Infrared imaging of the anterior deltoid during overhead static exertions

Infrared imaging has been used to detect the presence of neuromuscular disorders of the cervical spine and upper extremities. Despite diagnostic uses, evaluative or prognostic uses of thermography are limited. The objective of this study was to quantify surface temperature changes over the anterior deltoid and evaluate efficacy of thermography as an assessment tool. Surface temperature, discomfort ratings and endurance time were quantified during overhead static exertions until exhaustion at two work loads (15 and 30% maximum voluntary contraction) and shoulder angles (90 degrees and 115 degrees). Ten participants free of confounding conditions participated in the study. The 90 shoulder angle and 30% exertion level resulted in significantly faster thermal image rates of change, shorter endurance times and faster perceived discomfort increases. Thermography readings were more sensitive to changes in shoulder posture than load changes. This study provides preliminary evidence that thermography may be a useful exposure assessment tool. There is a need for new evaluation tools to quantify risk factor exposure for injury. Thermography was sensitive to changes in task loadings, illustrating its potential use for risk assessment. Specifically, changes in observed blood flow patterns during task performance are likely to conform to known physiological responses to injury.