for balance training with a total of 10 training sessions in 3 weeks.,, A randomized, controlled trial by Gusi et al. examined the effects of a 12-week BSS balance training program on institutionalized older individuals and they also showed a significant reduction in fear of falling and improvement in dynamic balance and knee strength was found following BSS training. BSS has been extensively used to challenge and train, dynamic balance following ankle and knee injuries but has not been used in the rehabilitation of neurological conditions such as PD. The primary aim of the present study was to evaluate if balance-specific training using the BSS improves balance in individuals with PD to a greater degree than standard supervised balance exercises and to determine if improvement in balance can translate into improvements in measures of gait.
| Methods|| |
All participants signed written informed consent for participation approved by the University of Kansas Medical Center's (KUMC) Institutional Review Board. Subjects between 40 and 70 years of age with a diagnosis of PD were recruited from the PD and Movement Disorder Center at KUMC. Subjects were diagnosed using the United Kingdom PD Society Brain Bank Criteria by the team neurologist. Further, inclusion criteria included Hoehn and Yahr stages I–III, Berg Balance Scale score below 50 out of 56, and independent in ambulation with or without an assistive device. Participants were excluded if they (1) had neurological disorders other than PD or significant head trauma; (2) received neurosurgical intervention for PD such as deep brain stimulation; (3) reported substance abuse; (4) reported any cardiovascular or medical dysfunction which could preclude participation a challenging balance training program; (5) had a history of any major injuries to the lower extremities such as replacements of hip, knee, or ankle; or (6) had a score of <20 on the Montreal Cognitive Assessment, indicating significant cognitive impairment.,
Participants completed a series of tests, which included postural sway measures, gait parameters, and other tests of balance and endurance such as the Timed Up and Go test (TUG) and 6-min walk test (6MWT), 2–3 days before the beginning of the intervention. During the study, the participants were instructed to take their usual anti-parkinsonian medications. All participants were tested and trained during the medication "ON" phase, i.e., between 1 and 2 h after taking medications. None of the participants had any change in their activity level, exercise participation, and medications during the 4-week study period.
Primary outcome measures
Participants were evaluated before and immediately after the completion of 4 weeks of training. CoP measures were collected using two force platforms (AMTI Measurements Group, Watertown, MA, USA). The signals were sampled at a frequency of 100 Hz., The participants were asked to stand on the force plates once with eyes open (EO) and then with eyes closed for the following four conditions: (1) feet shoulder-width apart; (2) feet together, but on separate force plates; (3) one foot ahead of the other as in stepping; and (4) tandem standing. A total of 5 trials of 20 s each were collected under each condition, with a 10-s rest between each trial. A gait belt and overhead harness were used to ensure patient safety. In addition, a research assistant always stood behind the participants during testing. The parameters included in the CoP measures were swayed area, CoP path length in AP and ML directions, and RMS velocity in AP and ML directions.
Secondary outcome measures
The Berg Balance Scale is a 14-item gold standard clinical scale for balance that has excellent test–retest reliability. A score below 52 suggests a fall risk. In addition, there are 3 different levels of scores identified as a minimal, moderate, and severe fall risk. TUG and 6-min walk, both reliable and valid tests in individuals with PD, were obtained to examine effects on gait.
Spatiotemporal gait parameters
The GAITRite system (CIR Systems Inc./GAITRite, Sparta, NJ, USA) was used to assess the spatiotemporal gait parameters (gait velocity, step length, and stride length) in this study. The GAITRite system is a computerized instrument consisting of a 4.6-m electronic walkway with embedded sensors to identify foot contacts and the spatiotemporal gait components during walking. Participants walked 1 m before the walkway and continued 1 m beyond the walkway. A total of 3 trials were collected, and the average of the 3 trials was used for analysis. A minimal detectable change of 0.19 m/s in walking velocity has been reported for PD.,
Participants were conveniently assigned to either the BSS group or the non-BSS group for 12 treatment sessions, 55 min each, 3 days a week (Monday, Wednesday, and Friday) for 4 consecutive weeks. The training was conducted in the Clinical Orthopedic Rehabilitation Research Laboratory at KUMC.
Biodex Stability System balance exercise program
The participants in the BSS group performed voluntary movements utilizing static or dynamic tasks [Table 1]. Under the static task, participants were required to maintain the CoP [shown as a small black dot on the front screen: [Image 1]] in the smallest circle during 4 different standing conditions: standing with feet shoulder-width apart, standing on left foot alone, standing on right foot alone, and standing with feet together. During the dynamic task in the second set of exercises, the training included moving the CoP in AP and ML directions, tracking the random dot on the screen in different directions, and finally moving the CoP in clockwise and counterclockwise directions.
The tasks required the participants to keep their CoP within the limits of stability to avoid possible falls. The training started at a low level (L1) and progressively challenged participants' balance as described in [Table 1]. All the participants performed 3 sets of 6 repetitions, which took 6 min for each exercise on average to complete the task. Limits of stability (where the participants tried to reach points on the screen, which challenged their balance) and maze control (where the participants tried to maintain the black dot within the boundaries of the maze while moving the dot clockwise and counterclockwise) exercises included 4–6 repetitions on average, which also took approximately 6 min [Table 1]. During the 4th week, the level of challenge was randomly selected (levels 1, 2, or 3) during the training session. The participants were given verbal instructions and provided the required assistance in carrying out the activities. The total training time was about 55 min, excluding warm-up and cool-down exercises of stretching and walking in the hallway.
Non-Biodex Stability System supervised exercise program
Supervised balance exercises taken from the National Parkinson Foundation's "Falls Prevention" booklet were used as intervention training in this group (www.parkinson.org). The booklet contained 6 different balance exercises [Table 2]. The training was supervised by a team member and lasted 55 min/exercise sessions, 3 days a week for 4 weeks.
All the participants from both the groups were instructed to take breaks as needed. Additionally, participants were instructed to sit down or stop exercising if they experienced undue fatigue, lightheadedness, or dizziness.
SPSS 22.0 (SPSS Inc., Chicago, IL, USA) was used for the statistical analysis. Levene's test of equality of variances was conducted to test the homogeneity of the samples. Wilcoxon signed-rank test was used to assess within-group differences, and Mann–Whitney U-test was used to assess between-group differences from the baseline and postintervention scores. An alpha level for significance was set up at 0.05.
| Results|| |
Eighteen participants completed the study. One participant from each group withdrew from the study due to time commitment and transportation problems. Demographic data and baseline measures are presented in [Table 3]. There were no differences between the groups at baseline.
Primary outcome measures
BSS intervention resulted in a significant decrease in total sway area (mean change = −435 ± 535 mm2; 95% confidence interval [CI] = −818.5, −52.25), path length in AP direction (mean change = −12.6 ± 14.5 mm; 95% CI = −23.1,-2.2), path length in ML direction (mean change = −9.15 ± 15 mm; 95% CI = −20.4, 2.11), RMS velocity in AP direction (mean change = −2.7 ± 3; 95% CI = −4.9, −0.5), and RMS velocity in ML direction (mean change = −1.8 ± 3.16, 95% CI = −4.09, 0.43) in the BSS group [Figure 1]. These measures were obtained with a force plate during quiet standing with EO.
|Figure 1: Changes in force plate measures in the Biodex Stability System group. a) Sway Area, b) Center of Pressure (CoP) path length in Antero-Posterior direction, c) Center of Pressure (CoP) path length in Medio-Lateral direction, d) Root Mean Square (RMS) velocity in Antero-Posterior direction, and e) Root Mean Square (RMS) velocity in Medio-Lateral direction|
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Due to the technical failure of the force plates, we were not able to capture the force plate data from the non-BSS group. The data on the BSS group were collected first. The data on the non-BSS group were collected later. During this study, the laboratory equipment was moved including the force plates. Later, it was found that the postural sway data for the non-BSS group were either not collected or got corrupted. Thus, we were not able to determine changes within the non-BSS group or evaluate between-group differences for the postural sway measures.
Secondary outcome measures
The Berg Balance Scale, spatiotemporal gait parameters-gait velocity, step length, and stride length, TUG, and 6MWT scores improved significantly in both the BSS and non-BSS groups following training (within-group, pre–post). However, no significant between-group differences were noted in any of the measured outcome measures following the interventions [Table 4].
| Discussion|| |
Balance training using the BSS over a relatively short period (4 weeks) improved balance and gait. Similar improvements were also seen in the non-BSS group. These results suggest that both exercise training programs are equally beneficial for people with PD. The 4-week intervention with BSS was found to be safe and feasible for individuals with PD in Hoehn and Yahr stages I–III. All the participants expressed satisfaction with the exercise program in both the groups.
Sway measures such as sway area, AP and ML CoP path length, and RMS velocity can be affected in individuals with PD as compared to healthy age-matched controls., The sway measures significantly improved following the BSS training in this study, indicating decrease in CoP displacement in both AP and ML directions. These results are consistent with the previously published studies.,,
Crizzle and Newhouse suggested that administering challenging balance exercises can result in better improvement in balance when compared to simple home exercises in individuals with PD. A recent study by Mhatre et al. found a significant improvement in postural sway following 8 weeks of training (3 times a week for 30 min) on a Wii balance board, using challenging balance exercises in a cohort of stage 2.5–3 PD patients. Esculier et al. also found a significant improvement in the CoP RMS velocity following 6 weeks of balance exercises (40-min sessions, 3 days a week) using Wii fit games at home. These studies suggest that challenging balance exercises can potentially improve balance and help reduce falls better than simple exercise sessions in individuals with PD. Challenging exercises, utilized in these studies, often involve exercises in standing with a smaller base of support, decreased assistance from upper extremities, and controlled movements of Center of Mass (CoM). Our study utilized similar exercises, which challenged balance statically and dynamically in both AP and ML directions, and resulted in significant improvements in the sway area, CoP path length, and CoP RMS velocity in both AP and ML directions. Although the BSS can provide 20° of tilt in every direction, we did not utilize the maximum tilt in our intervention, considering the ability and safety of the participants, which limited the range of movement in AP and ML directions. Future exercise programs focusing on even more challenging exercises by using maximum tilt of the BSS may result in better improvement in the overall balance in these individuals. We failed to demonstrate significant differences in the postural sway data between the BSS and non-BSS groups (due to technical issues), which could have provided strong evidence for use of the BSS for improving balance in PD.
The Berg Balance Scale is a valuable tool to assess responsiveness to change in balance in patients with neurological diseases. A minimal detectable change of 5 points on the Berg Balance Scale has been suggested to be a useful functional gain. We found an average improvement of 5.9 points in the BSS group and 6.7 points in the non-BSS group. These results are similar to previous work by Smania et al. who found significant improvements in the Berg Balance Scale (5.3 points) following 50 min of balance-specific exercises 3 times a week for 7 weeks. Other forms of exercise interventions such as YC and Hackney and Earhart which incorporate balance training including challenging balance exercises have been shown to improve balance in individuals with PD. Our study shows that even short-term balance training of 4 weeks can result in improvements in balance in individuals with PD.
Although several studies have examined the benefits of exercise training in PD, the effects of balance-specific exercises on gait parameters have not been fully investigated. Gait-directed exercise interventions such as treadmill training or aerobic exercises have been shown to improve gait velocity, step, and stride length., Our results suggest that balance-specific exercises, with or without BSS, can also improve gait speed, stride length, and step length, even after a short period of training. Studies that utilized balance-directed interventions such as Hackney and Earhart and Wii fit balance board report similar findings. Collectively, these results suggest that improvement in balance translates to an improvement in gait in individuals with PD.
PI and impaired gait are often associated with increased risk of falls in PD. We hypothesized that improvement in balance and gait would result in enhanced mobility in our study participants. Both the groups showed an improvement in TUG, which is a similar finding to previous studies;,, although, with our small sample size, the improvement in TUG was found to be less than the minimal detectable change range (3.5 s). The exercise program aimed at improving balance and reducing fall risk in PD has also shown improvement in the 6MWT. The 6MWT is considered a mobility endurance test for individuals with PD and a change of 82 m is considered a minimal detectable change in the 6MWT performance following an intervention. Our study is the first to examine the effects of balance training on 6MWT, demonstrating 57.3 m change in the BSS group and 40.2 m in the non-BSS group, suggesting that any form of challenging balance exercises can improve walking endurance in individuals with PD.
One of the major limitations of this study was a nonrandomized design. The availability of the force plate data would have helped to understand the potential usefulness of the BSS training as opposed to balance exercises without the BSS. A follow-up assessment to evaluate the long-term effects of training was not included. Additionally, our sample size was small, which may not adequately represent this population and the results should be interpreted with caution. Future studies on balance rehabilitation in PD should also take into account the use of more challenging exercises using the full tilt of the BSS. Further, future studies should also determine the adequate frequency, duration of treatment, and long-term effects of such interventions.
| Conclusions|| |
Our study suggests that regardless of the type of training methods, targeted balance training in individuals with PD results in improvements in balance, gait, and mobility. Patients at all stages of PD should be encouraged to engage in regular exercise to maintain good balance and reduce the decline in physical function. In conclusion, the results of this pilot trial show that short-duration balance training with BSS in individuals with PD is feasible and can improve PI and gait function. Additionally, a study by Kara et al. suggested that supervised exercises once a week for 12 weeks resulted in improvements in Dynamic balance.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4]