CLINICAL STUDIES / ETUDES CLINIQUES
BALANCE RETRAINING IN POST STROKE PATIENTS USING A SIMPLE, EFFECTIVE AND AFFORDABLE TECHNIQUE
REEDUCTATION DE L'EQUILIBRE APRES UN ACCIDENT VASCULAIRE CÉRÉBRAL GRACE A UNE TECHNIQUE SIMPLE, EFFICACE ET ACCESSIBLE
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Key Words: Stroke, Balance, Training, Exercise, Stepper.
Mots clés : Accident vasculaire cérébral, équilibre, rééducation, stepping
Balance dysfunctions common in stroke victims have significant impact on functional independence and overall recovery of the patient. Patients who have suffered a stroke present with abnormal and delayed postural responses in the extremity muscles during standing displacements (16) and distorted proprioception (21). They also demonstrate postural control problems such as loss of anticipatory activation during voluntary movements (13); increased sway during quiet standing-especially more on the affected side (10); and decreased area of stability during weight shifting while standing (9). All these could result in clinical presentations such as loss of static and dynamic stability and reduced functional abilities.
Re-establishment of balance function after a stroke is therefore an important construct in physiotherapy practice (22). Balance retraining programme is any intervention designed to help an individual attain body maintenance in both static and dynamic equilibrium. The importance of balance retraining in stroke rehabilitation is underscored by the fact that considerable changes in balance ability correlate significantly with changes in function (15). Since balance is an important pre-requisite for and prognostic factor for recovery of functional activities including walking and motor functions, it is paramount that clinicians in stroke rehabilitation have at their disposal balance retraining techniques which are simple, affordable and effective.
Techniques used to train balance include the force platform feedback, the Bon-Saint-Come device for axial postural rehabilitation, and deprivation of visual cues during balance training. Their differential efficacies have been reported by different authors (1, 5, 8). An important limitation of these techniques however is the high cost of procuring the equipment needed for less endowed health facilities. The need to evaluate a cheaper, easy-to- administer, readily-adaptable for home use and yet effective balance retraining technique for post stroke individuals was an important motivation for this study.
The use of a stepper which is a hybrid between a bicycle and a stair stepper that allows self-assistance, using upper limbs to assist lower limbs has been alluded to be of potential benefit during gait rehabilitation and particularly in balance training, in particular (14). The fact that while walking humans demonstrate neural coupling in reflex response between upper and lower limbs supports the premise that upper limb neuromuscular activation may affect lower limb neuromuscular activation during cyclic stepping movements (14). The active involvement of the upper limbs during gait rehabilitation is likely to increase neuromuscular activation and enhance activity dependent plasticity. A study by Gobert et al (12) reported an improvement in balance of stroke survivors after 8 weeks of total body reciprocal training using a stepper.
The Berg Balance Scale (BBS) is an instrument designed through a process that involved interviews of rehabilitation professionals and individuals with balance deficits to generate a pool of balance items (3) to assess functional balance in a clinical setting. The BBS involves evaluation of the subject’s performance in 14 different activities common in everyday life. It has been described as a valid, reliable and useful tool in determining change in functional standing balance over time (25), assessing patients at different recovery stages after stroke (19), and estimation of approximate length of stay and eventual discharge destination in stroke (26). A correlation greater than 0.70 between total BBS and total Fugl-Meyer scale (FMS) scores have been reported (4).
Many instruments are available to measure motor function in post stroke individuals; however, the Motor Assessment Scale (MAS) was used to measure motor function in this study. It is a brief, easily administered and valid assessment tool for measuring motor recovery in post stroke patients (18). Correlation of 0.88 was reported between the total MAS scores and the Fugl-Meyer Assessment (FMA) tool, while correlation score of 0.28 to 0.92 was observed between specific item scores (except sitting balance) of the MAS and FMA (24).
The aim of this quasi-experimental study was to determine the efficacy of the stepper in training balance and assess the effects of change in balance performance on motor function in post stroke hemiparetic individuals.
Eight individuals took part in this study; six males and two females first incidence, unilateral post-stroke hemiparetic patients undergoing physiotherapy on an out-patient basis at the University College Hospital (UCH) – a tertiary health facility in Ibadan, Nigeria. They had attained relatively independent walking status within their household, and could walk a level ground distance of 10 meters at a go without the use of any assistive device, had no proprioceptive deficits or visual problems, and who had normal mental and language capacity. Aged between 52 and 70 years (61.38 ± 6.04), they were recruited using a consecutive sampling technique.
The following materials were used in the study:
The protocol for this study was approved by the joint University of Ibadan/University College Hospital Institutional Review Board. The study was explained to each patient and informed consent was obtained prior to participation.
Subjects were dressed in a pair of shorts and vest so as to make them comfortable for the exercise. They also wore appropriate size exercise shoes. They were then instructed to step on and they were assisted by the trainer when necessary. The affected hand was strapped to the handle of the upright on stepper with a Velcro strap.
Training Schedule: The training was carried out in the morning hours (usually from 8 a.m. to 10 a.m.) to avoid fatigue from other daily activities, two times a week for six (6) consecutive weeks, giving a total of 12 sessions for each participant. All those who completed the training programme complied with the attendance schedule. The training programme was individualized for each participant and this was carried out by the same physical therapist. Each session lasted on average 25 minutes but rest during session was allowed. One of the participants was on anti-hypertensive medication whilst on this training programme.
Balance and Functional Assessments
The Motor assessment scale (MAS) and Berg balance scale (BBS) were used to assess the motor functional level and balance status respectively at baseline and at the end of the training programme. A licensed physical therapist with several years of clinical experience performed the balance and motor assessment tests. Intra-rater reliability score of the examiner was 0.97 and 0.95 for the BBS and MAS respectively using patients of similar status to those who participated in this study. This examiner was blinded to the expected outcome of the study.
Descriptive statistics of mean and standard deviation were used to summarize the data.
Eleven stroke survivors (7 males and 4 females) that met the inclusion criteria of the study were recruited. However only eight (two females and six males) completed the training programme, giving a 27.3% drop out. The mean time the participants had suffered a stroke was 21.73± 9.35 weeks. The dropout pattern of the participants was such that three participants had dropped out at the end of the 1st week of the training programme.
Several techniques have been employed to retrain balance in post stroke patients, yet there seem to be no gold standard technique for achieving this goal, going by the mixed results reported in literature. In addition, many of these training techniques also involve the use of special equipments and facilities that may not be available in many developing countries. Any mode of training that can be readily adapted to the community setting and physiotherapy clinics with minimal amenities, which are a common phenomenon in the developing nations of West Africa, would therefore be of importance in stroke rehabilitation. This is imperative as stroke is regarded as a major cause of morbidity and mortality (23).
Among those who consented to participate in the study, three (27.7%) did not complete the programme in spite of giving their informed consent. All the recorded dropouts were before or at the end of the 1st week. Non-compliance is an inherent problem in any study requiring several visits to the clinic or research centre, especially in studies involving exercise training over a period of time. Two of the participants who dropped out of the study actually did so because they stopped attending this physical therapy centre altogether while another one stated he had relocated to a new residence farther away from the clinic where this study took place, and thus could not adhere strictly to the training schedule. However there was no significant difference in age and pre-training BBS and MAS score between those who dropped out and those who completed the programme.
At the end of the 6-week training programme, a significant improvement in the post training performance by the participants in some of the BBS domains such as tandem standing, and standing on one leg, turning the trunk 360° with feet fixed, and stool stepping and forward reaching in standing activities. Although the training involved a static balance training, the trend of results was such that the participants recorded significant improvement in both the static activities (tandem standing, standing with eyes closed and standing on one leg) and in dynamic activities (turning 360°, stool stepping and forward reaching in standing) which involved more displacement of balance. Weight shifting activities that challenge the limits of stability and require accuracy and speed have been recommended for incorporation within the balance retraining therapy (22). Exercising on the stepper permits weight shift to the paretic limb. In addition, the neural coupling between the upper limbs and lower limbs, which the type of stepper used in this training programme provides, has been found to be an added advantage in restoring balance and function (14) . A similar study by Matjacic et al (20) who used balance retrainer which involved weight shifting activities after stroke reported significant changes in measures of static and dynamic balance. The results in this study however differed from the findings of a previous study by Brown et al (6) that reported no significant changes in scores of balance after an intervention using the limb loaded cycle ergometre, which also involved weight shifting. The difference between the two studies could be due to the fact that only 2 subjects who were in the acute stage of stroke and had not achieved independent standing were involved in the previous study (6), unlike the present study where all the subjects had attained independent standing.
It is pertinent to note that the activities in which significant improvement were recorded were those in which the participants had pre-training mean scores of 3.25 or less on the BBS scale. These are also static activities which involve lower extremity strength, suggesting significant increase in lower extremity strength among the participants after the 6-week training. All the functional activities that were significantly improved by this training technique are relevant to activities of daily living and could help the patients gain more confidence in functioning within their limited motor ability. For instance, one may posit that improved standing on one leg would improve weight transfer activities, turning 360° is necessary for smooth navigation in varying environments, stepping would facilitate accessibility and help overcome barriers that requires stepping over and forward reaching in standing is indicative of better stability with less likelihood of falls. The BBS had been reported to be responsive to change and thus useful in tracking progress made by the participants over time (19). Hence, it may be submitted that the progress made over the training period was captured by the BBS when used to evaluate the patient at the end of the 6-week training programme.
The results of the functional outcome showed significant improvement in the post training scores of the supine to side lying, sitting to standing, walking, hand movements and advanced hand movements of the motor assessment scale. Weight shifting activities like that involved in stepping have been found to have a beneficial effect on balance function (17). The significant changes observed in the hand and advanced hand activity could be due to the increased use of the paretic hand by recruiting previously silent ipsilateral corticospinal pathways, which is present even in poorly recovered stroke patients (15). The outcome in this study suggests that improvement in balance translate to better functional ability. Since motor impairment such as balance and lower limb ability accounts for functional recovery in the rehabilitation of patients after stroke (11), it is therefore not surprising that the improvement recorded in balance activities after training with the stepper translate into better motor function. An earlier report had observed that balance ability correlates significantly with changes in function (17). The outcomes of this study tend to corroborate that observation.
From a clinical standpoint, this study suggests that stepper with vertical upright may be used to train balance and enhance motor performance in the individuals who have suffered a stroke. The scoring of the 14 activities on the Berg Balance Scale separately as done in this study, rather than using the sum total score, may help the clinician identify the specific task that needs to be improved upon whilst rehabilitating a stroke patient. Using the sum total score may not provide such opportunity of localizing the aspect of balance and function that needs emphasis during stroke management.
Efficacy of stepper with vertical upright for upper limbs in training balance and motor function was investigated in a group of individuals with hemiparesis after stroke. Significant improvements in some activities on the BBS and motor functions were observed after 6-week training using the stepper. This suggests that this simple, easy-to-administer device can also be adopted for balance retraining and enhancement of motor function after stroke in the less endowed clinical settings.
Table 1: Comparison of pre and post training motor assessment scale for the subjects using wilcoxon signed rank scores analysis (n = 8)
*Indicates significant values at p ≤ 0.05
Table 2: Comparison of pre-and post training berg balance scale (bbs) scores for the patients using wicoxon signed rank scores analysis (n=8).
* Indicates significant difference at a-level ≤ 0.05