Design

A single-blind randomised controlled clinical trial that follows the recommendations of the Standard Protocol Items: Recommendations for Interventional Trials20 will be carried out (figure 1). Participants will be randomised to receive the exergames protocol (experimental group (EG)) and kinesiotherapy protocol (control group (CG)) (figure 2).

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Figure 1

Schedule of enrolment, interventions and assessments. t₁, 1st week; t₁₀, 10th week; t_post10, post-training; t₁₈, 18th week.

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Figure 2

The schematic study design.

Participants

The study population will consist of 42 patients who had a chronic stroke living in the city of Natal or nearby. A volunteer selection will be carried out at the stroke patient care centres in the city. The selection can also be carried out via spontaneous demand by the voluntary search of patients who had a stroke after project advertisement on social media. After this, the first telephone contact will be made to clarify any questions from the participants and the first screening for inclusion will be performed.

Inclusion and exclusion criteria

The participants will be selected according to the following criteria: (1) first episode of unilateral stroke (ischaemic or haemorrhagic); (2) postural balance deficits (Berg Balance Scale score (BBS))<45)21; (3) injury time ≥6 months; (4) age between 20 and 75 years; (5) at maximum level 2 of the modified Ashworth Scale to assess the spasticity of the paretic lower limb22; (6) good cognitive status based on the Mini-Mental State Examination (MMSE) (≥19 for illiterate, ≥24 for literate)23; (7) ability to walk without personal assistance indoors (Functional Ambulation Category (FAC)) scores≥3)24; (8) clinically stable, with no history of epilepsy or seizures in the last 6 months; (9) not having signs of unilateral neglect or sensory or global aphasia as assessed by National Institute Health Stroke Scale (NIHSS))25; (10) no uncorrected hearing and/or visual impairments; (11) not participating in a balance treatment protocol and (12) ability to understand and obey simple motor commands.

Exclusion criteria will include (1) presenting other clinical conditions affecting balance and (2) pregnancy.

Sample size

Using an online calculator26 and based on previous study values (51.0±4.6 and 46.2±5.7),27 a total sample of 42 participants (21 in EG and 21 in CG) will be sufficient to detect a clinically important difference between the groups on the BBS. A statistical power of 80%, an alpha of 5% and a loss rate of 10% were considered for the sample calculation.

Randomisation and blinding

A randomisation sequence will be generated by a computer28 in 3 blocks of 12 participants and 1 block of 6 participants, allowing participants to be equally distributed between the two groups. This stage will be conducted by a researcher who is not involved in the study, they will keep the randomisation list confidential until the end of the study and will organise the allocation in sequentially numbered opaque envelopes. These envelopes will be sealed, and the randomisation sequence will be enforced using colour coding for the study groups (blue and red), that will correspond to the protocol that will be executed. The contents of each envelope will be revealed at the beginning of each patient’s training by the study therapists responsible for the intervention to maintain allocation confidentiality. The same therapists involved in CG training will perform training in the EG. The researcher responsible for evaluations will be blinded to all intervention groups. The only variables that will be collected during the training will be evaluated by the study therapists (non-blind). Statistical analysis will be performed by a blind researcher who will treat the groups according to colour, and the equivalence between groups and colours will be revealed on completion of the statistical analysis. The main researcher will have access to the final trial dataset; this researcher will decide on terminating the trial. All information about participants will be confidentiality before, during and after the trial.

Evaluation procedures

The researchers will be trained before data collection procedures to ensure reliability of measurements, and the participants will be submitted to assessment using all the instruments mentioned below.

Measures

Outcome measures

All outcome measures will be assessed in both intervention groups. The primary outcome measures considered in this study are as follows:

Cortical activation pattern

Alpha and beta waves will be evaluated based on their relationship with the motor learning process,36 using the Emotiv EPOC portable 14 sensor EEG device, a gyroscope capable of detecting changes in the movement performed.

Gait kinematic analysis

The spatiotemporal and angular gait variables will be evaluated using the 6-metre timed walk test (6MTW) and Kinovea software.

• 6MTW: It is a valid and reliable test for the assessment of the walking ability of patients who had a stroke.37 Gait speed should be self-selected and considered comfortable and usual for the participant. Studies show variation in mean habitual speed (0.45–0.78 m/s) of gait in individuals with hemiparesis.38 39

• Software Kinovea: Kinematic evaluation will be performed during gait video capture (6MTW) using the Sony DCR-DVD850 digital camera, 02.7/6.7 cm LCD (liquid crystal display) screen and 60× optical zoom. Data will later be exported to Kinovea V.0.8.15 software for paretic lower limb angle and gait speed analysis. This is a public domain video editing and analysis software that is valid, reliable and capable of accurately measuring distances up to 5 m from the object.40

Functional independence

The Functional Independence Measure (FIM) scale is used because of its reliability, validity, precision and feasibility criteria. It is composed of 18 items, including motor and cognitive items. Here the patient’s answers are valued from 1 (total dependent) to 7 (complete independence), and the total punctuation ranges between 18 and 126. For this research, the FIM will be applied exclusively to the motor items, limiting the minimum score to 13 and the maximum to 91 points.41

Quality of life

Quality of life perception will be assessed through a quality-of-life assessment scale for stroke (Stroke-Specific Quality of Life Scale). It is valid and reliable in assessing the quality of life after stroke in the Brazilian population and has 49 items distributed over 12 domains.42

Motivation

The Intrinsic Motivation Inventory is a multidimensional measurement with six subscales used to assess the subjective experiences of participants when developing an activity and attends to the reliability and validity criteria. According to the inventory, instruction participants ranked their agreement with each statement on a Likert scale of 1 (‘not at all true’) to 7 (‘very true’).43

Participant monitoring measures

Participants will be monitored during interventions using the following measures:

• Cardiovascular parameter variables: heart rate (HR) will be checked using a portable oximeter and blood pressure using a sphygmomanometer (Visomat Comfort III, Incoterm, São Paulo, Brazil) on the non-paretic arm.

• Adverse symptoms, perceived effort and pain: information regarding headache, vomiting and dizziness will be collected. Quantification of perceived effort and pain will be used as indicators to monitor exercise tolerance through the CR-10 (Category-Ratio Scale) Borg Scale44 modified by Foster et al.45

Adverse events

Additional information such as hospitalisations, falls, out-of-routine medical consultation, medication change, new diagnosis and the presence of adverse events will be collected during the follow-up.

Interventions

The protocols in both groups will be performed individually through 40-minute sessions two times per week for 10 weeks (total of 20 sessions), totalling 13 hours of intervention.12 17 46 The same outcome measures and motivation will be collected again at the end of the interventions (post-training) and after 8 weeks of the end of the interventions (follow-up). All participants will be instructed not to perform any other physical activity that works on body balance during the study period.

During each session, absences, manifestations of adverse symptoms and occurrence of imbalance and/or falls will be recorded. Interventional modifications will be performed according to the patient’s level of adaptation involving optimisation of time or number of repetitions and/or rest time enlargement, and all will be registered.

Both groups will begin their protocols with adapted lower limb strength training for 10 min47 48 as described in table 1. Each exercise should be performed with respect to the patient’s level of adaptation and evolution will occur in the 6th and 13th sessions using the materials described.

Control group

Participants in the CG will receive a kinesiotherapy protocol (30 min) (table 2), focusing on balance based on previous studies and that promotes stimuli similar to the EG, selected so they demand identical motor sensors in both intervention environments, real and virtual.47–50 Two progressions will happen, in the 6th and 13th sessions.

Experimental group

Participants in the EG will receive seven Wii Fit Plus exergames on the Nintendo Wii (30 min) (table 3). This will use the Wii Balance Board accessory, a multimedia projector and the Wii Remote Controller. Initially, participants will have a moment to adapt to Nintendo Wii and its components. It is expected that the participants in this group will be able to deal satisfactorily with the games used in the protocol after adaptation. Otherwise, they will enter the non-adherence criteria.

The games were pre-established with focus on balance, and demands similar to that of the kinesiotherapy protocol: saccadic stimulation, visuovestibular cephalic movement, proprioceptive stimulus, dynamic balance training, static gait, ankle and hip strategies, fine CoP control, stimulus optokinetic, double task (motor) and motor coordination.51–53 All scores obtained in games will be noted. Progression will occur on adaptation of the patient, two evolutions will occur, in the 6th and 13th sessions.

Adherence

Participants will be contacted by telephone to confirm assessment and training sessions to avoid sample loss. Strategies to improve adherence include making up for missed sessions and interventions of motivated professionals. Regardless of the protocol, the criteria for non-adherence will be considered as follows: (1) absence >30% of the intervention, consecutively and without make-up sessions; (2) presenting persistent pain or severe discomfort (headache, vomiting, dizziness, etc), which prevents continuity in performing the proposed protocol in future sessions (or both); (3) presenting haemodynamic instability: decompensation of systemic arterial pressure (systolic and diastolic values >200 mm Hg and 110 mm Hg, respectively)54 and HR above the submaximal values allowed during the training maintained even after pauses, calculated by means of the formula (HR_sub=0.75 × (220−age)55) and (4) those who did not adapt to the proposed intervention.

Data acquisition

For data collection of the CoP variables, six static balance tests will be performed on the FP based on their complexity variation and common use in the literature56 57: bipodal support on a stable surface with eyes open and eyes closed for 30 s each; unipodal support of paretic limbs on a stable surface with eyes open and eyes closed for 30 s each; unipodal support of non-paretic limb on a stable surface with eyes open and eyes closed for 10 s each. The distance between the patients’ feet will be standardised51 and in unipodal support tasks, the contralateral knee may be slightly flexed and there may be no contact between the raised and support legs. Each test can have one successful attempt and a maximum of three unsuccessful attempts. The attempt is considered invalid if the participant moves their support leg or touches the floor with the contralateral leg.58

For gait analysis during 6MTW, the camera will be positioned perpendicular to the plane of motion, at a height of 1 m and 3 m away from the subject to capture the gait pattern of the hemiparetic side, and will be considered as a complete gait cycle. Markers will be placed on the main bone references of the paretic lower limb (greater trochanter of the femur, lateral tibial condyle, lateral fibular malleolus, fifth metatarsal head and lateral calcaneal bone tuberosity) for further analysis.

For encephalographic recording during the FP static balance and walking tests, the Emotiv EPOC headset will be positioned on the user’s head according to the international placement in the 10–20 positioning system following the manufacturer’s specifications.59

Data processing

The Bertec Model 4060 platform will be synchronised with Qualisys Motion Capture Systems (Qualisys Medical AB, 411 13 Gothenburg, Sweden), and through that system software, Qualisys Track Manager, data for CoP will be collected and converted to MATLAB compatible files (Mathworks, Natick, Rhode Island, USA). The sampling rate will be 40 Hz, and a Butterworth bandpass filter with a cut-off frequency of 15 Hz will be applied to eliminate noise contamination.

For kinematic analysis, the videos will be converted to an Audio Video Interleave file extension and exported to Kinovea software. The hip, knee and dorsiflexion flexion angles will be evaluated in the middle oscillatory phase of gait, using the following joints: hip, tibiofemoral metatarsophalangeal and calcaneal. Emotiv EPOC data processing will follow the model used by Oliveira et al.60 The encephalographic recording will take place during gait and static balance tests, using 10 s of single-leg support activity and a central 10 s cutout in bipodal support activities.

Statistical analysis

The SPSS V.21.0 software programme will be used, and a significance level of 5% and 95% CI will be implemented for all statistical analyses. A descriptive analysis of the sample characterisation variables will be performed through central tendency and dispersion measures.

Normality tests (Kolmogorov-Smirnov) will be used for outcomes and will be compared between groups within each training session by using intergroup comparisons, t tests for independent samples, or Mann-Whitney U tests. A mixed analysis of variance with repeated measures will be used to compare values and variations of outcome measures, comparing values between groups and between baseline, post-training and follow-up assessments.

The effect size will be calculated using GPower V.3.1.9.3 (University of Dusseldorf, Kiel, Germany). Cohen’s d will be used to calculate the effect size between the control and the EG, and the partial η² for intragroup analyses.61 Intention-to-treat analysis will be performed for dropout data, considering the last data obtained from the participant.

Risk of bias and study limitation

The present study has a low risk of selection bias due to randomisation and concealment of the allocation of participants; low risk of detection bias as the outcome assessor will be blind; high risk of performance bias because the participants will not be blind to the proposed therapies; reporting and attrition biases do not apply because it is a protocol study.62

The proposed follow-up time (8 weeks) can be considered a potential (minor) study limitation; it is not verified whether motor and neurophysiological changes resulting from the proposed intervention will be maintained over a long term (1 year). However, it is suggested that the effect of treatment with Nintendo Wii can be maintained for at least 2 months after the intervention, with improvements in motor recovery.

Patient and public involvement

Patients were not involved in the design of this trial, establishing the research question, or developing recruitment procedures. At the end of the study, the results will be reported to the participants in the form of a lecture, showing the effects found in the studied variables. The results of the study will be disseminated to participants through social networks and will be submitted to a peer-reviewed journal and scientific meetings.

Ethics and dissemination

This research was approved by the Research Ethics Committee of the Federal University of Rio Grande do Norte, with protocol number 3.434.350 on 3 July 2019. Participants will be informed of the study objectives, its risks and benefits and when eligible for inclusion, if they agree to participate, must sign the informed consent before the study begins. They will be free to abandon the study at any time without the obligation to give any explanation.

There will be prior contact with individuals through social networks, when all information about the study will be presented as well as the Resolution No 466/2012 of the Brazilian National Health Council of 2012, which provides guidelines and standards for research involving human participants. In case any negative effects occur, participants who suffer harm from trial participation will receive physical assistance according to the injury. The study results will be disseminated to participants through social networks and will be submitted to peer-reviewed journals and scientific meetings.

Protocol amendments

Protocol amendments will be documented with descriptions of the change and the date of the change.

Study status

Subject recruitment is underway, started in November 2019, but the first inclusion was in January 2020. To date, eight patients were enrolled in the study. The recruitment period spans till January 2021. The goal is to include 21 patients per treatment group, each patient completing the rehabilitation programme and evaluation before and after, and 8 weeks later.