Begreppsvaliditet för OMNI Hand Effort Scale och Borg CR-10 vid handintensivt arbete. En granskning av sambanden mellan subjektiva skattningar och objektiv greppkraft hos vuxna.

Perceived effort scales are an important part of assessing risks at work, specifically the risks of developing Musculoskeletal Disorders (MSDs) including repetitive strain injuries like carpal tunnel syndrome or epicondylitis. MSDs are still a significant global health issue and are the most common work-related disorders. The upper extremities and neck are particularly exposed as they represent the majority of all MSDs reported within the EU. There is a growing need for assessment tools that can assess multiple tasks while considering the cumulative effects. The Distal Upper Extremity Tool (DUET) offers a promising approach to address this gap. However, the current method to measure perceived effort within the tool, OMNI-RES, lacks specificity and relevance when evaluating hand and forearm exertion, highlighting the need for a specifically designed and targeted rating of perceived effort scale. This thesis evaluates the construct validity of the well-known Borg CR-10 and a newly developed OMNI-Hand Effort Scale (OMNI-HES) that are developed to assess perceived hand and forearm effort. The thesis investigates the relationship between the subjective ratings on both scales and the objective grip force (N) with a force gauge among adults. In addition, the thesis outlines how repeated measurement impacts the precision of both scales with the aim of providing recommendations on sample size and improving MSD risk assessments in the upper extremities. The findings support the construct validity of the newly developed OMNI-HES scale and Borg CR-10, and provides insights on sample size considerations for future ergonomic assessments.