Guideline Threshold Limit Values (TLVs) for discomfort in repetitive assembly work

This study focused on two of the main occupational risk factors associated with work-related musculoskeletal disorders in light repetitive electronic assembly work, namely repetition and force. Present-day evaluation techniques are primarily posture based and show low sensitivity with regard to rating repetition and force. A simulated assembly task was conducted to investigate the interactions of risk factors and the suitability of hand activity level (HAL) and TLV values for electronics assembly work. Subjects completed the assembly task for three levels of repetition and force. For each treatment a subjective rating of discomfort was recorded. Repeated measures ANOVA identified repetition and force as highly significant factors in light electronic assembly work (p <.001, p <.05, respectively). The task was also rated using HAL and normalized peak forces (NPF). This study questioned the ability of TLVs in rating discomfort and amendments to the TLVs are suggested.