Foot evaluation by infrared imaging.

For better assessment of foot injury severity during basic military training, we evaluated a simple noninvasive technique: thermography. With this infrared imaging method, we determined normal foot parameters (from 30 soldiers before training), thermographic findings in different foot stress fractures (from 30 soldiers so diagnosed), and normal responses to abnormal stresses in 30 trainees who underwent the same training as the previous group but did not have musculoskeletal complaints. We found that normal foot thermograms show onion peel-like progressive cooling on the plantar surface, with a medially located warm center at the instep. Thermograms of injured feet show areas of increased heat, but excessive weight-bearing pressures on feet, new shoes, or boots also cause increased infrared emission even without discomfort. Differentiation remains difficult; however, thermography can detect injury early. It does not reveal exact diagnoses, but its greatest benefit is easy follow-up to monitor severity and healing.