Title : From symptoms to capacity: Digital screening identifies at-risk workers before pain develops
Abstract:
Background and Purpose: Musculoskeletal disorders affect 1.71 billion people globally and represent the leading cause of workplace disability. A critical challenge in rehabilitation is that functional decline begins years before employees develop pain severe enough to seek care. Traditional MSK screening relies on symptom-based questionnaires or requires specialist assessment, limiting scalability for preventive rehabilitation programmes. We validated a digital four-domain MSK screening tool designed to identify at-risk workers based on functional capacity rather than pain perception, enabling early intervention before clinical deterioration.
Methods: We conducted a retrospective validation study analysing 243 working adults (mean age 42.4 years, 58% female) who completed digital MSK assessments through workplace wellness programmes. The assessment comprises four evidence-based functional domains (strength, balance, flexibility, dynamic posture) delivered via self-administered web interface without professional supervision.
Using rigorous known-groups validation methodology, we compared high-activity (≥3 sessions/week vigorous exercise, n=61) versus low-activity individuals (≤1 session/week, n=37), and pain-free (n=35) versus moderate-severe pain groups (≥4/10, n=66). Statistical analyses included Mann-Whitney U tests, Cohen's d effect size calculations, and Youden's Index optimisation. We examined which factors best predict functional capacity: modifiable activity levels or existing pain symptoms.
Results: Among 143 participants completing all domains, physical activity level emerged as the primary determinant of musculoskeletal function. High-activity individuals scored 12.35 points higher than low-activity individuals (76.5 vs 64.1, p<0.001, Cohen's d=0.889, large effect). This substantially exceeded pain effects (d=0.447), demonstrating the tool captures functional capacity rather than symptom perception. Activity benefits persisted across the lifespan with consistent large effects in younger adults aged 20-39 (d=0.824) and middle-aged adults 40-59 (d=0.926).
Critically, employees with low activity levels but minimal current pain represent an overlooked risk group. These individuals demonstrated significantly impaired function compared to active peers, yet traditional symptom-based screening would miss them entirely. This is the precise intervention window where preventive rehabilitation can be most effective. Cut-point analysis identified score <67 as optimal for risk stratification, demonstrating excellent specificity (93.8%), acceptable sensitivity (73.7%), and strong discrimination (OR=42.0,p=0.0001). Employees scoring below this threshold have 42-fold increased odds of MSK dysfunction.
An unexpected finding revealed gender-specific pain-function relationships: pain substantially impaired male function (11.42-point reduction, p=0.035, d=0.700) but had negligible effect on females (1.21-point reduction, p=0.664, d=0.085).
Clinical Significance: This research supports a fundamental paradigm shift in workplace MSK screening from reactive symptom management to proactive capacity assessment. The tool enables rehabilitation professionals to identify at-risk employees before they develop pain, when interventions are most effective. Physical activity emerges as a stronger, more modifiable determinant than pain status, indicating rehabilitation programmes should prioritise activity-based interventions for primary prevention. The digital format enables scalable implementation across distributed workforces without requiring specialist resources, addressing a critical barrier to preventive rehabilitation
Conclusions: Digital functional screening successfully identifies workers at elevated MSK risk before pain develops, enabling early rehabilitation intervention. Activity level proves to be the strongest predictor of musculoskeletal capacity, validating capacity-focused rather than symptom-focused screening approaches for workplace prevention programmes.
