Effects of Upper Limb Exercise or Training on Hand Dexterity and Function in People With Parkinson Disease: A Systematic Review and Meta-analysis.

OBJECTIVE:This systematic review investigated the effects of exercise and training on hand dexterity and function outcomes in people with Parkinson disease (PD). DATA SOURCES:We searched 5 databases (MEDLINE Ovid, CINAHL, PEDro, PubMed, Cochrane Database) from inception to October 2022. STUDY SELECTION:Included studies were randomized controlled trials delivering upper limb exercise or training interventions to people with PD and evaluating 1 or more upper limb activity outcomes. Two independent reviewers screened 668 articles for inclusion. DATA EXTRACTION:Two reviewers independently extracted data relating to study participants, intervention characteristics, and key outcomes. Cochrane Risk of Bias and GRADE tools assessed methodological quality of included studies, and strength of evidence for 3 outcomes: hand dexterity, self-reported hand function, and handwriting performance. Meta-analyses synthesized results for within-hand dexterity and self-reported function. RESULTS:Eighteen randomized controlled trials (n=704) with low to unclear risk of bias were identified. Experimental interventions varied considerably in their approach and treatment dose, and 3 studies focused on training handwriting. Meta-analysis showed moderate quality evidence of a small positive effect on within-hand dexterity (SMD=0.26; 95% CI 0.07, 0.44). Very low-quality evidence pointed toward a nonsignificant effect on self-reported hand function (SMD=0.67; 95% CI -0.40, 1.75). A narrative review of handwriting interventions showed low quality evidence for improved performance after training. CONCLUSIONS:There is moderate certainty of evidence supporting the use of exercise and training to address dexterity problems, but evidence remains unclear for self-reported hand function and handwriting. Our findings suggest that training could employ task-related approaches. Future research should interrogate aspects of clinical practice such as optimal dose and key ingredients for effective interventions.