A randomised controlled trial evaluating the effects of two workstation interventions on upper body pain and incident musculoskeletal disorders among computer operators

Abstract

Background: Call centre work with computers is associated with increased rates of upper body pain and musculoskeletal disorders. Methods: This one year, randomised controlled intervention trial evaluated the effects of a wide forearm support surface and a trackball on upper body pain severity and incident musculoskeletal disorders among 182 call centre operators at a large healthcare company. Participants were randomised to receive (1) ergonomics training only, (2) training plus a trackball, (3) training plus a forearm support, or (4) training plus a trackball and forearm support. Outcome measures were weekly pain severity scores and diagnosis of incident musculoskeletal disorder in the upper extremities or the neck/shoulder region based on physical examination performed by a physician blinded to intervention. Analyses using Cox proportional hazard models and linear regression models adjusted for demographic factors, baseline pain levels, and psychosocial job factors. Results: Post-intervention, 63 participants were diagnosed with one or more incident musculoskeletal disorders. Hazard rate ratios showed a protective effect of the armboard for neck/shoulder disorders (HR = 0.49, 95% CI 0.24 to 0.97) after adjusting for baseline pain levels and demographic and psychosocial factors. The armboard also significantly reduced neck/shoulder pain (p = 0.01) and right upper extremity pain (p = 0.002) in comparison to the control group. A return-on-investment model predicted a full return of armboard and installation costs within 10.6 months. Conclusion: Providing a large forearm support combined with ergonomic training is an effective intervention to prevent upper body musculoskeletal disorders and reduce upper body pain associated with computer work among call centre employees.

Risk Factors for Upper Extremity Musculoskeletal Symptoms among Call Center Employees

“…In particular, lack of forearm support has been consistently associated with an increased risk of symptoms in the elbow-wrist/hand region, apparently because of an increase in ulnar deviation of the wrist, which is a known risk factor for hand/wrist disorders 30) .…”

The impact of computer display height and desk design on muscle activity during information technology work by young adults

“…Monitoring posture and muscle activity over a number of weeks would be required to determine if the effect observed in this study was only transient. The randomised and controlled trial in call centres by Rempel et al (2006) provides the best evidence on the efficacy of forearm support to reduce neck/ shoulder musculoskeletal disorders. They reported a 50% reduction in diagnosed neck/shoulder incidents over 12 months when using a forearm support, though no change in the risk for right upper limb disorders was found.…”

Effort–reward imbalance and one-year change in neck–shoulder and upper extremity pain among call center computer operators

“…The association of carpal tunnel syndrome with keyboard use is weak, but there is some evidence of increased risk with increasing hours of computer mouse use (31,32). A randomized controlled study of ergonomic workplace interventions showed a protective effect of forearm support boards for neck-shoulder disorders and a reduction of neck-shoulder and right upper-extremity pain in call center employees after control for psychosocial job factors, individual worker characteristics, medical history, and other confounding factors (33).…”

“…This was a one-year prospective study of ERI and upper-body musculoskeletal pain among 165 call center operators who participated in a randomized ergonomic intervention trial with four treatment channels described previously (33). Employees at two customer service center sites of a large health maintenance organization (H�O) in California were eligible for participation if they performed computer-based customer service work for ≥20 hours per week and did not have an active workers' compensation claim involving the neck, shoulders, or upper extremities.…”