Postural sway measurements: a potential safety monitoring technique for workers wearing personal protective equipment.
Kincl LD; Bhattacharya A; Succop PA; Clark CS
Appl Occup Environ Hyg 2002 Apr; 17(4):256-266
This study investigated the use of postural sway measurements as a potential safety monitoring technique. Sixteen healthy male volunteers (age: 41.8 +/- 9.3 years) participated in this study. The level of neurophysiological strain and the ability to maintain upright balance for workers wearing personal protective equipment (PPE) were investigated. Three levels of PPE, the United States Environmental Protection Agency (USEPA)-defined levels A, B, and C, were worn in random order while performing two randomly ordered tasks, resting and a workload. After the workload task, the perceived exertion and discomfort were recorded. Postural sway, measured using a microprocessor-based force platform system, was assessed after each task. The variables of sway area and sway length were calculated from stabilograms. These measurements were taken for three sway tests: 1) Eyes open (EO), 2) Eyes closed on a four-inch foam (FC), and 3) a dynamic test with the subject reaching for a weight placed in front, lifting it to his chest, and lowering back to the shelf four times (RE). The heart rate was significantly higher for the workload task (p < 0.05), and the levels A and B PPE demonstrated significantly higher perceived exertion results than level CPPE (p<0.05). The heart rate and perceived exertion were not significantly correlated with the sway measurements. Level A produced significant self-reported discomfort results for the upper back, lower back, and thighs. The sway variables showed significant differences with the PPE levels and the task. The workload task produced significantly higher sway length than the resting task (p < 0.05) for all test conditions. The PPE level B produced significantly higher sway length than PPE level A (p < 0.05) in the FC test condition. These results indicate that postural stability is altered with PPE use and with fatigued postural muscles. In summary, postural sway measurements may be used as a potential safety monitoring technique.
Posture; Ergonomics; Motion studies; Musculoskeletal system; Age groups; Men; Workers; Measurement equipment; Biomechanics; Personal protective equipment; Safety monitoring; Monitoring systems; Neurophysiological effects; Task performance; Neuromuscular function; Physiological effects; Heart rate;
Author Keywords: Personal Protective Equipment; Postural Sway Measurements; Safety Monitoring Technique
Laurel D. Kincl, Department of Environmental Health, College of Medicine, University of Cincinnati, Cincinnati, OH 45267-0056
Applied Occupational and Environmental Hygiene
University of Cincinnati