Applied Ergonomics 38 (2007) 581–589 Designing ergonomic interventions for emergency medical services workers—part III: Bed to stairchair transfers Steven A. Lavender a,c,Ã , Karen M. Conrad b , Paul A. Reichelt b , Aniruddha K. Kohok a , Jessica Gacki-Smith b a Department of Industrial Welding and Systems Engineering, The Ohio State University, 1971 Neil Avenue, Room 210, Columbus, OH 43210, USA b School of Public Health, University of Illinois at Chicago, Chicago, IL, USA c Department of Orthopaedics, The Ohio State University, Columbus, OH, USA Received 10 February 2006; accepted 4 August 2006 Abstract The objective of the current work was to test interventions aimed at reducing the low-back musculoskeletal loads experienced by firefighters/paramedics (FFPs) providing emergency medical services (EMS) that involve transferring a patient between a bed and a stairchair. The interventions, developed or selected using focus groups, were a prototype Drew People Mover TM , and a Transfer Sling. These interventions changed the coupling between the EMS worker and the patient. They were compared with an under-axilla lift. Eleven FFP teams transferred a 75 kg dummy between a bed and a stairchair. Both interventions were tested using two-person transfers. In addition, the Transfer Sling was tested using a one-person transfer. Surface electromyographic (EMG) data were collected from 8 trunk muscles from each participant along with spine kinematic data. Additionally, ground reaction force data obtained from two forceplates were acquired for one member of each FFP team that was used to estimate directional spine moments using a 3D linked-segment model. In the two-person transfers, there was 191 less trunk flexion (p ¼ 0.002) for the FFP on the patient’s left side and a trend towards less motion for the FFP on the patient’s right side (p ¼ 0.079) when using the interventions. Both FFPs showed reductions in the ipsilateral Erector Spinae activity using the Drew People Mover and the Transfer Sling that averaged approximately 9% MVC, which corresponds to a 21% decrease in the muscle activation levels. While the overall EMG was greater when performing a single-FFP transfer, the Transfer Sling reduced the bilateral Erector Spinae activity by approximately 20%. During the two-person transfers, the FFP on the forceplate to the right side of the patient showed a reduction in the forward bending moment using the Drew People Mover relative to the Sling and under-axilla conditions. During the single-person transfers, only the twisting moment was significantly reduced through use of the Transfer Sling. These objective measures, when combined with the subjective ratings of perceived exertion and the verbal feedback lead us to recommend the use of these interventions for bed to stairchair transfers. r 2006 Elsevier Ltd. All rights reserved. Keywords: Low-back disorders; Emergency medical services; Intervention; Firefighter; Back pain 1. Introduction Musculoskeletal injuries consistently account for about half of all injuries to firefighters/paramedics (FFPs) engaged in emergency medical service (EMS) operations as well as to EMS workers in the private sector (Karter and Molis, 2004; Reichard and Jackson, 2004). These injuries result in lost work time, permanent disability, and high worker compensation costs (Karter and Molis, 2004; Walton et al., 2003). In a recent analysis of 1343 firefighter worker compensation claims, the per-claim average work- er’s compensation cost for sprain/strain injuries was over 50% greater than for claims overall (Walton et al., 2003). The back was the primary body part affected. As the prevalence of obesity in the general population increases (CDC, NCHS, 2004), so does the risk for injury to the EMS workers who are responsible for transporting these heavier patients. Many EMS runs begin with a seated patient being transferred from the bed to a stairchair for ARTICLE IN PRESS www.elsevier.com/locate/apergo 0003-6870/$ - see front matter r 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.apergo.2006.08.002 Ã Corresponding author. Tel.: +1 614 292 9980; fax: +1 614 292 7852. E-mail address: lavender.1@osu.edu (S.A. Lavender).