Effects of transcranial direct current stimulation (tDCS) for delayed-onset muscle soreness after resistance training. Protocol for a randomized clinical trial.
Transcranial Direct Current Stimulation, Musculoskeletal Pain, Motor Cortex.
The discomfort described as fatigue and pain after exercise known as late onset muscle pain (DOMS) is characterized by allodynia in skeletal muscles. Suggests to minimize the DOMS non-medical therapies such as Transcranial Direct Current Stimulation (tDCS), a complementary, non-invasive approach of easy use and low cost that applied on the area of the primary motor cortex (M1) modulates the functional connectivity of sensory networks. OBJECTIVE: To develop a protocol of a randomized controlled trial to evaluate the effects of the application of tDCS on late muscle pain in 24, 48 and 72 hours after a protocol of muscle damage induced by resistance exercise. METHODS: The study describes a randomized, controlled, double-blind two-arm clinical trial protocol following the recommendations of CONSORT/2010. The study will have 6 stages: initial assessment, application of five consecutive sessions of tDCS (second to sixth) blindly, then a protocol for induction of late onset muscle pain and evaluation of pain and functionality soon after application of the protocol; and functionality with 24 and 48 and 72 hours after the DOMS induction protocol. With this the total time of participation and monitoring in the research, will be 2 weeks. Muscle pain, assessed by EVA/END, will be the primary outcome of the study. The secondary outcomes evaluated will be the elbow joint amplitude for flexion and extension, muscle performance and muscle power, evaluated by the Isokinetic Dynamometer. The effects of stimulation shall be calculated using a model of analysis of variance (ANOVA). EXPECTED RESULTS: If the study presents positive results regarding the improvement of muscle strength and delayed muscle pain, this protocol can be implemented in the clinical routine in order to reduce the negative effects of strength exercise, such as fatigue and pain.