The proposed protocol study is a two-arm, randomized, assessor-blinded trial with two parallel groups.
The study population consists of ambulant people aged more than 18 years with a confirmed diagnosis of acquire brain injury at subacute or chronic stages. Participants who agree to participate in the study will be assigned to experimental group (EG) (exercise therapy and adapted physical activity program) or control group (CG) (usual care) after being screened and randomized according to the inclusion criteria.
A physiotherapist will perform the evaluation process, including physical performance and biopsychosocial aspects. Information on functioning and disability will be collected through the ICF components, including Contextual Factors such as "Personal" and "Environmental", and Functioning domains such as "Body Functions and Structures" (b-components), "Activities \& Participation" (d-components) as well as "Quality of Life components" . The main outcome measures of the study are: (i)"health-related quality of life" through the questionnaire Short Form 36; (ii) "functional capacity", attending to aspects of mobility and endurance on walking which will be measured through two tests: the 6 Minutes Walk Test and the 10 Meter Walk Test; (iii) motor control of the upper limb, through the Fugl-Meyer Upper Extremity test; (iv) "mobility" which will be measured with Timed Up and Go; (v) and "balance", through the Balance Berg Scale. As secondary outcome measures of the study, the level of physical activity through the Global Physical Activity Questionnaire will be measured. Moreover, demographic and anthropometric characteristics will be also considered.
Outcome measures will be assessed at baseline (T1) and immediately after 8 weeks of program (T2),
Participants in EG a progressive program based on a therapeutic exercise and adapted physical activity program based on racket sports, will be practiced for 60 minutes a day, 2 days a week for 8 weeks. In CG, participants will receive conventional management with general physical activity recommendation. The intervention will be guided and supervised by a physiotherapist and delivered in groups of 5 participants.
Randomization process (sequence generation, allocation concealment, and implementation) will be conducted by three different researchers from the team. After signing the informed consent and undergoing initial assessment, participants will be allocated to the experimental group (EG) or the control group (CG). It will be made using a computer-generated number sequence, with a 1:1 allocation ratio, without stratification.
The assessments (T1, T2) will be completed by two physiotherapists specifically trained to carry out the outcomes evaluations who will be blinded to group allocation during the entire study period.
The sample size is estimated to obtain statistically significant improvements through the two primary outcomes: (i) health-related quality of life (Physical Component Summary) and (ii) functional capacity (6-minute walk).
(i)The threshold for detecting changes in health-related quality of life is approximately 5 points (Norman et al. 2003). To detect this difference with a standard deviation (SD) of ±5 points between the groups with a 95% confidence interval and a statistical power of 80% in a two-side approach, it would be needed 16 participants. Considering that it could have 15% losses, the final sample size would be 18 subjects in each group.
(ii) On the other hand, since there are no published data on the 6-minute walk test in adults with ABI, it is considered the clinical difference to be significant in healthy adults (standard deviation of ±44). To detect the difference between groups with a confidence interval of 95% and a statistical power of 80%, the sample should be composed of 12 persons by group. Considering a 15% losses, the final sample size would be 14 participants in each group.
In addition, based on previous studies that carried out a similar intervention in persons with adquired brian injury, the total sample should ranged between 30-35 participants.
Both ethics approval and administrative site approvals have been granted by the local ethics committee (Ethics Committee for Clinical Investigation of Madrid, Spain). Full written informed consent will be obtained from all participants indicating voluntary participation in the study. All informed consent data will be collected and stored by the main researcher. This clinical trial has been performed in accordance with the Helsinki Declaration. Participants' personal data will be de-identified (they will be allocated a identification code generated by a random number sequence, which will be used to deidentify participant information). No data that could identify the participants will be published.
