The thermal profile of women and men soccer players. Are we equal?
Today we are investigating the differences in the thermal profile between women and men soccer players in the lower extremities. Due to the little literature on the matter, the relationship between this sport and its thermographic consequences seems to be not well defined. To establish this, we have made a comparison between two semi-professional soccer teams, one for women and the other for men. What do they have in common and what sets them apart?
On June 15th, the Board of Directors of the Superior Sports Council (CSD) in Spain approved the professionalization of the Women’s Soccer League. This one will be the first female sports competition having this classification in Spain. You can see all the information about it here. With the aim of showing our support for female soccer players, now officially professionals, and continuing with our monthly section on Women and Thermography, today we bring a comparison of the thermal profile of soccer in women and men.
The thermal profile in soccer
In the vast majority of thermographic studies, the goal is to evaluate contralateral differences in skin temperature (Tsk) in pathological conditions, such as cancer or disorders of the musculoskeletal system. Current evidence shows that higher contralateral scores could involve a deterioration or imbalance between symmetrical parts of the body (Marins et al. 2014). In addition, a thermal pattern has been established in the adult population with different ethnic characteristics, such as Taiwanese (Niu et al., 2001), Portuguese (Vardasca et al., 2011), Chinese (Zhu & amp; Xin, 1999), Finnish (Zaproudina et al., 2008) or Mexican children (Kolosovas-Machuca & González, 2011).
Infrared thermography in soccer has proven to be a useful tool in the prevention of injuries, both in the preseason (Gómez-Carmona et al., 2020) and during the season (Menezes et al., 2018; Corte et al., 2019).
It has also been widely studied in soccer to define the thermal profile of soccer players (Bouzas et al 2014) and even after matches to analyze the thermal responses 24h and 48h post-match (Fernandes et al. to 2017).
In the specific population group of high-performance soccer players, there are few scientific references to have in mind. The observational study carried out by Maior et al. (2017) in professional soccer players, shows asymmetry less than <0.2 ° C in the general set of thigh and leg, anterior and posterior. Marins et al. (2014), highlighted in their research that a mean Tsk higher than 33° C in any of the lower limb regions of interest could suggest an inflammatory process. Additionally, a Tsk below 27° C may be related to a hypothermic condition caused by reduced local blood flow.
But without any doubt, one of the most named investigations in this regard is Pedro Gómez Carmona’s article (Gomez-Carmona et al. 2020). In it, mean asymmetries are shown with a significant difference in the anterior region of the dominant leg. This fact is hypothesized to be related to the biomechanics of the sport itself, which favors the use of this musculature for handling the ball.
Our men’s and women’s teams
In figure 1, we can observe a comparison of the mean asymmetries of the lower limbs between two semi-professional female and male soccer teams. Quite large asymmetries can be seen, especially in the most distal regions. It must be taken into account that these regions are characteristic for having a lower precision, for several reasons. The size of the region (number of pixels), the closeness to the ground (which tends to cool the segment) and the thermoregulatory capacity of the feet, what makes that these distal regions have a relatively lower statistical power than other more proximal areas.
between female (red) and male (blue) amateur soccer team.
Another way to understand these data is through the asymmetries analysis right vs. left. When looking at figure 2, it is important to highlight the values with 0.3º C or more of asymmetry, since they are those to which we give more relevance, according to current evidence (Sillero-Quintana, et al. 2015). When we performed this analysis, we found the same situation, in which we observed that some of the most distal regions tend to have more extreme values.
Again, these kind of findings are invalid, as they are regions whose results tend to be highly fluctuating. However, we found a particularly interesting result in the anterior region of the leg, with scores between 0.3 and 0.49º C. This result appears in both women (red) and men (blue). This conclusion about the anterior region of the leg is consistent with current evidence (Gómez-Carmona et al. 2020) and goes hand in hand with their results. We can, therefore, see reflected the thermal similarities both between professional and semi-professional soccer and between the male and female categories.
Symptoms and injuries of soccer players in our thermal profile
It is important to emphasize the fact that this thermal profile has been made in semi-professional soccer. However, this fact seems not to be as key as we hope, since the players had an age, experience, symptoms and injuries very similar to those we find in the elite categories. The discomforts that have been most reported in the men’s team were in the posterior thigh, rectus femoris, ankles and lumbar region. These are related to the most common injuries in men’s soccer, according to UEFA between the 2003-2007 seasons (Barcelona & Mèdics, 2009).
On the other hand, in the women’s team, discomfort in the posterior thigh and knees has been described more frequently. In addition, several of the players had a clinical history of knee injuries, where a torn anterior cruciate ligament and damaged meniscus were the most common injuries. Again, these results are consistent with those reported in the First Division of the Spanish Women’s Soccer League in non-contact circumstances (Agustín et al. 2021).
Furthermore, in the qualitative analysis, an anterior crossover pattern was observed in both teams, where the contralateral thigh and leg appeared with slight hyperthermia in several subjects.
In conclusion, it only remains to assert that regarding the thermal profile of female and male soccer players, the results of this pilot study confirm those that already exist in the scientific literature. The anterior leg is the region that shows the most asymmetry, due to its very probable relationship with the mechanics of the game with the ball. In addition, a cross pattern between this leg and the contralateral thigh has been observed in both teams, which seems to relate this characteristic to the most common discomforts and injuries in female and male soccer players.
REFERENCES
Agustín, M. S., Medina-Mirapeix, F., Esteban-Catalán, A., Escriche-Escuder, A., Sánchez-Barbadora, M., & Benítez-Martínez, J. C. (2021). Epidemiology of Injuries in First Division Spanish Women’s Soccer Players. International journal of environmental research and public health, 18 (6), 3009.
Barcelona, F. C., & Mèdics, S. (2009). Clinical Practice Guide for muscle injuries. Epidemiology, diagnosis, treatment and prevention. Version 4.5 (February 9, 2009). Apunts: Medicine de l’esport, 179-203.
Côrte, A. C., Pedrinelli, A., Marttos, A., Souza, I. F. G., Grava, J., & Hernandez, A. J. (2019). Infrared thermography study as a complementary method of screening and prevention of muscle injuries: pilot study. BMJ open sport & exercise medicine, 5(1), e000431.
Gómez-Carmona P, Fernández-Cuevas I, Sillero-Quintana M, Arnaiz-Lastras J, Navandar A. Infrared Thermography Protocol on Reducing the Incidence of Soccer Injuries. J Sport Rehabil. 2020 Nov 1;29(8):1222-1227.
Kolosovas ‐ Machuca, E. S., & González, F. J. (2011). Distribution of skin temperature in Mexican children. Skin Research and Technology, 17 (3), 326-331.
Maior, Alex Souto et al. Profile of infrared thermography in elite soccer players. Motriz: Revista de Educação Física. 2017. 23(02).
Marins, J. B., de Andrade Fernandes, A., Moreira, D. G., Silva, F. S., Costa, C. M. A., Pimenta, E. M., & Sillero-Quintana, M. (2014). Thermographic profile of soccer players’ lower limbs. Andalusian Journal of Sports Medicine, 7 (1), 1-6.
Marins, J. C. B., Fernandes, A. A., Cano, S. P., Moreira, D. G., da Silva, F. S., Costa, C. M. A., … & Sillero-Quintana, M. (2014). Thermal body patterns for healthy Brazilian adults (male and female). Journal of thermal biology, 42, 1-8.
Menezes, P., Rhea, M. R., Herdy, C., & Simão, R. (2018). Effects of Strength Training Program and Infrared Thermography in Soccer Athletes Injuries. Sports, 6(4), 148.
Niu, H. H., Lui, P. W., Hu, J. S., Ting, C. K., Yin, Y. C., Lo, Y. L., … & Lee, T. Y. (2001). Thermal symmetry of skin temperature: normative data of normal subjects in Taiwan. CHINESE MEDICAL JOURNAL-TAIPEI-, 64 (8), 459-468.
Sillero-Quintana, M., Fernández-Jaén, T, Fernández-Cuevas, I., Gómez-Carmona, P. M., Arnaiz-Lastras, J., Pérez, M. D., Guillén, P. (2015). Infrared Thermography as a Support Tool for Screening and Early Diagnosis in Emergencies. Journal of Medical Imaging and Health Informatics, 5(6):1223-1228(6)
Vardasca, R., Ring, E. F. J., Plassmann, P., & Jones, C. D. (2012). Thermal symmetry of the upper and lower extremities in healthy subjects. Thermology international, 22 (2), 53-60.
Zaproudina, N., Varmavuo, V., Airaksinen, O., & Närhi, M. (2008). Reproducibility of infrared thermography measurements in healthy individuals. Physiological measurement, 29 (4), 515.
ZHU, W. P., & XIN, X. R. (1999). Study on the distribution pattern of skin temperature in normal Chinese and detection of the depth of early burn wound by infrared thermography. Annals of the New York Academy of Sciences, 888 (1), 300-313.
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ThermoHuman has had the support of the Funds of the European Union and the Community of Madrid through the Operational Programme on Youth Employment. Likewise, ThermoHuman within the framework of the Export Initiation Program of ICEX NEXT, had the support of ICEX and the co-financing of the European Regional Development Fund (ERDF). 
