An application of a dynamic thermography for studying a relation between thermal and mechanical activities of a skeletal muscle during a static load

A thermal distribution provides useful information of physiological and pathological processes. However, only a static thermography was applied in the most of medical studies. This paper shows an example of application of a dynamic thermography to study a physiological activity of a skeletal muscle. The goal of the presented work was to study a putative relationship between mechanical and thermal activity of the quadriceps during a static submaximal load. During a strain a dynamic temperature distribution on a thigh surface and a force moment of a knee erector were registered. The performed analysis used a time-dependent mean temperature, a time-dependent standard deviation and an impulse of a force moment. Moreover, we analyzed of autocorrelation functions to compare the dynamics of these parameters. Finally, we showed the nonlinear, statistically significant relationship between spatial-temporal variability of temperature and the force developing by a concentrative contracted quadriceps. A possible biological interpretation of the identified relation is also proposed taking the described mathematical model of muscle heat transfer into account.