The Relationship Between Hand and Wrist Musculoskeletal Disorders and Hand Activity and Posture

Musculoskeletal disorders are common in many industries such as automotive, manufacturing and line assembly. Risk factors include high frequency or hand repetition, long duration of work activities with short rest periods, unsustainable postures which put strain on the body and muscles, and activities that require significant force to fulfill duties. The current ACGIH TLV for hand activity uses hand activity level (HAL) and normalized peak force (NPF) to assess an individual’s risk of developing an MSD. The purpose of this study is to propose the use of Posture as an alternative to NPF and couple it with HAL to assess the risk of an MSD. The data used in this paper come from an automotive study conducted at four automotive manufacturing plants. An estimated 50 interviews were conducted at each of the four plants in an effort to document if any worker had recently experienced an MSD which would then be termed as a case. A case was determined by one of two methods, the first being if the employee visited the plant clinic for pain experienced while on the job, the second occurred through an interview conducted by a USF investigator in which the employee answered yes to having pain or discomfort that interfered with work, play or sleep and there was a treatment-seeking behavior. The analysis revealed HAL and Posture can be used to assess potential MSD development in exposed workers. Logistic regression was conducted, and it showed statistical significance when using HAL and Posture to assess MSDs developing in workers exposed in occupational settings. In place of NPF, Posture can be used with HAL to assess MSDs in occupational settings