Scientific Research—Evaluation of Infrared Thermal Imaging on Muscle Activity of Young People after Crawl Swimming

Evaluation of Infrared Thermal Imaging on Muscle Activity of Young People after Crawl Swimming

   In sports, injury prevention one of is the most essential applications of thermography. There is a higher risk on swimmers regarding the overload on the shoulder, followed by neck and back. For instance, infrared thermography is used to avoid muscle, joints, or bone injuries, and enables detecting the symptoms of potential fatigue and overload before they turn into an injury. Different levels of training may lead to high risk of injuries for athletes. That is why all professionals in physical activity sports should be aware of the existence of the methods to overcome this problem and use them.

   Current methods of evaluating the level of metabolic muscle activity in the course of human physical activity are based on analysis of the expired air and calculation of oxygen uptake. However, this method of indirect calorimetry only provides informations about the overall body energetic demands. Electromyography – EMG is the most suitable way for assessing the individual muscles’ activity. This method introduces information about electrical muscle activity which precedes metabolic activity itself. However, this method is too invasive and, thus, not acceptable. What might be taken into consideration is the use of the ultrasonography of muscles, which can identify the change in muscle capacity which might be related to preceding work activity (increase in blood flow and accumulation of fluid in the tissue).

   The fact that catabolic reactions in the course of muscle work activity produce thermal energy which increases the temperature of adjacent skin pushes us to the use of infrared thermography. Higher metabolic activity and blood supply to muscle tissue lead to a significant increase in the temperature of muscles. Thermal energy is consequently transferred by fluid flow in blood vessels to adjacent tissue, including skin. Thermography shows the emission of thermal energy off the body.

Figure 1. Examples of thermograms with selected muscle regions.

   The fact of the significant temperature increase in regions of agonists and synergists for the swimmer’s forward motion was discovered by of thermographic evaluation of the muscular activity after breast stroke swimming. The aim of this study was to find out and evaluate temperature changes of the skin on the arms and torso in the course of front crawl swimming, caused by muscle work. We would like to provide information relevant for targeted prevention, early diagnosis and suitable therapy concerning their overloading and injury.

   The increase in skin temperature has been proved on arms where the agonists of movement forward are located. In the course of front crawl, triceps may be related to muscle work and they are active metabolically. Another increase has been proven in temperature of deltoid muscle, and occurred in the movement when the arm was on the water surface. The temperature measured before swimming and 15 minutes later was symmetric. The results of the study might be useful in assessing the load put on the muscles of the upper limbs and torso during front crawl swimming for non-professional young swimmers.

Reference

Jan Novotny, Silvie Rybarova, Dan Zacha, et al. Thermographic evaluation of muscle activity after front crawl swimming in young men. Acta of Bioengineering and Biomechanics. 19(4):109-116, 2017.