Thermographic evaluation of muscle activity after front crawl swimming in young men.

PURPOSE: The information about the workload on individual muscles in the course of a specific physical activity is essential for targeted prevention, early diagnosis and suitable therapy concerning their overloading and injury. The aim of this study is to evaluate temperature changes in particular skin areas in the course of front crawl swimming, caused by muscle work. METHODS: Thermograms were taken of 13 students of Defense University immediately and 15 minutes after swimming 1,000 m focused on 20 regions of the skin over the selected agonists and synergists in upper extremities and body. FLUKE TiR infrared hand camera was used. RESULTS: The results indicated the significant increase in the relative temperatures in the areas of agonists of swimmers' movement - triceps brachii: from 0.952 to 0.997 of normalized units (nu) on the right and from 0.955 to 0.986 nu on the left. At the same time, the temperature of the muscles participating in lifting the arms above the water surface and stretching them forward - deltoids - increased as well (rear part: from 1.002 to 1.015 nu on the right and from 1.002 to 1.014 nu on the left, sides: from 1.008 to 1.023 nu on the right and from 1.011 to 1.023 nu on the left). CONCLUSIONS: In conclusion, the order of the other agonists is as follows: biceps brachii, pectoralis major muscle, and latissimus dorsi. This study provides the options for objective assessment of workload on specific muscles or muscle groups during front crawl swimming.

Evaluation of tactical training in team handball by means of artificial neural networks.

While tactical performance in competition has been analysed extensively, the assessment of training processes of tactical behaviour has rather been neglected in the literature. Therefore, the purpose of this study is to provide a methodology to assess the acquisition and implementation of offensive tactical behaviour in team handball. The use of game analysis software combined with an artificial neural network (ANN) software enabled identifying tactical target patterns from high level junior players based on their positions during offensive actions. These patterns were then trained by an amateur junior handball team (n = 14, 17 (0.5) years)). Following 6 weeks of tactical training an exhibition game was performed where the players were advised to use the target patterns as often as possible. Subsequently, the position data of the game was analysed with an ANN. The test revealed that 58% of the played patterns could be related to the trained target patterns. The similarity between executed patterns and target patterns was assessed by calculating the mean distance between key positions of the players in the game and the target pattern which was 0.49 (0.20) m. In summary, the presented method appears to be a valid instrument to assess tactical training.

The influence of breaststroke swimming on the muscle activity of young men in thermographic imaging.

The aim of this work is to describe and assess energetic-metabolic activity of selected muscles of upper extremities and body during breaststroke swimming through infrared thermography as electromyography cannot display such muscle activity. Thermograms were taken of 25 students from the University of Defence immediately and 15 minutes after swimming 1,000 m focused on 20 regions of interest, i.e., corresponding to selected agonists and synergists in upper extremities and body. We used FLUKE TiR infrared hand camera. It was found that there is a significant increase (normalized units) 15 minutes after swimming in triceps brachii (on the right prior to swimming 0.950 and after swimming 0.994; on the left prior to swimming 0.947 and after 0.990), and in side, rear and front parts of the deltoid muscles. On the contrary, there was a significant relative decrease in temperature in pectoralis, rhombic and lower trapezius, erector spinae lumbalis and latissimus dorsi. It can be concluded that swimming 1,000 m breaststroke affected significant increase in the temperature of regions of interest, i.e., corresponding to agonists and synergists of upper extremities for the swimmer's forward motion. A relative decrease in temperature occurred rather in body muscles. The problem of biased results due to water cooling was solved by using thermograms taken only in the 15th minute after getting out of water and calculating relative temperatures with normalized units.