Effects of a Multicomponent Protocol With Emphasis on Muscle Power Training on Bradykinesia in Individuals With Parkinson's Disease

Parkinson\'s disease (PD) is a chronic progressive neurological disorder that involves both motor and non-motor symptoms, culminating in functional decline and disability. One of the main symptoms of PD is bradykinesia and its deleterious effect on functionality. Muscle weakness has also been reported as an important symptom of PD, and muscle power may be even more affected and related to these symptoms. Typical conventional physical therapy treatment includes mobility exercises, strength training, gait training, and balance training, and it presents numerous benefits associated with the reduction of motor symptoms of PD. Physical therapy with power training has also been studied as an alternative to improve the ability to perform activities of daily living in other populations. However, the literature that includes power training in physiotherapeutic approaches for people with PD is scarce. Power training may minimize the problems arising from changes in motor function in older adults with PD; however, there is still a lack of evidence using this modality in the different subtypes of the disease. Knowing that motor function is associated with functional capacity and disease severity, physical therapy becomes an important treatment resource with exercises to improve muscle power. Therefore, the objective of this study is to investigate the effect of a multicomponent protocol with an emphasis on muscle power training concerning bradykinesia in individuals with rigid-akinetic type PD. A Randomized Clinical Trial will be conducted, in which individuals diagnosed with Parkinson\'s disease, rigid-akinetic type, classified from 1 to 3 on the Hoehn and Yahr Scale, aged between 50 and 85 years, and who sign the Informed Consent Form will participate. The individuals will be randomized into two treatment groups: G1 - traditional multicomponent training, and G2 - multicomponent training with an emphasis on muscle power. Assessments will be conducted at four time points for all participants: before (T0), during (T1 - 6 weeks), immediately after intervention (T3 - 12 weeks), and follow-up (T4 - 16 weeks). The assessments will consist of the analysis of: 1) motor function through the adapted Unified Parkinson\'s Disease Rating Scale (UPDRS III) (bradykinesia as the primary outcome); 2) mobility of the posterior chain of the trunk and lower limbs using the Wells Bench; 3) body composition by Dual-Energy X-ray Absorptiometry (DXA); 4) rigidity of the leg extensor muscles assessed by ultrasound elastography; 5) muscle power of knee extensors using a linear potentiometer (Peak Power, CEFISE); 6) functional capacity through the Vertical Jump - CMJ and the Sit-to-Stand Five Times Test (TSLCV); and 7) postural assessment using the NeuroPostureApp. Treatment sessions will occur twice a week for 12 weeks, lasting 60 minutes each, totaling 24 sessions for each intervention. Group 1 will perform an exercise protocol that includes warm-up, mobility, muscle strength, and flexibility. Group 2 will perform the same exercise protocol, with the caveat that, whenever feasible, exercises will be executed in the muscle power modality (at the highest possible speed). This latter training is characterized by a lower number of repetitions and a higher movement speed, guided by the therapists assisting. The progression of muscle power exercises will occur at 35%, 40%, 45%, 50%, 55%, and 60% of 1RM over the 12 weeks, distributed in 2 sets of 6 to 8 repetitions, with rest times of 60 to 120 seconds.