This was a pilot study to explore the feasibility of using Near Infrared Spectroscopy (NIRS) as an objective physiological measure of long-term muscle fatigue due to standing. NIRS allowed us to quantify oxygenation and blood flow in lower extremity muscles over time. We used this technology to quantify the impact of flooring on long term standing muscle fatigue, to understand the underlying mechanisms of this problem in occupational settings and to relate oxygenation and blood flow measures to subjective measures of discomfort. The long term goal of this line of research was to quantify and understand the impact of flooring on the physiological, biomechanical and psychological constructs of long term lower extremity fatigue in occupational settings.