The effects of customized orthopedic insoles on sickness absence and productivity among industrial employees

Abstract

Musculoskeletal disorders are a leading cause of sickness absence and reduced productivity in industrial occupations, prompting widespread adoption of workplace health interventions. Individually customized orthopedic insoles (ICOIs) have become a recommended ergonomic solution to enhance comfort, mitigate biomechanical stress, and potentially reduce work-related disability. However, their actual impact on core organizational outcomes remains debated. This systematic review synthesized findings from 74 published studies to assess the effectiveness of ICOIs on sickness absence, productivity, and implementation in industrial employees.

A comprehensive literature search was retrospectively conducted across major databases, encompassing randomized controlled trials, cohort studies, clinical interventions, and systematic reviews addressing ICOIs or comparable interventions in occupational contexts. Studies varied broadly in design, population, intervention protocols, outcome definitions, and analytical rigor. The methodological quality of included studies was assessed using design-appropriate bias criteria. Heterogeneity of outcome measures and reporting methods precluded meta-analysis; thus, results were narratively synthesized across key outcomes.

The review found that ICOIs consistently provided subjective benefits such as improved physical comfort, pain reduction, and enhanced foot alignment. These advantages, though valued by workers and employers alike, did not translate into a concomitant reduction in sickness absence or a robust improvement in objective productivity measures. Only a minority of studies directly measured absenteeism or reported quantifiable organizational gains; most results were confounded by co-interventions, short follow-up periods, and inconsistent outcome reporting. Evidence comparing ICOIs to prefabricated or standard insoles showed negligible differences in absenteeism or work performance, although individual comfort and user satisfaction were often higher with customized devices. Adherence challenges, compatibility with safety footwear, and resource constraints were frequently cited as practical barriers to sustained effectiveness.

The current evidence does not support the use of ICOIs as standalone interventions for improving attendance or productivity in industrial workplaces. Instead, their value is maximized when integrated into broader ergonomic or occupational health strategies. Decision-makers should remain cautious, prioritizing multi-component interventions and considering cost-effectiveness, particularly given the comparable effectiveness of high-quality prefabricated insoles in many cases.

Major gaps persist, notably the lack of standardized outcome definitions for absenteeism and productivity, insufficient longitudinal real-world studies, and limited cost-effectiveness analyses. Future research should address these limitations to clarify under which conditions ICOIs yield clear, sustainable occupational benefits.