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Effects of interactive video-game based system exercise on the balance of the elderly
Gait & Posture 37 (2013) 511–515
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Gait & Posture journal homepage: www.elsevier.com/locate/gaitpost
Effects of interactive video-game based system exercise on the balance of the elderly Chien-Hung Lai a,b, Chih-Wei Peng a,b, Yu-Luen Chen c,d,1, Ching-Ping Huang e, Yu-Ling Hsiao f, Shih-Ching Chen a,b,* a
Department of Physical Medicine and Rehabilitation, School of Medicine, College of Medicine, Taipei Medical University, Taiwan Department of Physical Medicine and Rehabilitation, Taipei Medical University Hospital, Taiwan Catholic St. Mary’s Medicine, Nursing and Management College, Taiwan d Department of Computer Science, National Taipei University of Education, Taipei, Taiwan e Department of Digital Technology Design, College of Science, National Taipei University of Education, Taiwan f School of Geriatric Nursing and Care Management, College of Nursing, Taipei Medical University, Taiwan b c
A R T I C L E I N F O
A B S T R A C T
Article history: Received 9 December 2011 Received in revised form 22 August 2012 Accepted 4 September 2012
This study evaluated the effects of interactive video-game based (IVGB) training on the balance of older adults. The participants of the study included 30 community-living persons over the age of 65. The participants were divided into 2 groups. Group A underwent IVGB training for 6 weeks and received no intervention in the following 6 weeks. Group B received no intervention during the first 6 weeks and then participated in training in the following 6 weeks. After IVGB intervention, both groups showed improved balance based on the results from the following tests: the Berg Balance Scale (BBS), Modified Falls Efficacy Scale (MFES), Timed Up and Go (TUG) test, and the Sway Velocity (SV) test (assessing bipedal stance center pressure with eyes open and closed). Results from the Sway Area (SA) test (assessing bipedal stance center pressure with eyes open and closed) revealed a significant improvement in Group B after IVGB training. Group A retained some training effects after 6 weeks without IVGB intervention. Additionally, a moderate association emerged between the Xavix measured step system stepping tests and BBS, MFES, Unipedal Stance test, and TUG test measurements. In conclusion, IVGB training improves balance after 6 weeks of implementation, and the beneficial effects partially remain after training is complete. Further investigation is required to determine if this training is superior to traditional physical therapy. ß 2012 Elsevier B.V. All rights reserved.
Keywords: Interactive video-game based training Older adults Balance Berg Balance Scale Timed Up and Go test
1. Introduction Falls are common problems among older adults worldwide. The consequences of falling include increased morbidity and health costs, fear of falling, and restriction of mobility and activity [1–4]. Stability requires a well-functioning muscular–skeletal system and an intact balance system [5]. Moreover, exercise programs incorporating a balance component for healthy older adults can help prevent falling [5]. Therefore, seeking an effective intervention to increase balance and to prevent falling is critical.
* Corresponding author at: Department of Physical Medicine and Rehabilitation, Taipei Medical University Hospital, No. 252, Wuxing St., Taipei 11031, Taiwan. Tel.: +886 2 27372181x1236; fax: +886 2 55589880. E-mail address: [email protected] (S.-C. Chen). 1 Equal contribution with the first author. 0966-6362/$ – see front matter ß 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.gaitpost.2012.09.003
Improving balance and reducing falls have been attempted by treating individuals with multidisciplinary fall-prevention programs and specific exercises. An evidence-based study could not verify that a particular multidisciplinary fall-prevention program was effective in preventing falls [6]. Several studies have also reported that properly designed exercise intervention can improve balance and reduce falls in older adults during exercise intervention [7–9]. However, the participation rates are low because such exercises are often repetitive and unattractive [10]. In addition, whether the effects on balance and falls are maintained after ceasing exercises remains unclear. Therefore, medical researchers are still seeking a potentially optimal therapy to prevent older adults from falls. Auditory or visual biofeedback input is commonly used to improve postural stability and balance in clinical practice [11,12]. Dozza et al. showed that audio-biofeedback can reduce postural sway and improve postural stability in healthy adults [12]. Another
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study found that visual guided weight shift practice develops a more stable postural base during obstacle avoidance [11]. Interactive video-game based (IVGB) exercise has been shown to increase individuals’ interest in performing related exercises [10,13]. However, few studies provide evidence supporting the positive effects of IVGB exercises on the balance of older adults. Therefore, this study evaluates the effects of IVGB training on the balance of older adults. Several objective outcome measures were used to determine the effects of IVGB training on the balance of older adults. 2. Methods
randomly assigned to 1 of 2 groups. Fifteen participants were recruited to Group A (7 men and 8 women; mean age, 70.6 [SD 3.5] years). Another 15 participants were recruited to Group B (6 men and 9 women; mean age, 74.8 [SD 4.7] years). All experiments and measurements were completed for 30 participants. Table 1 summarizes the participants’ characteristics. Participants were excluded if they had a neurological condition such as Parkinson’s disease, dementia, and stroke, or if they had arthritis, vision impairment, and cardiovascular disease that impaired walking, or if they were unable to walk without assistance. This study was conducted at Taipei Medical University Hospital and approved by the ethics board. The potential risks and benefits of participation were explained to each participant. All participants reviewed an informed consent document and provided written consent before participation. 2.2. Study design
2.1. Participants Participants in the study included 30 community-living persons over 65 years of age (13 men and 17 women; mean age, 72.1 [SD 4.8] years). The participants were
The study was designed as a prospective, randomized, crossover, single blind (The examiners were blind, but the participants were not blind), 12-week trial to determine the training effects of IVGB stepping exercise. Group A underwent the
30 participants (Mean age, 72.1 (4.8); 13 male, 15 female)
Randomly assigned into group A and B
15 parcipants in group A
15 parcipants in group B
(Mean age, 70.6 (3.5); 7 male, 8
(Mean age, 74.5 (4.7); 6 male, 9
female)
female)
) Week 0 Measurement of XMSS, BBS, TUG, Intervenon
MFES, UST, and Catsys 2000 (COP
Control phase,
phase, 6 weeks
velocity and area of bipedal stance
6 weeks
with open eyes and close eyes)
Week 6 Measurement of XMSS, BBS, TUG, MFES, UST, and Catsys 2000 (COP velocity and area of bipedal stance Control phase,
with open eyes and close eyes)
6 weeks
Intervenon phase, 6 weeks
Week 12 Measurement of XMSS, BBS, TUG, MFES, UST, and Catsys 2000 (COP velocity and area of bipedal stance with open eyes and close eyes) Compleon
Compleon
Fig. 1. Study procedures for Groups A and B. Xavix Measured Step System (XMSS), Berg Balance Scale (BBS), Timed Up and Go (TUG) test, Modified Falls Efficacy Scale (MFES), Unipedal Stance test (UST), and center of pressure (COP).
C.-H. Lai et al. / Gait & Posture 37 (2013) 511–515 Table 1 Demographic characteristics of participants.
Number of participants Age Sex Male Female Personal condition Height (cm) Weight (Kg) BMI Regular Exercisers Number of falls in the past year (person-year)
Group A
Group B
15 70.6 (3.5)
15 74.8 (4.7)
7 8
6 9
157.76 (6.60) 60.67 (6.93) 24.34 (3.63) 10 5
158.36 (6.86) 64.27 (7.22) 25.52 (3.32) 9 6
IVGB training in the initial 6 weeks (intervention phase), followed by no exercise in the subsequent 6 weeks (control phase). The Group B received no treatment in the first 6 weeks (control phase), and underwent IVGB training in the following 6 weeks (intervention phase), as shown in Fig. 1. 2.3. IVGB intervention The Xavix Measured Step System (XMSS), from SPECTRUM9000MB-500system, UIS Co., Japan, was used to perform the IVGB exercises The XMSS contains 1 console (XaviX port), an A/V cable connected to a television, a power cable connecting the console to a power source, and a one-step mat. A USB cable connected a custom XaviX computer software cartridge to a computer. Results were recorded using personal cartridges. The XMSS exercise was conducted for 30 min, 3 times a week for 6 weeks during the IVGB intervention phase for both groups. During exercise, to ensure uniformity in exercise posture, participants were asked to raise their knees above their waists, maintain their trunks in an upright position, and avoid too much compensation by postural sway while performing the stepping exercise. The trainer familiarized participants with the IVGB exercise before training. Time spent standing, time spent exercising and total virtual distance travelled can be recorded during the exercise. The IVGB exercise results were shown on the screen, providing instant feedback to participants. 2.4. Outcome measurement All participants completed a Berg Balance Scale (BBS), Timed Up and Go (TUG) test, Modified Falls Efficacy Scale (MFES), Unipedal Stance test (UST), and the XMSS stepping test before the experiment, after the initial 6 weeks, and after the following 6 weeks. The Sway Area (SA) and Sway Velocity (SV) of the center of pressure (COP) in a bipedal stance with eyes open and closed were also measured (Fig. 1) 2.4.1. BBS Participants performed a series of 14 functional balance tasks, including maintaining a quiet stance, sitting-to-standing, shifting weight and reaching, turning in place, standing on one leg, and maintaining a tandem stance. Each task was scored on a 5-point ordinal scale (from 0 to 4). A score of 0 denotes the inability of the participant to perform the task, and a score of 4 denotes that the participant can complete the task based on a preset criterion. The highest possible score is 56 [14]. Studies have shown that inter-rater and intra-rater BBS reliabilities are high in older adults and stroke patients [15]. 2.4.2. TUG The TUG test is a balance test that is commonly used to examine functional mobility in older adults living communally. The time required to complete the test is strongly correlated to functional mobility levels [16,17]. In this study, participants were asked to complete TUG tests. The test required participants to stand, walk 3 m, turn, walk back, and sit down. The time for completing the TUG test was recorded. The TUG test is a sensitive and specific indicator of whether participating community-dwelling older adults have fallen [17]. 2.4.3. MFES The MFES is a 14-item rating scale questionnaire that contains the original 10activity Falls Efficacy Scale and 4 additional activities. It is used to assess confidence of not falling while performing daily activities in many older adults. Items are rated from 0 (not confident at all) to 10 (completely confident), and the highest possible score is 140. Retest reliability for the MFES and internal consistency are high [18]. 2.4.4. UST The UST is a method of assessing static balance. It is a valid measure for balance and predicts injurious falls. Moreover, inter-rater reliability was
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excellent in trials [19,20]. Participants in this study were asked to stand barefoot on a leg of their choice with their other leg raised to ankle height. The duration that participants maintained balance while standing on one leg was measured 2.4.5. SA and SV of COP of bipedal stance with eyes open and closed The Catsys 2000 system (Danish Product Development Ltd, Denmark) tested postural sway. This SA test system is a platform with 3 orthogonal strain gauge devices [21]. The maximal and minimal sway-plate loads were 150 kg and 20 kg, respectively. The sampling rate was 31.25 Hz, and the frequency of the signal was collected below 15 Hz because the swing frequency of the subjects was typically less than 10 Hz. A previous study showed that the Catsys 2000 system has a high degree of reproducibility for balancing tests [22]. Participants were asked to stand on the platform (force plate), feet at 1 cm apart, with their arms at their sides. Thereafter, the participants were asked to look at a picture in front of them with their eyes open or closed for 75 s. For each participant, postural sway was measured for 75 s (standard test procedure: 10 s start-up period, 60 s recording period, and 5 s run-out period) first with their eyes open and then with their eyes closed, while standing directly on the platform [21]. The SA and SV of the COP were calculated and recorded, based on each participant’s performance. 2.4.6. XMSS To perform the XMSS stepping test, participants were asked to stand on a platform that contained a sensory detector. Participants were then required to step onto a corresponding platform, mimicking virtual people on a screen. The test contained 4 walking speed sequences (from fast to slow). The duration of each test was 70 s. The mean duration of a single-leg stance for each leg while stepping was calculated and was recorded in each test.
2.5. Statistical analysis All data are expressed as mean values, followed by the standard deviation in parentheses. Repeated-measures ANOVA was administered to compare differences between measurements for all outcome measurement parameters. Following a significant ANOVA result, Bonferroni’s post hoc analysis was conducted to further examine the difference. A P value <.05 was considered significant. Additionally, Pearson’s product–moment correlation (Pearson’s correlation coefficient) was examined to compare the relationships between the XMSS test and other outcome assessments (BBS, MFES, UST, and TUG test) at the baseline measurement. The magnitudes used to interpret the correlation coefficients were: (1) <0.10, trivial; (2) 0.10 jrj 0.29, small; (2) 0.3 jrj 0 .49, moderate; and (3) jrj 0.5, large [23,24]. The software package SPSS 18.0 was used for statistical analysis.
3. Results 3.1. Intervention effect 3.1.1. Group A In Group A, the BBS, MFES, TUG test, SV with eyes open and closed, and XMSS left and right leg stepping test improved significantly after IVGB exercises (Table 2). The UST time showed a trend of increase and the SA of the COP with eyes open and closed revealed showed a trend of decrease after IVGB exercises (Table 2). At the 12-week assessment for Group A, the BBS, TUG test and XMSS stepping test showed significant improvement compared with the initial assessment (Week 0 in Table 2). Furthermore, all outcome measurement parameters in Week 12 were not significantly different from the Week 6 measurements. These results implied that the training effects were partially maintained after 6 weeks without IVGB intervention. 3.1.2. Group B In Group B, there were no significant differences in all outcome measurement parameters between Week 0 and Week 6 (control phase). All outcome measures except UST improved significantly after the IVGB intervention compared to before the IVGB intervention (Week 6 in Table 2) and to initial measurement (Week 0 in Table 2). The UST showed a trend of increase after IVGB exercise.
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Table 2 Outcome variables of the baseline, 6th week, and 12th week. Group
XMSS T.R. (s)a XMSS T.L. (s)b BBS (score) MFES (score) UST (s) TUG (s) BiOE SA (mm2)c BiCE SA (mm2)d BiOE SV (mm/s) BiCE SV (mm/s) a b c d * y z §
A
B
Baseline
6th week
12th week
P value
Baseline
6th week
12th week
P value
1.01(0.44) 1.06(0.44) 50.53(4.75) 131.13(6.56) 31.80(18.39) 9.54(3.52) 320.80(273.45) 342.54(213.67) 9.37(2.30) 13.11(5.12)
2.13(0.92)y 2.55(0.97)y 53.87(3.56)y 136(6.07)y 48.74(26.67) 8.54(2.85)y 191.00(70.31) 262.20(142.11) 8.10(1.62)y 11.28(3.55)y
2.04(0.65)§ 2.21(0.65)§ 53.93(3.45)§ 133.4(7.41) 54.87(45.46) 8.53(2.88)§ 213.13(166.03) 318.87(184.76) 8.23(3.23) 12.00(4.36)
<0.001* <0.001* 0.001* 0.001* 0.062 0.046* 0.052 0.092 0.046* 0.024*
0.82(0.33) 0.83(0.36) 46.47(9.98) 114.67 (27.12) 18.87(22.35) 14.07(8.35) 347.73(196.50) 479.87(256.87) 10.65(4.22) 13.49(3.99)
1.15(0.58) 1.04(0.44) 46.20(11.48) 116.4(27.89) 23.00(21.52) 14.87(8.42) 319.47(150.41) 431.20(250.85) 10.28(2.83) 13.16(3.73)
1.86(0.58)z,§ 1.9(0.51)z,§ 50.67(8.19)z,§ 124.53(21.91)z,§ 38.33(36.82) 11.27(6.33)z,§ 202.07(130.43)z,§ 249.00(132.38)z,§ 8.30(2.64)z,§ 10.47(3.13)z,§
<0.001* <0.001* <0.001* 0.033* 0.063 0.002* 0.002* 0.002* 0.004* 0.001*
XMSS T.R., mean duration of right leg stance in XMSS stepping test. XMSS T.L., mean duration of left leg stance in XMSS stepping test. BiOE, bipedal stance with eyes open. BiCE, bipedal stance with eyes closed. P < 0.05, determined by repeated-measures ANOVA. P < 0.05, difference between outcome variables at baseline and at 6th week as determined by Bonferroni post hoc test. P < 0.05, difference between outcome variables at 6th week and at 12th week as determined by Bonferroni post hoc test. P < 0.05, difference between outcome variables at baseline and at 12th week as determined by Bonferroni post hoc test.
Table 3 Pearson’s product–moment correlation between outcome measures. XMSS stepping test XMSS stepping test BBS MFES UST TUG test a b
BBS
MFES
UST
TUG test
0.488a
0.461a 0.781b
0.357a 0.489a 0.412a
0.435a 0.888b 0.797b 0.379a
0.3 jrj 0 .49, moderate. jrj 0.5, large.
Investigation results showed a significant improvement in several outcome measurement parameters after 6 weeks of IVGB intervention in Groups A and B. These results implied that the intervention might have a sufficient duration and intensity. The training effects partially remained after 6 weeks of no IVGB exercises for Group A. The reason for the IVGB exercise effect persisting after ceasing the exercises is unknown. It might be because of the easy incorporation of IVGB stepping exercises into daily walking. Older adults might walk with longer strides and raise their legs higher while walking after participating in IVGB exercises. Another possible reason might be that participants performed exercise more often than they did before IVGB intervention because of their improved balance.
The activity of UST was not only involved in the balance measures but also associated with muscle strength [26]. In this study, the mean time of UST was approximately 31.8 for group A and 23.0 s for group B. These results are in accordance with the findings of Springer et al. [19], who found mean UST times approximately 32.1 s between ages 60 and 69 years and 21.5 s between ages 70 and 79 years. Mean UST time increased to approximately 48.7 s and 38.3 s after the IVGB intervention for Groups A and B, respectively. The TUG is the test recommended by the American and British Geriatrics Societies for assessing the risk of falling [27]. A study found that a TUG time of over 14 s is associated with a high risk of falling in older adults [28]. This study examined older people who were relatively healthy and living independently within the community. The average TUG test times were 9.54 s and 14.87 s before training for Groups A and B, respectively. The mean TUG test times improved to 8.54 s and 11.27 s for Groups A and B, respectively (Table 2). Most of older adults took less than 14 s to complete the TUG test after IVGB intervention. In this study, the SA and SV of the COP were sensitive to visual output. Results show that SA and SV were higher with eyes closed than with eyes open before and after IVGB intervention in both groups. These results agree with those obtained by Despre´s et al., whose results showed that postural sway was higher with eyes closed than with eyes open [21].
4.2. Interpretation of outcome measurement
4.3. Advantages of IVGB intervention
Most BBS test mimic daily life activities [14,25]. In this study, the mean BBS improvement was 3.33 (0.67) for Group A and 4.47 (1.18) for Group B. Shumway-Cook et al. showed that BBS was the single most accurate predictor of falls. They suggested that a 1-point decrease in BBS score leads to a 6–8% increase of fall risk in the range of 54–46 [25].
Coupling interactive video games with traditional stepping exercises exhibit numerous merits. First of all, conventional exercise may benefit the postural stability and balance of older adults. However, the participation rates are low because such exercises are often repetitive and unattractive [10]. The proposed IVGB exercise may be more feasible and attractive than conventional exercise to
3.2. Correlations between outcome measures The correlations between outcome measures were shown in Table 3. The correlations between XMSS stepping tests and other outcome measures were moderate (jrj = 0.3–0.49) for all (Table 3). 4. Discussion 4.1. Major findings
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healthy older adults. Secondly, this IVGB system provides an interactive environment. The number of steps, mean single-leg stance time, and avatar-mimicking movements are shown on the screen during the exercise, providing instant feedback to participants. Positive results were also seen when video games were incorporated into virtual environments [10,13,29]. Finally, the IVGB training also provides a purposeful and challenging exercise. In this study, older adults were asked to raise their knee above their waists, and maintain their trunks in an upright position while performing the IVGB stepping exercise. This typed of stepping exercise requires adequate postural control and lower-extremity strength. Therefore, it is expected that repetitions of the IVGB stepping exercise had a positive effect on several outcome measurements. 4.4. XMSS stepping tests as outcome measures In this study, there were considerable interests by using the XMSS stepping tests for the outcome assessment. Results showed a moderate association between the XMSS stepping tests and BBS, MFES, UST and TUG measurements (jrj = 0.3–0.49). Additional studies are necessary to examine retest reliability and internal consistency of XMSS stepping tests. 4.5. Study limitation This study had several limitations. One limitation was the impracticality of experimental blinding of the participants because they knew they had undergone training. However, the trainer and assessor was not the same person to allow for experimental blinding of the assessor. An additional limitation is that the XMSS system is not widely used. However, the findings in our study can probably be applied to other video-game based systems used to rehabilitate patients if the tasks are sufficiently functional and demanding. A further limitation was that fall statuses of participants were not measured. However, balance statuses were objectively assessed using several outcome measures that have been clinically demonstrated to predict falls. Furthermore, this study only conducted 6 weeks of IVGB training and 6 weeks of follow-up. A longer study is necessary to observe long-term effects. In addition, IVGB exercises’ various effects on balance were not compared to those of traditional physical therapy. Further investigation is required to determine if this type training is superior to traditional physical therapy. 5. Conclusion The IVGB intervention improved balance after 6 weeks of training. Furthermore, the beneficial effects persisted partially for 6 weeks of no IVGB intervention. Correlations between XMSS stepping tests and other outcome measures were moderate. Additional investigations are necessary to examine the reliability and the internal consistency of XMSS stepping tests. Acknowledgement This work was supported in part by Supreme Investment Co., LTD. Taipei, Taiwan. However, it had no role in study design, data collection, analysis or interpretation of data, writing the manuscript, or submission of the manuscript for publication. Conflict of interest All authors have disclosed any commercial association that might create a conflict of interest in connection with the submitted manuscript. There is no competing financial interest for any of the authors.
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References [1] Rizzo JA, Baker DI, McAvay G, Tinetti ME. The cost-effectiveness of a multifactorial targeted prevention program for falls among community elderly persons. Medical Care 1996;34:954–69. [2] Speechley M, Tinetti M. Falls and injuries in frail and vigorous community elderly persons. Journal of the American Geriatrics Society 1991;39:46–52. [3] Tinetti ME, Speechley M, Ginter SF. Risk factors for falls among elderly persons living in the community. The New England Journal of Medicine 1988;19:1701–7. [4] Vellas B, Cayla F, Bocquet H, de Pemille F, Albarede JL. Prospective study of restriction of activity in old people after falls. Age and Ageing 1987;16:189–93. [5] Davis JC, Donaldson MG, Ashe MC, Khan KM. The role of balance and agility training in fall reduction. A comprehensive review. Europa Medicophysica 2004;40:211–21. [6] Hendriks MR, Bleijlevens MH, van Haastregt JC, Crebolder HF, Diederiks JP, Evers SM, et al. Lack of effectiveness of a multidisciplinary fall-prevention program in elderly people at risk: a randomized, controlled trial. Journal of the American Geriatrics Society 2008;56:1390–7. [7] Barnett A, Smith B, Lord SR, Williams M, Baumand A. Community-based group exercise improves balance and reduces falls in at-risk older people: a randomised controlled trial. Age and Ageing 2003;32:407–14. [8] Bogaerts A, Delecluse C, Boonen S, Claessens AL, Milisen K, Verschueren SM. Changes in balance, functional performance and fall risk following whole body vibration training and vitamin D supplementation in institutionalized elderly women. A 6 month randomized controlled trial. Gait and Posture 2011;33: 466–72. [9] Campbell AJ, Robertson MC, Gardner MM, Norton RN, Tilyard MW, Buchner DM. Randomised controlled trial of a general practice programme of home based exercise to prevent falls in elderly women. BMJ 1997;315:1065–9. [10] Studenski S, Perera S, Hile E, Keller V, Spadola-Bogard J, Garcia J. Interactive video dance games for healthy older adults. The Journal of Nutrition Health and Aging 2010;14:850–2. [11] Hatzitaki V, Voudouris D, Nikodelis T, Amiridis IG. Visual feedback training improves postural adjustments associated with moving obstacle avoidance in elderly women. Gait and Posture 2009;29:296–9. [12] Dozza MCL, Peterka RJ, Wall C, Horak FB. What is the most effective type of audiobiofeedback for postural motor learning? Gait and Posture 2011;34:13–9. [13] Betker AL, Szturm T, Moussavi ZK, Nett C. Video game-based exercises for balance rehabilitation: a single-subject design. Archives of Physical Medicine and Rehabilitation 2006;87:1141–9. [14] Berg KO, Wood-Dauphinee SL, Williams JI, Maki B. Measuring balance in the elderly: validation of an instrument. Canadian Journal of Public Health 1992;83(Suppl. 2):S7–11. [15] Berg K, Wood-Dauphinee S, Williams JI. The Balance Scale: reliability assessment with elderly residents and patients with an acute stroke. Scandinavian Journal of Rehabilitation Medicine 1995;27:27–36. [16] Podsiadlo D, Richardson S. The timed ‘‘Up & Go’’: a test of basic functional mobility for frail elderly persons. Journal of the American Geriatrics Society 1991;39:142–8. [17] Nowalk MP, Prendergast JM, Bayles CM, D’Amico FJ, Colvin GC. A randomized trial of exercise programs among older individuals living in two long-term care facilities: the FallsFREE program. Journal of the American Geriatrics Society 2001;49:859–65. [18] Hill KD, Schwarz JA, Kalogeropoulos AJ, Gibson SJ. Fear of falling revisited. Archives of Physical Medicine and Rehabilitation 1996;77:1025–9. [19] Springer BA, Marin R, Cyhan T, Roberts H, Gill NW. Normative values for the unipedal stance test with eyes open and closed. Journal of Geriatric Physical Therapy 2007;30:8–15. [20] Vellas BJ, Wayne SJ, Romero L, Baumgartner RN, Rubenstein LZ, Garry PJ. Oneleg balance is an important predictor of injurious falls in older persons. Journal of the American Geriatrics Society 1997;45:735–8. [21] Despres C, Lamoureux D, Beuter A. Standardization of a neuromotor test battery: the CATSYS system. Neurotoxicology 2000;21:725–35. [22] Gyntelberg FFM, Mikkelsen T, Ryom C, Suadicani P. Computerized coordination ability testing. Acta Neurologica Scandinavica 1990;82:39–42. [23] Harris NK, Cronin JB, Hopkins WG, Hansen KT. Relationship between sprint times and the strength/power outputs of a machine squat jump. Journal of Strength and Conditioning Research 2008;22:691–8. [24] Cohen J. Statistical Power Analysis for the Behavioral Sciences, 2nd ed., Hillsdale, NJ: Lawrence Erlbaum; 1988. [25] Shumway-Cook A, Baldwin M, Polissar NL, Gruber W. Predicting the probability for falls in community-dwelling older adults. Physical Therapy 1997;77: 812–9. [26] Mayson DJ, Kiely DK, LaRose SI, Bean JF. Leg strength or velocity of movement: which is more influential on the balance of mobility limited elders? American Journal of Physical Medicine and Rehabilitation 2008;87:969–76. [27] American Geriatrics Society, British Geriatrics Society, American Academy of Orthopaedic Surgeons Panel on Falls Prevention. Guideline for the prevention of falls in older persons. Journal of the American Geriatrics Society 2001;49: 664–72. [28] Shumway-Cook A, Brauer S, Woollacott M. Predicting the probability for falls in community-dwelling older adults using the Timed Up & Go Test. Physical Therapy 2000;80:896–903. [29] Deutsch JE. Virtual reality and gaming systems to improve walking and mobility for people with musculoskeletal and neuromuscular conditions. Studies in Health Technology & Informatics 2009;145:84–93.
Contents lists available at SciVerse ScienceDirect
Gait & Posture journal homepage: www.elsevier.com/locate/gaitpost
Effects of interactive video-game based system exercise on the balance of the elderly Chien-Hung Lai a,b, Chih-Wei Peng a,b, Yu-Luen Chen c,d,1, Ching-Ping Huang e, Yu-Ling Hsiao f, Shih-Ching Chen a,b,* a
Department of Physical Medicine and Rehabilitation, School of Medicine, College of Medicine, Taipei Medical University, Taiwan Department of Physical Medicine and Rehabilitation, Taipei Medical University Hospital, Taiwan Catholic St. Mary’s Medicine, Nursing and Management College, Taiwan d Department of Computer Science, National Taipei University of Education, Taipei, Taiwan e Department of Digital Technology Design, College of Science, National Taipei University of Education, Taiwan f School of Geriatric Nursing and Care Management, College of Nursing, Taipei Medical University, Taiwan b c
A R T I C L E I N F O
A B S T R A C T
Article history: Received 9 December 2011 Received in revised form 22 August 2012 Accepted 4 September 2012
This study evaluated the effects of interactive video-game based (IVGB) training on the balance of older adults. The participants of the study included 30 community-living persons over the age of 65. The participants were divided into 2 groups. Group A underwent IVGB training for 6 weeks and received no intervention in the following 6 weeks. Group B received no intervention during the first 6 weeks and then participated in training in the following 6 weeks. After IVGB intervention, both groups showed improved balance based on the results from the following tests: the Berg Balance Scale (BBS), Modified Falls Efficacy Scale (MFES), Timed Up and Go (TUG) test, and the Sway Velocity (SV) test (assessing bipedal stance center pressure with eyes open and closed). Results from the Sway Area (SA) test (assessing bipedal stance center pressure with eyes open and closed) revealed a significant improvement in Group B after IVGB training. Group A retained some training effects after 6 weeks without IVGB intervention. Additionally, a moderate association emerged between the Xavix measured step system stepping tests and BBS, MFES, Unipedal Stance test, and TUG test measurements. In conclusion, IVGB training improves balance after 6 weeks of implementation, and the beneficial effects partially remain after training is complete. Further investigation is required to determine if this training is superior to traditional physical therapy. ß 2012 Elsevier B.V. All rights reserved.
Keywords: Interactive video-game based training Older adults Balance Berg Balance Scale Timed Up and Go test
1. Introduction Falls are common problems among older adults worldwide. The consequences of falling include increased morbidity and health costs, fear of falling, and restriction of mobility and activity [1–4]. Stability requires a well-functioning muscular–skeletal system and an intact balance system [5]. Moreover, exercise programs incorporating a balance component for healthy older adults can help prevent falling [5]. Therefore, seeking an effective intervention to increase balance and to prevent falling is critical.
* Corresponding author at: Department of Physical Medicine and Rehabilitation, Taipei Medical University Hospital, No. 252, Wuxing St., Taipei 11031, Taiwan. Tel.: +886 2 27372181x1236; fax: +886 2 55589880. E-mail address: [email protected] (S.-C. Chen). 1 Equal contribution with the first author. 0966-6362/$ – see front matter ß 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.gaitpost.2012.09.003
Improving balance and reducing falls have been attempted by treating individuals with multidisciplinary fall-prevention programs and specific exercises. An evidence-based study could not verify that a particular multidisciplinary fall-prevention program was effective in preventing falls [6]. Several studies have also reported that properly designed exercise intervention can improve balance and reduce falls in older adults during exercise intervention [7–9]. However, the participation rates are low because such exercises are often repetitive and unattractive [10]. In addition, whether the effects on balance and falls are maintained after ceasing exercises remains unclear. Therefore, medical researchers are still seeking a potentially optimal therapy to prevent older adults from falls. Auditory or visual biofeedback input is commonly used to improve postural stability and balance in clinical practice [11,12]. Dozza et al. showed that audio-biofeedback can reduce postural sway and improve postural stability in healthy adults [12]. Another
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study found that visual guided weight shift practice develops a more stable postural base during obstacle avoidance [11]. Interactive video-game based (IVGB) exercise has been shown to increase individuals’ interest in performing related exercises [10,13]. However, few studies provide evidence supporting the positive effects of IVGB exercises on the balance of older adults. Therefore, this study evaluates the effects of IVGB training on the balance of older adults. Several objective outcome measures were used to determine the effects of IVGB training on the balance of older adults. 2. Methods
randomly assigned to 1 of 2 groups. Fifteen participants were recruited to Group A (7 men and 8 women; mean age, 70.6 [SD 3.5] years). Another 15 participants were recruited to Group B (6 men and 9 women; mean age, 74.8 [SD 4.7] years). All experiments and measurements were completed for 30 participants. Table 1 summarizes the participants’ characteristics. Participants were excluded if they had a neurological condition such as Parkinson’s disease, dementia, and stroke, or if they had arthritis, vision impairment, and cardiovascular disease that impaired walking, or if they were unable to walk without assistance. This study was conducted at Taipei Medical University Hospital and approved by the ethics board. The potential risks and benefits of participation were explained to each participant. All participants reviewed an informed consent document and provided written consent before participation. 2.2. Study design
2.1. Participants Participants in the study included 30 community-living persons over 65 years of age (13 men and 17 women; mean age, 72.1 [SD 4.8] years). The participants were
The study was designed as a prospective, randomized, crossover, single blind (The examiners were blind, but the participants were not blind), 12-week trial to determine the training effects of IVGB stepping exercise. Group A underwent the
30 participants (Mean age, 72.1 (4.8); 13 male, 15 female)
Randomly assigned into group A and B
15 parcipants in group A
15 parcipants in group B
(Mean age, 70.6 (3.5); 7 male, 8
(Mean age, 74.5 (4.7); 6 male, 9
female)
female)
) Week 0 Measurement of XMSS, BBS, TUG, Intervenon
MFES, UST, and Catsys 2000 (COP
Control phase,
phase, 6 weeks
velocity and area of bipedal stance
6 weeks
with open eyes and close eyes)
Week 6 Measurement of XMSS, BBS, TUG, MFES, UST, and Catsys 2000 (COP velocity and area of bipedal stance Control phase,
with open eyes and close eyes)
6 weeks
Intervenon phase, 6 weeks
Week 12 Measurement of XMSS, BBS, TUG, MFES, UST, and Catsys 2000 (COP velocity and area of bipedal stance with open eyes and close eyes) Compleon
Compleon
Fig. 1. Study procedures for Groups A and B. Xavix Measured Step System (XMSS), Berg Balance Scale (BBS), Timed Up and Go (TUG) test, Modified Falls Efficacy Scale (MFES), Unipedal Stance test (UST), and center of pressure (COP).
C.-H. Lai et al. / Gait & Posture 37 (2013) 511–515 Table 1 Demographic characteristics of participants.
Number of participants Age Sex Male Female Personal condition Height (cm) Weight (Kg) BMI Regular Exercisers Number of falls in the past year (person-year)
Group A
Group B
15 70.6 (3.5)
15 74.8 (4.7)
7 8
6 9
157.76 (6.60) 60.67 (6.93) 24.34 (3.63) 10 5
158.36 (6.86) 64.27 (7.22) 25.52 (3.32) 9 6
IVGB training in the initial 6 weeks (intervention phase), followed by no exercise in the subsequent 6 weeks (control phase). The Group B received no treatment in the first 6 weeks (control phase), and underwent IVGB training in the following 6 weeks (intervention phase), as shown in Fig. 1. 2.3. IVGB intervention The Xavix Measured Step System (XMSS), from SPECTRUM9000MB-500system, UIS Co., Japan, was used to perform the IVGB exercises The XMSS contains 1 console (XaviX port), an A/V cable connected to a television, a power cable connecting the console to a power source, and a one-step mat. A USB cable connected a custom XaviX computer software cartridge to a computer. Results were recorded using personal cartridges. The XMSS exercise was conducted for 30 min, 3 times a week for 6 weeks during the IVGB intervention phase for both groups. During exercise, to ensure uniformity in exercise posture, participants were asked to raise their knees above their waists, maintain their trunks in an upright position, and avoid too much compensation by postural sway while performing the stepping exercise. The trainer familiarized participants with the IVGB exercise before training. Time spent standing, time spent exercising and total virtual distance travelled can be recorded during the exercise. The IVGB exercise results were shown on the screen, providing instant feedback to participants. 2.4. Outcome measurement All participants completed a Berg Balance Scale (BBS), Timed Up and Go (TUG) test, Modified Falls Efficacy Scale (MFES), Unipedal Stance test (UST), and the XMSS stepping test before the experiment, after the initial 6 weeks, and after the following 6 weeks. The Sway Area (SA) and Sway Velocity (SV) of the center of pressure (COP) in a bipedal stance with eyes open and closed were also measured (Fig. 1) 2.4.1. BBS Participants performed a series of 14 functional balance tasks, including maintaining a quiet stance, sitting-to-standing, shifting weight and reaching, turning in place, standing on one leg, and maintaining a tandem stance. Each task was scored on a 5-point ordinal scale (from 0 to 4). A score of 0 denotes the inability of the participant to perform the task, and a score of 4 denotes that the participant can complete the task based on a preset criterion. The highest possible score is 56 [14]. Studies have shown that inter-rater and intra-rater BBS reliabilities are high in older adults and stroke patients [15]. 2.4.2. TUG The TUG test is a balance test that is commonly used to examine functional mobility in older adults living communally. The time required to complete the test is strongly correlated to functional mobility levels [16,17]. In this study, participants were asked to complete TUG tests. The test required participants to stand, walk 3 m, turn, walk back, and sit down. The time for completing the TUG test was recorded. The TUG test is a sensitive and specific indicator of whether participating community-dwelling older adults have fallen [17]. 2.4.3. MFES The MFES is a 14-item rating scale questionnaire that contains the original 10activity Falls Efficacy Scale and 4 additional activities. It is used to assess confidence of not falling while performing daily activities in many older adults. Items are rated from 0 (not confident at all) to 10 (completely confident), and the highest possible score is 140. Retest reliability for the MFES and internal consistency are high [18]. 2.4.4. UST The UST is a method of assessing static balance. It is a valid measure for balance and predicts injurious falls. Moreover, inter-rater reliability was
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excellent in trials [19,20]. Participants in this study were asked to stand barefoot on a leg of their choice with their other leg raised to ankle height. The duration that participants maintained balance while standing on one leg was measured 2.4.5. SA and SV of COP of bipedal stance with eyes open and closed The Catsys 2000 system (Danish Product Development Ltd, Denmark) tested postural sway. This SA test system is a platform with 3 orthogonal strain gauge devices [21]. The maximal and minimal sway-plate loads were 150 kg and 20 kg, respectively. The sampling rate was 31.25 Hz, and the frequency of the signal was collected below 15 Hz because the swing frequency of the subjects was typically less than 10 Hz. A previous study showed that the Catsys 2000 system has a high degree of reproducibility for balancing tests [22]. Participants were asked to stand on the platform (force plate), feet at 1 cm apart, with their arms at their sides. Thereafter, the participants were asked to look at a picture in front of them with their eyes open or closed for 75 s. For each participant, postural sway was measured for 75 s (standard test procedure: 10 s start-up period, 60 s recording period, and 5 s run-out period) first with their eyes open and then with their eyes closed, while standing directly on the platform [21]. The SA and SV of the COP were calculated and recorded, based on each participant’s performance. 2.4.6. XMSS To perform the XMSS stepping test, participants were asked to stand on a platform that contained a sensory detector. Participants were then required to step onto a corresponding platform, mimicking virtual people on a screen. The test contained 4 walking speed sequences (from fast to slow). The duration of each test was 70 s. The mean duration of a single-leg stance for each leg while stepping was calculated and was recorded in each test.
2.5. Statistical analysis All data are expressed as mean values, followed by the standard deviation in parentheses. Repeated-measures ANOVA was administered to compare differences between measurements for all outcome measurement parameters. Following a significant ANOVA result, Bonferroni’s post hoc analysis was conducted to further examine the difference. A P value <.05 was considered significant. Additionally, Pearson’s product–moment correlation (Pearson’s correlation coefficient) was examined to compare the relationships between the XMSS test and other outcome assessments (BBS, MFES, UST, and TUG test) at the baseline measurement. The magnitudes used to interpret the correlation coefficients were: (1) <0.10, trivial; (2) 0.10 jrj 0.29, small; (2) 0.3 jrj 0 .49, moderate; and (3) jrj 0.5, large [23,24]. The software package SPSS 18.0 was used for statistical analysis.
3. Results 3.1. Intervention effect 3.1.1. Group A In Group A, the BBS, MFES, TUG test, SV with eyes open and closed, and XMSS left and right leg stepping test improved significantly after IVGB exercises (Table 2). The UST time showed a trend of increase and the SA of the COP with eyes open and closed revealed showed a trend of decrease after IVGB exercises (Table 2). At the 12-week assessment for Group A, the BBS, TUG test and XMSS stepping test showed significant improvement compared with the initial assessment (Week 0 in Table 2). Furthermore, all outcome measurement parameters in Week 12 were not significantly different from the Week 6 measurements. These results implied that the training effects were partially maintained after 6 weeks without IVGB intervention. 3.1.2. Group B In Group B, there were no significant differences in all outcome measurement parameters between Week 0 and Week 6 (control phase). All outcome measures except UST improved significantly after the IVGB intervention compared to before the IVGB intervention (Week 6 in Table 2) and to initial measurement (Week 0 in Table 2). The UST showed a trend of increase after IVGB exercise.
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Table 2 Outcome variables of the baseline, 6th week, and 12th week. Group
XMSS T.R. (s)a XMSS T.L. (s)b BBS (score) MFES (score) UST (s) TUG (s) BiOE SA (mm2)c BiCE SA (mm2)d BiOE SV (mm/s) BiCE SV (mm/s) a b c d * y z §
A
B
Baseline
6th week
12th week
P value
Baseline
6th week
12th week
P value
1.01(0.44) 1.06(0.44) 50.53(4.75) 131.13(6.56) 31.80(18.39) 9.54(3.52) 320.80(273.45) 342.54(213.67) 9.37(2.30) 13.11(5.12)
2.13(0.92)y 2.55(0.97)y 53.87(3.56)y 136(6.07)y 48.74(26.67) 8.54(2.85)y 191.00(70.31) 262.20(142.11) 8.10(1.62)y 11.28(3.55)y
2.04(0.65)§ 2.21(0.65)§ 53.93(3.45)§ 133.4(7.41) 54.87(45.46) 8.53(2.88)§ 213.13(166.03) 318.87(184.76) 8.23(3.23) 12.00(4.36)
<0.001* <0.001* 0.001* 0.001* 0.062 0.046* 0.052 0.092 0.046* 0.024*
0.82(0.33) 0.83(0.36) 46.47(9.98) 114.67 (27.12) 18.87(22.35) 14.07(8.35) 347.73(196.50) 479.87(256.87) 10.65(4.22) 13.49(3.99)
1.15(0.58) 1.04(0.44) 46.20(11.48) 116.4(27.89) 23.00(21.52) 14.87(8.42) 319.47(150.41) 431.20(250.85) 10.28(2.83) 13.16(3.73)
1.86(0.58)z,§ 1.9(0.51)z,§ 50.67(8.19)z,§ 124.53(21.91)z,§ 38.33(36.82) 11.27(6.33)z,§ 202.07(130.43)z,§ 249.00(132.38)z,§ 8.30(2.64)z,§ 10.47(3.13)z,§
<0.001* <0.001* <0.001* 0.033* 0.063 0.002* 0.002* 0.002* 0.004* 0.001*
XMSS T.R., mean duration of right leg stance in XMSS stepping test. XMSS T.L., mean duration of left leg stance in XMSS stepping test. BiOE, bipedal stance with eyes open. BiCE, bipedal stance with eyes closed. P < 0.05, determined by repeated-measures ANOVA. P < 0.05, difference between outcome variables at baseline and at 6th week as determined by Bonferroni post hoc test. P < 0.05, difference between outcome variables at 6th week and at 12th week as determined by Bonferroni post hoc test. P < 0.05, difference between outcome variables at baseline and at 12th week as determined by Bonferroni post hoc test.
Table 3 Pearson’s product–moment correlation between outcome measures. XMSS stepping test XMSS stepping test BBS MFES UST TUG test a b
BBS
MFES
UST
TUG test
0.488a
0.461a 0.781b
0.357a 0.489a 0.412a
0.435a 0.888b 0.797b 0.379a
0.3 jrj 0 .49, moderate. jrj 0.5, large.
Investigation results showed a significant improvement in several outcome measurement parameters after 6 weeks of IVGB intervention in Groups A and B. These results implied that the intervention might have a sufficient duration and intensity. The training effects partially remained after 6 weeks of no IVGB exercises for Group A. The reason for the IVGB exercise effect persisting after ceasing the exercises is unknown. It might be because of the easy incorporation of IVGB stepping exercises into daily walking. Older adults might walk with longer strides and raise their legs higher while walking after participating in IVGB exercises. Another possible reason might be that participants performed exercise more often than they did before IVGB intervention because of their improved balance.
The activity of UST was not only involved in the balance measures but also associated with muscle strength [26]. In this study, the mean time of UST was approximately 31.8 for group A and 23.0 s for group B. These results are in accordance with the findings of Springer et al. [19], who found mean UST times approximately 32.1 s between ages 60 and 69 years and 21.5 s between ages 70 and 79 years. Mean UST time increased to approximately 48.7 s and 38.3 s after the IVGB intervention for Groups A and B, respectively. The TUG is the test recommended by the American and British Geriatrics Societies for assessing the risk of falling [27]. A study found that a TUG time of over 14 s is associated with a high risk of falling in older adults [28]. This study examined older people who were relatively healthy and living independently within the community. The average TUG test times were 9.54 s and 14.87 s before training for Groups A and B, respectively. The mean TUG test times improved to 8.54 s and 11.27 s for Groups A and B, respectively (Table 2). Most of older adults took less than 14 s to complete the TUG test after IVGB intervention. In this study, the SA and SV of the COP were sensitive to visual output. Results show that SA and SV were higher with eyes closed than with eyes open before and after IVGB intervention in both groups. These results agree with those obtained by Despre´s et al., whose results showed that postural sway was higher with eyes closed than with eyes open [21].
4.2. Interpretation of outcome measurement
4.3. Advantages of IVGB intervention
Most BBS test mimic daily life activities [14,25]. In this study, the mean BBS improvement was 3.33 (0.67) for Group A and 4.47 (1.18) for Group B. Shumway-Cook et al. showed that BBS was the single most accurate predictor of falls. They suggested that a 1-point decrease in BBS score leads to a 6–8% increase of fall risk in the range of 54–46 [25].
Coupling interactive video games with traditional stepping exercises exhibit numerous merits. First of all, conventional exercise may benefit the postural stability and balance of older adults. However, the participation rates are low because such exercises are often repetitive and unattractive [10]. The proposed IVGB exercise may be more feasible and attractive than conventional exercise to
3.2. Correlations between outcome measures The correlations between outcome measures were shown in Table 3. The correlations between XMSS stepping tests and other outcome measures were moderate (jrj = 0.3–0.49) for all (Table 3). 4. Discussion 4.1. Major findings
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healthy older adults. Secondly, this IVGB system provides an interactive environment. The number of steps, mean single-leg stance time, and avatar-mimicking movements are shown on the screen during the exercise, providing instant feedback to participants. Positive results were also seen when video games were incorporated into virtual environments [10,13,29]. Finally, the IVGB training also provides a purposeful and challenging exercise. In this study, older adults were asked to raise their knee above their waists, and maintain their trunks in an upright position while performing the IVGB stepping exercise. This typed of stepping exercise requires adequate postural control and lower-extremity strength. Therefore, it is expected that repetitions of the IVGB stepping exercise had a positive effect on several outcome measurements. 4.4. XMSS stepping tests as outcome measures In this study, there were considerable interests by using the XMSS stepping tests for the outcome assessment. Results showed a moderate association between the XMSS stepping tests and BBS, MFES, UST and TUG measurements (jrj = 0.3–0.49). Additional studies are necessary to examine retest reliability and internal consistency of XMSS stepping tests. 4.5. Study limitation This study had several limitations. One limitation was the impracticality of experimental blinding of the participants because they knew they had undergone training. However, the trainer and assessor was not the same person to allow for experimental blinding of the assessor. An additional limitation is that the XMSS system is not widely used. However, the findings in our study can probably be applied to other video-game based systems used to rehabilitate patients if the tasks are sufficiently functional and demanding. A further limitation was that fall statuses of participants were not measured. However, balance statuses were objectively assessed using several outcome measures that have been clinically demonstrated to predict falls. Furthermore, this study only conducted 6 weeks of IVGB training and 6 weeks of follow-up. A longer study is necessary to observe long-term effects. In addition, IVGB exercises’ various effects on balance were not compared to those of traditional physical therapy. Further investigation is required to determine if this type training is superior to traditional physical therapy. 5. Conclusion The IVGB intervention improved balance after 6 weeks of training. Furthermore, the beneficial effects persisted partially for 6 weeks of no IVGB intervention. Correlations between XMSS stepping tests and other outcome measures were moderate. Additional investigations are necessary to examine the reliability and the internal consistency of XMSS stepping tests. Acknowledgement This work was supported in part by Supreme Investment Co., LTD. Taipei, Taiwan. However, it had no role in study design, data collection, analysis or interpretation of data, writing the manuscript, or submission of the manuscript for publication. Conflict of interest All authors have disclosed any commercial association that might create a conflict of interest in connection with the submitted manuscript. There is no competing financial interest for any of the authors.
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References [1] Rizzo JA, Baker DI, McAvay G, Tinetti ME. The cost-effectiveness of a multifactorial targeted prevention program for falls among community elderly persons. Medical Care 1996;34:954–69. [2] Speechley M, Tinetti M. Falls and injuries in frail and vigorous community elderly persons. Journal of the American Geriatrics Society 1991;39:46–52. [3] Tinetti ME, Speechley M, Ginter SF. Risk factors for falls among elderly persons living in the community. The New England Journal of Medicine 1988;19:1701–7. [4] Vellas B, Cayla F, Bocquet H, de Pemille F, Albarede JL. Prospective study of restriction of activity in old people after falls. Age and Ageing 1987;16:189–93. [5] Davis JC, Donaldson MG, Ashe MC, Khan KM. The role of balance and agility training in fall reduction. A comprehensive review. Europa Medicophysica 2004;40:211–21. [6] Hendriks MR, Bleijlevens MH, van Haastregt JC, Crebolder HF, Diederiks JP, Evers SM, et al. Lack of effectiveness of a multidisciplinary fall-prevention program in elderly people at risk: a randomized, controlled trial. Journal of the American Geriatrics Society 2008;56:1390–7. [7] Barnett A, Smith B, Lord SR, Williams M, Baumand A. Community-based group exercise improves balance and reduces falls in at-risk older people: a randomised controlled trial. Age and Ageing 2003;32:407–14. [8] Bogaerts A, Delecluse C, Boonen S, Claessens AL, Milisen K, Verschueren SM. Changes in balance, functional performance and fall risk following whole body vibration training and vitamin D supplementation in institutionalized elderly women. A 6 month randomized controlled trial. Gait and Posture 2011;33: 466–72. [9] Campbell AJ, Robertson MC, Gardner MM, Norton RN, Tilyard MW, Buchner DM. Randomised controlled trial of a general practice programme of home based exercise to prevent falls in elderly women. BMJ 1997;315:1065–9. [10] Studenski S, Perera S, Hile E, Keller V, Spadola-Bogard J, Garcia J. Interactive video dance games for healthy older adults. The Journal of Nutrition Health and Aging 2010;14:850–2. [11] Hatzitaki V, Voudouris D, Nikodelis T, Amiridis IG. Visual feedback training improves postural adjustments associated with moving obstacle avoidance in elderly women. Gait and Posture 2009;29:296–9. [12] Dozza MCL, Peterka RJ, Wall C, Horak FB. What is the most effective type of audiobiofeedback for postural motor learning? Gait and Posture 2011;34:13–9. [13] Betker AL, Szturm T, Moussavi ZK, Nett C. Video game-based exercises for balance rehabilitation: a single-subject design. Archives of Physical Medicine and Rehabilitation 2006;87:1141–9. [14] Berg KO, Wood-Dauphinee SL, Williams JI, Maki B. Measuring balance in the elderly: validation of an instrument. Canadian Journal of Public Health 1992;83(Suppl. 2):S7–11. [15] Berg K, Wood-Dauphinee S, Williams JI. The Balance Scale: reliability assessment with elderly residents and patients with an acute stroke. Scandinavian Journal of Rehabilitation Medicine 1995;27:27–36. [16] Podsiadlo D, Richardson S. The timed ‘‘Up & Go’’: a test of basic functional mobility for frail elderly persons. Journal of the American Geriatrics Society 1991;39:142–8. [17] Nowalk MP, Prendergast JM, Bayles CM, D’Amico FJ, Colvin GC. A randomized trial of exercise programs among older individuals living in two long-term care facilities: the FallsFREE program. Journal of the American Geriatrics Society 2001;49:859–65. [18] Hill KD, Schwarz JA, Kalogeropoulos AJ, Gibson SJ. Fear of falling revisited. Archives of Physical Medicine and Rehabilitation 1996;77:1025–9. [19] Springer BA, Marin R, Cyhan T, Roberts H, Gill NW. Normative values for the unipedal stance test with eyes open and closed. Journal of Geriatric Physical Therapy 2007;30:8–15. [20] Vellas BJ, Wayne SJ, Romero L, Baumgartner RN, Rubenstein LZ, Garry PJ. Oneleg balance is an important predictor of injurious falls in older persons. Journal of the American Geriatrics Society 1997;45:735–8. [21] Despres C, Lamoureux D, Beuter A. Standardization of a neuromotor test battery: the CATSYS system. Neurotoxicology 2000;21:725–35. [22] Gyntelberg FFM, Mikkelsen T, Ryom C, Suadicani P. Computerized coordination ability testing. Acta Neurologica Scandinavica 1990;82:39–42. [23] Harris NK, Cronin JB, Hopkins WG, Hansen KT. Relationship between sprint times and the strength/power outputs of a machine squat jump. Journal of Strength and Conditioning Research 2008;22:691–8. [24] Cohen J. Statistical Power Analysis for the Behavioral Sciences, 2nd ed., Hillsdale, NJ: Lawrence Erlbaum; 1988. [25] Shumway-Cook A, Baldwin M, Polissar NL, Gruber W. Predicting the probability for falls in community-dwelling older adults. Physical Therapy 1997;77: 812–9. [26] Mayson DJ, Kiely DK, LaRose SI, Bean JF. Leg strength or velocity of movement: which is more influential on the balance of mobility limited elders? American Journal of Physical Medicine and Rehabilitation 2008;87:969–76. [27] American Geriatrics Society, British Geriatrics Society, American Academy of Orthopaedic Surgeons Panel on Falls Prevention. Guideline for the prevention of falls in older persons. Journal of the American Geriatrics Society 2001;49: 664–72. [28] Shumway-Cook A, Brauer S, Woollacott M. Predicting the probability for falls in community-dwelling older adults using the Timed Up & Go Test. Physical Therapy 2000;80:896–903. [29] Deutsch JE. Virtual reality and gaming systems to improve walking and mobility for people with musculoskeletal and neuromuscular conditions. Studies in Health Technology & Informatics 2009;145:84–93.