Evaluation of occupational knee-joint stress using liquid crystal thermography: a case study.
Habes-DJ; Bhattacharya-A; Milliron-M
Appl Ergon 1994 Apr; 25(2):111-115
The use of liquid crystal thermography for the detection and evaluation of occupational stress on the knee was described. The thermography was performed using liquid crystal sheets with measurement capabilities ranging from 22 to 42 degrees-C. Based on the rapidity and nature of the color change of the sheets after application to the knees of subjects, the correct sheet for each individual was identified and the color patterns on the sheet were recorded with a video camera and analyzed. The system was used to evaluate the knees of two carpet installers. Increases in the hottest temperatures and decreases in the coolest temperatures of the knee were seen in the installers over the course of a workday. At the end of the workday, the hottest areas in both workers were concentrated in the suprapatellar portion of the knee. This area of the knee was reported by the workers to impact a carpet stretching tool during their work. The authors conclude that thermography using liquid crystal sheets is an effective way to measure knee temperatures at the worksite.
NIOSH-Author; Analytical-methods; Body-temperature; Case-studies; Skeletal-stress; Knee-injuries; Physical-stress; Musculoskeletal-system