Prolonged trapezing during sailing often results in low back pain among elite sailors. Modifications of the trapeze harness have been proposed as one approach to ameliorating this problem. To evaluate six harnesses incorporating novel features that had tested well during pilot work, myoelectric activity was monitored at C5, T6, and L5 levels of sacrospinalis and at an abdominal site while five elite sailors wore the harnesses. Integrated EMG (IEMG) values were stored by a microcomputer at periodic intervals during each 10-min trial, as each subject maintained a static horizontal trapezing position in the laboratory. Factorial repeated-measures ANOVA indicated no change in IEMG values over time, but significant (p<0.001) differences among harnesses at all four electrode sites. Features of trapeze harness design that appear to minimize muscular tension include heavy, rigid padding throughout the harness, full-length shoulder-to-buttocks support of the trunk, and adjustable leg strap supports as opposed to a crotch strap.
Susan J. Hall is with the Department of Kinesiology and Physical Education, California State University, Northridge, Northridge, CA 91330. Jane A. Kent is with the U.S. Yachting Racing Union, Newport, RI 02840. Vern R. Dickinson is with the Department of Physical Education, Oregon State University, Corvallis, OR 97331.