Introduction
Traumatic brain injury (TBI) is defined as a trauma to the head, which leads to impairment of the anatomical and functional structures of the brain.1 2 It is one of the main causes of death and long-term activity limitation and has an incidence of 383 per 100 thousand inhabitants in Brazil.3–6 Thus, patients with moderate or severe TBI can experience different impairments, restrictions on social participation and limitations in activities, such as walking limitations (ie, reduced walking speed, low cadence and asymmetry), requiring specific training and rehabilitation.7–11
Walking training (ie, treadmill and/or overground walking) is one of the most common activities performed in rehabilitation programmes aimed to improve walking in neurological health conditions.12 Previous studies showed the benefits of walking training for people with TBI.12–14 Although in some cases, after severe TBI, rehabilitation can be difficult due to the prevalence of more impairments and limitations, leading to a high level of training assistance. For many reasons, robotic devices, such as Lokomat, were developed to provide assistance, increasing the efficiency of walking training.9
The Lokomat device is considered a static robotic exoskeleton, consisting of a treadmill, a weight support system and activated walking orthoses for both legs, where the patient is secured by three handcuffs to the equipment.15 By controlling the equipment, a trajectory for movement is provided, which can be slightly or completely controlled, depending on what you want to achieve, known as guidance strength, and this also provides feedback through virtual reality present in the system, contributing to adherence and development of the patient.15 Therefore, Lokomat has the benefits of more intensive and prolonged training, more consistent movements and walking cycles closer to the expected, with reduced therapist assistance.9 15 16
One previous study, involving 22 participants, investigated the effects of three types of walking training, including a treadmill with body-weight support and Lokomat, for improving walking speed, symmetry and walking capacity.14 The results showed that Lokomat training can improve walking speed (0.14 m/s) and walking capacity (20 m), but the results were similar to the other groups. However, results were based on small groups (7 to 8 participants per group).14 Moreover, assessors were not blind, the allocations were not concealed, and intention-to-treat analysis was not performed; therefore, the methodological quality was considered ‘fair’ based on PEDro scores.17 Therefore, larger, high-quality trials are needed to increase our knowledge regarding the effects of Lokomat training to improve walking in people after TBI, as improvement results have been found in patients after stroke, but even with the possible similarities between these conditions, these results cannot be guaranteed or extrapolated to patients who have suffered TBI.18
As conducting a randomised clinical trial is difficult to conduct without first understanding the feasibility of this, the present study will investigate the feasibility of a randomised clinical trial aimed to investigate the walking training using the Lokomat device for people after TBI.19 Moreover, the relevance of the present study is due to the fact that there is still very little literature for this population on the use of robotic devices to improve walking and participation.15 Furthermore, in Brazil, there is no study with patients after TBI using Lokomat for walking training, and due to its social and economic differences, with the countries that already carry out this research, it is necessary to investigate whether it will be possible to carry out a study with such equipment, population and physiotherapists’ availability in aspects such as recruitment and adherence of these so that a randomised clinical trial can subsequently be carried out.19
Therefore, this is a protocol study; the objective of the feasibility study will be to evaluate the feasibility of using Lokomat for walking training in patients after severe TBI. In this way, the results obtained will support the design of the study that will be able to fully explore this therapy, which aims to improve the walking speed of these patients and their social participation linked to quality of life. The specific research question will be:
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What is the rate of recruitment, attendance, adherence, efficiency, safety and acceptability of the protocol?
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Is there any benefit to walking speed assessed by the 10 m walk test, mobility assessed by the Timed Get Up and Go test, quality of life and social participation assessed by the SF-36 scale?
Methods and analysis
Trial design
The protocol for this feasibility study will be a single-group study. The study received ethical approval from the Institutional Research Ethics Committee (CAAE 75039923.4.0000.5060) of the Federal University of Espírito Santo, Vitória, Brazil.
Study setting
The study will be carried out at the Interprofessional Health School Clinic of the Universidade Federal do Espírito Santo, located in Vitória, Espírito Santo, Brazil.
Participants and therapists—inclusion and exclusion criteria
A convenience sample of individuals with severe TBI classified as ⩽8 on the Glasgow Coma Scale at hospital admission will be recruited through advertisements and outpatient clinic screening. Individuals will be included if they are: (1) ≥18 years and <50 years of age, (2) Walking at speeds between 0.2 m/s and 0.6 m/s, (3) Time since TBI between 6 months and 3 years and (4) Provide written informed consent prior to data collection (attached file). Patients may continue to undergo medication and rehabilitation treatment freely. The exclusion criteria are in table 1. The participants’ timeline is shown in figure 1.
Participant timeline. TBI, traumatic brain injury.
Exclusion criteria
Patient and public involvement
Patients who have suffered TBI and their families are not involved in defining the research question or outcome measures, but are involved in improving the intervention protocol and its acceptability in terms of the number of sessions, fatigue, and interest and satisfaction. Patients and their families can also contribute to disseminating information about the implementation of the protocol to the intended community and improving recruitment of new patients.
Intervention
The participants will undertake walking training in the Lokomat device, 30 min per day, 3 days per week, over 5 weeks, that is, 15 sessions of Lokomat training.15 18
Before starting the intervention, participants will undergo an examination aimed at preparing the equipment for the participant. Information related to weight, height, femur length, age and size of the leg will be used to determine the size of braces necessary to conduct the intervention.
The first week of training will be used for adaptation and adjustment. The device speed will be similar to the participant’s speed obtained during the 10 m walk test, with 50% of body weight support and 100% of guidance force. After the second week, the device parameters, including body weight support, guidance force and speed, will be changed. The body weight support will be reduced by 5% per week, or more, according to the participant’s ability to walk with less support. The guidance force will be reduced by 10% per week, or more, according to the participant’s ability to generate movement and follow the device. As participants with TBI can present with hemiparesis, the guidance force between legs can be different. The device speed will be increased according to the participant’s ability to walk faster without compromising the walking quality.
During the intervention, participants will receive encouragement phrases, such as ‘you are doing great’ or ‘keep going’. Participants will be able to stop two times during the training to rest. If more than three stops occurred in one session, the training will finish and start over in the next session. If any adverse event, such as nausea, dizziness, extreme tiredness, fainting, injury due to the equipment harness, muscle and joint pain, inflammation in the tendons, general excessive effort in the musculoskeletal system or others not yet known, is reported, training may be stopped due to such discomforts.15
A daily evolution will be answered as shown in table 2 provided to the physiotherapists responsible for training, and must be completed on each training day scheduled for the participant. Assessment of resources, how many physiotherapists trained to use the equipment were needed, how much time was needed to place and remove the patient from the equipment, and whether any maintenance occurred on the equipment. If help is needed for the participant at this stage, it is provided by the caregiver or a communicator who could respond to the participant. Finally, at this stage, we seek to obtain sufficient data to establish the study design and sample size, with possible modifications that may occur.
Google Forms evolution diary
Outcomes
Primary outcomes
Primary outcomes of interest will be: recruitment, attendance, adherence, efficiency, acceptability and safety.
Recruitment will be determined by the proportion of participants contacted, through lists of previous or running projects and advertisements, and by evaluating the rates of refusals to participate in training or further ineligibility commonly reported. The interpretation of these data is to understand if inclusion and/or exclusion criteria or recruitment sources are sufficient to include more participants in a future project. Efficient recruitment sources will be used for future recruitment.
Attendance will be determined by the proportion of participants who attended evaluations and walking training sessions. Participants are supposed to attend 15 planned sessions. Participants who attended <50% of training sessions were classified as ‘poor attenders’.19
Adherence will be determined by the proportion of participants who completed the training. The number of sessions where the participant completed the full 30 min of walking training and the reasons for not completing the 30 min will be noted. This information will be used to determine: (a) The number of sessions where the participant completed the full training and (b) The reasons for not completing the full training protocol.
Efficiency will be determined by comparing training parameters such as walking speed, orientation force and weight support offered at the end of the training protocol, thus obtaining an average of how much these parameters are increased or reduced for the last two, respectively.
Acceptability will be assessed through the questions answered within a questionnaire presented in table 3, and then the proportion of these responses will be evaluated. If at least 50% of the responses are affirmative, then it will be considered a positive response regarding the acceptability of the training.
Acceptability of walking training on the Lokomat for patients
Safety will be defined through the number of adverse events that occurred during training or shortly after, within the total number of sessions to be carried out.
Data instruments
The data instruments will be: walking speed, step length, mobility, quality of life and social participation. Tests will be performed at baseline, after 5 weeks (end of intervention) and after 1 month after the end of treatment (follow-up).
Walking speed will be measured using the 10 m walk test. Walking speed will be calculated by dividing the covered distance, that is, 10 m, by the time to cover the distance, and reported in metres per second (m/s). Step length will be calculated by dividing the covered distance, that is, 10 m, by the number of steps to cover the distance, and reported in metres. Walking cadence will be calculated by dividing the number of steps by the time to cover the distance, that is, 10 m, and reported in steps/min. The 10 m walk test will be carried out in a 14 m corridor, with 2 m in the beginning to accelerate and 2 m in the end to decelerate.20 After a practice trial, the value obtained during a single test will be used for analysis.21
Mobility will be measured using the Timed Up and Go test, and results will be provided in seconds (s). The Timed Up and Go will be carried out in a 3 m corridor. The participant will be seated in a chair, will stand without using arms if possible, walk the 3 m corridor, and turn and sit again.22 After a practice trial, the value obtained during a single test will be used for analysis.
Quality of life and social participation will be measured using the Medical Outcomes Study 36 Short-Form health survey, and results will be reported on a scale of 0 to 100 points, where higher values indicate better outcomes. This questionnaire consists of a multidimensional instrument of 36 items, with eight domains, including functional capacity, physical aspects, pain, general health status, social aspects, emotional aspects and mental health. The various domains cover different aspects that can provide a general idea of how training can impact the quality of life of these patients.23 Its translation and validation into Portuguese were satisfactory and statistically significant for the eight domains with test-retest reliability and 0.5542 to 0.8101 for interobserver reliability, and satisfactory construct validity, with the correlation coefficients between SF-36 and HAQ, AIMS-2 and NHP being statistically significant.23 Furthermore, if the patient needs help from a physiotherapist or caregiver to answer the scale, he or she can count on it as long as it is registered.23
Data management
The evaluated physiotherapists will be trained by therapists with at least 3 years of experience, and the professionals responsible for walking training on the equipment will be carried out by physiotherapists who have undergone training provided by the company or who have received training from physiotherapists already trained by the company. In this way, the data will be collected and stored in tables that will receive information and conferences from at least two physiotherapists every month, to carry out an audit on the results of recruitment, evaluations and the implementation of interventions with patients. Further details will be provided on request to the study authors. A committee for data monitoring is not necessary due to the nature of the feasibility study and its way of collecting and analysing statistical data. If it is necessary to interrupt the research, the authors will be responsible for making the decision on what will be done with the provisional data and on the completion of the project.
Allocation and randomisation
Participants will be allocated to a single group; no type of randomisation will be performed. Furthermore, there is no blinding of any of the parties involved, either the recruiters and physiotherapists responsible for assessment and training, or the patients themselves.
Sample size
Due to the nature of the feasibility study, it may not be possible to calculate the sample size.24 Therefore, based on the recommendations for pilot studies where it is not possible to calculate the sample size, a flat rule of thumb can be used according to Kunselman (2024), approximately 12 participants can be used in each group.25 26 The objective is to be able to find the results that are desired to obtain with the feasibility of this study.25
Data analysis
Due to the nature of a feasibility study, no formal sample size calculation was performed. Our goal was to include 20% of the total number of recruited individuals and sessions initially planned. Due to the nature of the study, it will not have statistical power to detect clinically significant differences between groups in the outcomes assessed.26 27 For participant characteristics and feasibility results, descriptive statistics are presented as mean (SD) or percentage (%), as well as the number of representations.26 27 Thus, the recruitment rate will be positive if at least 20% of the sample is eligible for the study and is willing to participate. Adherence will be positive if at least 50% of the sessions are completed by the end of the protocol, while efficiency will be determined by determining the mean values of increase in speed and reduction in driving force and weight support, with an ideal improvement ≥20%. Regarding acceptability, it will be good if at least 50% of the questionnaire responses are positive. Safety will be defined by the number of adverse events occurring during all training sessions, being expected to be ≤5%. Regarding the data instruments, the results will be demonstrated by mean and SD for pre-test and post-test and follow-up differences, for gait speed, mobility and scores in the domains of the SF-36 scale.
Ethics and dissemination
Possible modifications to the protocol, such as changes to eligibility criteria, results and analyses, will be communicated through a note in the publication, written information to participants and regulations to the ethics board. The evaluator will obtain informed consent from the participant (attached file), and the participant will be free to withdraw from the study at any time, but data collected from this patient will be used unless there is a request that it not be used.
The reliability of the data is that only researchers have full access to the study data, which is kept in a secure location. Data will be available to authors on reasonable request, but any information related to participant identification will be withheld. The results obtained through the study will be communicated to healthcare professionals and other relevant groups through publications, reporting the results in a database and presenting them at congresses and conferences.
