Effects of team size on the maximum weight bar lifting strength of military personnel.
Teamwork is an essential element in the majority of critical Army lifting tasks. Therefore, an understanding of the relationship between individual and team lifting capacity is of great tactical importance. Twenty-three male and 17 female U.S. Army soldiers were randomly assigned to single- and mixed-gender teams of two, three, and four persons. Individual lifting strength was the one-repetition-maximum (1RM) load lifted from floor to knuckle height using a weight bar. A square-shaped bar was used for two- and four-person lifting, and a triangular-shaped bar was used for three-person lifting. Team lifting strength as a percentage of the sum of individual lifting strength (%sum) did not change with team size. The %sum for teams of men (87.3%) was less than for teams of women (91.1%, p < 0.05). The %sums for both single-gender teams (all men and all women) were greater (p < 0.01) than for mixed-gender teams (80.2%). The number of people lifting a large object was increased to four with no decrease in the effectiveness of the individual lifter beyond that found for two persons. The 1RM loads presented in this paper were lifted under ideal conditions by young soldiers and do not represent norms for an industrial population.
Sharp
M A
MA
U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts 01760-5007, USA.
Rice
V J
VJ
Nindl
B C
BC
Williamson
T L
TL
D003299:Cooperative Behavior; D006804:Ergonomics; D005260:Female; D006801:Humans; D017770:Lifting; D008297:Male; D008889:Military Personnel; D011187:Posture