The effects of gender, team size, and a shoulder harness on a stretcher-carry task and post-carry performance. Part II. A mass-casualty simulation

Abstract

This study examined repeated, short-distance stretcher carries and the effects of gender, a shoulder harness, and team size on simulated transportation, defense, and medical treatment of patients. Participants carried a 6.8-kg stretcher, loaded with an 81.6-kg manikin, for a distance of 50 m, lifted it onto a simulated ambulance, and returned 50 m to retrieve the next patient. Participants completed as many cycles as possible in 15 min. Dependent measures included number of carries, weapon firing, fine-motor coordination, heart rate, perceived exertion, and physical symptoms. Analysis of variance and post-hoc Newman-Keuls comparison of means revealed that men completed more carries than women (18.0 ± 1.6 vs. 14.5 ± 2.0 carries, p < 0.001), and women reported more upper extremity discomfort ( p < 0.05). Harness use resulted in slightly faster fine-motor performance (46.1 ± 8.3 vs. 47.6 ± 7.7 s; p = 0.03) and less discomfort in the upper extremities ( p < 0.05) than hand carries. Four-person teams resulted in reduced discomfort in the neck and upper extremity ( p < 0.05) and improved post-carry fine-motor coordination (47.6 ± 8.3 vs. 46.0 ± 7.7 s; p = 0.02), as well as increasing weapon firing accuracy for women ( p < 0.05). Four-person hand-carry teams completed more carries than any other team-size × harness combination ( p < 0.01). For mass-casualty scenarios, four-person teams are recommended. A harness system should be available for two-person and female teams.