# Manual Dexterity Rehabilitation in Parkinson’s Disease and Paranoid Schizophrenia: A Controlled Study

## TL;DR

A structured rehabilitation program improved manual dexterity in Parkinson's disease and paranoid schizophrenia patients compared to standard therapy.

## Contribution

A structured, progressive physiotherapy program with targeted manual dexterity training was shown to significantly improve upper limb function in PD and PS patients.

## Key findings

- The experimental group showed significant improvements in thumb opposition and psychomotor processing speed.
- Large to very large effect sizes were observed for unilateral and bilateral fine motor performance improvements.
- No significant improvements were found in complex sequential assembly tasks between groups.

## Abstract

Background: Manual dexterity (MD) impairment is a frequent and disabling feature in patients with Parkinson’s disease (PD) and paranoid schizophrenia (PS), significantly affecting functional independence and activities of daily living. However, rehabilitation strategies specifically targeting fine motor control remain insufficiently integrated into routine physiotherapy (PT). Objective: This study investigated the effects of a structured, progressive PT program incorporating targeted MD training on upper limb function in patients with PD and PS. Methods: A prospective, exploratory, interventional study was conducted in 30 patients, allocated to either an experimental group (EG, n = 20) or a control group (CG, n = 10). Participants had PD (Hoehn and Yahr stages II–III) or chronic, clinically stable PS. MD was assessed using the Purdue Pegboard Test, Coin Rotation Task, and Kapandji opposition score. The EG completed a four-phase, 40-week dexterity-oriented rehabilitation program, while the CG received standard disease-specific PT. Between-group differences in change scores were analyzed using one-way ANOVA. Results: The EG showed significantly greater improvements than the CG in thumb opposition, psychomotor processing speed, and unilateral and bilateral fine motor performance (p < 0.001 for all), with large to very large effect sizes (η2 = 0.45–0.76). No significant between-group differences were observed for complex sequential assembly tasks. Conclusions: Integrating targeted MD training into structured PT programs significantly improves fine motor performance in patients with PD and PS, supporting its inclusion in rehabilitation protocols for residential and outpatient care settings.