In this case study, we explore the return-to-play process for a football player from SC Braga, following a common muscle injury. Recovery from such injuries often presents challenges, particularly in restoring the injured limb’s resistance to fatigue, a critical factor for both training and in matches.
Return to play process
After an injury, resistance to fatigue, (i.e. the ability to withstand a training load), is an essential element to be measured throughout the rehabilitation and return-to-play phases. The injured limb is generally at rest during the recovery phase. It therefore loses its ability to resist fatigue. It is gradually put back under load and, as the healing process progresses, the volume and intensity of the training load increases.
Once a player returns to play, What should we look out for in the injured limb’s ability to resist fatigue and whether it has returned to its previous level?
It is not unusual to observe that the healthy limb exerts a protective effect on the injured limb during the return to play phase. The healthy limb tires more because it compensates for the injured limb.

With Myocene, it is now possible to measure perfectly the ability of one leg compared to the other to resist fatigue. This is particularly useful for measuring any imbalances between the 2 legs and for checking that the injured limb follows the fatigue and recovery kinetics of the healthy limb, i.e. that it tires little during routine training and recovers fully before the competition. If this is not the case and the imbalance is not treated, the player is particularly vulnerable and these mechanisms increase the risk of recurrence.
“Unlike other physical performance evaluation techniques, the evaluation using the fatigue index measured by the Myocene of the variations in the pre- and post-training fatigue index during the player’s rehabilitation phase, allows us to objectively measure not only the workload to which the athlete is exposed, but also, more specifically, the amplitude in which the injured leg is used. During the training sessions on the field, the Myocene therefore played a fundamental role in ensuring that the player returned with the lowest risk of further injury.” Said Sandro Tito, sports scientist of SC Braga
S.C. Braga Player Case Study
A player suffered a muscle injury to the left quadriceps, causing pain on gait, palpation and resistance exercises.
Figure 1 shows the evolution of the fatigue index before and after training on the pitch during the initial rehabilitation phase, i.e. shortly after the injury. At this point, there is clearly a protective effect on the right leg, which is the only one to fatigue during exercise. During the advanced phase of recovery, i.e. after several training sessions and specific work, the player is more confident and uses the injured leg more. As the injured leg recovers its capacity to resist fatigue, the protective effect of the healthy leg disappears, and both legs fatigue in a similar way during intense training (see figure 2).
Figure 1

Caption figure 1:
This figure shows the case of a player with a left leg injury. The graph shows the evolution of fatigue before and after training on the field during the initial phase of return to play, i.e. shortly after the injury. After training on the field, there is marked fatigue in the right (healthy) leg (orange) but no impact on the left (injured) leg (blue). This demonstrates the protective effect on the injured leg, resulting in fatigue on the healthy limb but no fatigue on the injured limb.
Figure 2 :

Caption figure 2:
This figure shows the case of a player with a left leg injury. The graph shows the evolution of fatigue before and after training on the field during the advanced phase of the rehabilitation period. After training, it can be seen that the training had an impact on both legs. In contrast to the initial return-to-play phase, the injured leg was put under strain during training. There has been a reduction in the protective effect on this leg. The player is more confident and puts more strain on the injured leg.