BackgroundTrunk impairment produces disorders of motor control, balance, and gait that are correlated with increased risk of falls and reduced mobility in stroke survivors. This creates disability and dependency to perform their activities of daily living. Alterations in body alignment occur, requiring treatment strategies focused on improving the postural control. bearing. Core stability exercises (CSE) are a good strategy to improve local strength of trunk, dynamic sitting, standing balance, and gait. There is some evidence about its effectiveness but it is still necessary to run a large multicenter trial to ratify that existing evidence.MethodsThis is a single-blind multicenter randomized controlled trial. Two parallel groups are compared and both perform the same type of therapy. A control group (CG) (n=110) performs conventional physiotherapy (CP) (1 hour per session) focused on improving balance. An experimental group (EG) (n=110) performs CSE (30 minutes) in addition to CP (30 minutes) (1 hour/session in total). EG is divided in two subgroups, in which only half of patients (n=55) perform CSE plus transcutaneous electrical nerve stimulation (TENS). Primary outcome measures are dynamic sitting, assessed by Spanish-version of Trunk Impairment Scale and stepping, assessed by Brunel Balance Assessment. Secondary outcomes are postural control, assessed by Postural Assessment Scale for Stroke patients; standing balance and risk of fall assessed by Berg Balance Scale; gait speed by BTS G-Walk (accelerometer); rate of falls, lower-limb spasticity by Modified Ashworth Scale; activities of daily living by Barthel Index; and quality of life by EQ-5D-5L. These are evaluated at baseline (T0), at 3 weeks (T1), at 5 weeks -at the end of the intervention (T2), at 17 weeks (T3) and at 29 weeks (T4). Study duration per patient is 29 weeks (a 5-week intervention, followed by a 24-week post-intervention). DiscussionThe study will provide useful information on the short and long term effects of a physiotherapy rehabilitation program based on core stability exercises performed in subacute phase.Trial registrationClinicalTrials.gov Identifier NCT03975985. Data registration June 5th, 2019. Retrospectively registered. Date of registration in primary registry: June 5, 2019. Protocol version 1