Study protocol: Acute effects of lower limb strength exercises on gait asymmetry in people with Parkinson’s disease - AsymmGait-Parkinson study

BACKGROUND: Gait asymmetry in individuals with Parkinson's disease (PD) refers to an imbalance in the movement between the left and right sides of the body during walking, which is often associated with disease progression. This asymmetry is associated with more severe gait deficits, such as freezing of gait, falls, and stumbling. Because PD progression is associated with motor asymmetry, it is crucial to address this issue when developing targeted rehabilitation strategies. Physical exercise focused on lower limb strengthening shows promise in reducing gait asymmetry. AIM: The proposed randomized clinical trial will compare the immediate effects of physical exercise focused on the most affected lower limb, the least affected lower limb, and both lower limbs on gait asymmetry in people with PD. METHOD: The study will involve 36 participants with idiopathic PD (Trial registration: Brazilian Clinical Trials Registry RBR-5s234bn). Participants will attend seven laboratory visits, which will include clinical evaluations, strength exercise sessions, and gait assessments conducted at three specific time points: baseline (before the intervention), immediately after the intervention, and 24 hours post-intervention. Each intervention will involve strength exercises specifically targeting the lower limbs, focusing on improving muscle function and addressing gait asymmetry in people with PD. Three acute interventions will be tailored to i) the most affected limb, ii) the least affected limb, and iii) both. Gait assessments using inertial sensors will acquire the spatial-temporal parameters. Surface-electromyography signals from lower-limb muscles as well as prefrontal cortex activity recorded from a portable functional near-infrared spectroscopy will be analyzed. RESULTS AND CONCLUSION: This paper provides a thorough description of a randomized, controlled, cross-over, and single-blind clinical trial. Results can bolster understanding of the immediate impact of targeted strength exercise on gait asymmetry in PD, which can help in developing rehabilitation strategies to improve gait deficits in people with PD.