## 2 Materials and Methods  
This study considered a group of volunteers, none of whom were professional female basketball athletes, divided into level 1 and level 2 according to their experience, which was defined based on the number of games played and whether the athlete belonged to a regional basketball elite team or not. Initially, the group was formed by 11 athletes; however, during the season, the group was reduced to 9 due to injury and scholarly reasons. This study was approved by the local ethics committee and was performed according to the Declaration of Helsinki, with all the participants' data considered and stored anonymously and confidentially. All subjects were fully informed of the nature of the study and gave written informed consent. Table 1 shows the sample characteristics and their experience level. The data acquisitions were performed at two time-points of the sports season, the first one in November (T1), corresponding to the beginning of the season, and the second one in March (T2), corresponding to the peak of the season. Five different movements were considered, namely, running with the ball (RB), running without the ball (RNB), lay-up on the right side (LR), lay-up on the left side (LL), and rebound (R). The rebound was the only movement in these five without having an association with running; however, all these movements recruit the lower limb in different ways. Each athlete performed 7 repetitions of each movement for each test condition, which resulted in a total of 630 valid trial data. To avoid predisposition in the assessment, the test order was randomized. Between movements, the athletes had 1 min to rest, and between repetitions in the same movement, they had 30 s.  
Surface electromyography data were collected via the BioSignalPlux system after skin preparation to decrease the impedance between the skin and the electrode. This telemetric system contains a data acquisition box and Bluetooth communication with the computer. The sensors used to record sEMG amplified signals with a bandwidth of 25-500 Hz, a common-mode rejection ratio of 100 dB, and an input impedance greater than 100 G0 hm. The surface electrodes (Al/AgCl, AMBU BlueSensor N) were placed aligned with the muscle fiber orientation (center-to-center distance of 22 mm) at the most prominent part of the muscle bellies following SENIAM recommendations [37]. The same researcher performed electrode placement. The medial (MG) and lateral gastrocnemius (LG) muscles in both legs were identified through palpation of the muscle belly, with skin shaved, abraded, and cleaned using standard medical alcohol swabs for electrode placement. The reference electrode was placed in the tibial tuberosity (Figure 1). The sEMG data were sampled at 1000 Hz. To analyze and observe the signal in the OpenSignals software, a frequency amplitude of the signal between 20 and 400 Hz was used. During the tests, athletes were equipped with sEMG apparatus, supported by a belt, which registered muscle activity. All acquisitions were achieved in the same gym, with the same ball (0.62 bar), and using the same basket table. All players used their normal basketball shoes, which were not changed between the two evaluation time-points of the season. In the present study, data normalization was performed in reference to the maximal contraction (%MC) during the activity [38; 39]. Data were analyzed using IBM SPSS software (version 25.0) [40]. Descriptive statistics are presented using mean \(\pm\) standard deviation. The normality test of the data was performed with the Shapiro-Wilk test. As the data lacked normality, the Wilcoxon test was used to compare the two assessment time-points (T1 and T2). The [PERSON] test was considered for multiple non-parametric comparisons between the different levels of athlete experience, muscles, and types of sports movements [41]. The significance level was set at 5%.