This is the first prospective, randomized controlled study to show that additional training with a newly developed Balance Control Trainer (BCT) could achieve greater improvements in mobility and balance in chronic stroke patients.
The asymmetrical stance due to reduced weight bearing in the affected lower limb is one of the problems that frequently occurs in hemiplegic stroke patients, and it is known to adversely affect mobility and activities of daily living.22
Therefore, special attention has been given to therapies that help increase weight bearing on the affected side.24
As mentioned earlier, many conventional treatments such as neurodevelopmental training (NDT) and sensory stimulation have been performed to help patients shift their weight to the affected side. Nowadays, more functional walking training methods like weight unloading devices and robots and new balance training systems such as the Balance Master System and Balance Retrainer have been developed to make patients shift their weight to the affected side.4
The outcomes of these types of training are still under debate.
The treadmill, on which many recent studies have been conducted, is known as a more task-specific approach for improving gait in hemiplegic patients. Moseley et al.26
reported that the treadmill with body weight support improved walking dependence, velocity, and endurance more than the treadmill without body weight support.
Therapies that use robots have also been shown to be more effective than conventional physical treatments in achieving independent walking. This method was superior when assessing the distance walked in six minutes.27
Despite their potential therapeutic efficacy, these treatment methods require expensive equipment and have yet to demonstrate sufficient cost-effectiveness.
Yavuzer et al.28
reported that an additional 15 minutes of balance training with the Force Plate Visual Feedback produced superior results in pelvic excursion as compared to neurodevelopmental training (NDT) alone, not including walking velocity. However, Eser et al.,29
who used an identical method in their study, but used more functional testing tools such as the Brunnstrom stage, Rivermead Mobility Index (RMI), and Functional Independence Measurement (FIM), reported that there was no statistically significant difference between the outcomes of the two treatment regimes. Winstein et al.25
reported that 3-4 weeks of visual feedback treatment significantly improves symmetry, but not for walking. There is insufficient evidence to suggest that Force Plate Visual Feedback treatment leads to a significant improvement in the performance of functional activities such as walking.30
This treatment is used only in the horizontal plane, even though many activities of daily living are performed in the vertical plane even in normal people.
Our team developed the BCT in order to incorporate the vertical component of the center of gravity movement by means of knee joint involvement and the horizontal component into therapy, thus overcoming the main limitations associated with the Balance Master System.
We found that the ability to control the affected knee and the scores of the "board cleaner" game correlated with all clinical parameters including FAC, BBS, 10mWT, TUG, MBI and MMT of the knee extensor in a preliminary study.15
We used this device to rehabilitate hemiplegic stroke patients and to compare their improvements in balance and ability to walk to those of patients who received only conventional rehabilitation treatments.
In this study, there were statistically significant improvements in clinical parameters such as FAC, 10mWT, TUG, and BBS over 4 weeks of treatment. But there was no significant difference during the first 2 weeks in MMT of the knee extensor and last 2 weeks in MBI. However after 4 weeks there were definite improvements in MBI and MMT. It was explained in two ways. First, MBI consists of many items relating to patients' functional performance as well as the item evaluating gait ability. Therefore the interventions that improve gait ability might have no influence on the activities of daily living in last 2 weeks. The definite improvement in the MMT of the knee extensor was shown over the last 2 weeks. Its visible effect needs an even longer intervention period than other parameters.
Although this study also showed that conventional treatments were helpful in improving clinical parameters, we found that additional training with a newly developed BCT could be a better treatment option for mobility and balance in chronic stroke patients.
Barclay-Goddard et al.30
showed that the Balance Master System failed to improve BBS or TUG while moving or walking. These results may have been due to the fact that vertical movements of the center of gravity, which are essential components of independent walking and other activities of daily living such as standing up from a chair and sitting down again, were not taken into consideration in the treatment design.32
They suggested that the learning methods used in previously mentioned studies were not appropriately task-specific for walking or other activities of daily living.30
This means that a BCT may be a more effective rehabilitation treatment than conventional treatments in improving mobility and balance because a BCT takes into consideration the importance of movements in the vertical plane.
This study has some limitations. It was not a blind study as previously mentioned. It was impossible to hide the intervention intended for each patient from both the patient and the physiotherapist who were directly involved. Also the control group did not receive placebo therapy. This may have influenced the results but we did not consider it ethical to provide the patients with no treatment for 20 minutes.
In addition, the attention of physiotherapist on the experimental group may have caused a bias, even though it was only for 20 minutes of extra management. Long-term treatment of more than 4 weeks is needed to evaluate and confirm the effect on MMT. Also assessing the long-term effects of the treatment is also necessary; thus there should be ongoing follow-up beyond the completion of the treatment. Because we recruited only patients with a certain level of independent walking ability, these findings may not be applied to patients in the chronic stage of their illness, who have greater mobility problems. Such a study is currently in progress, working on the assumption that the experiment could be useful for severely impaired individuals, including those who are unable to walk, if a weight unloading system is used.
Despite these limitations, this study showed that training chronic stroke patients with a newly developed balance trainer is a feasible and potentially effective intervention to improve balance and mobility.