## 4 Discussion
### Scapular Muscular Activity and Ratio Data
This hypothesis is supported by a previous study that reported scapula elevation as a compensatory mechanism used by subjects with shoulder pain conditions, particularly to reduce possible impingement [16]. However, such compensation may compromise shoulder functional status [16], and other research has suggested a possible increase in scapular elevation as a consequence of scapular dyskinesis [105]. In fact, in the present study, more than half of the symptomatic group presented a scapular dyskinesis type associated with excessive elevation of the scapula's superior border and/or excessive/insufficient scapular upward rotation. Nevertheless, it seems that scapular adaptations could be both a cause or a consequence of the shoulder pain [2; 18; 22], which raises questions about the reason for the increased activity of LS. Although explored in fewer studies, LS has been previously mentioned as a muscle that possibly presents an increased activity [23], as observed in the present study, or even shortened length [23; 37]. Considering these facts and LT's crucial role in counteracting scapular elevation [97], the increased activity of this muscle could also be a way to resist excessive shoulder elevation. Contrary to the significant differences mentioned above, a statistically significant reduction of the SAlow muscle activity level, which was also higher than the intra-session minimal detectable change values [95], was observed in the symptomatic group. The presence of differences only for SAlow could be attributed to the different functions of each portion of the SA. While the upper/middle portion of SA [69; 70] is related to stabilizing the scapula's superior angle [106] and promoting scapular protraction [69], SAlow is more involved in scapular upward [69] and lateral [106] rotation, stabilizing the scapula's inferior angle, and preventing scapular wing [42; 106]. Thus, the decreased activity of SAlow observed during the shoulder lowering in the frontal plane with load (a movement requiring eccentric activity and, consequently, higher scapula and shoulder stabilization and muscular force [107]) and during the drinking phase (which may also require greater control, given the increased shoulder range of motion [91; 92] and the need to maintain the bottle in a correct position for drinking [32; 34]) seems to reinforce the consequences of shoulder pain and the necessity for compensation to maintain the scapula against the thorax. Similar compensatory needs were also mentioned in a study documenting fatigue of the SA [108]. The findings of the present study align with the commonly reported reduction in SA activity level in subjects with shoulder conditions compared to asymptomatic subjects, both in shoulder movements within a restricted plane [8; 15; 20; 26; 38; 42] and during daily activity tasks [26]. Although differences in isolated muscular activity were not consistently found, changes in muscular ratio were more consistent. Apart from the shoulder elevation phase without load, symptomatic subjects presented an increased AdvsAb ratio during shoulder movements and drinking tasks. A previous study [83] reported no significant differences between groups for isolated muscular activity, but when the relationship between agonist and antagonist muscles was considered (by a ratio), muscular imbalances were highlighted. In the mentioned study, symptomatic subjects presented a decreased ratio of MT/SA, which was related to the role of these muscles as scapular stabilizers [83]. Conversely, in another study, the ratio of LS/SA changed but in different directions according to elevation or lowering movements [109]. In the present study, the increased AdvsAb ratio suggested that, for the symptomatic group, the relative activity of MT and LT is increased in relation to SA portions. Such findings appear to agree with the hypothesis expressed earlier regarding the necessity of muscular compensation to achieve better scapular stabilization.