The Effect of Physical Load and Environment on Soldier Performance

A study was conducted to characterize the interaction between physical load and environment on dismounted Soldier performance in navigation and auditory vigilance tasks. Three issues were explored: the effect of a 24-kg physical load on performance, the effect of real and virtual environments on performance, and the potential of radio check response time, duration, and accuracy as measures of cognitive performance. Handheld paper maps were used to navigate through four different environments: a warehouse site with no load carried, a warehouse site while wearing a 24-kg (53-lb) load, a virtual warehouse environment shown on a computer monitor, and a virtual warehouse environment shown on a CAVE display, all while listening and responding to radio checks. Results indicate that physical load and environment affect navigation and radio check task performance. Carrying a load increased navigation time but decreased radio check response time. Navigation times were longer in the virtual environments than in the Warehouse Without Load condition, and more navigation errors occurred in the virtual than in both real environments. Radio check response duration was longer in the CAVE than the other environments. The results also indicate that the radio check task can be a meaningful metric of cognitive performance. The original document contains color images.