The evolution graph of an anterior cruciate ligament (ACL) injury.

The evolution graph of an anterior cruciate ligament (ACL) injury.

23/08/2023 Home

The return after an injury is always a delicate moment due to the numerous factors influencing recovery. Therefore, having a greater quantity of criteria and objective data about the athlete’s condition will benefit a safe return to competition.

Thermography is a quick and non-invasive tool that enables the measurement of body temperature in different body regions. This temperature data allows for objective differentiation between regions and facilitates targeted monitoring evolution for both injury prevention and tracking.

The asymmetry between extremities has proven to be a robust and reliable metric when employing various thermography analysis methodologies. Through the analysis of our database at ThermoHuman, we’ve constructed an evolution graph depicting the asymmetry progression of different regions affected by major sports injuries, such as ACL injuries.

This has enabled us to obtain an evolution graph for a safer return to competition, establishing progression criteria based on thermography.

The evolution graph of the ACL injury until recovery.

By tracking over 100 cases of ACL injuries, we’ve developed an evolution graph where we monitor the knee’s inflammation throughout the process. We measure the asymmetry between knee regions to position the evaluated individual on a graph compared to the normal data from the database.

In other words, we understand how the knee should behave in the first 365 days post-injury and compare the evaluation data with ThermoHuman’s database.

In this case, we present a professional judoka who sustained an injury to their right knee during Olympic training preparation. Due to its rotational component under load, judo places significant stress on the knees, with ACL injury being one of the most severe.

The judoka followed a progression program at the German High-Performance Center, while undergoing thermographic evaluations over 184 days with the objectives of:

  1. Monitoring knee inflammation throughout the process.
  2. Detecting imbalances in other structures resulting from the injury (commonly known as “functional overload due to compensation”). As important as the knee is evaluating the tone of the quadriceps or hamstrings, which provide stability.
  3. Individualizing the process to control associated anomalies (such as arthrogenic inhibition or knee osteoarthritis).

As depicted in the figure, the evolution process is lengthy and entails numerous neuromuscular changes. Temperature control serves as an additional quality indicator in the progression of ACL recovery.

graph evolution

Figure 1. Graph evolution of ACL.


Cano, S. (2016). Use of infrared thermography as a tool to monitor skin temperature along the recovery process of an anterior cruciate ligament surgery.

Colné, P., & Thoumie, P. (2006). Muscular compensation and lesion of the anterior cruciate ligament: Contribution of the soleus muscle during recovery from a forward fall. Clinical Biomechanics (Bristol, Avon), 21(8), 849-859.

Kuenze, C. M., Hertel, J., Weltman, A., Diduch, D., Saliba, S. A., & Hart, J. M. (2015). Persistent neuromuscular and corticomotor quadriceps asymmetry after anterior cruciate ligament reconstruction. Journal of Athletic Training, 50(3), 303-312.

Europa Thermohuman 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).

CDTI Thermohuman has received funding from the Centre for the Development of Industrial Technology (CDTI), in participation with the European Regional Development Fund (ERDF), for the R+D activities involved in creating a new tool, based on thermography, for the prediction and prevention of rheumatoid arthritis. See project detail.