Work-Related Thumb Pain is a Common Occupational Hazard in Physiotherapists: A Systematic Review and Meta-analysis

Systematic Review

Phys Med Rehabil Int. 2023; 10(1): 1209.

Work-Related Thumb Pain is a Common Occupational Hazard in Physiotherapists: A Systematic Review and Meta-analysis

Keith Shun Kei Tang*; Bobby Ho Yin Chung; Sophia So Wa Ip; Tiffany Ching Man Choi

School of Health Sciences, Caritas Institute of Higher Education, Tseung Kwan O, New Territories, Hong Kong

*Corresponding author: Keith Shun Kei TangSchool of Health Sciences, Caritas Institute of Higher Education, Chui Ling Lane, Tseung Kwan O, New Territories, Hong Kong. Email: shunkei1042@gmail.com

Received: February 15, 2023 Accepted: March 24, 2023 Published: March 31, 2023

Abstract

Questions: Is prevalence of Work-Related Thumb Pain (WRTP) high in Physiotherapists (PTs)? Can any risk factors be identified?

Design: Systematic review with meta-analysis of observational studies.

Participants: Practising registered physiotherapists using manual techniques at work without history of injuries or diseases affecting the thumb.

Intervention: Prevalence of WRTP in PTs and risk factors associated to WRTP.

Outcome measures: Current and lifetime prevalence of WRTP in physiotherapists and risk factors associated with WRTP such as preferred manipulation techniques, occupational factors and demographic factors.

Results: Fourteen studies were identified and included in the analysis of the prevalence of WRTP and risk factors associated with WRTP. The lifetime prevalence, one year prevalence and current prevalence were 57.1%(95% CI=47.4%-66.2%), 38.0%(95% CI=28.7%-48.2%) and 42.4%(95% CI=27.8%-58.5%) respectively. In qualitative evidence synthesis, there was strong qualitative evidence showing that using soft tissue mobilization, working hours on manipulation, workplace experience, age and gender were not risk factors associated with WRTP while qualitative evidence for associations with using general mobilization and joint mobilization, workplace setting, and handedness was conflicting. As there are no studies reporting the association between risk factor of thumb overuse and WRTP, limited evidence is found.

Conclusion: WRTP is a common occupational hazard in PTs. Further studies are warranted to investigate the causes and risk factors of WRTP.

Keywords: Prevalence; Physiotherapist; Risk factors; Work-related thumb pain

Introduction

High Risk of Work-Related Thumb Pain in Physiotherapists

Physiotherapists (PTs) are usually required to perform a number of manual techniques when providing treatments to patients with musculoskeletal problems and these techniques are performed by using their thumbs. There will then be a longitudinal force transmitted through their thumbs to mobilize tissues and manipulate joints of the patients. The anatomical structure of a thumb is weak in with standing biomechanical load and repetitive compression. Therefore, PTs are considered to be under a high risk of Work-Related Thumb Pain (WRTP) [1,2].

Research Gap in the Review of WRTP in PTs

WRTP is a kind of Work-Related Musculoskeletal Disorders (WRMD) that is aggravated or induced by occupational risk factors [3]. There are different studies continuously reporting the prevalence rate of WRTP in PTs these years [4-6]. Nevertheless, there are no systematic reviews and/or meta-analyses providing a summary specifically on the prevalence rate of WRTP. While there are other studies investigating a wide variation of work-related factors associated with WRTP, the quality and result of such studies varied, and no dominant factors could be identified. On the whole, the overall influence of WRTP in PTs remains unclear and further review is necessary.

Occupational Safety and Health of PTs

In clinical practice, WRTP may cause PTs to alter the way they perform manual techniques [7]. This could result in reduced efficiency and effectiveness of manual therapy. Besides, WRTP could be a factor leading practising PTs to leave their working position [8]. Consequently, WRTP negatively affects the welfare of patients and increases costs of social health. To address the problems associated with WRTP, this review provides a more comprehensive investigation on the characteristics of its prevalence and various risk factors associated with WRTP.

The results of this review would contribute to the development of prevention strategies on WRTP and would be beneficial to the occupational safety and health of PTs in the long run. This review aims to systemically appraise published studies which primarily focus on the prevalence and risk factors of WRTP in PTs.

Therefore, the research questions for this study were:

1. Is prevalence of WRTP high in PTs?

2. Can any risk factors be identified?

Method

Identification and Selection of Studies

Search strategy: An extensive literature search was conducted in March 2021 on electronic databases Pubmed, Europepmc, NCBI-NIH and Research Gate by using keywords: “physiotherapist” or “physical therapist” or “manual physiotherapist” AND “work-related thumb disorder” or “work-related thumb pain” or “thumb pain” or “thumb disorder” OR “prevalence” or “trend” OR “risk factors” or factors”. There was no restriction on publication years and types of study in the search. In addition, a manual search on the reference list of the selected studies was also carried out to access potential literature for the review.

Selection criteria: The studies meeting the inclusion criteria were selected for this review. Studies were included if they (1) were observational studies published in English and (2) provided data investigating the prevalence and/or risk factors of WRTP among practising PTs who had no history of injuries and/or diseases affecting their thumbs.

Data which included other types of WRMD and/or data retrieved from PTs applying manipulation and/or grade five mobilization which involved high velocity sudden thrust were excluded (Table 1).

Selection process: The titles and abstracts of all the identified studies were screened by three reviewers independently according to the predetermined eligible criteria. When a study was found to be potentially eligible, reviewers would review the study in full text. If there was disagreement on eligibility, it was resolved by discussion among the three reviewers until consensus was reached.

Assessment of Characteristics of Studies

Quality appraisal: Two critical appraisal tools from Joanna Briggs Institute (JBI) were adopted for the quality appraisal of the selected studies - JBI Critical Appraisal Checklist for Studies Reporting Prevalence Data for studies investigating prevalence of WRTP (Appendix 1) and JBI Critical Appraisal Checklist for Analytic Cross Sectional Studies for studies investigating risk factors related to WRTP (Appendix 2).

This appraisal aimed to assess the methodological quality of a study and determine the extent to which a study has addressed the possibility of bias in its study design, conduction and data analysis. Three independent reviewers assessed the quality of the selected studies. Any disagreement was resolved by discussion until consensus was reached among the three reviewers.

According to the JBI reviewer manual, a decision over the scoring and cut-off point should be agreed by at least two reviewers before the quality assessment of the selected studies was conducted [9]. Therefore, in the current review, the scoring and cut-off point of the two critical appraisal checklists were pre-determined by the three independent reviewers [10].

The available answers to each item in the two checklists included “Yes”, “No” and “Unclear”. It was determined that one score would be given to the answer “Yes” while no score would be given to the answers “No” and “Unclear”. The maximum score of each checklist should be the same as the number of items in that checklist. The overall score of each selected study would be presented in percentage and the quality would be rated as “low” (0-50%), “fair” (51-80%) or “high” (81%-100%). Selected studies investigating the prevalence of WRTP being rated as low quality would be excluded to secure the validity of the included data used for meta-analysis [11].

Data Analysis

Data extraction: Data extraction was carried out by the three reviewers and cross-check was done. Disagreement was resolved by discussion among the reviewers until consensus was reached.

Data for analysis were extracted from the selected studies to two pre-designed tables which included study characteristics (author, year of publication, study design, country, participant condition, sample size, workplace setting, measurement tool used and study focus) and statistical data (prevalence rate, risk factors, level of pain intensity, consequence and treatment of WRTP).

Data Synthesis

Data of prevalence and risk factors of WRTP were synthesized separately according to the following methods.

Prevalence of WRTP: Selected studies investigating the prevalence of WRTP with quality rated as “fair” and “high” were included for meta-analytical prevalence. Other analyzable data including level of pain intensity, consequence and treatment of WRTP were also investigated as the secondary outcome measures.

The meta-analysis was calculated by using the software “Comprehensive meta-analysis”. Data of prevalence of WRTP were first categorized into three subgroups, namely “lifetime prevalence”, “one-year prevalence” and “current prevalence”, which meant the participants had at least experienced one time of thumb pain in a lifetime, the past one year, and at the current time respectively.

Data of the same subgroup were then pooled to calculate the weighted prevalence rate across studies with 95% CI presented. The data for the secondary outcomes were also weighted. Heterogeneity among studies was determined by the Cochran's Q test and I² index. If there was heterogeneity, the random-effect model was adopted. The significant level was set at p<0.05.

Risk factors associated with WRTP: The number of studies evaluating risk factors associated with WRTP was counted. The strength of evidence of the selected studies reporting significant and non-significant associations between WRTP and different risk factors were assessed respectively. The strength of evidence was pre-determined according to the evidence assessment criteria as set out in Table 2 [12,13].