A Parkinson’s Disease Handwriting Rehabilitation Kit—A Forensic Exploratory Study ^†

Abstract

Legal documents signed by individuals with Parkinson’s disease are often disputed due to inconsistencies in their signatures when compared to those executed prior to the disease. This exploratory study aims to develop a handwriting rehabilitation kit designed to improve fine motor skills in the elderly diagnosed with Parkinson’s disease. This study involved ten subjects with a diagnosis of Parkinson’s disease, four of whom participated in the rehabilitation program and used the kit, while the remaining six were assigned to the control group. All participants underwent traditional rehabilitation and clinical evaluation before and after the twelve-week intervention, as well as satisfaction questionnaires following the intervention. The main changes observed in the intervention group indicated progress, including a reduction in tremor and bradykinesia. The potential clinical and handwriting benefits, as well as the positive feedback and program adherence from participants, support the development of a user-friendly kit for this subset of the elderly population.

1. Introduction

Graphoscopy is a branch of forensic science that involves the study and analysis of handwriting and provision of scientific forensic reports in legal proceedings [1]. In this context, alterations resulting from neurodegenerative diseases such as Parkinson’s disease (PD), which affect motor skills (rigidity, bradykinesia and tremor), can compromise handwriting performance [2]. Evidence suggests that physiotherapy and physical exercise programs can promote the recovery of motor skills, while occupational therapy can facilitate the recovery of handwriting, which in turn can contribute to improvement in instrumental activities of daily living (IADLs) [3,4]. This work aims to develop an at-home self-administered handwriting rehabilitation eco-kit (from disposable clinical materials with recycling potential) designed to improve fine motor skills in the elderly.

2. Materials and Methods

The kit, presented in Figure 1, was created to facilitate at-home self-administration of occupational therapy exercises and improve adherence to the rehabilitation program (RP). The kit consists of 1 ping-pong ball, 1 anti-stress ball, 1 plastic coin, 2 rubber bands, 2 beans and 10 paper clips, along with a registration handbook for handwriting occupational therapy exercises (H2OTEs), which enabled patients to follow the program and perform fine motor exercises (hand manipulation, finger isolation, finger flexion and extension and coordination).

The procedures implemented in this exploratory study, involving 10 subjects recruited through Clínica de Fisioterapia Egas Moniz at Monte da Caparica, were subject to registration in clinicaltrials.gov (NCT06693401), scientific approval (Egas Moniz Scientific Council) and ethical approval (EM Ethics Committee: protocol code 1171/2023), in accordance with the Declaration of Helsinki (Declaration of 1975, revised in 2000).

The participants were allocated to the control group (CG) or the intervention group (IG) and all of them underwent the traditional physiotherapy rehabilitation program (TPRP) (practice for 1 h, twice a week), which was implemented according to the European Physiotherapy Guideline for Parkinson’s Disease [5,6]. The IG also underwent the occupational therapy rehabilitation program (OTRP), which was implemented through workbooks, practiced for 30 min, three times a week [7], and the motor tasks, adapted from Aragon & Kings [8], consisted of performing, 2–3 times a week, exercises included in a workbook (drawing the upper- and lower-case letters of the alphabet guided by dotted lines, writing a sentence with and without spatial limits) and performing 4 groups of fine motor tasks: hand manipulation (2 exercises: (a) hold a dry bean in the palm of the hand, move it to the fingertips and back to the palm of the hand; (b) hold a ping-pong ball in the hand and turn it clockwise and anticlockwise); finger isolation (3 exercises: (a) place the palm and fingers on a table, lift one finger at a time and repeat with all fingers; (b) make an “O” by touching each finger with the thumb; (c) pick up a coin from the table using the thumb and another finger to pinch it, and repeat using each finger); finger flexion and extension (2 exercises: (a) squeeze and release an anti-stress ball; (b) put a rubber band around two fingers at a time and stretch it out); and coordination (1 exercise: make and unmake a chain with 10 clips). All exercises were performed 10 times, in triplicate, for each hand.

The clinical evaluation was performed through the official Portuguese Translation of Movement Disorder Society Unified Parkinson Disease Rating Scale (MDS-UPDRS), which comprises four distinct sections, namely Part I (non-motor aspects of daily life), Part II (motor aspects of daily life), Part III (motor assessment) and Part IV (motor complications) [9]. In this study, the following subgroups were considered: writing (item 2.7); bradykinesia (items 3.4, 3.5 and 3.6) and tremor (items 3.15, 3.16 and 3.17).

To analyze the effect of using the rehabilitation kit in addition to physical therapy on the MDS-UPDRS scores for bradykinesia and tremor, a linear mixed-effects model was developed using the lmerTest v.3.1-3 library for R. The model incorporated a fixed effect for time and group and a random intercept for subjects to account for repeated measures. The assumptions of normality and homoscedasticity of the residuals were evaluated through visual inspection of the residual plot, residual quantile–quantile plot and residual histogram, which was performed using the ggResidPanel v.0.3.0 library for R. Planned contrasts were subsequently performed to evaluate differences to compare scores between T0 and T1 for each group, and for the slope T0, T1 between groups. These comparisons were performed using the package emmeans v.1.8.7 for R, using the Kenward–Roger method to adjust the degrees of freedom and Sidak p-value correction for multiple comparisons.

Adherence to the study was monitored, with records of each assessment at each weekly follow-up visit. The workbooks subjectively assessed performance through a questionnaire after each exercise, in which participants indicated whether they performed the exercises wholly or partially, and all the information was digitally registered.

3. Results

The 10 participants recruited for this study were assigned to the IG and CG while ensuring homogeneity between the two groups, concerning the number of participants, level of education, gender, ethnicity, age, years of PD and other diagnosed pathologies. The main constraint is the limited number of participants, which significantly influences the disparities between initial scores and the values of both intergroup and intragroup interventions. However, despite this constraint, the results presented in

Table 1. MDS-UPDRS scores for bradykinesia and tremor across two assessment moments (t0, t1) and study groups.

	CG		IG
	t0	t1	t0	t1
Bradykinesia	11.2 (±4.40)	10.3 (±3.67)	11.3 (±4.50)	4.00 (±2.94)
Tremor	2.83 (±3.13)	2.83 (±1.72)	2.25 (±2.63)	1.25 (±1.26)

show that, for the CG MDS-UPDRS scores, there were no significant differences between t0 and t1 for bradykinesia (t(8) = −0.942, p = 0.755) as well for tremors (t(8) = 0.000, p = 1.000), while for the IG, there were significant differences between t0 and t1 for bradykinesia (t(8) = −6.690, p < 0.001) but not for tremors (t(8) = −1.069, p = 0.680). However, there is an observable decrease in tremors in the IG, which is not observed for the CG. In addition, there was a significant difference between the slope (t0-t1) of both groups for bradykinesia (t(8) = −4.586, p = 0.005) but not for tremors (t(8) = −0.828, p = 0.816).

Concerning adherence and compliance to the study, participants remained engaged for approximately 90.2 days throughout the study and most exercises were completed to a high degree, particularly in categories such as “Hand manipulation,” “Finger isolation,” “Finger flexion and extension,” and “Coordination”, as shown in

Table 2. Completeness of exercise performance in IG.

Exercise	Completely	Partially	Not Done
Hand manipulation	67.1%	21.1%	11.8%
Finger isolation	86.7%	13.1%	0.2%
Finger flexion and extension	72.5%	26.8%	0.7%
Coordination	97.9%	0.0%	2.1%
Handwriting	96.4%	3.3%	0.2%

.

4. Conclusions

These preliminary results indicate that individuals with Parkinson’s disease who participate in a handwriting rehabilitation program can improve their graphomotor skills, which may aid in recovering their handwriting abilities. Moreover, performing the exercises included in the developed kit results in a significant decrease in bradykinesia and a visible decrease in tremors compared to physiotherapy alone. However, future studies should include a larger sample size to confirm these findings and to better understand the variability in handwriting among people with Parkinson’s disease. In addition, based on the potentially beneficial clinical results and the qualitative feedback from the participants’ satisfaction questionnaires, which revealed a high level of adherence and satisfaction, it is intended to improve the current kit using a sustainable approach by utilizing disposable hospital waste, converting it into an eco-friendly kit before its future clinical implementation. According to the clinic staff, the most commonly discarded items are disposable bibs, face masks, rubber gloves and surgical sleeves, which, after decontamination and recycling programs, will be explored for conversion into 3D printing filament and production of several kit components.