The purpose of this study was to investigate the effects of an additional weight aquatic exercise program on the balance and lower extremity strength on aquatic environment in persons with stroke.
Randomized controlled trial.
All subjects were randomly divided into three groups where thirteen subjects were in the additional weight aquatic exercise group, twelve subjects in the aquatic exercise group, and fifteen subjects in the control group. Subjects received a graded aquatic exercise program for 30 minutes, with 3 sessions per week for 6 weeks, and subjects in all groups received conventional physical therapy. All subjects were assessed with the Medical Research Council (MRC), the Berg Balance scale (BBS), Timed Up and Go test (TUG), and 10-meter walk test (10MWT) pre and post intervention.
The MRC, BBS, TUG, and 10MWT scores significantly improved post-intervention (
The findings of this study suggested that the additional weight aquatic exercise program improves lower extremity and balance in persons with stroke.
Stroke survivors with motor function loss and muscle weakness due to neurological symptoms, such as sensory abnormality and decreased exercise capacity, show limitations in basic mobility such as walking and stair climbing [1,2]. In addition, person with stroke show greater body sway in weight shift compared to normal subjects due to improper posture control [3]. Because of these problems, persons with stroke who have difficulty in normal walking use various compensatory movements to maintain functional walking. Such abnormal compensatory movement is inefficient compared to normal walking and consumes a lot of energy [4]. As a result, stroke survivors exhibit slow walking speed and asymmetric gait pattern due to decreased stride length and ratio in the affected side stance phase [5,6]. Such gait disorders increase the likelihood of secondary damage such as falls [7]. Therefore, restoring the balance and walking ability of persons with stroke is essential for functional independence in everyday life [8]. Therefore, proper exercise methods are needed to improve walking ability of stroke patients.
Balance involves maintaining postural stability by maintaining the center of gravity. Such balance has static and dynamic balance ability to control the stability of the human body during dynamic movement [9]. Park
This study included a pretest-posttest control group design where the subjects were divided according into intervention methods, such as the additional weight aquatic exercise program group, aquatic exercise program group, or control group. Forty subjects who were admitted in Chungnam National University Hospital in Daejeon. In addition, the subjects were not experienced in aquatic exercise program, and the stroke participants were those who had no overlapping diseases within the past 6 months after the onset of stroke to minimize the possibility of natural restoration. To minimize the selection bias, the following selection criteria were applied randomly to the three groups. The inclusion criteria were as follows: (1) diagnosis of stroke (after minimum 6 months); (2) ability to walk 10 minutes with or without an assistive device; (3) impairment of balance ability (maximum berg balance scale score 45); (4) cognitive abilities enabling communication (minimum Mini-Mental Status Examination score 24); (5) medically stable and free of major cardiovascular or other medical conditions; and (6) no history of orthopedic surgery within the past 6 months and seizure. Subject general characteristics can be viewed in Table 1. This study trained forty-two patients for six weeks, but two patients were discharged. Four therapists intervened to conduct the study on a large number of patients. All groups measured lower extremity strength and balance abilities before intervention. For objective evaluation, three therapists with at least five years of clinical experience conducted the evaluation. This study was approved by the Institutional Review Board of the Sahmyook University (IRB No. 2-1040781-AB-N-01-2016112HR), and all subjects provided their informed consent after being explained of the study details (Figure 1).
The aquatic exercise program involved wearing a sandbag on the affected side ankle that was 5% of the body weight. For the aquatic exercise program, the exercises were conducted in a pool with water at chest height depth and temperatures of 30°C to 32°C. The aquatic exercise program applied in this study was a program that was made by modifying the exercise program from preceding studies conducted in the form of sufficient stretching and strengthening in the water. The movements performed were weight shifting, single leg stance, and various task-orientated exercises in the standing posture (climbing, squatting, heel lifting, kicking, and step up and step down). After 10 minutes of exercise, 20 minutes of gait training was performed (Table 2, Figure 2).
For mediation of speed during underwater gait training, researchers used metronomes to adjust to the tempo of the subject’s comfortable walking speed. The intervention periods for the subjects were 6 weeks, 3 times a week, for 30 minutes each. In addition, all patients who participated in the study participated conventional physical therapy for 6 weeks, 5 times a week. For subject safety, guidance during training was provided by physical therapists with 3 or more years of experience of aquatic exercise training and one assistant per subject as research assistants.
The Medical Research Council (MRC) is the clinical method for evaluating muscle strength as a sequence scale. MRC assesses the strength of the agonist and antagonist muscles of a variety of persons with neurological disease, including stroke. The MRC is divided into six grades: Normal (5), Good (4), Fair (3), Poor (2), Trace (1), and Zero (0). Hip flexion, extension, abduction, knee flexion, extension, ankle dorsiflexion, plantar flexion of affected side lower extremity was assessed and was calculated as 0 points out of a total of 30 points. The mean value was taken from three measurements, and to minimize the degree of fatigue, there was a 30-second rest period between measurements.
The Berg Balance Scale (BBS) includes 14 items that can quantitatively assess balance and fall risk. Each item can be scored between 0 to 4 points, with a maximum of 56 points possible. A score of 45 or less represents the need for use of an assistive device, a score of 41 to 44 represents having a low risk of falls, 21 to 40 represents having a greater fall risk, and a score of 0 to 20 represents having a very high fall risk. The duration of the BBS is approximately 15 minutes and evaluates both static and dynamic balance abilities. The therapist who performed the BBS before and after intervention had greater than 3 years of experience in the clinic.
The Timed Up and Go test (TUG) evaluates the duration of the process of rising from a sitting position, walking 3 meters, and then returning to the chair and assuming a complete seated position. The subjects performed the TUG three times in order to obtain an average value. The TUG has a reliability of r=0.99 and a high inter-rater reliability of r=0.98.
The 10-meter walk test (10MWT) is a standardized test used to assess gait ability, and can be used to assess gait disabilities in those with neurological damage.
The PASW Statstics ver. 19.0 (IBM Co., Armonk, NY, USA) was used for data analysis. A normality analysis was conducted for the general subject characteristics, and the paired t-test was conducted to analyze the differences between each group before and after intervention. The one-way analysis of variance was performed to investigate for significant changes in balance and gait abilities per group after six weeks, the Duncan post-hoc analysis test was conducted, and the level of significant was set at
Both general and medical subject characteristics in the additional weight aquatic exercise program group, aquatic exercise group and control were all homogenous (Table 1).
Significant increases in MRC, BBS, TUG, and 10MWT scores were observed in the additional weight exercise group, aquatic exercise group, and control group (
Functional recovery in persons with stroke is limited by muscle weakness [18]. The weakness of the ankle muscle strength causes problems in balance and walking ability [19]. Based on this evidence, Lee and Kang [20] reported that the loss of balance in persons with stroke was associated with weakening of the ankle muscular strength. This is because the ankle with plantar flexor spasticity does not reach the ground resulting in a shortened stance phase and the push-off not occurring, and the foot-drop is caused at the diagonal period, resulting in slow walking speed and inefficient walking. As a result, those affected by stroke showed asymmetric balance ability and increased risk of falls [21]. Therefore, it is necessary to restore the balance and the walking ability with strengthening of the lower extremities in order to create an effective movement for persons with stroke [20]. The purpose of this study was to investigate the effect of applying additional weight during the participation in an aquatic exercise program in persons with stroke. Masumoto
In addition, repetitive task-oriented training in the water has been reported to be an effective intervention for restoring balance and gait ability [15,31,32]. Sim and Oh [33] showed a significant increase in balance and gait ability as a result of applying task-oriented functional training to persons with stroke. It was reported that the task-oriented repetitive training showed an increase in neuro-plasticity focused on the re-organization of the central nervous system and that cerebral cortex and central nervous system activation affected movement speed and balance ability [34]. Based on the results, the aquatic exercise program was very effective in improving balancing ability by observing the changes in balance ability between the aquatic exercise group and control group.
Improvement in walking ability for persons with stroke is a major goal of clinical rehabilitation research [35]. Among them, walking speed is used as a measure of the level of functional recovery in order to perform daily life activities [6]. The underwater gait training showed improvements in walking speed by strengthening of the lower extremity muscles such as the rectus femoris, biceps femoris, and vastus medialis [36,37]. Also, underwater gait training can be conducted easily and with stability by using buoyancy, which also provides psychological stability. In this study, we performed an aquatic exercise program including underwater gait training with these advantages [38]. Park
In conclusion, we conclude that applying additional weight during the performance of aquatic exercise is very effective for improving balance ability due to improvements in lower extremity strength in persons with stroke. However, there are some limitations that affect the results of this study. First, it is difficult to generalize the results due to a small number of subjects. Second, the subjects had various balance and gait abilities. Third, the duration of the study period was six weeks, which was short-term. Fourth, the intervention was performed by several therapists, which may have produced an error in the level of treatment between therapists. Future studies should address these limitations and be conducted for further development of various aspects of aquatic exercise programs for the stroke population.
This paper was supported by the Fund of the Sahmyook University in 2017.
The author declared no potential conflicts of interest with respect to the authorship and/or publication of this article.
Characteristics of participants (clinical features) (N=40)
Characteristic | Additional weight (n=13)a | Non-weight (n=12)b | Control (n=15) | F ( |
---|---|---|---|---|
Age (y) | 55.5 (9.98) | 56.9 (4.42) | 57.0 (10.90) | 0.830 (NS) |
Height (cm) | 167.4 (6.55) | 165.5 (4.33) | 165.9 (7.49) | 0.630 (NS) |
Weight (kg) | 67.9 (4.95) | 66.9 (6.96) | 68.0 (8.67) | 0.932 (NS) |
Delay (mo) | 7.3 (1.12) | 7.1 (1.85) | 7.8 (1.76) | 0.630 (NS) |
MMSE-K | 28.3 (1.03) | 28.5 (1.16) | 28.5 (0.74) | 0.898 (NS) |
Gender | 0.606 (NS) | |||
Male | 8 | 9 | 9 | |
Female | 5 | 3 | 6 | |
Hemiplegic side | 0.179 (NS) | |||
Left | 10 | 4 | 8 | |
Right | 3 | 8 | 7 | |
Mechanism | 0.185 (NS) | |||
Haemorrhage | 4 | 8 | 9 | |
Ischaemia | 9 | 4 | 6 |
Values are presented as mean (SD) or number only.
MMSE-K: Mini-Mental Status Examination-Korea, NS: non-significant.
bGeneral aquatic exercise program group.
Aquatic exercise program
Aquatic exercise program course | Time |
---|---|
First. Weight shift and stretching in a static posture in the water | |
1. Weight shifting in various directions and single leg standing | |
2. Stretching in various directions | |
Second. Weight shift and task-oriented training in a single leg standing position in water | 20 minutes |
1. Hold on Single leg standing position | |
2. Squatting | |
3. Step up & Step down | |
4. Ankle exercise (heel up and down in stand posture) | |
5. Kicking | |
Third. Underwater gait training | 10 minutes |
Changes in balance ability and muscle strength of the participants in this study (N=40)
Variable | Additional weight (n=13) | Non-weight (n=12) | Control (n=15) | F ( | |||
---|---|---|---|---|---|---|---|
Pre-test | Post-test | Post-test | Post-test | Pre-test | Post-test | ||
MRC (score) | 15.30 (0.48) | 20.20 (1.04) | 15.30 (0.65) | 18.50 (0.67) | 15.60 (0.72) | 18.00 (0.70) | 46.70 (<0.001) |
Difference (post-pre) | 4.80 (0.66)a,b | 3.10 (0.57)a | 2.40 (0.73) | ||||
t ( | −25.37 (<0.001) | −19.00 (<0.001) | −12.61 (<0.001) | ||||
BBS (score) | 40.70 (1.24) | 49.80 (1.99) | 41.00 (2.84) | 48.10 (1.80) | 40.90 (1.80) | 46.20 (1.27) | 10.35 (<0.001) |
Difference (post-pre) | 9.00 (2.16)a,b | 7.00 (1.92)a | 5.30 (1.79) | ||||
t ( | −14.52 (<0.001) | −12.44 (<0.001) | −13.44 (<0.001) | ||||
TUG (sec) | 27.10 (3.31) | 14.30 (3.17) | 27.80 (4.70) | 17.20 (4.30) | 27.20 (3.95) | 19.50 (2.44) | 5.71 (<0.001) |
Difference (post-pre) | −12.60 (3.20)a,b | −10.50 (4.37) | −7.70 (3.89) | ||||
t ( | 13.45 (<0.001) | 8.37 (<0.001) | 7.68 (0.01) | ||||
10MWT (sec) | 28.30 (3.31) | 17.30 (1.43) | 28.50 (5.38) | 19.10 (4.64) | 28.40 (3.33) | 20.60 (2.40) | 2.87 (0.06) |
Difference (post-pre) | −11.00 (3.48) | −9.40 (3.91) | −7.70 (3.30) | ||||
t ( | 10.93 (<0.001) | 8.32 (<0.001) | 9.06 (<0.001) |
MRC: Medical Research Council, BBS: Berg Balance scale, TUG: Timed Up and Go test, 10MWT: 10-meter walking test.
bSignificant difference compared with non-weight (