BACKGROUND: Healthcare workers are among the most injured workers in the United States. This is due to the high rate of patient handling. The low back is the most injured in this population. This study observed biomechanical factors and how these factors affect low back and ground reaction forces. This study further investigated pain and its relationship to low back force, multifidus cross-sectional area, and multifidus activation in healthcare workers. METHODS: The 45 participants included 10 healthy subjects in the preliminary study and 35 active healthcare workers in the main study. Subjects filled out the VAS to determine current pain level. Ultrasound images of the multifidus muscles were taken. The participants were fitted with reflective markers and surface EMG sensors. A series of patient transfers at various bed heights using three different transfer devices was undertaken. The transfer devices included a Cotton sheet, a Skil-Care™ Transfer Sling, and an AirPal® device. RESULTS: There was a downward trend in resultant low back force when comparing lower bed heights to higher. Therefore, the highest bed position was determined to be optimal. There were significant differences in low back force between self-chosen and optimal bed heights among healthcare workers. There was no significant difference between peak low back or ground reaction forces between pain and nonpain groups. There was a significant difference in multifidus cross-sectional area between these groups at S1, a trend toward significance at L5, and no difference at L4. There was a trend toward significance when comparing multifidus activation between these groups as recorded by surface EMG. CONCLUSIONS: Healthcare workers should choose higher bed heights and appropriate equipment to reduce low back force and those who have smaller multifidus have more pain.



College and Department

Life Sciences; Exercise Sciences



Date Submitted


Document Type





sheets, nurse, posture, body mechanics, multifidus, patient handling



Included in

Life Sciences Commons