Handgrip strength in Parkinson’s disease: A systematic review of observational studies

Abstract

Introduction: People with Parkinson’s disease may present muscle weakness. The handgrip test is used to identify upper limbs strength. There are different protocol descriptions of this assessment. Objective: To carry out a systematic review on the assessment of handgrip strength in people with Parkinson’s. Methods: The review was carried out according to the PRISMA guidelines, the PubMed, SciELO, LILACS and Scopus literary databases, and registered at PROSPERO (CRD420201 9018). Quantitative analysis was performed using the Newcastle-Ottawa Scale. Twenty-seven articles were analyzed. Results: The most referenced protocol is that of the American Society of Hand Therapists. The most used instrument is the hydraulic dynamometer. Of the sixteen studies that compared handgrip strength between people with Parkinson’s and healthy people, seven identified a statistically significant difference. No article was classified as unsatisfactory. Conclusion: It is not possible to affirm that handgrip strength is reduced in Parkinson’s disease, when compared to healthy subjects. Protocol and instrument standardization can help comparisons between results from different studies. There are few longitudinal studies, making it difficult to understand what happens to handgrip strength as the disease progresses.