562111
research-article2014
NNRXXX10.1177/1545968314562111Neurorehabilitation and Neural RepairLiao et al
Original Articles
Virtual Reality–Based Training to Improve Obstacle-Crossing Performance and Dynamic Balance in Patients With Parkinson’s Disease
Neurorehabilitation and Neural Repair 1–10 © The Author(s) 2014 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1545968314562111 nnr.sagepub.com
Ying-Yi Laio, PhD1,2, Yea-Ru Yang, PhD2, Shih-Jung Cheng, MD3, Yih-Ru Wu, MD4,5, Jong-Ling Fuh, MD2,6, and Ray-Yau Wang, PhD2
Abstract Background. Obstacle crossing is a balance-challenging task and can cause falls in people with Parkinson’s disease (PD). However, programs for people with PD that effectively target obstacle crossing and dynamic balance have not been established. Objective. To examine the effects of virtual reality–based exercise on obstacle crossing performance and dynamic balance in participants with PD. Methods. Thirty-six participants with a diagnosis of PD (Hoehn and Yahr score ranging 1 to 3) were randomly assigned to one of three groups. In the exercise groups, participants received virtual reality–based Wii Fit exercise (VRWii group) or traditional exercise (TE group) for 45 minutes, followed by 15 minutes of treadmill training in each session for a total of 12 sessions over 6 weeks. Participants in the control group received no structured exercise program. Primary outcomes included obstacle crossing performance (crossing velocity, stride length, and vertical toe obstacle clearance) and dynamic balance (maximal excursion, movement velocity, and directional control measured by the limits-of-stability test). Secondary outcomes included sensory organization test (SOT), Parkinson’s Disease Questionnaire (PDQ39), fall efficacy scale (FES-I), and timed up and go test (TUG). All outcomes were assessed at baseline, after training, and at 1-month follow-up. Results. The VRWii group showed greater improvement in obstacle crossing velocity, crossing stride length, dynamic balance, SOT, TUG, FES-I, and PDQ39 than the control group. VRWii training also resulted in greater improvement in movement velocity of limits-of-stability test than TE training. Conclusions. VRWii training significantly improved obstacle crossing performance and dynamic balance, supporting implementation of VRWii training in participants with PD. Keywords obstacle crossing, balance, virtual reality, exercise training, Parkinson’s disease
Introduction Parkinson’s disease (PD) is a progressive neurodegenerative disease. With progression of the disease, patients may demonstrate postural instability, gait dysfunction, difficulty managing functional tasks, such as obstacle crossing, and frequent falls.1-4 More than two thirds of community-dwelling individuals with PD experience falls once per year, and tripping over obstacles is the major cause of these falls.5 During obstacle crossing, participants with PD usually step their leading foot closer to the obstacle than age-matched controls because of their smaller steps, which may result in hitting the obstacle and subsequent falls.6 These individuals also adopt a conservative strategy during obstacle crossing and maintain their center of mass (COM) more medially to their stance leg.7 This alteration reduces the distance between the center of pressure (COP) and COM throughout
the obstacle crossing task compared with normal older adults.8 Therefore, strategies to improve balance and
1
Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli, Taiwan 2 Faculty of medicine, National Yang-Ming University, Taipei, Taiwan 3 Mackay Memorial Hospital, Taipei, Taiwan 4 Department of Neurology, Chang-Gung Memorial Hospital, Linkou, Taiwan 5 Chang-Gung University College of Medicine, Linkou, Taiwan 6 Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan Corresponding Author: Ray-Yau Wang, Department of Physical Therapy and Assistive Technology, National Yang-Ming University, 155, Sec 2, Li-Nong Street, Shih-Pai, Taipei, Taiwan. Email: [email protected]
Downloaded from nnr.sagepub.com at GEORGIAN COURT UNIV on March 3, 2015
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obstacle crossing ability may help improve functional ability and to reduce the incidence of falls. Some patients with PD may lack satisfactory to drug regimens or surgical options, and they still have considerable symptoms while on medications. The lack of satisfactory treatment options provides motivation to investigate the effects of exercise on functional improvement. Stretching, strengthening, balance exercise, and gait training improve motor function, balance, and gait performance in participants with PD.9-13 Treadmill training has also been used widely in participants with PD to improve gait performance and walking economy.14-16 However, the effects of such training on obstacle-crossing performance has not yet been investigated. Combining resistance, aerobic, balance, stretching, and treadmill training are likely to be optimal for improving gait speed in participants with PD.17 Whether the combination of training can carry-over to obstacle crossing performance need further investigation. Virtual reality (VR) systems are novel and potentially useful technologies that allow users to interact with a computer-generated scenario.18 Augmented visual, sensory, and auditory feedback are provided when subjects performing tasks in virtual environment.19 VR training has been used in older adults and stroke patients to improve postural control, increase mobility, and reduce fall risk.20-24 In PD participants, VR training has been demonstrated to improve sensory organization.25 VR combining treadmill training was also reported to improve gait performance during usual and complex challenging condition (dual task and obstacle crossing) in PD participants.26 However, VR combining different types of exercise on obstacle-crossing and balance performance has not yet been explored. Recently, the gaming industry has developed a variety of affordable and accessible VR systems, such as Wii Fit, that have been reported to improve functional ability in PD participants, such as timed up and go (TUG), sit to stand, unipedal stance, balance, walking speed, and overall quality of life.27-30 These effects, however, have yet to be validated in a randomized controlled trial. Furthermore, whether this VR-based Wii Fit exercise is more effective than traditional exercise, especially regarding its effects on advanced gait function such as obstacle crossing, warrants investigation. Therefore, the purpose of this study was to elucidate the effects of VR-based Wii Fit exercise on obstacle crossing and dynamic balance ability in participants with PD by comparing the results of Wii Fit training, traditional exercise, and a no-exercise control.
Methods Participants Participants were recruited from a medical center in Taiwan and were diagnosed with idiopathic PD by a neurologist.
The diagnostic criteria were at least 2 of the 4 features (resting tremor, bradykinesia, rigidity, and asymmetric onset) in which the resting tremor or bradykinesia must be present.31 All participants met the following inclusion criteria: (a) Hoehn and Yahr stages I to III, (b) ability to walk independently without any walking aids, (c) stable medication usage, (d) with or without deep brain stimulation, and (e) a score of ≥24 on the Mini-Mental State Examination (MMSE). The exclusion criteria were as follows: (a) unstable medical condition; (b) history of other neurological, cardiopulmonary, or orthopedic diseases known to interfere with participation in the study; (c) past history of seizure; (d) use of cardiac pacemaker; and (e) vision deficits. In total, 43 individuals were identified as potential participants for this study. Of these, 36 participants provided informed consent, which was approved by the Institutional Human Research Ethics Committee of Chang Gung Medical Foundation (Figure 1).
Experimental Design This study was a single-blinded, stratified, randomized controlled trial. The stratification was achieved based on the Hoehn and Yahr stage as follows: stage 1 to 1.5, stage 2 to 2.5, and stage 3. An individual who was not involved with the study selected sealed envelopes to assign participants to 1 of the 3 groups. Participants received VR-based Wii Fit exercise (VRWii group) or traditional exercise (TE group) for 45 minutes with additional treadmill training for 15 minutes. The exercise was administered for a total of 12 sessions (2 sessions per week) over a 6-week period by the same physical therapist. Individuals in the control group received only fall-prevention education, such as minding the environmental factors (slippery surface, obstacles, stairs, uneven ground) after the baseline assessment and were encouraged to carry out their regular exercise. All outcomes were measured the day before intervention (pre), the day after completing the intervention (post), and the 30th day after completing the intervention (follow-up) by the same rater blinded to group assignment. The measurement and intervention were conducted with patients in the “on” state.
Interventions Traditional Exercise (TE). This program included 10 minutes of stretching exercises, 15 minutes of strengthening exercises, and 20 minutes of balance exercises in each session as described below. 1. Stretching exercises: The stretching exercises focused on upper body and upper and lower extremities with gentle joint extension and flexion and trunk rotation in a standing position. Deep breathing was emphasized during the exercise.
Downloaded from nnr.sagepub.com at GEORGIAN COURT UNIV on March 3, 2015
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Liao et al
Figure 1. Flowchart of participants recruited in this study.
2. Strengthening exercise: The strengthening exercises focused on the lower extremity muscles that are important for posture, balance, and gait. Participants performed the following exercises in standing position: (a) one leg forward/sideward swing, (b) stepping up and down, (c) multidirectional leg raising, (d) heel and toe raising, and (e) squatting. Participants performed 3 sets of 10 to 15 repetitions for each activity. Participants used ankle weights that started at 1 kg and were gradually increased to 2 kg for each leg. Natural breathing was emphasized during the exercise. 3. Balance exercises: The balance exercises were combinations of dynamic balance training and sensory integration training. The dynamic balance training exercises were symmetric weight shifting with slow and fast speed, catching and throwing balls, and multidirectional stepping in a standing position. The sensory integration training exercises included single leg stance with eyes open and closed and standing on foam with eyes open and closed. The progressions in both TE and VRWii group included adding more weights during strengthening exercise,
increasing the number of repetitions, and increasing difficulty of exercise, such as increasing the height of the blocks during the stepping-up exercise, increasing the forward/sideward stepping distance during the stepping exercise, holding the squatting position for longer duration during the squatting exercise. The criteria for progression were determined by the ability of the participant to perform the activities without difficulty and by the perceived exertion (Borg rate of perceived exertion
research-article2014
NNRXXX10.1177/1545968314562111Neurorehabilitation and Neural RepairLiao et al
Original Articles
Virtual Reality–Based Training to Improve Obstacle-Crossing Performance and Dynamic Balance in Patients With Parkinson’s Disease
Neurorehabilitation and Neural Repair 1–10 © The Author(s) 2014 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1545968314562111 nnr.sagepub.com
Ying-Yi Laio, PhD1,2, Yea-Ru Yang, PhD2, Shih-Jung Cheng, MD3, Yih-Ru Wu, MD4,5, Jong-Ling Fuh, MD2,6, and Ray-Yau Wang, PhD2
Abstract Background. Obstacle crossing is a balance-challenging task and can cause falls in people with Parkinson’s disease (PD). However, programs for people with PD that effectively target obstacle crossing and dynamic balance have not been established. Objective. To examine the effects of virtual reality–based exercise on obstacle crossing performance and dynamic balance in participants with PD. Methods. Thirty-six participants with a diagnosis of PD (Hoehn and Yahr score ranging 1 to 3) were randomly assigned to one of three groups. In the exercise groups, participants received virtual reality–based Wii Fit exercise (VRWii group) or traditional exercise (TE group) for 45 minutes, followed by 15 minutes of treadmill training in each session for a total of 12 sessions over 6 weeks. Participants in the control group received no structured exercise program. Primary outcomes included obstacle crossing performance (crossing velocity, stride length, and vertical toe obstacle clearance) and dynamic balance (maximal excursion, movement velocity, and directional control measured by the limits-of-stability test). Secondary outcomes included sensory organization test (SOT), Parkinson’s Disease Questionnaire (PDQ39), fall efficacy scale (FES-I), and timed up and go test (TUG). All outcomes were assessed at baseline, after training, and at 1-month follow-up. Results. The VRWii group showed greater improvement in obstacle crossing velocity, crossing stride length, dynamic balance, SOT, TUG, FES-I, and PDQ39 than the control group. VRWii training also resulted in greater improvement in movement velocity of limits-of-stability test than TE training. Conclusions. VRWii training significantly improved obstacle crossing performance and dynamic balance, supporting implementation of VRWii training in participants with PD. Keywords obstacle crossing, balance, virtual reality, exercise training, Parkinson’s disease
Introduction Parkinson’s disease (PD) is a progressive neurodegenerative disease. With progression of the disease, patients may demonstrate postural instability, gait dysfunction, difficulty managing functional tasks, such as obstacle crossing, and frequent falls.1-4 More than two thirds of community-dwelling individuals with PD experience falls once per year, and tripping over obstacles is the major cause of these falls.5 During obstacle crossing, participants with PD usually step their leading foot closer to the obstacle than age-matched controls because of their smaller steps, which may result in hitting the obstacle and subsequent falls.6 These individuals also adopt a conservative strategy during obstacle crossing and maintain their center of mass (COM) more medially to their stance leg.7 This alteration reduces the distance between the center of pressure (COP) and COM throughout
the obstacle crossing task compared with normal older adults.8 Therefore, strategies to improve balance and
1
Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli, Taiwan 2 Faculty of medicine, National Yang-Ming University, Taipei, Taiwan 3 Mackay Memorial Hospital, Taipei, Taiwan 4 Department of Neurology, Chang-Gung Memorial Hospital, Linkou, Taiwan 5 Chang-Gung University College of Medicine, Linkou, Taiwan 6 Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan Corresponding Author: Ray-Yau Wang, Department of Physical Therapy and Assistive Technology, National Yang-Ming University, 155, Sec 2, Li-Nong Street, Shih-Pai, Taipei, Taiwan. Email: [email protected]
Downloaded from nnr.sagepub.com at GEORGIAN COURT UNIV on March 3, 2015
2
Neurorehabilitation and Neural Repair
obstacle crossing ability may help improve functional ability and to reduce the incidence of falls. Some patients with PD may lack satisfactory to drug regimens or surgical options, and they still have considerable symptoms while on medications. The lack of satisfactory treatment options provides motivation to investigate the effects of exercise on functional improvement. Stretching, strengthening, balance exercise, and gait training improve motor function, balance, and gait performance in participants with PD.9-13 Treadmill training has also been used widely in participants with PD to improve gait performance and walking economy.14-16 However, the effects of such training on obstacle-crossing performance has not yet been investigated. Combining resistance, aerobic, balance, stretching, and treadmill training are likely to be optimal for improving gait speed in participants with PD.17 Whether the combination of training can carry-over to obstacle crossing performance need further investigation. Virtual reality (VR) systems are novel and potentially useful technologies that allow users to interact with a computer-generated scenario.18 Augmented visual, sensory, and auditory feedback are provided when subjects performing tasks in virtual environment.19 VR training has been used in older adults and stroke patients to improve postural control, increase mobility, and reduce fall risk.20-24 In PD participants, VR training has been demonstrated to improve sensory organization.25 VR combining treadmill training was also reported to improve gait performance during usual and complex challenging condition (dual task and obstacle crossing) in PD participants.26 However, VR combining different types of exercise on obstacle-crossing and balance performance has not yet been explored. Recently, the gaming industry has developed a variety of affordable and accessible VR systems, such as Wii Fit, that have been reported to improve functional ability in PD participants, such as timed up and go (TUG), sit to stand, unipedal stance, balance, walking speed, and overall quality of life.27-30 These effects, however, have yet to be validated in a randomized controlled trial. Furthermore, whether this VR-based Wii Fit exercise is more effective than traditional exercise, especially regarding its effects on advanced gait function such as obstacle crossing, warrants investigation. Therefore, the purpose of this study was to elucidate the effects of VR-based Wii Fit exercise on obstacle crossing and dynamic balance ability in participants with PD by comparing the results of Wii Fit training, traditional exercise, and a no-exercise control.
Methods Participants Participants were recruited from a medical center in Taiwan and were diagnosed with idiopathic PD by a neurologist.
The diagnostic criteria were at least 2 of the 4 features (resting tremor, bradykinesia, rigidity, and asymmetric onset) in which the resting tremor or bradykinesia must be present.31 All participants met the following inclusion criteria: (a) Hoehn and Yahr stages I to III, (b) ability to walk independently without any walking aids, (c) stable medication usage, (d) with or without deep brain stimulation, and (e) a score of ≥24 on the Mini-Mental State Examination (MMSE). The exclusion criteria were as follows: (a) unstable medical condition; (b) history of other neurological, cardiopulmonary, or orthopedic diseases known to interfere with participation in the study; (c) past history of seizure; (d) use of cardiac pacemaker; and (e) vision deficits. In total, 43 individuals were identified as potential participants for this study. Of these, 36 participants provided informed consent, which was approved by the Institutional Human Research Ethics Committee of Chang Gung Medical Foundation (Figure 1).
Experimental Design This study was a single-blinded, stratified, randomized controlled trial. The stratification was achieved based on the Hoehn and Yahr stage as follows: stage 1 to 1.5, stage 2 to 2.5, and stage 3. An individual who was not involved with the study selected sealed envelopes to assign participants to 1 of the 3 groups. Participants received VR-based Wii Fit exercise (VRWii group) or traditional exercise (TE group) for 45 minutes with additional treadmill training for 15 minutes. The exercise was administered for a total of 12 sessions (2 sessions per week) over a 6-week period by the same physical therapist. Individuals in the control group received only fall-prevention education, such as minding the environmental factors (slippery surface, obstacles, stairs, uneven ground) after the baseline assessment and were encouraged to carry out their regular exercise. All outcomes were measured the day before intervention (pre), the day after completing the intervention (post), and the 30th day after completing the intervention (follow-up) by the same rater blinded to group assignment. The measurement and intervention were conducted with patients in the “on” state.
Interventions Traditional Exercise (TE). This program included 10 minutes of stretching exercises, 15 minutes of strengthening exercises, and 20 minutes of balance exercises in each session as described below. 1. Stretching exercises: The stretching exercises focused on upper body and upper and lower extremities with gentle joint extension and flexion and trunk rotation in a standing position. Deep breathing was emphasized during the exercise.
Downloaded from nnr.sagepub.com at GEORGIAN COURT UNIV on March 3, 2015
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Liao et al
Figure 1. Flowchart of participants recruited in this study.
2. Strengthening exercise: The strengthening exercises focused on the lower extremity muscles that are important for posture, balance, and gait. Participants performed the following exercises in standing position: (a) one leg forward/sideward swing, (b) stepping up and down, (c) multidirectional leg raising, (d) heel and toe raising, and (e) squatting. Participants performed 3 sets of 10 to 15 repetitions for each activity. Participants used ankle weights that started at 1 kg and were gradually increased to 2 kg for each leg. Natural breathing was emphasized during the exercise. 3. Balance exercises: The balance exercises were combinations of dynamic balance training and sensory integration training. The dynamic balance training exercises were symmetric weight shifting with slow and fast speed, catching and throwing balls, and multidirectional stepping in a standing position. The sensory integration training exercises included single leg stance with eyes open and closed and standing on foam with eyes open and closed. The progressions in both TE and VRWii group included adding more weights during strengthening exercise,
increasing the number of repetitions, and increasing difficulty of exercise, such as increasing the height of the blocks during the stepping-up exercise, increasing the forward/sideward stepping distance during the stepping exercise, holding the squatting position for longer duration during the squatting exercise. The criteria for progression were determined by the ability of the participant to perform the activities without difficulty and by the perceived exertion (Borg rate of perceived exertion
